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Scientific Information Database (SID) - Trusted Source for Research and Academic Resources
Scientific Information Database (SID) - Trusted Source for Research and Academic Resources
Scientific Information Database (SID) - Trusted Source for Research and Academic Resources
Scientific Information Database (SID) - Trusted Source for Research and Academic Resources
Scientific Information Database (SID) - Trusted Source for Research and Academic Resources
Scientific Information Database (SID) - Trusted Source for Research and Academic Resources
Scientific Information Database (SID) - Trusted Source for Research and Academic Resources
Scientific Information Database (SID) - Trusted Source for Research and Academic Resources
Issue Info: 
  • Year: 

    1400
  • Volume: 

    31
  • Issue: 

    1
  • Pages: 

    143-159
Measures: 
  • Citations: 

    0
  • Views: 

    193
  • Downloads: 

    0
Abstract: 

زمینه مطالعاتی: یکی از مهم ترین مشکلات تغذیه ای دنیای کنونی، سوء تغذیه ناشی از کمبود پروتیین و فیبر در رژیم غذایی است. با غنی سازی محصولات اکسترود شده توسط فیبر می توان به تولید محصولی با کالری، چربی و کلسترول کمتر دست یافت. عناب اثرات درمانی گوناگونی مانند کاهش دهندگی قند خون، خواص آنتی اکسیدانی، ضد التهاب و اثرات محافظت کبدی دارد. هدف: هدف این پژوهش اثر افزودن آرد عناب به اسنک حجیم غنیشده و بهینهسازی شرایط تولید آن است. روش کار: در این پژوهش بر پایه طرح مرکب مرکزی چرخش پذیر، اثر متغیرهای فرایند اکستروژن شامل سرعت چرخش ماردون (120، 150 و 180 دور بر دقیقه)، آرد عناب (5، 10 و 15 درصد) و رطوبت خوراک ورودی (12، 16 و 20 درصد) بر ویژگی های فیزیکوشیمیایی (انبساط، تخلخل، جذب آب و چربی) و پذیرش کلی فراورده حجیم شده بر پایه ذرت-گندم (50-50) مورد بررسی قرار گرفت. نتایج: نتایج نشان داد؛ افزودن آرد عناب سبب کاهش نسبت انبساط و تخلخل شد و با افزایش هم زمان دو پارامتر سرعت چرخش و آرد عناب به واسطه کاهش ویسکوزیته، خصوصیات اسنک بهبود یافته و در نتیجه نسبت انبساط و تخلخل افزایش یافت. بیشترین مقدار پذیرش کلی (33/4) مربوط به نمونه دارای کمترین مقدار آرد عناب و رطوبت و بالاترین سرعت مارپیچ بود. افزودن آرد عناب اثر منفی بر پذیرش کلی نمونه ها داشت. با افزودن آرد عناب، به دلیل قند بالای عناب، طی حرارت اکستروژن، فرآیند کارامل شدن انجام شده؛ تغییر رنگ قابل توجه ای در محصول مشاهده، بافت فراورده چسبنده و طعم و مزه سوختگی حاصل می گردد. شرایط بهینه تولید محصول اکسترود شده، شامل میزان رطوبت خوراک 19/13 درصد، میزان آرد عناب 30/6 درصد و سرعت چرخش ماردون 2/122 دور بر دقیقه تعیین گردید. نتیجه گیری نهایی: نتایج پژوهش بیانگر کارایی مناسب آرد عناب در فرمولاسیون انواع اسنک حجیم سلامتی را بود.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Author(s): 

Filban zadeh M. | SHARIFI A.

Issue Info: 
  • Year: 

    2021
  • Volume: 

    31
  • Issue: 

    1
  • Pages: 

    1-15
Measures: 
  • Citations: 

    0
  • Views: 

    213
  • Downloads: 

    0
Abstract: 

Introduction: Citron (Citrus medica L. ), belonging to citrus genus and native to southeast Asia (Dalia, 2014). Citrus fruits are rich sources of different vitamins, minerals, and fibers. In recent years, more attention has been paid to the antibacterial properties of non-edible parts of fruits (Tavasoli et al., 2009). Essential oil of the fruit peel (located in the inner layer of citron peel) have repetitively demonstrated antibacterial bioactivities. The citron juice along with honey is also known as an effective antidote to poisons. Citron peel contains citronellal, terpenes, aldehydes, ketones, esters, alcohols, and organic acids. Limonene, most abundant cyclic monoterpene of the fruit, has demonstrated considerable antimicrobial activity in many studies. Moreover, geraniol and other monoterpenes found in the extract of citron peel have exhibited anti-cancer properties (Mina et al., 2011). In recent decades, many are studying the ways of converting low-value products (byproducts) to value-added products. Carbonated beverages are products made of water, sugar, carbon dioxide, additives, and, other sweeteners (Elhami Rad & Mohammadi, 2006). The harmful effect of consuming industrial soft drinks can be examined from different perspectives (Bawa, 2005). There are some reports that show benzene forms by a reaction between benzoate in soft drinks and ascorbic acid, which is a cancer-causing compound. Due to the health risks attributed to consumption of industrial soft drinks, many researchers are looking for ways to optimize the consumption of natural drinks, as synthetic materials make up most of the compounds used in industrial soft drinks (hunter, 2003). In this study, given the beneficial effects of citron, we used the ethanolic extract of citron peel as a natural preservative in the formulation of lemon soft drinks. Furthermore, we studied the antimicrobial activity of extract against soft drink contaminating microorganisms in a culture medium and lemon carbonated beverages. Materials and methods: In this study, we added ethanolic extract of citron peel with increasing concentrations of 0, 0. 8, 1, 1. 5, and 2 mg/ml to the formulation of lemon soft drinks, as a natural preservative. Furthermore, antimicrobial activity of the additive was investigated against a series of soft drink contaminating microorganisms (Lactobacillus delbrueckii, Leuconostoc mesenteroides, Saccharomyces cerevisiae, and Candida krusei). The total phenolics of the lemon soft drink was measured based on the Folin-Ciocalteu method (Lin & Tang, 2007). The characteristics of color, taste, and flavor as well as the overall acceptability of final products were evaluated by ten evaluators using the hedonic method and an assessment questionnaire (Karami et al., 2012). Data were analyzed based on a completely randomized design, one-way ANOVA, using SPSS (version 19). The charts were plotted using Excel software. The statistical comparison of results was conducted at a 95% confidence level. Results and discussion: Ethanolic extract of citron peel exhibited an inhibitory effect on the growth of our test microorganisms. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extract against Lactobacillus delbrueckii were 0. 6 mg/ml and 0. 8 mg/ml, respectively. Moreover, the extract had inhibitory and bactericidal effect against Leuconostoc mesenteroides at the concentration of 1 mg/ml. Per our results, saccharomyces cerevisiae and candida krusei were killed and inhibited at the concentration of 0. 8 mg/mL. Overall, the ethanolic extract of citron peel exhibited significant inhibitory activity against Lactobacillus delbrueckii, Leuconostoc mesenteroides, saccharomyces cerevisiae, and candida krusei. The results of the total count of mesophilic aerobic bacteria (colony forming unit per mL (CFU/mL)) indicated the antimicrobial activity of citron peel extract in lemon soft drinks. The citron peel extract, with its antibacterial properties, was able to reduce the microbial load of samples. Comparable results were obtained by sodium benzoate. The count of acid-resistant microorganisms showed the antimicrobial activity of citron peel extract in the lemon soft drink. The count of acid-resistant bacteria dropped to zero over the time of storage in the control and T4(2 mg/ ml) treatment samples. Our results indicated the antimicrobial activity of citron peel extract in the lemon soft drink (based on yeast and molds count (CFU/ml). There was no significant difference between the treatments and the control at day 0 (P>0. 05). Treatments 𝑇 1, 𝑇 2, and 𝑇 3 were significantly different from other samples at day 30, 60, and 90 of the experiment. Furthermore, 𝑇 1, 𝑇 2, and 𝑇 3 treatments had higher colony counts than the control and 𝑇 4(2 𝑚 𝑔 /𝑚 𝑙 ) group (P<0. 05). The antimicrobial effect of extract was concentration and time dependent. There was an increasing trend in the amount of yeast and molds in 𝑇 1, 𝑇 2, and 𝑇 3 treatments yet growth of the microorganisms in T4 and control group was completely inhibited over the storage time. At day 90, yeast and mold count reached the standard set by Institute of Standards and Industrial Research of Iran (negative). As expected, increasing concentrations of the extract lead to higher total phenolics in the produced soft drink. Considering the acidic pH, total phenolics in the produced lemon soft drinks containing citron peel extract significantly increased after 30 days, and then remained constant throughout the storage period was. There was a significant difference between the total phenolics of treatments and the control at day 0 and other time points. Phenolics were significantly higher in all the treatments containing the citron peel extract compared with the control (P<0. 05). The results of sensory evaluation showed that there was no significant difference between all the treatments containing the citron peel extract and the control sample in terms of taste, flavor, and color (P>0. 05). By increasing the amount of citron peel extract, the rates of taste, flavor, and overall acceptability decreased compared with the control. However, rate was not evaluated as significant by the evaluators (P>0. 05). No significant difference was detected between treatments and the control in terms of color by the evaluators(P>0. 05). Conclusion: The results of current study indicated that phenolics-rich citron peel extract has notable antimicrobial activity against soft drink contaminating microorganisms. The results showed that we can produce a quality product, in terms of microbial quality and chemical properties, by adding 2 mg citron peel extract per mL of soft drink. In terms of sensory properties, the final product could compete with sodium benzoate containing lemon soft drinks.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    31
  • Issue: 

    1
  • Pages: 

    17-31
Measures: 
  • Citations: 

    0
  • Views: 

    424
  • Downloads: 

    0
Abstract: 

Introduction: The interest in using natural antimicrobials and antioxidants instead of chemical preservatives in food products has been increasing in recent years. The toxicity of synthetic antioxidant for preservation of fresh foods, at the level of higher than allowable doses, has raised concerns and using of natural antioxidant are more taken into consideration. Some of the plant phytochemicals such as plant resin, extracts and essential oils are believed to have high antioxidant effects. In regard to this, essential oils, natural and liquid secondary plant metabolites, are gaining importance for their use in the protection of foods, since they are accepted as safe and healthy. Different studies on therapeutic and biological potential of different species of basil seed extract have exhibited numerous activities such as anticancer, anticarcinogenic, rejuvenating properties, antiseptic effect, anti-allergic, activation of antioxidative enzymes, adaptogenic and antistress properties, antiradiation activity, antioxidant activity, immuno-modulatory and antimicrobial properties. The process of oxidation in the human body produces unstable chemical compounds, called free radicals, which damage cell membranes and other cell structures. Antioxidants are compounds in foods that scavenge and neutralize free radicals. Evidence suggests that synthetic antioxidant additives do not work as well as the naturally occurring antioxidants in foods such as fruits and vegetables. The diets containing high antioxidants may reduce the risk of many diseases, including heart disease and certain cancers. In human body, antioxidants scavenge free radicals produced in the cells and prevent or reduce the damage caused by oxidation. The protective effect of antioxidants continues to be studied around the world. Today, due to concerns related to obesity and heart disease, application of fat replacer in food formulations are more considered. High ratio cakes contain more sugar than flour and widely used in the baking industry. However, due to its high caloric content, over consumption of this type cake may contribute to obesity. With the current trend in food industry, foods that contain low-calorie sugar-and fat-replacers are popular due to increase in nutritional and health awareness of people about the calorie reduction in the diet. However, altering the ingredients and their levels such as to reduce the calorie and fat content of the food product potentially causes readily detectable losses in appearance, mouthfeel and texture. In this study, basil seed gum used as fat replacer due to having gummy texture. The aim of this study was to evaluate the effect of anti-oxidation and anti-microbial properties of oregano essential oil and basil seed gum in the low-fat chocolate cake. Eeffects of basil seed gum (0. 2-0. 4-0. 6 %) and essential oil oregano (0. 002-0. 004%), as a rich source of natural antioxidant, on the cake batter rheology. Physiochemical characteristics such as pH, acidity, peroxide value of chocolate cakes were evaluated. Also, the texture and sensory properties of chocolate cakes such as odor, taste, texture, color and overall acceptance during storage were analyzed. Material and methods: In this study, the effects of basil seed gum (0. 2-0. 4-0. 6 %) and oil oregano (0. 002-0. 003-0. 004%) were investigated on density and viscosity of batter and texture and organoleptic properties of chocolate cake. Oxidative characteristics such as peroxide value and acidity of chocolate cakes were also analyzed. Wheat flour with the extraction rate of 72% (Alborz industrial group), Oil (Bahar – industrial group), sugar (sucrose) (Varamin industrial group), egg (Talavang company) and baking powder ( Sisaroon corporation) and vanilla (Jivadan corporation), oregano essential oil (Barije essence company) were prepared. Cake production was done at the Nan Sahar Institute. The formulations differed in ratios of flour, fat, basil seed gum, oregano essence oil and water. The eggs, sugars, sucrose were mixed up for 2 and 5 min (Kitchen Aid Mixer), respectively. The mixture was then mixed at speed 8 for 2 min to form lighter, creamier and ‘ floppy’ batter. After mixing, the sifted self-rising flour and cocoa powder were then added into a mixing bowl and mixed for 2 min. Milk and then oil were added to the mixture. The mixture was poured into bowl and mixed for 1 minute. The batter (250 g) was then transferred to 12 cm × 5 cm × 4 cm greased cake pan and baked in an oven at 180 º C for 35 min. The chocolate cakes were then removed from the oven and allowed to cool for 2 hours and were later packed in a 25 cm × 15 cm low-density polyethylene packages at room temperature for 24 hours prior to physical quality analysis. Statistical analysis using response surface methodology (RSM) and central composite design were presented in this study. Physical and rheological properties of batters such as density and viscosity were analyzed. Texture characteristics and shelf life related parameters of the chocolate cakes including the pH, acidity, and peroxide were evaluated during 45 days of storage. Results and discussion: The results of this study showed that by increasing the concentration of basil seed gum and oregano essential oil, the density of batters decreased in all treatments. Also, it was showed that batter viscosity was increased by increasing the concentration of oregano essential oil and basil seed gum. Results of peroxide value at the first day of storage showed that by increasing the amounts of basil seed gum and oregano essential oil in chocolate cakes, the peroxide value decreased. The Peroxide value of cakes was also decreased by increasing the mounts of basil seed gum and oregano essential oil after 45 days of storage. The pH and acidity of all samples were increased by increasing basil seed gum and oregano concentrations. Antioxidant properties of chocolate cakes were increased by increasing the concentrations of Basil seed gum and oregano essential oil. Results showed that basil seed gum increased the overall acceptance in all samples of chocolate cakes. Conclusions: According to the results of the present study, it can be concluded that using 0. 6% oregano essential oil and 0. 002% basil seed gum in cake samples created good texture in chocolate cakes. These samples showed softer, more acceptable texture and the highest overall acceptance. So, it selected as the optimal formulation and can be used in producing of reduced fat chocolate cake.

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    31
  • Issue: 

    1
  • Pages: 

    33-54
Measures: 
  • Citations: 

    0
  • Views: 

    236
  • Downloads: 

    0
Abstract: 

Introduction: Carrot juice is one of the most consumed and healthy fruit juices and is a rich source of carotenoids, such as beta-carotene, which is responsible for its orange color and is a precursor of vitamin A (Zhou et al., 2009). In conventional methods of food heating, due to the transfer of heat by the conduction method and the presence of a hot surface in contact with the food, particles near the surface are exposed to heat more than distant particles; therefore, food compounds are damaged and there is a possibility of burning of surface part of the food (Kamali and Farahnak 2015). Ohmic heating is a thermal process that produces heat by passing an alternating current through the food. This heating system differs from conventional heating methods in terms of heat generation and heat transfer, as well as in terms of temperature distribution that occurs during heating. Studies show that this method has a very high thermal uniformity, environmentally friendly, high efficiency and easy control over other common thermal techniques. Ohmic heating is also used as a method to inactivate microbial activity (such as pasteurization), extraction, dehydration or solid to liquid transformation (Pereira et al., 2007). Many agricultural products spoil very quickly due to high humidity, which makes them particularly difficult to store. In addition, due to the seasonality of these products and on the other hand the demand for its consumption in other seasons, the need to processing of these products (such as drying and concentrating of its extract) seems necessary (Darvishi et al., 2013). The amount of heat generated by ohmic heating directly depends on the electrical resistance of the food and the voltage gradient applied (Marcos et al., 2010). Ohmic heating derives its name from Ohm's law, which is the known relationship between current, voltage and electrical resistance. In ohmic heating, the food placed between the electrodes acts as a resistor in the electrical circuit. This food must be physically able to conduct electricity (Sakr and Liu 2014). The purpose of this study was to investigate the quality characteristics of carrot juice such as color changes, pH and specific energy consumption. Materials and methods: Carrot samples used in this study were prepared from the city of Khorramabad in 2018. After washing the fruits with water, the surface water of the fruits was taken with absorbent paper. An industrial juicer extracted the juices. It should be noted that no filtration was performed on the extracted fruit juices because the heating rate of a substance in the ohmic heating method is strongly dependent on the particle size of the substance. The presence of pulp increases the heating rate and thus increases the final quality of the product (Shiby et al., 2014). In addition, fruit pulp has a very high percentage of vitamins and minerals. The amount of fruit pulp was about 12% by weight. The initial humidity of carrot was calculated using AOAC (2002) standard of oven heating (24 hours heating at 103° C) equal to 89. 7%. In all experiments, the weight of the carrot juice sample was considered constant and equal to 100 g. Ohmic heating system used include temperature sensor, digital scale, power analyzer, voltage variable (voltage regulator-to select the required voltage), ohmic cell (ohmic container) and computer. The ohmic container is a rectangular cubic tank made of glass with a thickness of 4 mm and a height of 18 cm in the form of a piece. Two electrodes (made of stainless steel, aluminum, zinc and copper) with dimensions of 10 × 11 cm (electrode surface) and with a thickness of 1 mm are connected vertically to the inner walls of the chamber with steel screws to the inner body of the ohmic container. The distance between the electrodes is 9. 5 cm. Heating tests were performed at voltage gradient levels of 15, 20 and 25 V/cm until the weight of the material reached 60 g (40% concentration) and the variable voltage was switched off. Prior to testing, the samples were placed in the laboratory for 10 minutes to be at the same temperature as the environment. After heating, the parameters of temperature, weight, electric current and voltage passing through the food material were measured and recorded. A digital power analyzer was used to measure changes in voltage, current and energy consumption during the heating process. In order to make changes in the input voltage to the ohmic heating system, a number of voltage variable devices with a working range of 0 to 330 volts were used. The pH of carrot juice samples before and after ohmic heating was measured and recorded by a pH meter. It is noteworthy that the pH of the heated samples was measured after isothermal exposure to the Environment. Lab color space was used to obtain the color of the product and also to compare the product obtained from different treatments with each other. Photoshop software was used for this purpose. In this study, the effect of changing the voltage gradient and the type of electrode material on the quality characteristics of carrot juice was studied by performing a basic test in a completely randomized design with three replications. Independent variables include voltage gradient (15, 20 and 25 V/cm) and type of electrodes (steel, copper, zinc and aluminum) and dependent variables include product quality characteristics before and after the ohmic heating process including color changes, pH and special energy consumption. Data analysis of variance was performed using SPSS 16 software. Results and discussion: The results showed that the interaction of electrode material and voltage gradient on the total color change (Δ E) of carrot juice was significant (P<0. 05) and the best performance (lowest Δ E index) was related to the use of copper and steel electrodes and voltage gradient of 25 V/cm. The interaction of electrode material and voltage gradient on the specific energy consumption of carrot juice was significant (P<0. 05). The results also showed that the interaction of electrode material and voltage gradient on the percentage of pH changes in carrot juice was significant and the lowest percentage changes in pH of carrot juice were related to steel and copper electrodes in the voltage gradient of 25 V/cm, respectively. As the voltage gradient increased, the specific energy consumption decreased. Specific energy consumption was changed from 3. 45 to 3. 87 MJ/kg for copper electrode in voltage gradient of 25 V/cm and steel electrode in voltage gradient of 15 V/cm, respectively. Conclusion: The interaction of electrode material and voltage gradient on the percentage of pH changes, total color change (Δ E) and specific energy consumption of carrot juice was significant. In this research, the best performance of the ohmic heating system with the least energy consumption, the least changes and the least changes were related to the copper electrode and voltage gradient of 25 V/cm.

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    31
  • Issue: 

    1
  • Pages: 

    55-66
Measures: 
  • Citations: 

    0
  • Views: 

    256
  • Downloads: 

    0
Abstract: 

Introduction: Measuring the effect of thermal process on nutritional value of food products is one of the most important indicators of qualitative evaluation. That depends on the amount of heat and time of the process, considering that tissue is very important in food products and should be considered for the thermal process. The aim of our study was too investigated of thermal processing on nutritional value of Kilka (Clupeonella engrauliformis) pre-and post-canning and reports the optimal condition. The principle of food preservation is to perform processes protecting food products from the negative effects of corrosive and biological agents as well as undesirable chemical and physical reactions. Generally, food preservation methods can be classified into two types of thermal and non-thermal methods. These processes not only protect food from spoilage extending shelf life of the final product but also affect its quality parameters. The use of heat is of particular importance among various types of food preservation methods and has long been used. The thermal processes could effectively prevent microbial, chemical, and physical spoilage. High temperature could destruct pathogenic microorganisms and spoilage organisms. Additionally, heat could stop enzymatic reactions thus preventing oxidation and chemical decomposition (inactivating the enzymes by hot water and or hot water vapor). Moreover, thermal processes could avert tissue damage to food products at different stages of preparation and packaging. Pasteurization and sterilization are well known thermal processes that are used for the elimination of microorganisms in a sterile environment. However, high temperature of these processes (240-250 degrees Fahrenheit) would lead to the loss of some food nutrients. The amount of heat to the extent that it is sterilized during a suitable period can also eliminate the most resistant microbial growths in the food. These methods are commonly used in canning and preparation of dairy products. Thermal processes serve two purposes in food industry: (1) Destruction of pathogens making a safe final food product for the consumer, and (2) cooking the product for preparation of ready-to-eat food. Cooking could be dry heat or moist heat cooking using microwave ovens as well as grilling and or frying. Each of the cooking methods has their own advantages and disadvantages. Therefore, an appropriate processing for a food product could be inappropriate for the other. Main advantages of food storage thermal methods are: Relatively easy control of the production process of stable products that do not need to be stored in cold conditions, beneficial nutritional effects include the destruction of anti-nutritional factors, soy-based trypsin inhibitors or the degradation of allergen compounds and increased nutrient availability. The methods of cooking food, the use of many baked foods is more consistent with our physiological conditions. Cooking and making them safer, the nutritional value of such flavored foods. Lower temperature of moist heat cooking would biologically be less damaging to food nutrients. Yet the longer cooking time at relatively low temperatures would result in leaching of the soluble nutrients out of the product into the liquid utilized for cooking. Wet cooking methods include boiling, steaming. The boiling method may be the most common one since heat is effortlessly transferred to the food liquid (generally water). One of the disadvantages of using water for baking is its high solubility because it can lose some of its nutrients in water. Although heat destroys some nutrients, it increases body access to some other nutrients. As a result, each method of cooking food has some advantages and disadvantages. Even raw materials are not the best. Although most members of the group of meat, fruits and vegetables can be consumed raw. But for some of the other food groups, cooking improves their properties, another goal of the thermal process is to improve the health of the product through the elimination of microorganisms. Thermal processes are carried out in different ways in order to be healthy, depending on the type of product, the process purpose, the target organism, and the maintenance life of the desired process, from the mild to the extreme. Material and methods: In this research study, we investigated the effect of thermal processes on nutritional value (in particular, amino acid profile), composition and sensory properties of fish pre-and post-canning. Kilka fish was transferred to the canning plant immediately after catch and kept on ice throughout the transfer and after washing, undergoing preliminary preparation and sterilization stages, in150 g cans with sunflower oil, salt was added to the sterilization at 121 o C for 60 minutes, to ensure the application of the appropriate thermal process in quarantine and its quality was investigated. Results and discussion: The thermal process in the canning stage did not have a significant effect on composition of the product (protein, fat, moisture, and ash content) compared with the unprocessed samples pre-canning (P> 0. 05). In the studies, measurement of 16 types of amino acids in both treatments, respectively, is Glutamic 0. 05). Evaluation of the sensory properties showed that cooking increased the taste and aroma of the samples which may be related to the release of aromatic compounds derived from aromatic amino acids. Conclusion: In the final conclusion, it was found that canning has the greatest effect on sensory and taste factors and this method can be very important for small fish that are directly less marketable and has a significant difference with other methods (P<0. 05).

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    31
  • Issue: 

    1
  • Pages: 

    67-82
Measures: 
  • Citations: 

    0
  • Views: 

    267
  • Downloads: 

    0
Abstract: 

Introduction: Chicken egg is one of the most important foods because of its high protein and fat-soluble vitamins. The freshness of chicken egg is dependent on its carbon dioxide content and moisture which usually emit into the surrounding atmosphere through shell-pores during storage. Correspondingly, this would affect the quality of chicken egg. Numerous studies have established techniques to prevent the CO2 emission using biopolymer coating thus extending the shelf life of chicken egg. Starch is commonly utilized for this purpose. Starch is a bio-based, accessible and cost-effective. On the one hand, hydroxyl groups in the starch chain create hydrogen bonds between starch and water. On the other hand, free space between the starch chains facilitates movement of water molecules through this space. However, high permeability of starch to water vapor is an obstacle to achieving this aim. Nevertheless, virgin starch can be decreased water vapor permeability by increasing water transition distance. Barrierity of starch based coating can be enhanced by adding hydrophobic materials i. e. lipids to coating formula. Oleic acid (OA), mainly present in animal and vegetable fats and oils, can reduce water vapor transition rate of the hydrophilic biobased materials. This fatty acid is liquid at room temperature, hence, miscible with biobased material without the need of further heating treatment. On the one hand, mixing starch with fatty acids can reduce its hydrophilicity and permeability to water vapor. On the other hand, UV irradiation can be applied as an inexpensive, easy to operate and environmental-friendly (green) technology, to modify the biopolymers. It is of note that other ionizing beams such as Gamma can improve packaging properties of biopolymers yet, due to its nuclear waste is rarely used (Goudarzi et al, 2018). UV radiation induces the production of free radicals in aquatic solutions. The free radicals attack to starch chains. As a result, the injured chains possess a tremendous potential to produce cross-links. Accordingly, it seems that the exposure of the aqueous film solution to UV ray can be used as a green process to modify the packaging properties of biopolymers. The extension of the shelf life of chicken egg by the coating during the storage is the main purpose of this study. Material and methods: Aqueous dispersion of starch (5% (w/w)) was prepared and heated until its gelatinization (85 ° C for 90 min). Glycerol as plasticizer (40% of dry base (w/w)) was added and agitated for 15 min. Oleic acid (1% of dry base (w/w)) was mixed with Tween 80 as emulsifier (10% of OA (w/w)). The solution was thoroughly mixed and heated (50 ° C for 10 min). Subsequently, 10 ml of distilled water was gradually added to the solution and homogenized by ultrasonic homogenizer (Dr. Hielscher, Teltow, Germany) for 7 min. The OA based emulsion was gradually added to starch solution and mixed for 10 min. Furthermore, the solution was homogenized by ultrasonic homogenizer for 7 min and mounted under three UV-C lamps (8w, Phillips, Holland) at a distance of 5 cm. The solutions were stirred during this time with a magnetic stirrer. The virgin and UV irradiated coating solutions for 30, 60, and 90 min, hereafter call, SO 0, SO 30, SO 60 and SO 90, respectively. The coating solutions were applied on fresh, unwashed, feces-free, white-shell chicken eggs (with weight range of 60 to 65 g ( were obtained from poultry farm of University of Zanjan. Then the coated chicken eggs were dried by cabinet dryer at 37 ° C for 20 min. After that uncoated and coated chicken eggs were incubated at 25 ° C for 7 weeks. Percentage of weight loss, pH, Haugh index, Yolk index and overall egg quality were investigated during storage time. Results and discussion: Weight loss of eggs during storage is mainly caused by evaporation of water from the albumen through the porous shells. The weight loss increased during 7 weeks of storage. The greatest water loss (11. 83%) was observed in control group (uncoated eggs). Coating the eggshell led to minimum weight loss. Starch-oleic acid solution limit the moisture exchange into eggshell. This phenomenon was intensified by UV-C irradiation for 90 min. According to our results, Haugh index (HU) and Yolk index (YI) decreased in all treatments yet the reduction was highest in the control group. Starch-oleic acid, and modified starcholeic acid for 90 min by UV-C showed the highest HU and YI. This is influenced by CO2 and moisture exchange into eggshell. The pH of albumen is an important factor in the quality of chicken egg. Moisture and carbon dioxide of the white evaporate through the pores and replaced by air. Decreasing the CO2 content would lead to higher pH. The properties of the albumen were affected by this phenomenon. The pH of albumen was increased in control, while remained almost constant in the coated eggs. The albumen of the coated eggs by starch-oleic acid and modified starch-oleic acid for 90 min by UV-C had the least pH. Conclusion: According to our results, starch-oleic acid and modified starch-oleic acid for 90 min by UV-C could be the best eggshell coating material for extending the shelf life of chicken eggs. The shelf life of coated eggs was double the uncoated ones. It seems, the combination of coating by starch-oleic acid and curing by UV-C can be applied as a new approach to simultaneous sanitation and extending the shelf life of the chicken egg. However, UV-C irradiation for 90 min was optimum condition to modifying the eggshell coating. But the long process of this method limit its industrial application. Therefore, accelerating the modification process is highly necessary to extend this process in egg packaging.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Author(s): 

Dalvi Isfahan M.

Issue Info: 
  • Year: 

    2021
  • Volume: 

    31
  • Issue: 

    1
  • Pages: 

    83-94
Measures: 
  • Citations: 

    0
  • Views: 

    230
  • Downloads: 

    0
Abstract: 

Introduction: Tomato (Solanum lycopersicum) is the second most consumed vegetable next to potato, with an estimated world production of over 180 million tonnes per year. Iran has always been among the top tomato producing countries in the world due to the diverse topography and climactic conditions prevailing in different parts of Iran. Tomato paste is the most important tomato product that is produced by removal of water content from tomato juice by evaporation and or thermal processing (Singh and Headman, 2014). Water removal from the juice would not only extend the shelf life of product but could also control its microbial growth and guarantee its safety. Conventional thermal processing (pasteurization and sterilization) is still widely used in the Iranian food industry though several emerging food preservation technologies have been developed (e. g., ohmic heating, microwave heating, and non-thermal processing techniques such as pulsed electric fields and highpressure processing). However, the challenges of accurately determining both optimal operating conditions and developing a control system for industrial pasteurization process to prevent either under-or over-processing are significant (Chen and Ramaswamy, 2007). Mathematical modeling and simulation are one of the most used methods to gain a better understanding of processes. Modeling can cost-effectively provide insights into complex processes, shorten the design cycle, and optimize the process as a function of various variables in shorter time. Different mathematical methods for solving heat conduction problems have been proposed, but numerical methods are more useful, especially when problems cannot be handled by exact analysis because of nonlinearities, complex geometries, and complicated boundary conditions (Incropera and De Witt, 1990). Among the numerical methods developed so far, finite difference and finite element techniques have been widely used to analyze heat transfer phenomena in cylindrical cans of food. Many have attempted to develop mathematical models based on numerical methods for predicting temperatures in tomato products during thermal processing (Bichier et al., 1995), (Nicolai et al., 1998), (Tattiyakul et al., 2002) and (Plazl et al., 2006). Nonetheless, to the knowledge of authors data about thermal processing of tomato paste in Iran is scarce. In this study, the efficiency of two different modeling approaches (finite difference vs. finite element) for predicting temperature of tomato paste during pasteurization process were compared. The model would contribute to energy consumption reduction during operations while producing high-quality products in a short time. Material and method: Experiments were run with batches of 400 g of tomato paste (pH of 4. 1 and 28° Brix) in cylindrical cans (211×400 inches). Hot water was used as the heating medium. The chemical analysis of tomato paste sample (Brix, pH salt, moisture, fat and protein) was performed in the first step and the thermal properties of the tomato paste product including thermal conductivity, specific heat and density were determined based on the sample chemical composition and structures model. Temperature changes at various positions in the container were checked with a data logger (Testo, Germany) coupled with computer and thermocouples type-K (at 2 min intervals). The cylindrical can was immersed in a vertical position in the water bath and the temperature recording was started. After finishing the heating time, the can was cooled in another water bath (20º C). The data were used to validate the developed model. In the next step, 2D heat transfer model was developed in a cylindrical can by using the numerical solution of the Fourier second law with two different methods; (1) finite difference (explicit scheme) and (2) finite element methods. Computer simulation was done using MATLAB R2009a software (Math works, Inc., Natick, MA, USA) and COMSOL Multiphysic, Ver. 4. 0. To evaluate the best model, two criteria, coefficient of determination (R 2 ) and root mean squared error (RMSE) were used. Result and discussion: The results showed that, by placing the sample in the bath, the surface temperature rises rapidly, while the temperature in the center is much lower. In addition, as expected, increasing hot water temperature enhanced the heating rate considerably due to the larger temperature gradient between the center and surface of the can at the higher temperatures. The models were verified by comparing results with two analytical solutions and validated against experimental data. The statistical analysis results showed that the finite element model (developed by COMSOL software) can more accurately predict temperature compared to the finite difference. The variation in the results could be due to the consideration of a layer of air-steam mixture on the top of the can (head space) in the finite element method which increases the accuracy of the model in temperature prediction. After validation, the developed model was used to determine the cold spot location of the tomato paste can. In addition, results showed that the cold point was a stationary point and located at the radial center at a height of 60% of the can height from the bottom (Tattiyakul et al., 2002). Two simulations were conducted at two different head space volume (6 and 12% of total can height) to determine the importance of head space volume on cold point location. Results showed that there was no significant difference in the location and temperature of the cold spot in two simulations (Khakbaz Heshmati et al., 2014). Conclusion: In this study, the pasteurization process of tomato paste (Brix=28) was investigated by two different numerical methods (finite difference and finite element). The results were compared with experimental data and it was found that the predicted temperature by finite element model is more accurate than finite difference method. Moreover, we demonstrated that the slowest cooling point was located at a height of 60% of can height from the bottom which was in disagreement with others reporting geometric centre of cylinder being the coldest point of a solid product. The developed model can predict temperature in tomato paste with different degree of concentration (brix) or different thermal processing conditions. The model, with slight modifications, may be used to design and control industrial pasteurization for various solid products. In addition, the results of this study is expected to be a significant contribution for further optimization studies.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Author(s): 

Mahrousi T. | POURFARZAD A.

Issue Info: 
  • Year: 

    2021
  • Volume: 

    31
  • Issue: 

    1
  • Pages: 

    95-114
Measures: 
  • Citations: 

    0
  • Views: 

    294
  • Downloads: 

    0
Abstract: 

Introduction: Rice (Oryza Sativa), a member of Gramineae family, is one of the most important cereal grains which can be annual or perennial. The grain has many varieties which are divided into Asian and African classes. Rice grain and its related products are food staple of over 40% of global population (Sereewatthanawut et al. 2008). Rough rice (paddy) is surrounded by a loose outer hull or husk. The white starchy endosperm kernel of rice is enclosed by a firmly adhering bran coat and germ. In general, rice is milled before utilization, producing hull, bran, germ, and white rice. Rice bran, process discard, is extensively used as animal feed, fuel or fertilizer throughout the world (Saunders 1985). Rice bran is rich in protein (12-16%), fat (16-22%), raw fiber (8-12%) as well as vitamins and minerals (e. g., thiamin, niacin, aluminum, chlorine, iron, magnesium, phosphorus, potassium, silicon, sodium, and zinc). This byproduct is good source of vitamin E such as tocopherols (alpha, beta, sigma, and gamma). Numerous studies have shown the beneficial effects of vitamin E in the prevention, control, and treatment of various disease. Moreover, over the years many studies have confirmed the health benefiting effects of rice bran (Ryan et al. 2011). Recently, immunoregulatory effects of rice bran, against enteric pathogens, have been reported (Kumar et al. 2012; Nealon et al. 2019). Rice bran, as a fermentable substrate for the growth of the probiotic microorganisms, has been successfully used for the production of functional foods (Poletto et al. 2019). To the best of our knowledge, there are no reports on the use of rice bran in the formulation of Fouman cookie. Thus, the present study was designed: (a) to examine the effects of rice bran on the chemical, physical and organoleptic properties of Fouman cookie; (b) to obtain the relationship between Fouman cookie parameters using multivariate mathematical-statistical methods such as partial least squares regression analysis (PLSR) and principal components analyses (PCA) as ways to offer simple ways to measure texture, sensory and shelf-life aspects. Material and methods: The stabilized rice bran was kindly provided by the Giltaz Company (Langarud, Guilan, Iran). The obtained bran powder was stored at-18℃ till further analysis. In this research, we investigated the effect of different levels of rice bran (0, 10% and 20%) in production of Fouman cookie. Moisture, protein, ash, fat, total dietary fiber, phytic acid, acidity, peroxide, and vitamins (thiamin, niacin, B6, E and pantothenic acid) were analyzed by method of American Association for Clinical Chemistry (AACC (2000). The prepared samples were coded by two-digit codes and presented in random order to 10 trained evaluators. They were asked to score the cookies in the range of 1 to 5 in terms of odor, taste, color, texture, and overall quality (5-point hedonic scale). All the assessments were conducted on the same day at room temperature. A texture analyzer (Brookfield, Model CT310K, US) was used to measure the force required for compression of a round-bottom (2. 5 cm diameter × 1. 8 cm height) probe on the samples. The test velocity was set at 0. 5 mm/s with a compression depth of 5 mm and the trigger load of 100 g. In a typical process, the samples were placed vertically inside the device and the probe landed on it with the mentioned velocity and compression depth (El-Arini and Clas 2002). The texture of samples was evaluated after 1, 72 and 168 hours of storage for shelf-life monitoring. Crumb texture was determined by a texture analyzer (Brookfield, Model CT310K, US) provided with the software “ Texture Expert” . The aluminum cylindrical probe (25 mm diameter) was used in a “ Texture Profile Analysis” double compression test (TPA) to penetrate to 50% depth, at 2 mm/s speed test, with a delay of 30 s between first and second compression. Hardness (N), springiness and resilience were calculated from the TPA graphic (Gó mez et al. 2008). A central region image of each sample was captured using a flatbed HP Scanjet G4010 Photo Scanner (Hewlett-Packard, Palo-Alto, CA, USA) supporting Desk Scan II software (Hewlett Packard, USA). A single 8 mm×8 mm square field of view was analyzed for each image. Brightness was adapted to150 units and contrast to 170 units. Images were scanned in 256 grey levels at 150 dots per inch (dpi) each containing 355 columns by 355 rows of picture elements (pixels) (Crowley et al. 2002). ImageJ 1. 4g (National Institute of Health, USA) was used for analyzing of the JPEG image file. The CIE L*a*b* (or CIELAB) color model was operated for the examination of color (Figure 1). The three parameters of such model represent the color lightness (L*), redness-greenness (a*) and blueness-yellowness (b*) (Pourfarzad and Habibi-Najafi 2012; Quevedo et al. 2009). To evaluate crumb structure, color images were converted to 8-bits 256 gray level images. The thresholding method (conversion to a binary image) of the 256 gray level digital images was used for image segmentation. The selected crumb grain features were the average size and porosity (FarreraRebollo et al. 2011, Angioloni and Collar 2011). To assess the significant differences among samples, a completely randomized design was performed (Minitab 15, Minitab Inc., State College, PA, USA). To investigate the significance of differences between the mean values, Duncan’ s multiple range tests were employed after the one way analysis of variance at the confidence level of 95%. Each test was conducted in three replicates. Principal component analysis and PLSR were performed on physicochemical, texture and sensory data sets. Results and discussion: The results showed that there was no significant difference between the color score, texture and the overall quality of control and samples containing 10% bran, but their scores decreased significantly with increasing bran amount up to 20%. The moisture and ash contents of the samples increased significantly with increasing rice bran amount. Also, by adding rice bran, the parameters of crumb L, crust L, crust b, porosity, and average size of Fouman cookie significantly decreased. Moreover, addition of rice bran increased the hardness of samples on the first day, but there was no significant difference between the hardness of the control and samples containing10% rice bran during storage. Conclusion: The best physico-chemical, sensory properties and shelf-life of Fouman cookie were obtained at 10% fortification level. Obtained Partial least squares regression models had very high R 2 indicating the high efficiency of these equations in predicting the sensory properties of Fouman cookies using color analysis indices.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    31
  • Issue: 

    1
  • Pages: 

    115-128
Measures: 
  • Citations: 

    0
  • Views: 

    365
  • Downloads: 

    0
Abstract: 

Introduction: Celiac, a chronic digestive disease, is common in gluten-sensitive individuals. Celiac disease is strongly associated with the inflammation of small intestine leading to impaired absorption of several important nutrients and damage to the intestinal mucosa. Celiac disease is caused by the consumption of gluten-containing cereals such as wheat, barley, and rye. The only effective treatment for this disease is the use of gluten-free diets that improve and restore the intestinal mucosa. Adhering to a gluten-free diet can help manage the disease and heal the gut. Sesame, a member of pedaliaceae family, is one of important oilseeds. The seed contains highquality unsaturated fatty acids with several high-quality double bonds and high stable fatty acids preventing the oil from oxidation. Sesame is used to produce various food products (e. g., oil, seeds and milled sesame (Tahini). The most important sesame seed products used in different countries are soup sesame seeds with or without skin and raw or roasted in most bakery products such as biscuits, bread, and crackers. In Japan, roasted sesame is used in the production of a food called instant cake (Eshaghi et al 2014). Tahini is a semi-liquid, smooth and product obtained through the process of hulling, washing, roasting, and grinding sesame seeds without the lubrication process. Sesame oil is rather rich in non-soapable compounds. These include sterols (mainly beta-sitosterol, campesterol and stigma sterol), triterpene and triterpene, tocopherols, sesame and sesamulin. Sesame oil has more unsaturated fatty acids than other types of fats and is relatively important source of essential fatty acids in the diet. One of the most important gluten-free food products is rice flour, used in the production of many pastry products. Rice flour is one of the most convenient cereal flours for preparation of celiac food. Highly nutritious, and allergen-free, cereal rice is used to prepare baby food, puddings and especially gluten free foods. Rice cookie is an Iranian traditional cookie consisting of flour (wheat and rice), sugar, oil, water, egg, and milk powder. The product is suitable for celiac individuals since cookies are gluten-free (Eshaghi et al 2014). Material and methods: In this study, we replaced hydrogenated semi solid oil with sesame oil (5, 10, 15 %) and tahini (5, 10, 15 %) in rice cookies (8 treatments including one control). Subsequently, we measured the physiochemical (moisture, total ash, acid– insoluble ash, acidity, water activity, and weight loss), rheological (viscosity), texture (chewiness, gumminess, hardness) and sensory (taste, aroma, crumb and crust color, texture, and total acceptance) properties. One was designed and the measurement was done in triplicate. Data were analyzed by SPSS 21 software and the means were compared by Duncan tests at 95% confidence level and the diagrams were drawn by Excel 2013. Results and discussion: The results of physicochemical analyses showed that as the level of sesame oil and tahini increased, moisture, total ash, acid– insoluble ash, acidity, viscosity, and water activity decreased, and pH and weight loss increased significantly (p≤ 0. 01). Tahini– containing samples had superior physicochemical properties. Moisture loss may be due to lack of gluten and protein network and migration of water from crumb to crust (Eshaghi et al., 2014). Ash content was higher in sesame containing sample due to the presence of insoluble minerals (iron, calcium, magnesium, potassium, sodium, zinc (~ 4-7% g 100 mg of sample) in tahini. Acidity was lower in sesame containing products due to reduced water activity and autoxidation thereby increasing the pH of sample. Increasing amount of sesame oil and tahini led to higher pH value due to enzymatic activity of rice flour maintaining moisture. In general, oil containing samples absorb less water stimulating hydrogen ions thereby increasing the pH value. Lower weight loss, viscosity, and water activity in the sample may be directly related to the reduced moisture. With increasing sesame and sesame oil, the amount of moisture has decreased significantly. The results of texture analyses, obtained by a Texture analyzer (CT3 Texture Analyzer Brookfield), showed that as the level of sesame oil and tahini increased, chewiness, springiness, cohesiveness, hardness and gumminess decreased (p≤ 0. 01) decreased. The reason of reduced cohesiveness may be due to high fiber and low moisture in tahini-containing samples. Texture hardness represent the resistance of food against compressive force. In general, fat could surround the starch granules in rice cookie dough thus preventing the adhesion of granules to one another in the baking process and reducing the hardness. The results of sensory evaluation showed that with increasing sesame oil level taste, aroma and crumb color indexes increased, total acceptance decreased while crust color and texture remained unchanged. As the amount of tahini increased, taste, texture and total acceptance were given the highest score (5) and aroma, crust and in general, tahini– containing treatment were given the highest score for sensory properties. The results revealed that tahini treatments were accepted by the panelists showing significant difference from the control sample. The reason may be due to higher moisture, viscosity, water activity and the lowest weight loss. The reason of higher scores for aroma and flavor of sesame oil and tahini treatments was the presence of aromatic compounds such as tocopherols. Tocopherols are fat– soluble compounds promoting aroma and flavor of the rice cookies. Treatment containing 5% tahini was selected as the superior one given the highest score of moisture, water activity, viscosity, texture and the lowest weight loss as well as the best sensory scores for aroma, texture, taste and total acceptance. Conclusion: The results showed that addition of sesame oil and tahini to the formulation of rice cookies could significantly improve the physiochemical, texture, and sensory properties of the final product.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    31
  • Issue: 

    1
  • Pages: 

    129-142
Measures: 
  • Citations: 

    0
  • Views: 

    228
  • Downloads: 

    0
Abstract: 

Introduction: Cocoa is one of the most important agricultural and economic commodities worldwide. Cocoa is a basic ingredient in the production of chocolate and cocoa powder. Cocoa powder is mainly used in the preparation of beverages and confectionaries (Aprotosoaie et al. 2016). Cacao beans are polyphenol rich (12-18% of total bean dry weight) and these bioactive molecules are associated with flavor, color, and the nutritional value of cocoa products (Niemenak et al. 2006). Alkalization, by complex polymerization, reduces the bitterness of polyphenols producing darker colored products (Giacometti et al. 2014). Alkalization is one of several processes used by the manufacturer for the modification of cocoa color. These processes may lead to the development of oquinones and Maillard reactions, especially non-enzymatic brown compounds (Bonvehí 2005). Researchers have reported that the percentage of color and aromatic compounds can be modified by adjusting the amount of sodium or potassium carbonate used during the alkalization process (Yue et al. 2012). Polyphenols present in cocoa powder contribute to the development of specific cocoa color during roasting and alkalization. Handful studies have focused on the relationship between the alkalizing conditions, the color of cocoa products, and the polyphenol content. The objectives of the present study were to determine the effects of cocoa alkalinization on physicochemical and qualitative properties of cocoa powder. In this study, cocoa powder was treated with different types and concentrations of an alkali solution (sodium hydroxide, potassium carbonate, and ammonium bicarbonate) and its effects were investigated on color, the anthocyanin and polyphenol contents and selected physicochemical properties (moisture, ash content, acid-insoluble ash content and pH). Material and methods: In this study, we used Cameroon cacao beans (Forastero cultivar, Cameroon) that were dried and fermented in Cameroon conforming to the local practices. Therefore, data on the quality of process is inaccessible. Cameroon cacao beans were cleaned, dried (100 ° C), shelled and crushed to cocoa nibs. Samples were alkalized with NaOH, K2CO3, and NH4HCO3 alkaline solutions at their different concentrations and combinations. The alkalized cocoa nibs were roasted at 130 ° C for 20 min by laboratory oven (Funke Gerber, Germany (. Samples were pulverized in a laboratory mill to obtain the cocoa powders. Results and discussion: The optimization of the alkalization parameters is commonly considered in the processing of cocoa powder to improve its color and flavor qualities. The pH values were augmented proportionally with increased concentration of alkali. According to results, ash and acidinsoluble ash contents were positively correlated with the alkali concentration. These parameters were also influenced by the type of alkali. Different types and concentrations of alkali showed a significant effect (P ≤ 0. 01) on the moisture content of the samples. The analysis of variance (ANOVA) showed that the total polyphenol content of the cocoa powders significantly changed (p ≤ 0. 01) with the type and concentration of alkali solution. The lowest total value of polyphenol of the alkalized samples was observed in A9 samples with 3% K2CO3 solution. The analysis of variance (ANOVA) showed that the browning index of the cocoa powders was significantly affected (p ≤ 0. 01) by the alkali solution type and its concentration. The highest value of the browning index was observed in A7 samples with 1. 5% K2CO3 and 0. 5% NH4HCO3 solution (unprocessed (A0: 1. 158) and alkalized cocoa powder (A7: 1. 787)). The lowest value of the browning index of the alkalized samples was observed in A1 samples with 1% NaOH solution. Cocoa powder alkalized with 3% (w/w) K2CO3 solution exhibited a darker color and had a higher OD460/OD525 value than the one alkalized with 3% (w/w) NaOH solution. All alkalized samples had lower ratios of monomer anthocyanins to yellow/brown polymer content than the un-alkalized sample. This observation shows that more anthocyanins changed into brown polymers, compared with the un-alkalized cocoa powder. The OD460/OD525 values (browning index) for the alkalized samples were higher than those for the nonalkalized samples. The values of browning index (OD460/OD525) were negatively correlated with the total polyphenol content, indicating that a darker color was related to lower total polyphenol content. Thus, less astringent taste and darker cocoa powder were associated with a decreased polyphenol content. Cocoa powders displayed dark color with K2CO3 processing and darker colors with NH4HCO3+K2CO3 and NH4HCO3+NaOH alkalization. In this study, the range of F1/F3 values of cocoa powders were lower at 0. 33. The values of F1/F3 for cocoa powders were changed significantly (P≤ 0. 01) with the type of alkali solution. All alkalized samples had lower ratios of monomer anthocyanins to yellow/brown polymer content than the un-alkalized sample, suggesting that more anthocyanins were changed into brown polymers, compared with control. Alkalization with a combination of NH4HCO3 and NaOH or K2CO3 solution produced lower F1/F3 values than other alkali solutions. Conclusions: The formation of color compounds during the Maillard reaction is dependent on the time and temperature of roasting stage and the pH of alkalization stage; therefore, the color properties of cocoa powder could be modified by improving alkalization parameters. The cocoa powder alkalized with different types and concentrations of alkali was studied for its color, color fractions, polyphenol content and qualities. Alkalization increased the browning index (OD460/OD525 value), while it decreased F1/F3 of cocoa powder. The alkalized cocoa powders displayed darker color than the non-alkalized cocoa powders. The alkalization process affected the moisture, total polyphenol, ash, acid-insoluble ash contents and pH. It was also observed that the combination of alkali type and concentration affected the parameters under investigation. Alkalized sample with combination of 1% NaOH + 1% K2CO3 solution (A4) had a high polyphenol content and a low content of ash and moisture, which could be considered as a fine sample, compared with other alkalized powders. Furthermore, among the studied alkalized powders, A6 (alkalized with NaOH + NH4HCO3 solution) and A7 (alkalized with K2CO3 + NH4HCO3 solution) displayed better color property (high browning index and low value of F1/F3). In conclusion, alkalization improves some of the quality properties of cocoa powder.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    31
  • Issue: 

    1
  • Pages: 

    129-141
Measures: 
  • Citations: 

    0
  • Views: 

    388
  • Downloads: 

    0
Abstract: 

Introduction: Nowadays, many types of probiotic dairy products are available on worldwide. Probiotic yogurt is still among the most popular probiotic products (Shori, 2016). To provide health benefits related to probiotic organisms, the minimum viable counts of each probiotic strain in gram or milliliter of probiotic products is a critical value. Generally, the amount of 10 6 cfu/mL or cfu/g has been accepted as minimum level and the amounts of 10 7 8 and 10 cfu/mL or cfu/g as satisfactory levels (Sidira et al., 2017). Prebiotics are non-viable and non-digestible (or very low digestible) food ingredients selectively metabolized by beneficial intestinal bacteria and enhance their growth and/or activity. They are mostly sugar-like compounds comprising between two and ten monomers that largely resist against digestion by pancreatic and brush board enzymes. The term “ symbiotic” is used to describe products that contain both probiotics and prebiotics (kumar et al., 2015). Prebiotic compounds are used for the survival and growth and higher activity of probiotic bacteria in the formulation of these products. Inulins are storage polysaccharides of many plants consisting of beta2, 1-linked fructosyl units with a terminal glucosyl unit. The main source of commercial inulin for food application is the chicory roots. The functional attributes of inulin are dependent on its degree of polymerization (Delavari et al., 2014). Because they are indigestible and not absorbed in the human small intestine, they arrive intact in the large intestine where they promote the proliferation of beneficial probiotic bacteria (Crispí n-Isidro et al., 2015; Shori et al., 2016). Moreover use of herbs and flavors in dairy products increases nutritional, medicinal value and consumption of these products (Elsayed and yousef, 2019). Shallot is an important part of the diet of many populations and there is long-held belief in their health enhancing properties. Shallot (Allium ascalonicum L. ) is a major component of many Asian diets and is widely believed to be beneficial for human health. This bulb is darker than garlic and has a stronger odor that correlates with its sulfide content. Analysis of shallot extracts has confirmed the presence of flavones and other polyphenolic derivatives. This study is aimed to assay the physicochemical and antioxidative properties of probiotic yoghurts containing inulin as prebiotic and shallot. Material and methods: For the preparation of yogurt, firstly the solid fat content of the raw milk with 3. 3% fat content was increased by addition of 3% skim milk powder. Secondly inulin was mixed at different concentration (0, 0. 5 and 1. 5%). Homogenization and heating process were applied and after that, cooling was performed until starter culture inoculation temperature (42° C). Inoculation was carried out with yogurt starter culture (Lactobacillus bulgaricus and Streptococcus thermophilus) and Lactobacillus acidophilus as probiotic bacteria. At the end of fermentation, the cured cooled and stirred gently, then shallot in two levels (0. 6 and 0. 3%) and salt (0. 5%) were added to the mixture. Finally filling was conducted and yogurt samples stored at 4° C until analysis. The prepared probiotic yoghurt samples were evaluated for chemical properties (pH, acidity based on Dornic degree), texture properties (water holding capacity and viscosity), total phenolic content based on gallic acid equivalent, antioxidative property based on DPPH scavenging capacity and survival of probiotic bacteria during storage period (0, 7, 14 and 21 days of storage). The sensory evaluation of probiotic yogurt samples enriched with inulin and shallot was performed 7 days after production with 30 semi-trained panelists (15 males and 15 females). Sensory analysis consisting of appearance and texture (abnormal color, gel strength or weakness, whey-off, mouth-feel), aroma (unusual odor), taste (bitter, too high or low acid), and overall acceptability were based on 5-point hedonic scales (1: dislike extremely; 7: like extremely). Preparation of treatments were carried out in triplicate and the data obtained from the above mentioned evaluation parameters were analyzed based on Factorial design and Duncan's multiple range comparison test. Results and discussion: The results showed that acidity increased and pH decreased during storage of yoghurt samples as a result of lactic acid production by lactose consuming bacteria (p<0. 05). Addition of shallot accelerated pH reduction rate. Due to the ability of inulin to form a gel network and absorbing water, it increases the water holding capacity and viscosity of yogurt samples at all storage times. Similar results have been reported by Silva et al., (2018). The shallot containing samples had higher acidity in comparison to others so it leads to decreasing effect on water holding capacity. The addition of shallot also increased the total phenol content of samples. As well as, it increased DPPH radical scavenging capacity because shallot contained sulfur compounds (Lu et al., 2011). The highest total phenol content and antioxidant activity related to 1. 5 inulin + 0. 6 shallot treatments. At the end of the storage period, all of the probiotic yogurts had an acceptable number of Lactobacillus acidophilus bacteria (more than 10 6 cfu/ml). Shallot with sulfur compounds probably provided the suitable conditions for the growth of probiotic bacteria; moreover inulin could support survival of probiotic bacteria too as a result of gelling properties and oxygen depletion in samples. Sensory properties analysis showed that inulin addition lead to significantly improvement of surveyed parameters except aroma. The inulin containing yogurt had a creamy and pleasant texture according to the responses of panelist. Inulin 1. 5% + shallot 0. 3% and inulin 0. 5% + shallot 0. 3% samples had the highest and lowest overall acceptability, respectively. Overall, the addition of shallots and inulin could lead to the production of probiotic yogurt with an acceptable microbial population until 21 days of storage and acceptable sensory characteristics.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    31
  • Issue: 

    1
  • Pages: 

    143-159
Measures: 
  • Citations: 

    0
  • Views: 

    325
  • Downloads: 

    0
Abstract: 

Introduction: For millenniums, jujube (Ziziphus jujuba), has been used as food and medicine for thousands of years (Baytop, 1984). In the recent yers, jujube fruit has been used by food and pharmaceutical industry as additive and natural medicine. Studies have shown that fruits and their derivatives have protective effects against cancer, stroke, and coronary heart diseases, (Kalt et al., 1999). To date, many varieties of the fruit have been characterized for its bioactive compounds such antioxidants (Ercisli and Orhan, 2007). The fruit is rich in dietary fiber, minerals and phenolics and has floury structure as well as desirable taste (Gultekin, 2007). Dehydrated fruit, in powder form, may be used as a functional ingredient in the production of many food products such as bread, yoghurt, ice cream, infant food, chocolate, confectionery. Fiber rich whole Jujube powder, with very low allergenicity and various health benefits, can be used as a functional ingredient in food product formulations. Fruit fiber contain water soluble and insoluble fractions (Akbolat et al., 2008). Among various food processing technologies, short time high-temperature extrusion cooking is one of the commonly practiced and cost-effective processes. Extrusion combines high pressure with a moderately high-temperature and usually high shear for a short period of time. Extrusion processing completely gelatinizes the starch and partially or destroys antinutritional factors present in many legumes (Potter, 2013). Extrusion cooking technology is a versatile and efficient method of converting raw materials into finished food products. The process id used for the preparation and production of various types of snack foods, mainly from corn meal, rice, wheat flour, or potato flour in many shapes and variety of textures. Several reports show that bean starches have very good expansive and functional properties under extrusion conditions (Selan, 2014). Extrusion is a hightemperature /short time technology (HTST) that offers numerous advantages including versatility, high productivity, low operating costs, energy efficiency, high quality products, and an improvement in digestibility and biological value of proteins (Potter, 2013). The purpose of this study was to study the suitability of jujube flour incorporation into an extruded snack formulation, and to produce a nutritious snack with appropriate organoleptic and technological characteristics. Material and methods: In this project, central composite design was used to study the effect of feed moisture (12 and 16. 18%), jujube flour addition (5, 10 and15%) and screw speed (120, 150 and 180 rpm) on physicochemical properties (expansion, porosity, water, and fat absorption) and the total acceptance of extrudates based on corn-wheat flour (ratio of 1: 1). The extrusion experiments were carried out on a pilot-scale, co-rotating, twin-screw food extruder typed DS56 (Jinan Saxin., China) with the following parameters: length 80 cm, diameter 16 mm, the maximum rotation speed 320 rpm, and die diameter (D) 3 mm. Steady-state conditions were reached after 20 min. Based on preliminary experiments, barrel temperature zones profile and feed rate were kept constant at 140° C and 40kg/h, respectively. After extrusion, extruded products were oven-dried (model FD 115, Binder, Germany) with forced convection at105° C for 30 min, then cooled immediately and placed in appropriate laminated bags in room temperature for further analysis (porosity and expansion ratio, overall acceptance, color, texture of product). Ash, protein, fiber, and fat content of raw materials were measured according to standard procedures. Moisture content of prepared blends was determined by infrared moisture analyzer (Sartorius, Germany) at 105° C. Results and discussion: Results showed that the addition of jujube flour reduced the porosity and expansion of the extrudates. Nevertheless, increasing screw speed and jujube flour simultaneously leaded to viscosity reduction and boosting expansion and porosity. Therefor caused an improvement in characteristics of snacks. The highest total acceptance score (4. 33) was for the sample with lowest amount of jujube flour and moisture and the highest level of screw speed. Addition of jujube flour had a negative effect on the overall acceptance of samples. Moreover, due to the high amount of sugar, caramelization occurred during the heat extrusion resulting in darker color, sticky texture and burned taste of product. Optimum condition for puffed snack production was found to be 13. 19% feed moisture content, 6. 30 % jujube flour and 122. 2% screw speed. Conclusion: It is possible to enrich extruded snacks with jujube flour which is protein rich and good source of fiber. The functional and physical properties of extrudates produced from jujube flour/ corn grit using a twin-screw extruder were influenced by the raw material, screw rate, and feed moisture content. The good characteristics of extruded snack (high WAI, high OAI, high expansion and porosity, high total acceptance) were produced at lower jujube content, and high feed moisture content. It was observed that feed moisture content was the most important parameter with significant effect on the responses studied. The earlier studies have reported that the properties of dietary fiber are affected by food processing such as extrusion (Chau et al., 2004). Shear stress caused by high screw speed during extrusion cooking could significantly affect fiber solubility (decrease insoluble dietary fiber and increase soluble fiber) (Alam et al., 2016). The findings of our research demonstrated the feasibility of developing value-added products containing jujube flour by extrusion processing, but further studies are necessary to assess the sensory attributes of final product.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Author(s): 

JALILI M. | RASHIDI L.

Issue Info: 
  • Year: 

    2021
  • Volume: 

    31
  • Issue: 

    1
  • Pages: 

    161-176
Measures: 
  • Citations: 

    0
  • Views: 

    323
  • Downloads: 

    0
Abstract: 

Introduction: Today olive oil is widely produced and consumed in different countries due to its good taste and valuable nutritional properties (Moldao-Martins et al. 2004). Olive oil fatty acid profiles consist of saturated fatty acids (about 11%), monounsaturated fatty acids (in particular oleic acid) (about 80%), and polyunsaturated fatty acids (approximately 9%). In addition, olive oil contains antioxidant and anti-inflammatory compounds such as squalene, phytosterol, tocopherols, polyphenols, aromatic compounds and coloring pigments (Rafehi et al. 2012; Hernaez et al. 2015). These compounds have important effects on human health, nutritional value, sensory properties and oil stability (Kalua et al. 2007). Based on definition provided by Iranian national standard (1446) olive oil is obtained solely from the fruit of the olive tree to the exclusion of oils obtained using solvents or re-esterification processes and of any mixture with other kind of oil. It is marketed in accordance with the following designations and definitions: virgin olive oils, refined olive oil, olive-pomace oil and olive oil. Virgin olive oils are more expensive than other kind of olive oils because of their good taste and good nutritional values; therefore, sometimes virgin olive oil sold is adulterated, cut with poor quality olive oil or cheaper oils such as sunflower and soybean oil (Moreda et al. 2003). Recently, there is a suspicion among consumers and regulatory agencies that some manufacturers (to increase their profits) have labeled lower quality olive oils as a virgin or extra virgin olive oil. A comprehensive study of food fraud over a 30-year period showed that the highest amount of food fraud was related to the olive oil. The study used scientific papers published between 1980 and 2010 (Moore et al. 2012). Therefore, the aim of the current study was to investigate the properties of different types of olive oils (including virgin, refined and olive oil), distributed in the Iranian market. Material and methods: Total of 18 samples of olive oil including, virgin olive oil (5 samples), ordinary virgin (3 samples), refined olive oil (5 samples) and olive oil (5 samples) were collected from the market (Table 1). The samples were transferred to the laboratory and kept in the refrigerator (4 ° C) until they were analyzed. physicochemical and qualitative experiments (including acidity, peroxide, moisture content, insoluble impurities, extinction coefficient (K270, K232,  k)); and oil purity (including identification and determination of sis and trans fatty acid, sterols, erythrodiol and uvaol content, 2-glyceryl monopalmitate, unsaponifiable matter, and  ECN 42) were determined. Each sample was tested three times and the results were reported as "mean± standard deviation". Physicochemical properties including acidity, peroxide, moisture and insoluble impurities were measured according to the national standards No 4178, 4179, 4291, and 4095 respectively. The extinction coefficient (K232, K270,  K) was determined using a spectrophotometer (EU 2200, ONLAB). Fatty acid profile was determined according to standard No 13126 (2016). Oil samples were sterified in methanol solution (2 M) for 30 min at 50 ° C and methyl ester of fatty acids were determined by gas chromatography (GC-Yung Lin 6500) equipped with flame ionization detector (FID). Nitrogen gas (at the flow rate of 4 ml/min) was used as the carrier gas. The  ECN 42 was calculated based on Iranian National Standard No17379. The 2monoglycerol palmitate was measured using a gas chromatography equipped with a flame ionization detector (FID). The chromatographic column used was DB-5 (15m*0. 25mm*0. 53µ m). Sterol and triterpene dialcohol composition including, desmethylsterol composition (% total sterols), Total sterol content, and Erythrodiol and uvaol content were determined using GC based on method provided by Iranian national standard (ISIRI 16324). All obtained results for olive oils were subjected to statistical analysis using statistical software (Minitab, 17: 0, PA., State College, USA). The significant differences between mean values were determined by analysis of variance (ANOVA) with Post Hoc Tukey’ s test. A probability value of 0. 05 was used to determine the statistical significance. All data are reported as means ± standard deviations. Results and discussion: Results showed that 8 out of 18 samples (44%), did not comply with standard 1446 (at least in one of the specifications). In 4 samples (about 22%) acidity was higher than the maximum permitted level in national standard No 1446 (Table 2). Acidity is one of the important criteria in the classification of olive oil types. This characteristic indicates the quality of the fruit used for oil production and its production conditions. One reason for the increase in acidity is the activation of enzymes by damage to olive fruit (Zegane et al. 2015). All samples were in compliance with the national standard 1446 in terms of peroxide values, moisture content, volatiles compound, and extinction coefficients (Table 2). The results of insoluble impurities in light petroleum showed that in two samples of olive oil and one sample of refined oil this value was higher than the maximum permitted level set by Iranian national standard (Table 2). Unsaponifiable matter in all samples varied between 0. 71 and 1. 82 g/kg and was in agreeing with related standard (Table 5). The fatty acid profiles of the investigated olive oil samples (C16 to C20) are shown in Table 3. In all samples, oleic and palmitic acids were the most abundant fatty acids followed by linoleic and stearic acid, respectively. The highest mean oleic acid (72. 04± 2. 2) was related to refined olive oil. The results of this study were in agreement with those of other researchers (Matthaus et al., 2011). The trans fatty acids were not detected in any of the samples. The results obtained for sterol and triterpene dialcohol composition including, desmethylsterol composition (% total sterols), Total sterol content (mg/kg), erythrodiol and uvaol content (% total sterols) are presented in Tables 4 and 5. Desmethylsterol is composed of cholesterol, brassicasterol, campesterol, stigmasterol, delta-7-stigmastenol, and apparent beta-sitosterol. In two oil samples (43 and 14), the amount of Brassica sterol was higher than the standard limit (maximum 0. 1%), showing that the other vegetable oils may have been added to olive oil. Maximum difference between the actual and theoretical ECN 42 triacylglycerol content are presented inTable 5. Results showed in 3 out of 18 samples (about 17%) Δ ECN 42 was higher than standard limit. In all 18 samples, the amount of 2-monoglycerol palmitate ranged from 0. 1% to 0. 8% and was in accordance with national standard 1446 (Table 5). Conclusion: Examination of 18 olive oil samples showed that olive oils distributed in the market, has an acceptable level of quality. The highest amount of non-conformity was related to the amount of sterols followed by acidity. Trans fatty acids were not detected in any of the samples. However, the characteristics studied in this study were not able to detect the virgin olive oil from those with lower quality (refined and olive oil). Therefore, other experiments such as wax content and aliphatic alcohols are necessary to determine the small amount of olive pomace oil and stigmastadiene is needed to determine whether the olive oil is mixed with other vegetable oils. This study showed that it is difficult to distinguish between different types of olive oils and further research is necessary.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Author(s): 

DARVISHI M. | YAZDANPANAH S.

Issue Info: 
  • Year: 

    2021
  • Volume: 

    31
  • Issue: 

    1
  • Pages: 

    177-190
Measures: 
  • Citations: 

    0
  • Views: 

    310
  • Downloads: 

    0
Abstract: 

Introduction: Pectin is a complex sugar soluble and it use widely as a gelling and stabilizing agent, texturizer and emulsifier in the food industry with increasing production and processing of fruits and vegetables, is created many byproducts. Pumpkin skin and cap, often discarded as waste, are a valuable source of pectin. Therefore, its use for pectin production, in addition to producing a valuable product, can be beneficial from the aspect of economically and environmentally and it also reduces problems related to exclusion of waste. The use of acidified hot water with mineral acids is a traditional and widely used method of pectin extraction. The use of mineral acids not only causes corrosion of equipment and apparatus; it also follows environmental damage. Also this method be time-consuming and it reduces the quality of produced pectin. Therefore, it is necessary to replace this method with a better and newer method that minimizes the problems arising from it. The use of microwave waves has been one of the new methods of extraction that recently, it has received the much attention of researchers. This method has many advantages compared to traditional methods such as shorter process time, lower consumed solvent, higher production efficiency, producing higher quality product and spend of lower cost. The use of microwaves is one of the new methods of effective extraction of certain compounds. This method has many advantages over traditional methods, including a shorter process time, less solvent consumption, higher production efficiency, higher quality product production and lower cost. Purpose: In this study, pectin was extracted from the skin and cap of pumpkin by microwave waves and then its yield and physicochemical properties were compared. Material and methods: In this study, the cap and skin of pumpkin were cut and crushed and was exposed to sunlight for 4 days to dry against air flow. Then was grinded the dried cap and uniformity powder was made from it. The obtained powder in packed containers, keep away from moisture. Extraction of pectin from pumpkin skin and cap using microwave done at 80 and 90 ° C, with power of 20 watt and times of 10, 15, 20 and 30 min, pH 1. 5 and 2 and ratio of sample to solvent 20 and 30 % w/v. Determination of galacturonic acid content of extracted pectin by colorimetric method, degree of esterification by titration, emulsion properties, rheological properties using rotational viscometer and FTIR spectroscopy to determine the presence of functional groups (such as OH, C-O-H, C-O-C gropes) to confirm the quality of extracted pectin was performed on selected treatments with higher yield. The results were analyzed based on a completely random design by ANOVA and in binary comparisons of t tests. Data analysis was performed at 5% confidence level using software of SPSS 16. Results and discussion: The treatment obtained at constant power of 20 W, 90 ° C for 30 minutes, 30 % w/v, was determined as theselected treatment, its extraction efficiency was 24. 21 % in pumpkin skin and 3. 24 % in cap. The extraction efficiency of pectin has been increased by increasing the temperature from 80 ℃ to 90. The extraction efficiency increased by increasing the extraction time, so that the highest extraction efficiency occurred in 30 minutes. The extraction efficiency for pH= 1. 5 is more than a condition that was used of pH= 2. The extraction efficiency increased by increasing the ratio of solid to liquid from 20% to 30%. The percentage of galacturonic acid in pumpkin skin and cap was 38. 04% and 46. 6%, respectively. The cap pectin has a higher purity than the pumpkin skin pectin. According to the degree of obtained esterification for the samples, pumpkin pectin is a low ester group. The highest degree of esterification was in the extracted sample from pumpkin skin (44. 3). Using higher temperature for extraction reduces the degree of esterification, this is due to the pectin de-esterification at high temperatures. What ever the pH of the extraction solution be lower, the resulting pectin will have a lower degree of esterification. Emulsion stability of pumpkin skin at 4 ° C on first day and tenth day was 90. 2% and 77. 2%, respectively, indicating high emulsion stability, which indicates the high stability of the emulsion. But emulsion stability at 23 ° C on the first day of the tenth day is 85. 5% and 49. 2% respectively, that indicates a decrease in emulsion stability at higher temperatures. The extracted pectin solution from the pumpkin is not different at different concentrations, so that pectin had newtonian behavior (flow index (n) equal 1) at four concentrations of 0. 1, 0. 5, 1 and 2% w/v and the viscosity remains constant with increasing shear rate. The obtained solution from cap pectin has a higher viscosity than obtained pectin from pumpkin skin. The reason for this viscosity difference can know presence of structures with higher molecular weight in the cap pectin. Because compounds with high molecular weight have more ability to absorb water and create viscosity. The suggested model in this study was the newtonian model because for all samples, R 2 had a value above 0. 9. That's mean, this model had the ability to predict 90% from changes in rheological traits related to the studied samples. FT-IR results showed that the peaks of extracted pectin from the cap and skin were different together. That can be concluded that the produced pectin from the pumpkin cap has different structure from the extracted pectin from the pumpkin skin. The cap pectin has structurally more similar to the standard pectin. Conclusion: Therefore, from this kind of agricultural waste can use as a promising source in pectin production for provide the needs of the food industry.

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