JOURNAL OF FOOD RESEARCH (UNIVERSITY OF TABRIZ)
Year:2022 | Volume:31 | Issue:4|Papers Count:12

Introduction: Compressing materials during the tableting process is an appropriate solution to increase the bulk density of agricultural materials and thus reduce their transportation and storage costs. Other benefits of using compact tablets include reducing environmental contamination due to the absence of fine particles and dust, increasing the nutritional value per unit volume due to compression, and also facilitating the control of compacted nutrients to meet nutritional needs (Kaliyan and Morey 2010). In order to improve the quality of the tablet, it is necessary to know the optimum conditions and working points of the device, as well as to find the relationships between the effective factors and the final product for the researchers, so optimizing the food processing processes is one of the most important. One of the most important steps in increasing the efficiency of the food industry. Numerous analytical and numerical methods are available for this purpose. Nowadays, statistical methods are used for optimization such as Response Surface Methodology (RSM). Response level methodology is a set of statistical techniques used to optimize the processes in which the response is affected by a number of variables. The graphical representation of the mathematical model has defined the word surface methodically. With the help of this statistical design, the number of trials is reduced and all the coefficients of the quadratic regression model and the interactions of the factors can be estimated. In general, the models developed in response surface methodology are generally quadratic (Lee et al., 2007). Increasing the speed of operation and increasing accuracy in achieving the desired goal are some of the criteria that are considered as an optimization method for quality evaluation (Asefi et al., 2015; Wani et al., 2017). Finding the best pelletizing conditions for agro-materials is of particular importance in order to achieve the highest quality pellets including the lowest wrinkles and the highest compressive strength. Therefore, it is necessary to find the optimum conditions for the variables of the tableting process such as moisture content, temperature of the feedstock, and mold size. Soy is used in the preparation of a variety of sauces, syrups, meat substitutes and ready-made foods (Dasilva et al., 2012). So far, no research has been done to optimize the pellet production from soy powder. The purpose of this study was to investigate the effects of independent variables of moisture content, die diameter, inlet temperature and stress relaxation time on the mechanical and physical properties of soybean powder and tablet formulations in order to determin the optimum conditions for achieving the highest density and compressive strength and the lowest amount of shrinkage of the tablet. Material and methods: In this research, soybean powder was used for tabletting experiments. Soybean dough prepared and used in a laboratory scale hydraulic press machine with a closed die to produce cylindrical tablets. When the hydraulic pressure reached 75 bar, the movement of the hydraulic jack was stopped, and the materials were kept in the closed die for the specified time (three levels of 5, 10 and 15 s) to reduce stress and prevent spring compression. At the end of the compressive relaxation process, the pressure of the jack was removed from the material and the tablet formed was removed from the bottom of the mold. The effect of the tabletting process on particle density, compressive strength and shrinkage of soybean tablet was studied. The experiments were carried out using soybean powder at feedstock moisture content of 30, 40 and 50% w. b., feedstock temperature 25, 45 and 60 ° C, relaxation time of 5, 10 and 15 s, and die diameter of 6, 8 and 10 mm. To measure the compressive strength of the tablets made from soybean powder, the Hounsfield Model K-S H50, was used for compressive strength testing. The test method was that a number of cylindrical compact tablets (in diameter) were positioned between the two fixed and removable flat jaws. The jaw was then moved downward at a constant velocity of 1 mm/s, compressing the cylindrical shape along the diameter until it was removed and fractured, and the amount of force and displacement in the memory of a data logger at a sampling rate of 1000 data points. Finally, the maximum recorded force for breaking the tablet was considered as compressive strength. To measure the particle density of the tablets, a number of tablets were inserted into the graduated cylinders containing a volume of 50 ml (readable to 0. 5 ml) of toluene. The volume of each cylinder was measured and recorded according to the volume changes of the cylinder. To measure product shrinkage, the height and diameter of a cylindrical compact tablet were measured in three different directions once before the drying process and once at the end of the drying process by a digital caliper. Then the average geometric diameter of the tablet was calculated from the related equation. The response surface method (RSM) with central composite design and six replications for central point was also used to analyze the data and optimize the process. Results and disscussion: The result showed that the highest particle density was 3714. 32 kg/mm 3 under conditions of the feedstock moisture content of 50% w. b., feedstock temperature of 25 ° C, relaxation time of 5 s, and the die diameter of 10 mm. During the tabletting prosses, the highest compressive strength (518. 18 N) was obtained at the feedstock moisture content of 50% w. b., feedstock temperature of 65 ° C, relaxation time of 5 s, and the die diameter of 6 mm. The highest shrinkage of soybean powder (57%) was obtained at the feedstock moisture content of 50% w. b., feedstock temperature of 65 ° C, relaxation time of 15 s, and the die diameter of 6 mm. The best optimization results for tabletting conditions for soybean powder was under feedstock moisture content of 50% w. b., feedstock temperature of 42. 03 ° C, relaxation time of 5 s and die diameter of 10 mm. The predicted values of particle density, compressive strength and shrinkage at the optimized conditions were 4895. 49 kg/mm 3, 433. 17 N and 9. 03% with a desirability of 0. 853, respectively. By increasing simultaneously, the temperature of the feedstock to the die from 30 to 45 ° C and decreasing the stress relaxation time from 15 to 5 s, the desirability index increased. Stress relaxation time had the most effect on this index. Conclusion: In this study, the effect of moisture content of raw materials, temperature of feedstock, die diameter and stress relaxation time on particle density, compressive strength and shrinkage of soybean tablets were studied. Also, the optimum conditions of the tableting process were determined by using the response surface method to obtain the best physical and mechanical properties. Under optimum conditions of the tableting process, a particle density of 4895. 49 kg / mm 3, compressive strength of 432. 31 N and shrinkage of 9. 03% were obtained. These compact soy tablets can be used in all cases where powdered or dried soy is used.

Introduction: Fruits and juices contain high amounts of water (75-90%) which, due to the high activity of enzymes and microbes in water, make them susceptible to enzymatic and microbial destructive reactions. Therefore, the extracted juice should be concentrated for long-term storage and easier transportation (Kano Lamadrid et al., 2017). Taking water from food, which makes it resistant to microorganisms, is called concentration. Concentration is a common step in the juice production process. During this process, most of the water or soluble material can be separated by boiling the juice and a concentrated solution is obtained (Nawaz et al., 2018). Concentration process is an important operational unit in the fruit and vegetable process due to the significant effects it has on the color, flavor and quality of the final product (Yousefi et al., 2012). There are several ways to reduce food water. One of the most common methods is to evaporate food water using thermal evaporators. Concentration of juices is done in order to achieve goals such as the possibility of producing a product with uniform quality at different intervals due to the seasonality of fresh juice production, reducing price fluctuations due to seasonal production of fresh juice, increasing production capacity, reducing load The drying process that is sometimes used in the juice industry to produce powdered products (Soto Rees et al., 2017), (Sunny et al., 2013). Turnip with the scientific name of Brasica Napus from the Brasicaceae family is a biennial plant that is useful in the treatment of kidney diseases, bladder inflammation, gout, joint pain, abscesses and frostbite due to its medicinal properties (Tirvongadam et al., 2016). Its antioxidants have also been reported to reduce the risk of diseases such as high blood pressure and rheumatoid arthritis. Therefore, due to these antioxidant effects and having compounds such as flavonoids and anthocyanins, this plant is said to be effective in improving diabetes (Jasperit et al., 2003). Turnip contains biologically active compounds such as: 1-Flavonoids include isoramentin, kimperol and quercetin glycosides 2-Phenylpropanoid derivatives 3-Indole alkaloids and 4-Sterol glucosides. Flavonoids have very beneficial effects, especially in diabetes (Song et al., 2006). Given the high nutritional value of turnip, a method that can produce a product that maintains its nutrients and is available throughout the year and everywhere is very useful. The purpose of this study is to investigate the effect of microwave concentrating method in two different powers (180 and 540 watts) and heating method in atmospheric condition on some quality properties of turnip root extract and to introduce a better method to produce higher quality concentrate. Material and methods: In this research, the qualitative properties of condensed turnip root juices were investigated by microwave (180 and 540 Watt) and conventional concentrations at atmospheric pressure during process times. The qualitative properties of the product were ascorbic acid, the percentage of free radical inhibitory DPPH, color indexes, brix and rheological properties. Results and discussion: The results showed that by increasing concentration time, the amount of brix increased. Also, by increasing the amount of brix, the amount of L * and b * indices decreased and a * increased. The results showed as the concentration time increased the inhibitory percent and the percentage of remaining vitamin C in all methods decreased. The results of rheological properties showed that all methods and condensation times followed the Herschel-Balkh's law. Conclusion: In general, in conjunction with the general changes in the color of samples during condensation, as well as in the nutritional properties of the condensed turnip extract, the microwave technique, especially in lower power, is more effective than the atmospheric method, and it can be said that the use of microwave method is a potential way to concentrate turnip juices.

Introduction: Dehydration of fruits and vegetables is a widely used unit operation (Funebo et al., 2000). Intermittent infrared radiation, in which the product surface maintained at constant temperature, is a novel drying method to produce high quality dehydrated fruits and vegetables (Zhu and Pan, 2009; Zhu et al., 2010). During the drying, one of the most important physical changes in the quality of food is the decrease in external volume. This change in volume is called shrinkage and is an unavoidable phenomenon during the dehydration process. Shrinkage is usually expressed by the ratio between the volume of the sample after and before drying (Yan et al., 2008). Shrinkage also affects the porosity of dried materials and it is the parameter determining about the mass transfer properties, mechanical properties, and the texture of food product (Witrowa-Rajchert and Rzą ca, 2009). The three qualitative parameters such as the degree of shrinkage, density and firmness of the product are related to each other (Funebo et al., 2000). Maximal shrinkage and structural collapse were shown to decrease until kept quality characteristics (Barzaghi et al., 2008). The factors affecting shrinkage include volume of water extracted from the product, mechanical mobility of the solid matrix, drying rate, and process conditions such as temperature, air flow rate, and relative air humidity (Moreira et al., 2000). The mechanical mobility of texture in plant based foods during processing is affected by dry matter, starch and cell wall constituents, and it can be said that due to the high thickness of the cell wall, cell separation due to water evaporation pressure is more than cell rupture (Sabbaghi et al., 2017). The important consequences of shrinkage occurring during drying result in a loss of rehydration ability. Dehydrated products are usually rehydrated prior to their use (Krokida and Marinos-Kouris, 2003). The rehydration behavior is studied as an indicator of texture damage (Giraldo et al., 2006). Rehydration is a complex process that is intended to restore the properties of the fresh product by contacting dehydrated products with a liquid phase. This process to be composed of three simultaneous steps: (1) absorption of water into the dry material, (2) swelling of the rehydrated product, and (3) loss or diffusion of soluble components. Rehydration ability or capacity measures the ability of a dehydrated product to rehydrate (Maldonado et al., 2010). Mathematical models of rehydration will be useful in designing and optimizing this operation that have been applied as exponential models or capillary absorption theory or Fick’ s diffusion laws (Lee et al., 2006). In this research, the effect of this heating method on the physical-qualitative characteristics of dried apple slices, including volume, density, shrinkage and behavior of rehydration were studied. Material and methods: Apples (Golden Delicious variety) were purchased from a local market and according to Acevedo et al., 2008 kept in 0° C± 1° C and relative humidity ranging from 90% to 95%. The samples were skinned manually and then cut into slices with different thicknesses of 5mm, 9mm and 13mm and all with 20mm in diameter. The average moisture content of apple was measured using oven (Binder FD53) at 103 ° C for 24 hours and it was equal to 84. 11% based on wet weight (AOAC, 2000). Operation of infrared radiation with intermittent heating method was performed at three constant temperatures of 70, 75 and 80 ° C using the infrared dryer similar to Liu et al., 2014. Shrinkage coefficient of product was estimated with both theoretical (β theo) and practical (β ) methods according to Talla et al., 2004. Also, the mathematical models as Peleg (Reyes et al., 2011) and Exponential (Krokida et al., 2003) equation were compared to describe the rehydration process in dried product using adjusted R-squared (Adj. R 2 ) and root mean squared error (RMSE). Statistical analysis of the effect of thickness and temperature on the shrinkage coefficients (β theo, β ) was performed in SPSS software in version of 19. To achieve this aim, a completely randomized design (CRD) with factorial arrangement with two factors as thickness (at three levels) and temperature (at three levels) was used. Also, two methods of computing the shrinkage coefficients (theoretical and practical) were compared together with one-way F test. Mean comparison was performed by Duncan test with 95% confidence level (P<0. 05). All experiments were performed in three replications. Results and discussion: The results showed that increasing of the temperature caused greater volume and density changes during rapid dehydration of the product. The density changes were more intense for the thin product (reducing the final density to about 0. 6 g/cm 3 ). Also for thicker products, the density changes were slower during the process (reducing the final density to about 0. 7 g/cm 3 ). During process, the variation of product shrinkage indicated an exponential rising trend which was influenced by the amount of evaporated water. Shrinkage coefficient is significantly increased at higher processing temperature and thickness of product (β equal to 0. 164), representing that the product is heavily affected by the structural collapse phenomenon. The observations were similar to those reported by many researchers (Mayor and Sereno, 2004; Nowak and Lewicki, 2004; Katekawa and Silva, 2006). The temperature of 80 ° C showed significantly higher theoretical and practical shrinkage coefficient than the other two tested temperatures (70, 75 ° C). The difference between the two methods of calculation in shrinkage coefficient (theoretical and practical) was also significant and the difference increased with the increase of temperature (more than 6%). Jannot et al., 2002 reported that the error in the practical method can be due to the noisy data (deviation from the actual value). Limitation of rehydration capacity (RC) in slices with high shrinkage stress confirms the damage of the texture of the product (reduction in predicted equilibrium moisture content: Xe from 6. 523 to 4. 148 kg/kg, db). Rehydration process in different product thicknesses is described better using Peleg model (higher Adj. R 2 and lower RMSE) compared with the exponential one. The observations were similar to those reported by many researchers (Krokida and Marinos-Kouris, 2003; Nathakaranakule et al., 2010). Conclusion: The physical properties including shrinkage and density in the dried product are affected by process and product conditions. The low occurred shrinkage that reflects the preservation of the internal structure of the product and will be effective in rehydration behavior. In fact, reabsorption cannot be simply defined as the returned process of dehydration. Because of moisture reabsorption is completely affected by the texture, structure and properties of the dried product. Therefore, mild thermal conditions prevent the structural breakdown of apple slices and, at low thicknesses, due to the reduced volume of water evaporated from the slices, the shrinkage coefficient is reduced, thus preserving the internal physical structure of the infrared dried product.

Introduction: Grape (Vitis vinifera), a member of Vitaceae family, has many varieties of which have nutritional importance. Chemical composition of grape is dependent on the type of cultivar, planting conditions and degree of ripeness. Per FAO report, grape (100 grams of fresh fruit) contains 81. 6 grams moisture, 16. 7 grams sugar, 0. 4 grams fat, 80 international vitamins units, 0. 05 mg B1, 0. 03 mg B2, 2 mg sodium and 0. 6 mg iron (Yu et al. 2000). Among many food processing methods, dehydration is one of the oldest and commonly practiced preservation techniques. Dehydration would reduce weight and volume thus requiring less packaging and storage. Raisins, dehydrated grapes, are good source of fibers, polyphenols, vitamin D, iron and calcium (Rankin et al 2008). Recently, osmotic dehydration has replaced the conventional process due to its high speed, low energy cost and reduction of damage to product tissue, good taste, and color (singh et al 1999). However, the process has few drawbacks (e. g., penetration of large amounts of osmotic dissolving material into the food leading to resistance of food for water disposal in subsequent drying processes and changes the sensory and nutritional properties of the product) limiting its practice. Application of edible coatings prior to osmotic dehydration has been suggested to prevent the adverse effects of the process on foodstuff (Fissot 2012). (Khen 2007). Pectin and cellulose derivatives (structural polysaccharides in fruits and vegetables) can be used as edible coatings for preservation of fruits and vegetables. In order to increase the efficiency of edible coatings, antimicrobial, antioxidant and other active substances can be added to the formulations (active coatings). Perez-Gago et al. studied the effect of type and concentration of antioxidants alone and in combination with edible coatings (including whey protein and natural wax) on freshly peeled apples. Later, Garcia et al. investigated the effect of chitosan coating on osmotic dehydration of sliced papaya. They investigated the rate of dehydration and mass transfer in sucrose osmotic solution (40 ° Bx) in fruit to solution ratio (1 to 60), osmotic dehydration (WL), solids adsorb (SG) and weight loss, and. Correspondingly, chitosan coating improved osmotic and WL process efficiency while reducing SG. In a similar study, Singh et al. investigated the effect of sodium alginate coating (0. 5-5%) and temperature on osmotic dehydration (by sucrose solution), quality parameters of dried pineapple and mass transfer kinetics. The results showed that the dehydration time for uncoated samples was less than the coated samples at all three temperatures (55 ° C, 65 ° C, 75 ° C). Moreover, coating resulted in reduced activation energy, high re-dehydration while preserving the color of product compared with the uncoated samples. Antioxidants can increase quality and shelflife of food product when are used in edible coating and films. Ascorbic acid, as an antioxidant, can be added to the coating material to prevent browning reactions while compensating for vitamin C lost during the process. Studies have demonstrated that the active edible coating containing antioxidants, such as vitamin C and cysteine, are more effective in prevention of enzymatic browning in peeled fruits than antioxidants alone. Moreover, numerous studies have shown that the application of edible coating in osmotic dehydration process of different fruits can decrease solid gain (SG) while improving the efficiency of process. The application of coating on food prior to osmotic dehydration process is one of the common techniques used to decrease the solid gain. The aim of this study was to investigate the effect of different coatings on the efficiency of osmotic dehydration and sensory-nutritional quality of raisins. In this context, two types of coatings (pectin and carboxymethyl cellulose based) in combination with two types of antioxidants and reducing ingredients (ascorbic acid and cysteine) were used for pre-treating the Shahroodi grapes prior to osmotic process. Material and methods: For osmotic dehydration, a combination of fixed osmotic solution similar to the natural composition of fruits (containing fructose, calcium, and citric acid) was used (with sample to solution ratio of 1 to 10). Optimum samples (coating contained cysteine 0. 5% and ascorbic acid 0. 5%) were selected based on maximum osmotic efficiency coefficient and osmotic dehydration and minimum amount of solid gain. Osmotic dehydrated samples were placed in hot air oven for supplemental drying. The effect of coating and osmosis pre-treatments on quality characteristics of raisins (vitamin C, color, and rehydration rate) was investigated. Results and discussion: The lowest osmotic dehydration percentage (12. 6%) was observed in the uncoated sample and the highest osmotic dehydration percentage (27. 66%) was related to the pectin-based coated sample (containing ascorbic 0. 5% and cysteine 0. 5% (w/w)). The lowest osmotic re-hydration percentage (20. 23%) was observed in the CMC-based coated sample. The lowest osmotic coefficient of efficiency (6. 20%) was related to the uncoated sample. Among the coated samples, the highest osmotic dehydration efficiency coefficient of 21. 95% was related to the sample pectin-based coated (containing ascorbic acid 0. 5% and cysteine 0. 5% (W/W)). The lowest osmotic dehydration efficiency coefficient of 15. 58% was observed in the CMC-based coated sample. The coated sample showed lower color change (∆ E) than the uncoated samples. Among the coated samples, the highest amount of vitamin C was related to pectin-based coated sample (containing ascorbic acid 0. 5% and cysteine 0. 5% (W/W)) and the lowest was related to the CMC-based coated sample. Conclusion: The use of edible CMC-and pectin-based coatings can effectively increase osmotic dehydration efficiency coefficient. The coated osmotic dehydrated samples showed higher vitamin C and lower rehydration ratio in comparison with the control and uncoated samples. Coating and osmosis reduced the overall color change of the final raisins.

Introduction: Cholesterol with the formula of C27H45OH is a requisite component in cell membrane and cell growth (Nataf et al., 1948). The compound has a major role in human heart health. It has been proved that high cholesterol is a risk factor for human cardiovascular diseases and coronary heart diseases. Cholesterol is synthesized in mammalian cells (Ma and Shieh 2006). It is mostly found within the milk fat globule membrane and asymmetrically distributed in the both layer of the outer bilayer and it is found in triglyceride core in less amount (Lopez and Menard 2011). Beta-cyclodextrin (β CD) is known as a safe food ingredient which is a cyclic oligosaccharide consisting of seven glucopyranose molecules that are linked together with α 1-4 bonds. The size and geometry of the β CD hydrophobic internal cavity allows good complexing with free and esterified cholesterol (Chafic Awad and Gray 1999). Absorption of cholesterol in human intestine decreases by consumption of green tea catechins. Phosphatidylcholine (PC) is an important substance for cholesterol solubility in micelles containing of bile salts, PC and cholesterol. This effect is probably due to the interaction of catechins and PC in bile salts micelles (Ogawa et al., 2016). It is assumed that catechin hydrate can help cholesterol removal from fat globules with similar mechanism. Then, separated cholesterol molecules can be easily entrapped in β CD cavity. The aim of this study is evaluating the effect of using catechin hydrate to decrease the amount of necessary beta-cyclodextrin for achieving maximum cholesterol reduction in homogenized and sterilized milk. Material and methods: Sterilized and homogenized milk with 3% fat was purchased from Pegah Dairy Co (Isfahan, Iran). Beta-cyclodextrin was purchased from Merk and catechin hydrate was purchased from Sigma Chemical CO (St. Louis, MO, USA). All reagents and solvents were of analytical grade. Response Surface Methodology (RSM) was used to optimize conditions that affect milk cholesterol reduction. Central composite design with 20 experimental points (6 center points, 6 axial points, 8 corner points, 3 blocks, 3 factors and 5 levels) was used. 70 ml of milk with different catechin hydrate concentrations was stirred (Alfa D 500 stirrer) at 750 rpm for 30 min at 25℃ . Then, samples were stirred with different beta-cyclodextrin concentrations at various mixing time (according to RSM design) and centrifuged at 1000 × g, 25℃ , for 10 min. The supernatant was separated and used for cholesterol determination by gas chromatography (GC) (Alonso et al., 1995). Protein and fat content of milk were assayed at central points of experimental design using milkoscan. Radical scavenging and total anti-oxidant capacity were measured by 2, 2-diphenyl-1picrylhydrazyl (DPPH) (Balakrishnan and Agrawal 2014) and ascorbic acid methods (Taj khan et al., 2017), respectively. Sensory evaluation of samples was carried out with 10 panelists (5 females and 5 males, ages 25 to 40 years old). A five-point hedonic scale was provided to the panelists (Keshtkaran et al., 2012). The amount of fat, protein, radical scavenging DPPH and total antioxidant capacity were measured in central points. The statistical analyses were based on the mean ± standard deviation (SD) in experimental samples. Mean value of control and treated samples were compared using studentʹ s t-test (P ≤ 0. 05). Sensory evaluation data was analyzed by SPSS software. Results and discussion: The interaction between β CD and mixing time at constant catechin hydrate concentration (0. 01%) showed that maximum cholesterol reduction (96. 96%) was obtained at β CD concentration of 0. 12% and mixing time of 38 min. The reason for this result is due to the interaction of catechin hydrate with some of fat globule membrane components such as PC and casein in homogenized milk that decreases cholesterol solubility. So, cholesterol can be easily separated from milk fat globules. Then, maximum cholesterol reduction was achieved at low concentration of β CD (β CD: cholesterol molar ratio of 4: 1). The interaction between catechin hydrate and mixing time at constant concentration of β CD 0. 12% showed that by increasing catechin hydrate concentration to more than 0. 03%, cholesterol reduction decreased. This effect is due to the competition between cholesterol and catechin hydrate for entrapping in β CD cavity. The interaction between catechin hydrate concentrations and mixing time at constant β CD concentration (1. 3%) showed reverse correlation between these two factors. Maximum cholesterol reduction was obtained at catechin hydrate concentration from 0. 01% to 0. 08% and mixing time from 27. 5 to 49 min; or catechin hydrate concentration from 0. 08% to 0. 12% and mixing time from 6 to 27. 5 min. Comparison between control and treated milk at central points showed that fat content decreased in treated samples. Because cholesterol molecules are a part of milk lipids that is separated from treated milk. On the other hand, some of milk free fatty acids could be entrapped in β CD cavity. Also, the amount of protein in treated samples decreased because of entrapping of amino acids in β CD cavity and absorption of negative charge of proteins on the outer surface of β CD. Therefore, part of milk proteins together with β CD– cholesterol complex leaves the environment during centrifugation process (Maskooki et al., 2013). While, the amount of antioxidant activity measured by ascorbic acid and DPPH methods increased which was due to the residual catechin hydrate in treated milk. Sensory evaluation results showed that no significant difference was observed between control and treated sample. Conclusion: According to results, it seems that catechin hydrate has dual effects on cholesterol reduction from sterilized and homogenized milk. A positive effect is observed at the low concentration of catechin hydrate due to the separation of cholesterol from fat globules that decreases the needed amount of β CD and negative effect is due to the competition between catechin hydrate and cholesterol for entrapping in β CD cavity. Overall, the positive effect dominates the negative one at low concentration of catechin hydrate. It should be mentioned that the reasonable β CD: cholesterol molar ratio for cholesterol separation is 1: 1 but practically this molar ratio is not enough, because cholesterol is placed in fat globule membranes. In previous studies β CD: cholesterol molar ratio was 34: 1 while in this study the molar ratio decreased to 4: 1, because catechin hydrate separates cholesterol from fat globule membranes and cholesterol easily entraps in β CD cavity. Therefore, by decreasing the amount of needed β CD for milk cholesterol removal, this process can be done in industrial scale.

Introduction: In recent years, adequate intake of vitamin D has become an important issue that has been the cause of the strong development of bone disease worldwide (Pearce & Cheetham, 2010; Clarke & Page, 2012). Bone softness is a progressive disease in childhood that results in bones softening and bending under body weight (Wharton & Bishop, 2003). Extensive studies have shown that high dietary calcium intake is associated with reduced risk of osteoporosis, hypertension, colon cancer, and renal stones (Singh & Muthukumarappan, 2008). The absorption of calcium in the blood takes the form of calcium ions from the intestinal wall. Increased calcium absorption is due to vitamin D, which is why calcium supplements usually contain vitamin D, so if you consume sources that contain these two substances, the calcium in them will be better absorbed. If there is a substance in the food called oxalate, its calcium absorption is reduced. The regulation of calcium levels in the body is caused by hormones secreted by the thyroid gland (Lau et al., 2000). Vitamin D3 is required to regulate the absorption of calcium and phosphorus from the diet and placement of bone in it. Inadequate calcium intake can also lead to bone softness in children and bone pain, muscle weakness and osteoporosis in adults. The daily requirement for vitamin D3 per adult is 10 micrograms or up to 2000 units per day. This is even higher in childhood and aging (Braegger et al., 2013; Glerup, 2000). Enriching popular foods among children and adolescents, such as snacks and confectionary products, can be a good solution to this problem. Vitamins are one of the most important micronutrients that are vital to human health and are essential for survival in the body. Vitamins are organic compounds that are essential to the metabolism of nutrients, vital to the body, and to the growth and development of health (Dennehy and Tsouronis, 2010). Adding one or more micronutrients to the staple diet is said to be one of the most effective strategies to prevent micronutrient deficiency (Jafarpour and Mazandarani, 2013). Material and methods: For pastille production, 6 g of gelatin was first dissolved in bloom 260 in distilled water (twice the weight of gelatin) using a magnetic stirrer at 60 ° C in 12 g of water. Simultaneously, sugar syrup (boiling liquid glucose (35 g), sugar (35 g) in 20 ml of water and bubbling to 77-78) was prepared and after lowering the temperature, the gelatin solution was added and the resulting mixture was added to the water bath. Heat (70 ° C) (Abbasi et al., 2011) and to reach pH 3± 0. 25, citric acid (1. 5 g), cherry color (0. 03 g) and cherry essential oil (07 (0) g) was added with vitamin D3 (100, IU 100, 70, 40 g) and calcium (1000, 750, 500 g, 100 g / 100 g) and mixed gently to prevent air bubbles from entering. Calcium-free and vitamin D3 samples were used as controls. It should be noted that the calcium consumed was calcium carbonate and the vitamin D3 used in this study was powdered and water soluble. After mixing, the gelatin-sugar solution was poured into the mold with 40 × 5 3 3 mm dimensions and placed in the oven at 37 ° C for 24 hours at room temperature for 24 hours and then cooled to room temperature. The mold came out (Demars & Ziegler, 2001). Chemical tests (amount of brix, acidity and ash) and tissue properties (hardness, cohesiveness and chewiness) were evaluated on the first day, and tests of calcium and vitamin D3 stability and sensory properties (color, taste and smell, texture and acceptance overall) were evaluated at the first day of production, 30 and 60 days. In order to evaluate the quantitative and qualitative characteristics of the data with 10 treatments and 3 replications, one-way ANOVA was used and for comparing the mean of data, Duncan's test was used at 95% confidence level and the two-way ANOVA was used to evaluate the interaction of factors It turned out Minitab 16 software was used to analyze the statistical data and Excel software was used for drawing graphs. Results and discussion: The results showed that The use of different concentrations of calcium had a significant effect on increasing the amount of brix, ash, acidity and texture properties (hardness, cohesiveness and chewiness), calcium stability and reducing the sensory properties of color, taste and smell of pastille and there was a significant difference between treatments. According to the results of using different concentrations of vitamin D3, a significant effect on chemical properties (brix and acidity, ash), tissue properties (hardness, cohesiveness and chewiness), the stability of vitamin D3 and calcium, and sensory properties (color, taste and smell, texture and overall acceptance of pastilles were not significant compared to the control sample (p<0. 05) and did not show a significant decrease during storage. The texture score of pastilles enriched with calcium and vitamin D3 was not significantly different from the control sample and did not show a significant decrease during storage. The amount of brix in the present study was higher than the minimum standard of 2682 (80%) in all treatments. The amount of ash obtained in all treatments was lower than the maximum value of 2682 (0. 5%) in all treatments. It should be noted that the amount of acidity in the present study was lower than the maximum value of 2682 (2. 5%) in all treatments. As the amount of calcium increased due to the increase in calcium, tissue density increased and eventually resulted in increased chewing ability of pastille (Rezaee et al., 2011). Treatments 10 (containing 100 mg/100 mg of calcium and 100IU/100mg of vitamin D3) were identified as superior treatments for acidity, ash, brix, vitamin D3 and calcium stability and sensory evaluation (overall acceptance). Conclusion: According to the results of this study calcium in 1000 mg/100g and vitamin D in 100 mg IU/100mg can be used in pastille formulation without adverse effect on sensory properties (general acceptance).

Introduction: Plastic contamination, especially in packaging application, has been the main issue for universities and industry. Bio-composite of biodegradable Starch is considered as an appropriate replacement for starch due to low price, availability and biodegradability. The film or coating is placed on the food as an integrated and thin layer of different polymer compounds. Today, contaminants from synthetic polymers have drawn attention to the use of biodegradable materials, and over the past two decades, the study of biodegradable materials derived from proteins and carbohydrates has expanded. These macromolecules could potentially be a viable alternative to synthetic polymers derived from petroleum products. Material and methods: In the present study, different starch films have been produced by corn starch and natural cellulose booster from 0% to 20% applying melt mixing with twin extruder. The aim of this study is to obtain a suitable combination of starch with cellulose (natural and degradable) that makes starch similar to synthetic polymers with low water permeability and high mechanical strength and can be a good alternative for them. In addition, food additives such as citric acid and stearic acid are used in a constant amount to facilitate the process and improve the properties of the film. The current study aims at investigating the effect of cellulose, as an intensifier, and different ratio of glycerol/sorbitol, as a plasticizer, on the improvement of starch bio-composite. The optimum point for starch bio-composite is obtained by Design Expert Software and structural tests, TGA and XRD, were conducted on this point. First, a suspension of cellulose and a certain amount of water were homogenized or subjected to ultrasound so that the starch could be well dispersed in the matrix. Raw material for the production of starch biocomposites, including corn starch (as a matrix), glycerol and sorbitol (as a softener and each from 10 to 20% by weight of starch), different amounts of cellulose fiber (from 0 to 20% by weight of starch), citric acid 1% by weight to improve the biocomposite, starch and stearic acid were physically mixed as a process aid (to prevent starch from adhering to equipment and 1% by weight of starch). The main mixing was done uniformly in the two-screw face extruder. The produced starch biocomposite or sheet was exposed to 50% relative humidity and 30° C for one week and then the necessary tests were performed on them. In the next step, the mold was used under pressure, until a starch sheet with a thickness of 1 mm was produced. The sheets were produced at a temperature of 160° C and a pressure of 25 Mpa for 2 minutes. The temperature reached 50-40° C by the flow of cold water flowing around the mold and the pressure was removed. Then each sheet was qualified separately at 58% RH and 30° C and entered the test stage. The thickness of the film was measured randomly in 5 positions with the micrometer of incision (model W-3275-A, USA) with a resolution of 0. 01 mm and their average was used for calculations. Results and discussion: Tensile strength, Young’ s modulus and elongation at break were measured from the stress-strain curves gained from the prepared starch sheets. Table1 shows that there was irregularity effect with the addition of cellulose, glycerol and sorbitol in the composite. The lowest yield of tensile strength was 0. 51 MPa at 5% cellulose, 15% glycerol and 20% sorbitol and the highest level was 1. 52 MPa with 15% cellulose, 12. 5% glycerol and 12. 5% sorbitol. The mechanical properties are prejudiced by the ingredients of a composite. The adding of component is estimated to rise the mechanical properties of a composite because of the increasing affinity in the composite. Different trends were observed for Young’ s modulus. A significant improvement for Young’ s modulus from 283 to 915 MPa was obtained for different starch biocomposites. The best result for Young’ s modulus was obtained with 10% of cellulose, 10% glycerol and 20% sorbitol. Elongation at break had range from 1. 01 to 10. 24 that could be related to the percentage increase in length that a material will achieve before breaking. A higher percentage usually indicates a better quality material when combined with good UTS. Negative coefficient of sorbitol and glycerol means they caused to fall down elongation of starch biocomposite. Those starch biocomposites with cellulose had more elongation at break. The optimum point was 5% cellulose and 17. 5% of each emollient which has Water Vapor Permeability (WVP) as 7. 81*10-10 gs-1-1-1 m Pa, tensile strength of 0. 85 Mpa, Young module 277. 56 Mpa and elongation at break point 7. 08%. The optimum glass transition temperature of bio-composite starch increases to 130 o C. Although optimum bio-composite XRD show high picks demonstrating crystals, the findings from thermal weighting reveal that optimum bio-composite will be decomposed about 300. According to decomposition of natural starch at 220 o C, this thermal resistance can be ascribed to the cellulose in its structure. Conclusion: The aim of this study was to obtain a suitable combination of starch with cellulose (natural and degradable) and glycerol and sorbitol softeners that make starch similar to synthetic polymers with low water permeability and high mechanical strength. In this study, optimization of starch biocomposite formulation was performed by epithelial mixing method. The main purpose of optimization was to place the parameters of tensile strength, elongation and elastic modulus in the desired range and to minimize water vapor permeability. According to the modeling, the optimal treatment in the production of starch biocomposite was 5% cellulose, 17. 5% glycerol and 17. 5% sorbitol. The validation results of the answers showed that the results of the model have an acceptable similarity with the practical results. X-ray diffraction test to investigate the distribution of particles in the polymer matrix showed that the components of the composites are well dispersed. Behavioral patterns related to heat-weight changes of starch biocomposite showed that three main stages of degradation and weight loss were observed in starch biocomposites. It is It is concluded that the composition of microcrystal cellulose and equal glycerol/sorbitol ratio lead to the development of starch bio-composite properties. The results of this study can open a new window towards the use of biodegradable packaging in the food industry to improve food quality and safety and reduce food waste. More research is needed to replace conventional plastics with green composites to at least protect human health and the environment.

Introduction: Functional food represents food that can be healthier than the usual ingredients in the food (Mazjoobi et al., 1392(b)). Cereal products are the main source of calories and energy in the diet. Among them, biscuits are popular because of their lower moisture, higher shelf life, relatively low cost and a wide variety of flavors (Anton et al., 2009; Hager et al., 2011). In recent years, there has been many research on the effect of adding various compounds to cereal products such as mango peel powder (Ajila et al., 2008), date juice (Mazjoobi et al., 2016), vegetable and fruit wastes (Sharboa et al., 2013), potato peel powder in cakes (Jedo et al., 2017), pineapple powder in bread (Solani et al., 2014) and oat bran in biscuit (Mazjoobi et al., 1392(a)) has been done to improve the nutritional properties of the products. Oak fruit contains nutrients such as magnesium, calcium, minerals, fiber and biologically active compounds with antioxidant properties and tannins that make it practical and functional (Ozkan and Baiko 2005). Acorn also has useful properties including disinfectant; eliminate anemia, vascular swelling reduction and more. Recently, studies on the use of acorn flour in Barbari bread (Majzoubi et al., 1392(b)), sponge cake (Molavi et al., 1393), and cupcake (Roshani and Naghipour, 1395) acorn flour with soy flour in cake (Sorouki et al., 1392) And baguette bread (Hojjati and Atash Saz, 1392) was made to enrich cereal products. Triticale is a new plant from hybrid between wheat and rye (Nassimento 2003) that contains high amounts of protein, minerals, vitamins, and high phenolic content compared to other cereal especially wheat, as well as it has rapid growth and production capacity in poor and low-yielding lands(Serena et al., 2004). This flour is more suitable for making bulgur bread, thin and flat breads and extruded products (Farash et al., 2016). Triticale flour has been used to enrich products such as crackers (Gabriela et al., 2003), biscuits (Blanco et al., 2017) and cookies (Alberto et al., 2000). In recent years, extensive efforts have been made to improve and enrich cereal products; Therefore, according to the society's need to improve the nutritional value of foods, the purpose of this study is to investigate the possibility of replacing wheat flour with acorn flour and triticale flour in the production of biscuits and to study the physicochemical, textural and sensory properties of the product. Material and methods: Acorn flour and Triticale flour have been considered because of their good nutritional properties and can be used to enrich cereal products; so the aim of this study was to produce biscuits enriched wit acorn flour and Triticale flour with texture quality and suitable nutrition. In this study, the effect of replacing acorn flour and Triticale flour at levels of 0-30% with wheat flour on the physicochemical, textural and sensory properties of biscuits was investigated with using the mixture design based on D-optimal. For this purpose acorn fruit was harvested from the forested areas of West Azerbaijan in early autumn and after separating the outer hard layers and the second layer (pair), dried at room temperature for 72 hours and then the acorn kernel was milled and after sieving, it was kept in thick polyethylene bags in the refrigerator until consumption. Formulation of control biscuit dough was included 200 grams of wheat flour, 100 grams of granulated sugar, 70 grams of margarine, 2-3 grams of vanilla, 1-2 grams of baking powder and 1 egg. Replacement of acorn flour and triticale flour at the level of 0-30% with wheat flour was based on mixture design. To make the biscuit, all the ingredients were well mixed after weighing. The resulting dough was rested for 15 minutes after kneading and uniformity of texture. After this time, the doughs were spread with a rolling to 2-3 mm of thickness and after molding (with a diameter of 5 cm), it was baked in an industrial oven at 160 o C for 12 minutes. After leaving the oven and cooling, the samples were thermally packaged in polyethylene bags and kept at room temperature until the tests (Caponio et al. 2007). Biscuits were characterized for moisture, fat, protein, ash, carbohydrates, calories, water activity, antioxidants capacity, density, spread ratio, and colorimetric indices, textural, and sensory properties. Results and discussion: Triticale is a good alternative to other cereals, especially wheat, due to its good nutritional composition such as protein, minerals, vitamins, and high fiber content. Also, the improvement effect of triticale flour is due to its high alpha-amylase activity, which compensates for the low activity of alpha-amylase in wheat flour. On the one hand, acorn flour is rich of fiber and minerals, so adding acorn flour to biscuits could improve maintenance of moisture, increase nutritional value, and improve the texture properties of the product. Therefore, this study was designed to evaluate the effect of replacing acorn flour and triticale flour on the physicochemical, textural and sensory properties of biscuits. The results showed that moisture content and water activity of the samples containing triticale and significantly increased(P<0. 05) due to the high mineral and fiber content of triticale flour and acorn flour compared to wheat flour, which absorbs more water and thus increases moisture. The fat content of the samples significantly increased with replacement of acorn flour due to the high fat content of acorn flour (9%) compared to other consumed flours. Also, with replacement of acorn flour, the amount of carbohydrate and calorie of the samples decreased (P≤ 0. 05). With replacement of acorn flour, the spread ratio of the samples increasedwhich is due to the decrease of gluten in wheat flour and the inability to retain gas and water vapor in the biscuit and thus reduce the thickness of the biscuit. The replacement of triticale flour with wheat flour had no significant effect on spread ratio. With replacement of acorn flour, the antioxidant capacity of the samples significantly increased that due to the presence of alpha and gamma-tocopherols, gallic acid, tannins and phenolic substances in acorn fruit. Interaction effect of acorn-triticale flours was significant on textural parameters. By addition of triticale flour up to 10% (at low levels of acorn flour), the required force and energy for penetration of the samples increased, but with more substitution, these properties decreased. Addition of acorn flour at high levels of triticale led to decrease of firmness and energy. The replacement of triticale and acorn flours had no significant effect on protein, ash, density and b* value of samples (P>0. 05). Also, overall acceptance in sensory evaluation decreased with the replacement of triticale and acorn flour, but all samples had acceptable grade (0. 74) in the range of 0-1. Conclusion: The results of optimization showed that the biscuits with high desirability in terms of textural and sensory properties can be developed by the substitution of 15% triticale and 15% acorn flour together. In general, according to the results replacement of wheat flour with acorn and triticale flours in biscuit formulation, let to producing functional biscuit with low calorie and high nutritional value.

Introduction: Celiac disease is an immune-mediated enteropathy triggered by the ingestion of gluten in susceptible patients (Kennedy et al., 2000). The reaction of celiac patients to gluten leads to the malabsorption of several main nutrients such as folic acid, iron, soluble vitamins, etc. Gluten is the main structural forming protein in baked products which cause the elasticity, cohesiveness and viscosity characteristics of dough. Gluten eliminatiom and its replacement with other protein causes technological problems like poor quality mouthfeel, crumbly structure, and a quick staling (Miñ arro et al., 2012). Therefore, a redesign of the gluten-free bakery goods is necessary for obtaining products with suitable qualitative properties and nutritional composition. Therefore, to overcome these technological problems, several additives have been employed to mimic gluten properties. Emulsifiers are used in the baking industry because of their ability to interact with different flour components and other dough ingredients, which causes the softer crumbs (Khatami et al., 2015). Hydrocolloids have positive effects on crumb structure, taste, global acceptability and shelf life. Rice and oak flour also has been used to prepare gluten-free bakery products, such as bread and cake. Rice is naturally gluten-free and contains proteins that are known to be nutritious and hypoallergenic (Gadallah et al., 2017). The compounds in free gluten oak flour also increase the porosity of product and the consistency of the dough during mixing. This research has developed a cup cake formulation which contains sage seed, guar gum and DATEM based on rice and oak Flour using Response Surface Methodology. Material and Methods: The purpose of the present study is to prepare an optimal formulation of gluten-free cup cake based on different ratio of oak flour to rice flour (10: 50 ratio). In this regard, the effect of equal ratio of hydrocolloids Sage seed and Guar (%0 to 6) and DATEM (%0 to 1) on quality properties of product, including moisture, porosity, density and texture characteristics (firmness, springiness and cohesiveness) were evaluated and modeled using Response Surface Methodology. To compare the control cupcake with optimum samples, chemical and physical analysis, Ash, color (crust and crum) and sensory characteristics were performed to introduce the best products with high nutritional quality, favorable textural features, and reasonable price. Results and discussion: According to the results, by increasing the ratio of oak flour to rice flour and also enhancing the hydrocolloid concentrations, the density of samples were increased. Fiber in oak flour increased water absorption and delayed gelatinization of starch, which caused a large amount of air bubbles leave the dough before setting the cake texture. The higher concentration of hydrocolloids also prevented the expansion of air bubbles in dough due to higher viscosity and increased the density of sample. The porosity of cake texture was due to stability of gas cells in dough. The porosity was reduced in high concentration of oak flour and hydrocolloids due increasing dough viscosity and non-uniform distribution of gas bubbles. However, emulsifier at suitable concentration reduced the interfacial tension of the liquid phase of the dough. Therefore, the air bubbles can distribute constantly in dough and suitable porosity in cake was created. The effect of Independent variables (ratio of oak flour to rice flour, amount of hydrocolloids and emulsifier) on textural characteristics of gluten-free cake showed that by increasing the ratio of oak flour to rice flour and the amount of Sage seed and Guar, the hardness and cohesion of tissue was increased. This is due to the presence of insoluble fibers of oak flour. Furthermore, by increasing the hydrocolloid concentration, the viscosity was increased and the cell wall of the gases was gotten strengthened, which resulted an increase in tissue hardness. On the other hand, water absorbability and gel-like network of hydrocolloid improved the elasticity and cohesiveness of the tissue. Suitable concentration of DATEM improved textural properties of gluten-free cake. Based on the results, 2 formulations were considered as the best. The level of oak flour to rice flour in the first and second optimal samples were respectively 16. 67% and 27. 76%, while the amount of hydrocolloid and DATEM were 0. 1% and 0. 83% in both samples. Textural hardness of control sample was more than optimal samples during storage. The presence of emulsifier and gums in the gluten-free cakes were the main factors in maintaining moisture and elasticity of texture and reducing staling of samples. Using oak flour in the sample affects the organoleptic properties of product. For example, the presence of oak flour reduces the brightness of gluten-free cake compared to the control. Also, in the sample containing emulsifier (DATEM) and hydrocolloids, the brightness of cake crust was decreased due to the reduction of moisture removal rate. The desirability of texture in control sample was higher than optimal samples, which could be attributed to the presence of oak flour compounds such as fiber, natural pigments, and creation of new colors and odors in product. However, the presence of Sage seed, Guar and emulsifier at suitable levels improve organoleptic properties of product. In nutritional aspect, the content of Mg, P and Fe in both selected optimized samples were significantly higher than the control sample, which was due to the high nutritional value of oak flour. Conclusion: In this study, different ratio of oak to rice flour was used to produce gluten-free cake with appropriate quality and high nutritional value. Sage seed, Guar gums and DATEM were used for improving quality of free gluten product. By considering the quality characteristics of product, two samples with different levels of oak to rice flour ratio (16. 67 and 27. 76), 0. 1% Sage seed and Guar gum and 0. 83% DATEM were introduced as appropriate levels of independent variables in this study. Investigation staling process of samples during storage was found that the use of appropriate amount of gums and emulsifier at medium level of oak flour reduce staling of product. Also, in terms of nutritional, qualitative and overall acceptance of the product, the optimized sample No. 1 (oak flour to rice flour was 16. 67%, the amount of hydrocolloid was 0. 1% and the DATEM emulsifier was 0. 83%) was selected as the best.

Introduction: Acrylamide, also known as acrylic amide and prop-2-enamide, is a white, odorless, crystalline, water-soluble solid, with the chemical formula (C3H5NO) and relative molecular mass of (71. 08). Acrylamide is classified by the International Agency for Research on Cancer (IARC) as a probable human carcinogen. Acrylamide is formed in some foods such as potato chips, French fries, and toast due to heating. French fries are one of the most popular products in the world; their texture characteristics and special taste are attractive to customers. The sensory attributes of French fries depend both on the raw material and technological parameters used for French fries production. A factor affecting the flavor and texture of French fries is the frying (temperature, time, and type of frying oil). They are widely consumed among teenagers and young people in the community, which makes this age group more exposed to the dangers of acrylamide. The major pathway leading to acrylamide formation in foods is a part of the Maillard reaction with free amino acid (Asparagine) and reducing sugars through the decarboxylation of the Schiff base in a Streckertype reaction. Although the formation of acrylamide in foods has its major routes through asparagine and reducing sugars, several other formation routes are suggested via Acrolein and ammonia. Oil is one of the most important components in the preparation of French fries due to its heat transfer and effects on taste. Due to the use of oil at high temperatures for a long time, the deteriorative chemical processes of hydrolysis, oxidation, and polymerization occur. Finally, various compounds such as aldehydes, epoxides, hydroxy ketones, and decarboxylated compounds are formed; these compounds can be reacting with amino acids. Therefore, these compounds may react with the asparagine in potatoes and increase the concentration of acrylamide in fried potato products. Material and methods: 15 kg of Agria potatoes were prepared from the (SPI) Institute. Four kinds of oil (Sunflower oil, frying oil, and canola oil) were purchased from a chain store and soybean oil prepared from Korosh food industries. 1. 5 liters of oil were poured into the fryer, the temperature reached 180° C and, stabilized. After 1 hour, 200 g of sliced potatoes (2×2×2 cm) was poured into the hot oil. Frying time was 5 min. Heated oil and fried potatoes were sampled for testing. The fryer remained on at 180° C. After 3 hours, the second sample of raw potatoes was fried for 5 min. The third and fourth samples were prepared 3 hours apart. GC-ECD method was used for acrylamide measurement. 2 g of sample and 20 ml of distilled water were poured into the Falcon tube. Then 3 ml of Carrez I, II solution was added to the solution and centrifuged at 5000 rpm. The water layer was discarded. Then 2 ml of hexane was added. The solution was centrifuged again. The hexane layer was discarded. 10 ml of the remaining solution was extracted with potassium bromide, bromic acid, and bromine water and injected into the GC. The fatty acid profile test was performed by ISIRI 13126 2 & 4 methods. ISIRI 4093 was used as a method for Peroxide value measurement. Anisidine and totox values are determined by methods defined in ISIRI 4093 was calculated by the ISIRI 4093 method. Data were verified by ANOVA variance analysis. Results and discussion: According to the obtained results, values of total monounsaturated fatty acids are canola oil (%65. 74), frying oil (%39. 32), sunflower oil (%23. 11), and soybean oil (%22. 00). Also total polyunsaturated fatty was determined 65. 41, 61. 04, 26. 21 and 43. 99% for sunflower, soybean, canola and frying oils respectively. Oils containing polyunsaturated fatty acids (PUFAs) have less resistant to oxidation than monounsaturated fatty acids (MUFAs). Oxidative stability decreases with increasing number of double bonds. Accordingly, oleic acid has the highest thermal stability among unsaturated fatty acids, followed by linoleic acid and the lowest stability of linolenic acid. The results of peroxide, anisidine, and totox values determination showed that changes in these factors are affected by time (P<0. 05). At most heating times, the highest values of peroxide were observed in soybean oil, and the lowest values were observed in frying oil (P<0. 05). In all treatments by increasing of heating time, the amounts of anisidine and totox values increased significantly (P<0. 05). The results of statistical analysis of different treatments indicated that in most heating times, the highest levels of anisidine and totox values and the lowest values were observed in soybean oil and canola oil respectively. Increased Peroxide value indicates that the level of the primary lipid oxidation products increased, which resulted in the formation of hydroperoxides. Peroxide and anisidine values indicate the rate of oxidation reactions at the beginning and the end of the process. In fact, the totox values simultaneously measures the amount of peroxides and their degraded products and provides a better estimate of the progress of oxidative degradation of oils and fats. Based on the results obtained from calculate of the totox value, the oxidation ratio of the studied oils was as follows: Soybean oil > Sunflower oil > Frying oil > Canola oil. According to the results, by increasing of heating time, the amounts of acrylamide in all treatments increased significantly (P<0. 05). Therefore, the highest amounts of acrylamide were obtained in soybean oil and the lowest values were observed in canola oil (P<0. 05). The correlation coefficient between totox value and acrylamide at different heating time was as follows: In the first hour of heating (R 2 = 0. 967), in the fourth hour of heating (R 2 = 0. 95), after 7 hours (R 2 = 0. 646) and in the tenth hour of heating was equal (R 2 = 0. 98), respectively. It shows that the levels of totox and acrylamide had a high correlation with each other and in fact the values of totox had a direct effect on the values of acrylamide. Conclusion: The amounts of unsaturated fatty acids are effective in the oxidation of oils, and this effect is mostly due to double bonds. Oxidation of oils produces primary oxidation (hydroperoxides) that are degraded and secondary oxidation products such as aldehydes, ketones, and other might be produced. Secondary oxidation products in oil might be converted to acrylamide precursors in food without the presence of sugars, and by increasing the production of these products, more acrylamide might be formed. The results of this study showed that there is a high correlation between acrylamide in fried potato samples with the totox values in the oils. Therefore, the type of oil and heating duration influenced on formation of acrylamide in French fries.

Introduction: During thousands of years, human has unconsciously benefited from lactic acid bacteria (LAB) in the production of fermented food. This is due to the potential of these bacteria to release odor and flavor, and inhibit the growth of pathogens and food-spoilage microorganisms (Alvarez-Sieiro et al., 2016). LAB is Gram-positive, catalase-negative, microaerophilic and non-spore forming. In addition to their health-promoting effects, they have numerous technological and microbiological properties in food products. LAB is usually known as the microorganisms highly consumed in food products, which can be utilized as protective culture media, owing to their specific characteristics (Abney and Hewlings, 2019). Probiotics are living microorganisms that when consumed in adequate amount (10 7 CFU/mL) can maintain or improve the intestinal microbial balance and have health-promoting effects on the host. Considering a microorganism as a probiotic strain requires in vitro tests and their confirmation during in vivo experiments. Features that are considered a probiotic for a strain include: bacterial survival during the process of preparing a functional product, gastrointestinal survival, ability to attach to intestinal epithelial cells, as well as the ability to deal with pathogens (De Melo Pereira et al., 2018). The present study aims to examine the probiotic potential (viability in acidic and simulated gastrointestinal conditions, hydrophobicity, auto-and coaggregation) of the LAB isolated from Behbahan local Doogh. Next, their technological properties (acidification and autolytic activities, and heat resistance) were determined. Finally, the antimicrobial activity of the strains was measured against some food pathogens. Material and methods: In this study, the LAB strains of Behbahan local Doogh were identified through 16S rRNA gene replication by a polymerase chain reaction. First, 85 Gram-positive and catalase-negative isolates were categorized using biochemical and sugar fermentation tests. One representative was selected from each group for the molecular identification test. In order to investigate the resistance of the bacteria to acidic conditions, their viability was examined at pH values of 2. 5, 3. 5 and 5. For determining the LAB viability in the gastrointestinal system, 30 µ l of each bacterium was added to 270 µ l of simulated gastric juice (2. 5 g pepsin/l and 2 g NaCl/l) whose pH had been set at 2. 75 and incubated at 37° C for 1. 5 h. Then, 30 µ l was mixed with 270 µ l of simulated intestinal juice (1 g trypsin/l, 5 g bile salt/l, 2 g pancreatin/l, 11 g sodium bicarbonate/l and 2 g sodium chloride/l) whose pH had been adjusted to 8 and incubated at 37° C for 4 h. Afterwards, the bacteria were cultured on MRS agar at 1. 5, 2, 3 and 4 h. The results were expressed as the reduction of log CFU/ml relative to time zero (time zero: 8 log CFU/ml). The other probiotic properties of the LAB, including hydrophobicity, auto-and co-aggregation were also investigated. Their technological potential was determined though acidification ability, autolytic activity and resistance to heat. Eventually, the antimicrobial activity of the strains with better probiotic and technological properties was examined against 5 food pathogens (Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium, Micrococcus luteus and Staphylococcus aureus). One-way analysis of variance was conducted using statistical package for the social sciences (SPSS) version 22. Duncan`s multiple range test was employed for mean comparison at 95% confidence level. Results and discussion: Lactobacillus plantarum, Lactobacillus delbrueckii and Pediococcus pentosaceus were the most resistant strains to the pH values of 2. 5 and 3. 5, while Lactobacillus pentosus and Enterococcus faecium showed the most pronounced reduction of log CFU/ml. At the pH value of 5, all the bacteria were able to grow without being reduced. Relative to the simulated gastric juice, L. plantarum was the most resistant one with a reduction of zero log CFU/ml and E. faecium was the most sensitive one with a reduction of 3 log CFU/ml. After 3 h of digestion by the simulated intestinal juice, L. plantatum and L. delbrueckii were the most resistant strains with a reduction of 1 log CFU/ml and E. faecium was the most susceptible one with a reduction of 5 log CFU/ml. The hydrophobicity of the strains was reported to be 17. 5-58. 3%, the highest of which belonged to L. plantarum. The co-aggregation of the LAB varied from 25. 3 to 48. 2%, the highest of which was associated with P. pentosaceus. In addition, all the strains showed coaggregation activity against E. coli, and L. plantarum had the highest value of co-aggregation (46. 3%). In terms of the technological properties, the results revealed that all the strains were capable of acid reduction up to 0. 4 except L. pentosus. During 24 h of incubation, P. pentosaceus and L. delbrueckii caused the largest pH variations. The results of the autolytic activity of the LAB isolates indicated that all the L. pentosus, L. plantatum and L. delbrueckii could be grouped as relatively good. The highest viability and heat resistance belonged to P. pentosaceus and L. delbrueckii and the lowest viability was related to L. pentosus and E. faecium. In general, L. delbruckeii and P. pentosaceus showed the best results in all the technological tests. Moreover, the antimicrobial activity of L. plantarum, L. delbrueckii and P. pentosaceus was investigated against E. coli, P. aeruginosa, S. typhimurium, M. luteus and S. aureus. In all the samples, the acidic cell-free supernatant had a greater antimicrobial effect than the neutralized cell-free supernatant. The neutralized supernatant of L. plantarum and L. delbrueckii had no antimicrobial effect on E. coli. The shortest inhibition zone diameter of the acidic supernatants of L. plantarum, P. pentosaceus and L. delbrueckii was associated with E. coli. Furthermore, S. aureus was the most sensitive strain against the acidic supernatant of L. plantatum and S. aureus, whereas M. luteus had the longest inhibition zone diameter against the acidic supernatants of L. delbrueckii and P. pentosaceus. Conclusion: Considering the obtained results, L. delbrueckii, L. plantarum and P. pentosaceus had superlative performances and can be used as complementary strains in the production of food products. It is suggested that supplementary tests, including the adhesion ability to intestinal epithelial cells, anti-adhesion ability against specific pathogens, and the lipolytic and proteolytic activity of these three strains be evaluated.

Introduction: Environmental pollution characterizes a chief problem in both developed and underdeveloped countries. Increased population with the progress of technology and production can lead to an absence of attention to environmental safety. Industrial waste, public and agricultural sewage, mining of metals, means of transportation emissions via shipping traffic, all caused the heavy metals as non-biodegradable poisonous materials to enter marine environments and bioaccumulation by aquatic populations, particularly over the last few decades. Heavy metals present in the environment can be absorbed into living organisms from the surrounding water, sediment, and diet. Consequently, population exposure to toxic metals through seafood consumption is unavoidable and may pose a threat to human health. Unfortunately, heavy metal pollution's effect on marine ecosystems and humans is intense and very extensive. These metals are lethal to aquatic life at low concentrations, mainly in soft water. Such metals may be collected from water to higher levels in fish (USEPA, 1977). Metals are found all over the earth including the atmosphere, earth, water bodies, and can also accumulate in biological organisms including plants and animals. These metals generally termed heavy metals include: antimony, tellurium, bismuth, tin, thallium, gold, arsenic, cerium, gallium, cadmium, chromium, cobalt, copper, iron, lead, mercury, manganese, nickel, platinum, silver, uranium, vanadium, and zinc. This category of metals named heavy metals has not only been recognized for their high density but the most significant for their adversative effects on the ecosystem and living organisms. Fish is considered an important part of a healthy, well-balanced diet owing to its excellent nutritional properties (excellent proteins, vitamins, essential omega-3 fatty acids). Fish and seafood are unique dietary sources of cardioprotective docosahexaenoic (DHA) and eicosapentaenoic (EPA) fatty acids. Therefore, numerous public health authorities recommend regular fish consumption equivalent to at least 1-2 servings per week to prevent diet-related chronic diseases. Fish can accumulate heavy metals in their tissues by absorption along the gill surface and kidney, liver, and gut tract wall to higher levels than environmental concentration. The content of metals in fish tissues and organs shows the concentration of metals in the water and their food. Thus, the problem of heavy metal contamination in fish is increasing worldwide attention. Meanwhile, different fish tissues have different abilities to accumulate these metal elements due to the different chemical compositions. The heavy metals concentrations of fish fillets can be affected by processing or cooking methods and therefore, it is important to determine the concentrations of heavy metals in raw and cooked fish fillets and it is possible to reduce the heavy metal concentration in fish fillets by choosing a suitable method of cooking (Atta et al., 1997; Ersoy et al., 2006; Diaconescu et al., 2013). Material and methods: Specimens of white fish (Rutilus kutum), carp (Common carp), mullet (Liza aurata) each in three numbers in equal sizes were purchased freshly from Sari fish market in December 2017 and after unloading the viscera and scales were immediately transferred to the laboratory of the Department of Food Science and Engineering of SANRU and stored in the refrigerator. Fish samples were prepared by four different cooking methods. For this purpose, a sample weighing 100 g was removed from the inner tissue of each fillet and in the next step, each sample was cooked for the required time for optimal consumption. These conditions are for microwave (Solardem model, made by LG company) for 10 minutes at 900 watts, grilling (in a onefloor electric oven made by Baking Industries Company, Mashhad) for 20 minutes at 180 ° C, roasting (in an electric oven one Construction floor of Mashhad Baking Industries Company) was 180 degrees for 20 minutes and frying (made by Pars Khazar Company) was 180 degrees for 4 minutes. Measurement of heavy metals: For this purpose, the acid digestion step was performed with the help of nitric acid. To digest the samples, the first one gram of each sample was dissolved in 10 ml of 1 M nitric acid, then boiled until complete digestion. In the next step, the filtration operation was performed and the resulting precipitate was washed with 1 M nitric acid and transferred to a 25 ml test tube and the rest was made up to volume with distilled water. The desired elements (lead, cadmium, zinc, copper, nickel, chromium, and manganese) were read by the plasma induction diffuser (ICP_AES model 4100). Results: Regarding the effect of the cooking process on the cadmium element, cadmium was decreased in all treatments and the least amount of cadmium was observed in roasted white fish. In the white fish, the lowest chromium content was observed in grill and microwave treatments. Grill and microwave processes were reduced in chrome in the white fish. The highest amount of nickel element in the white fish was observed in the roasted type and the lowest amount of grilled sample. In the white fish, only the roasting method caused a significant decrease in copper. In mullet fish, all treatments reduced this element significantly, but the lowest amount was found in frying. Zinc content in mullet and carp fish was significantly higher than other elements. The roasting process resulted in a decrease in this element. The roasting and grilling process significantly reduced Mn. In the white fish, the least amount was related to the frying method. In mullet and carp fish, the highest decrease was in fried samples. Conclusion: Overall, whitefish and carp fish were the unhealthiest fish among the three species. In comparison between different cooking processes, roasting and after that grilling resulted in the highest reduction in the sum of three heavy metals and seven elements, in contrast, in most cases microwaves preserved these elements in cooked fish.