IRANIAN JOURNAL OF FOOD SCIENCE AND TECHNOLOGY
Year:2016 | Volume:12 | Issue:49|Papers Count:23

Low SCC (<200 000 cell/ml), Medium SCC (200 000<SCC<800 000), High SCC (>800 000cell/ml) and mix of these three levels of SCC were considered as four categories of raw milk samples in this research.yoghurt was produced by addition of lactose, WPC and skimmed milk powder in order to the amount adjustment of lactose and casein after determining significant difference in the content of lactose, casein and whey proteins in all four levels of SCC. Results showed that a little reduction of lactose can effect on yoghurt properties.In the present study, evaluated the effect of different somatic cell counts on some rheological and sensory properties of set yoghurt. Yoghurt samples were analysed on days 1, 15 and 28 after production. Frequency sweep test results revealed that for all samples elastic behaviour dominates the viscous one over the whole range of frequency but by increasing SCC, G’ became more frequency dependent which means a weaker and also less gel structure, for samples with higher SCC. It was indicated that somatic cell count of milk is a critical factor which affects the quality of yoghurt.

Soybean oil is the most important vegetable oil, which is produced in the world because of oil good quality and high yield. The quality is affected by factors such as damage to the seeds of soybean oil, high humidity, high temperatures during storage and processing, exposure to air (oxygen), especially at high temperatures, contact with oxidizing agents Starter and exposure to light altered. The purpose of this study was to determine the best conditions for optimization of products and maintenance of test oil was to prevent the destruction of its chemical oxidant and corruption. In the present study the stability of soybean oil peroxide index aggravating factors that affect corruption oxidative the time of production, was assessed. The results of the average of 4 replicates Peroxide samples of soybean oil under different levels of temperature, antioxidants, and the amount of iron metal showed that the effects of temperature, antioxidants and iron metal on Peroxide soybean oil at 1% level is significant. The interaction of temperature - temperature antioxidants - iron was significant at the 1% level. Peroxide highest maximum level temperature of the oil at 80oC. The amount of antioxidant added to the oil, soybean oil had a significant effect on the peroxide index was 1% level. The maximum amount of oil in the peroxide index absence of antioxidants in the oil obtained. Levels of iron metal significant effect on the rate of 1% soybean oil peroxide index showed. Peroxide highest amount of iron in soybean oil was obtained 3 ppm and temperature of 80oC.

Whey protein based edible coating containing 0.5, 1 and 1.5% (w/v) thyme essential oil was used for inhibition of bacterial growth of rainbow trout fillets during cold storage. Microbial analyzes (total viable counts, psychrophilic counts, lactic acid bacteria and Enterobacteriacea) as well as total volatile basicnitrogen (TVB-N) and pH measuring was performed periodically every four days. Results showed that whey protein coating containing thyme essential oil was able to inhibit bacterial growth of fish fillets. Also the TVB-N and pH values in the coated samples were significantly (p<0.05) lower than those of non-coated treatment. Among the treatments used in this study, treatment with 1.5% thyme essential oil containing edible coating was the most effective treatment against evaluated bacteria in this study, As could extend the shelf-life of rainbow trout fillets stored at refrigerator for at least 4 days compared to control.

Rutilus frisii kutum is one of the most important and economic fish in our country. Since the passage of time and temperature on the quality of fish caught continuous reduced, so decreasing the temperature by ice storage, immediately after fishing, is a good method to avoid loss of quality fall. In this study change of some quality parameters of R. frisii kutum during ice storage for 16 days such as expressible moisture, pH, thiobarbituric acid, total volatile nitrogen, free fatty acid, psychrotrophic count and total viable count to assessment the effects of delay of putting ice on fish caught and loss in quality product was measured. According to these results, the chemical and bacterial indicators were increased significantly during the storage in ice. Delayed icing caused the higher degree of oxidation. Furthermore, delayed icing, lack of attention to correct method of storage, and ice storage for a long time can decrease the quality of meat. It is better that fish be ice storage after fishing immediately. Shorten the shelf life of the product on the ice and accelerate cooling, helps to increase the shelf life of the product.

In present study, dried pomegranate peel of three dominant Iranian varieties was extracted by soxhlet extraction (SE) method via four solvents. In this study Five anthocyanins were identified and quantified in the extracts by high performance liquid chromatography (HPLC) coupled with ultraviolet-visible (UV-Vis) spectrometric detector at wavelength of 517 nm according to their retention times and external standard method. According to the results extraction yield of Poost Siyahe Shirine Ardestan (PSSA) variety is more than other two varieties and extraction yield of ethanolic extracts is more than other solvents in p£0.05. HPLC analysis was indicated pomegranate peel include of more mono glucoside anthocyanins than di glucoside anthocyanins also the most of anthocyanins particularly mono glucoside anthocyanins were detected in ethanolic extract obtained from dried peel of PSSA variety.

Iran has a long history in manufacturing a wide range of dairy products and cheese is one of the most important fermented dairy product which is high in protein. Lour cheese (Lour is similar to cottage cheese) is prepared traditionally in the mountainous region of Gilan province, north of Iran, using sheep or cow’s milk. This cheese is very well known cheeses in the region and is preferred by many locals. It is prepared through heating (up to the boiling point) the cheese whey with addition of milk (LCM) or Doogh (buttermilk) (LCB).In this study, batched of Lour cheese (with milk and with buttermilk) were produced in the traditional way and were examined for sensory, physicochemical and rheological properties.The results showed that the moisture content of LCM and LCB was 66.45% and 72.82 %, respectively. The amount of fat measured was 22.33% and 13.70 %, respectively. LCM contained less protein (8.77%) compared to LCB (9.73%). The study also showed significantly different preference for over LCB over LCM by 40 untrained panelists. These finding were backed up by the rheological analysis Overall, Lour cheese proved to be a healthy alternative for feta type cheese however, more work is to be done to commercialize it.

Nowadays because of several problems and diseases that treat human health, considering special attention to suitable nutrition and achieving confidence about safe and rich content foods is a very important and unavoidable issue. Folic acid is one of required vitamins for our body that must be provided sufficiently. So there are numerous efforts has been done for more reliable measuring of this vitamin in foods. There are several methods available for measuring folic acid. In this research, two methods have been investigated. The main mentioned method was tri-enzyme extraction and microbiological assay which performed by a-amylase, protease, conjugase and a folate dependent microorganism which was Lactobacillus rhamnosus. Second method was High performance liquid chromatography that is performed in order to proving reliability and accuracy of the first method. Final results of this research showed that tri-enzyme extraction and microbiological assay has more accurate results comparing to high performance liquid chromatography. The reason is that the amount of folic acid detected by microbiological assay is about 50% more than those detected by High performance liquid chromatography. The main reason for existence of this difference in indicated values is due to complete extraction in microbiological assay. We concluded that tri-enzyme extraction and microbiological assay has more efficiency than High performance liquid chromatography to determine accurate amount of sensitive vitamins such as folic acid. In addition, by this method the amount of total folate can be determined.

In this study, the possibility of coating of paper using non-aqueous extracts obtained from peels and leaves of mandarin has been investigated. The extraction was carried out using non polar solvents (hexane, chloroform, dichloromethane, petroleum ether) at room temperature. The antioxidant activities of the extracts were determined using DPPH as free radical scavenger. Coating of the kraft paper was performed by its immersion in the extract solutions and evaporation of the solvents. The results showed that hexane-chloroform (1:1 v/v) system was the best solvent for the extraction and coatings. The weight of coated paper increased with an increase in concentration of extracted materials.The mechanical properties of coated paper (Tensile Strength, Young modulus, Elongation at Break) decreased in comparison with uncoated paper. The extracted materials obtained from peelleave were stronger than that of extracted materials from the peel. The antioxidant activities of both extracted materials were weaker than that of BHA. In conclusion, the extracted materials from peel and peel-leaves caused to a oily coating layer on the paper. Such coating layer with antioxidant properties has potential to be employed in active packaging, but results in a reduction in mechanical properties of the paper.

The effect of adding Eleaagnus angustifolia powder to quality characteristics of burger’s bread an 5, 10 and 15 percent levels was checked. Moisture and tissue’s characteristics (Hardness, Springiness, cohesivness) of treatment and blank breads were measured in first, third and fifth days. A test was done Hedonic test, color measurement and, assessment of porosity and scattering of cavities in bread’s texture in first day. The results show increasing levels of Eleaagnus angustifolia in breads lead to increase moisture, decrease volume, porosity and darker appearance than to control sample. The evaluation of textural preperties determined above the 10 perecent levels of Eleaagnus angustifolia powder lead to increase textural Hardness of bread. on the other hand, adding Eleaagnus angustifolia’s powder, in all levels, lead to reduction in of intransitive powder for cutting beard. In terms of staling process, during the retention time, the sample which contains 10 perecent of Eleaagnus angustifolia’s powder staled slower than the other sample in the period of maintenance and 15 percent’s sample had most stale’speed. According to analysing the sensory evaluation, 10 percent sample had most acceptance. Generally according to the results treatment bread included 10 percent of eleaagnus angustifolia’s powder, will suggest for greater acceptance, lower hardness, procrastination in staling and increas the amount of fiber.

The ability of bacteria to tolerate low pH is a very important trait to survive in a variety of environments. In the literature, there is a lot of information about the acid tolerance of different bacteria. However, little is known about the acid tolerance of Morganella morganii, the most prolific histamine former in fish and seafood products. Therefore, in the present study, the effect of growth phase, type of acid and medium on the acid tolerance of M. morganii at different pHs were evaluated. To achieve this purpose, cells of M. morganii in exponential or stationary growth phases were exposed to low pHs (3, 4 and 5) adjusted by adding hydrochloric, acetic, lactic, citric or tartaric acids into TSB or PBS for one hour. Survival percentage was obtained by dividing the surviving population by the initial population. In general, results of the present study showed a high acid tolerance of M. morganii. For all the acids tested, the lower the pH of the mediums used, the lower the survival percentage observed. Cells of M. morganii in the stationary phase were more resistant to acidic conditions tested and no significant difference was observed (p<0.05) in the acid tolerance of M. morganii in TSB and PBS at different pHs. In addition, acetic acid and lactic acid showed more antimicrobial effect on both the stationary and exponential phase cells than the other acids use.

Due to disadvantages of synthetic packaging materials such as migration into food, polluting of environment, difficulty of recovery, high costs of raw materials and production, also for development of properties of starch based edible film, in this study nanocomposite films from starch and montmorillonite (MMT) fabricated and their properties investigated. In this regard, nanocomposite films formulated by mixing starch and four levels of nanoclay (0, 1, 3 and 5%) and three different concentrations of glycerol (20, 30 and 40%), then the physical and mechanical properties of film measured and appropriate film selected. 5 % nano-clay could improve tension resistance (38%) and moisture permeability (33%). The results from XRD showed that nanoclays spread evenly in starch polymer. The effects of ultrasound waves on the optimum film were investigated. These waves improve mechanical properties and permeability of films remarkably. 30 minutes was the best time of ultrasounication processing. Results showed that optimum nanocomposite of starch-nanoclay could be used as a biodegradable suitable packaging for preserving food.

In this study, full fat soy flour was used in the formulation of breakfast cream containing 30% fat. Different levels of full fat soy flour (5 - 22.5%) and water content (15 - 37.5%) in two type of formulated cream with 55 and 70 % breakfast cream were evaluated. The effect of formulation on physicochemical properties (viscosity, syneresis, acidity and pH ), sensory properties (taste, texture, color and appearance and total acceptance) and economical yield were evaluated. The results of this research showed that the effect of formulation on all physicochemical and sensory properties of cream and also economical yield was significant .The E sample had the least difference with control in physicochemical properties (viscosity 4.86 Pa.S, syneresis 21%, and moisture content 65.8%) and the C sample received higher scores of texture and total acceptance than the other formulations.

In this study, effects of coating materials: methylcellulose-wax, and wax on physic-chemical and sensorial characteristics of Thomson navel orange at 8oC were evaluated. Weight loss, vitamin C, total soluble solid (TSS), acidity (TA), and sensory evaluation every two weeks for 16 weeks of storage were analyzed. Fruits were coated with commercial wax or composite methylcellulose-wax (MC, 9: 10, w/w) using immersion treatment. Uncoated fruits were used as control ones. This research was performed using a factorial experimental model in a completely randomized design with 5 replications at an accuracy rate of 95%. Coatings by wax were the most effective in reducing weight loss. Fruits coated with composite coating materials, had the highest level of vitamin C in comparison with other samples. TSS and TA of all samples decreased during storage, while the TSS / TA ratio increased in all treatments. Fruits treated with methylcellulose-wax within 10 and 16 weeks of storage preserved TA values more than other treatments. The results of sensory evaluation showed that the least desirable flavor was related to 8 weeks after storage. Within 10 and 16 weeks, the highest off-flavor was related to the fruits coated by wax Freshness of fruits decreased during storage. No significant difference was observed between the fruits coated by MC-Wax and wax.

The aim of present study was to compare antioxidant properties and investigate the possibility of synergism or antagonism interaction between green tea and oak extracts. Green tea extract in all concentrations had a significant (p<0.05) higher effect than BHT in DPPH free radical scavenging assay and total antioxidant capacity, and in two concentration in reducing power, and in all of the assays was better than oak extract, While only in DPPH free radical scavenging assay the oak extract was better than BHT. Among different combinations of these two extracts, synergism was found in three combination according to DPPH free radical scavenging assay, four combination in total antioxidant capacity assay and all combination in reducing power assay. In the peroxide value assay, the chosen combination showed antagonism, although it was significantly (p<0.05) more effective than BHT in soy bean oil stability. The result shows that it is possible to use these natural antioxidant as substitute of synthetic antioxidant BHT.

Time-temperature indicators (TTIs) are used to check the safety of the fresh foods with reduced oxygen packaging (ROP). Already, the behavior of TTIs with zero-order kinetic was described based on Skinner-Larkin model. For TTI expiration before toxin formation, the Arrhenius curve of TTI (in the coordinates system of lnk versus 1/T) should be located above the zero-order Skinner-Larkin- Arrhenius curve (SLA0) for all possible temperatures. However, SLA0 may incorrectly describe TTIs behaviors since they often provide first-order kinetic (similar to most natural processes). Developing a new model to describe the behavior of all types of TTIs (with zero or first-order kinetic) for fresh seafoods with ROP is the main goal of this research. In this paper, the first-order Skinner-Larkin- Arrhenius (SLA1) model is proposed as a pencil of curves to extend SLA0 for the TTIs with firstorder kinetic. Furthermore, because of including the SLA0 curve, the SLA1 model can be equivalently used for both zero-order and first-order TTIs. Simulation results demonstrated that SLA0 could not correctly predict the behavior of first-order TTIs. By using the proposed model, we can successfully predict the behavior of both zero-order and first-order TTIs for fresh seafoods with ROP.

Ice cream frozen mixture of milk composition, materials, sweeteners, stabilizers, emulsifiers and flavor is produced. Ice cream is a combined food with a variety of colloidal features due to the structure of the various components, such as ice crystals and dispersed air cells in serum phase. In this study sensory evaluation of ice-cream was studied by using different ratios of sucralose as a substitute of sugar in the ice cream. Vanilla ice cream with 19% sugar was used as a control sample and sucralose in five levels (20, 40, 60, 80 and 100%) was substituted for sugar in the formulation. Then sensory evaluations were investigated. During the Results showed that in this study, there was no significant difference in samples (p<0.05). Sensory properties by judges taste was used five-point hedonic scale. But only 20% substitution level had a significant effect on the properties of texture, mouth feel and overall acceptability.

This study investigates the effect of olive oil on the caseinate‐based films. Edible films based on caseinate (5% (w/v)) and glycerol (30% (w/w)) by varying olive oil concentrations (0, 10, 20 and 30% (w/w), were prepared by casting method films. The impact of the incorporation of olive oil into the film matrix was studied by investigating the physical and mechanical properties of films. Scanning electron microscopy (SEM) was also used in order to analyse films microstructure. Increasing the olive oil concentration up to 30%(w/w) decreased values for thickness and solubility from 0.050mm and 92.18% to 0.042mm and 61.84% respectively and caused the films to become opaque. Also addition of olive oil to caseinate emulsion significantly improved the WVP (upto9´10-10g/s.m.pa)of prepared films, but lowered the mechanical properties. The results indicate that the structure and properties of caseinate edible films were modified and improved by the olive oil.

This study is aimed to investigate the effect of microbial Lipase enzymes in different concentration of 10, 30 and 50 ppm and ckecking it effect on bugget’s quality. Physicochemical characteristics of bread such as moisture, volume, texture tough, color and intuitive traits are evaluated. The results revealed that there aren’t any remarkable differences in smell, volume, taste, crust color, shape coordination, crack and rupture and exterior characteristics between experiments and control experiment in intuitive evaluation (P>0.5). Bread produced in 10, 30 ppm values of Lipase enzyme have more prominence in characteristics like inner texture, crust quality, improving the ability to br chewed, proper perforation of the texture than control experiment, but using 10 ppm Lipase showed the most prominence in receiving overall intuitive characteristics. According to the results of texture examinations, using10, 30 ppm concentrations lipase is better than 50 ppm lipase. Bread produced with 10ppm lipase showed the maximum volume and best crumb color, and 30 ppm lipase enzyme the best crust color of the all, and it has the maximum moisture between experiments and it was a remarkable difference among all experiments (P<0.5).

Consumption of breaded food has become very popular over the last few years. In this study the effects of soy and corn flour and ultrasound in batter on quality of deep-fat fried chicken nuggets with compeletly randomized design was evaluated. Wheat flour in batter formula was replaced with 5, 10% soy and corn flour and batter was sonicated 70-KHZ. Chicken nuggets were fried at 170oC. Properties like texture, color, moisture content and sensory properties were determined. Means were compared with Duncan test, Results showed that compering with control batter, soy flour addition provided the highest texture in batter formulation. Batters containing 10% corn flour without ultrasound showed the lower moisture content. The lowest moisture loss was batters containing 10% soy flour with ultrasound. Sensory evaluation didn't show any significant reduction (P<0.05) in texture and overall acceptability scores of treatment products, L* value in corn flour10% with ultrasound Increased, The lowest was in 10% (not sonicated) soy flour. Best texture was in5% soy flour with ultrasound and the worth was in corn flour 10% (not sonicated).

This study investigated the effect of different methods of cooking on quality characteristics of chicken breast fillet. This assay applied 120oC autoclaving for 5 and 10 minutes, 180oC deep frying for 5 and 8 minutes and 600 watt microwaving for 3, 6 and 9 minutes and compared cooking loss, hardness, normal shear, toughness, L*a*b* color parameters and sensory attributes of cooked chicken fillet. The cutting tests demonstrated that 5 minute deep fried treatment and control experienced the lowest hardness respectively, while the 9 minute microwaved treatment showed the highest hardness and toughness (P<0.05). The 8 minute deep fried (without any flour cover) treatment showed the highest brightness (L*) and lowest redness (a*) values. It must be mentioned that deep fried treatments gained the highest sensory preferences with lowest cooking loss percentage. The study revealed that deep frying is the best cooking method of chicken breast fillet in order to achieve better color, cooking loss, texture and sensory attributes.

Delphi was the principle procedure used to conduct this study. In its most basic form, the Delphi consists of at least three different instruments which in the present study will be referred to as round one, round two and round three. Brooks (1972) stated that the number of rounds could either be predetermined by the researcher or continued until group consensus is reached. The primary purpose of this study was to identify strategies regarding commercialization of academicals research findings in dealing with agricultural food Industry.Seventy-Four faculty members of Agricultural Food Industry Departments employed at public universities were identified to serve as a panel of experts for this study. However, 25 faculty members responded to our e-mailed questionnaires. From the review of literature, an open-ended questionnaire consisting of one question was developed for round one. This question was validated for content regarding its appropriateness to the objective of the study by a panel of faculty members in the Departments of Agricultural Extension and Education and Food Industry at Tarbiat Modares University. Seventeen strategies regarding commercialization of academic research findings in Agricultural Food Industry were collected from the panel of experts as the result of round one. Consensus was achieved for 15 of these statements in round three. The data in Table 3 shows the level of agreement of panel of experts in commercialization of academic research findings that more than (80%) of them reached consensus.