IRANIAN JOURNAL OF FOOD SCIENCE AND TECHNOLOGY
Year:2021 | Volume:18 | Issue:112|Papers Count:30

Gilan’ s black tea is obtained via the fermentation of the fresh leaves of Camelia sinensis var. assamica. In this study, the effect of tea production process and brewing methods, microwave and conventional methods were studied on their phenolic and flavonoid content and antioxidant activity (DPPH radical scavenging assay, iron atom reducing power). The results showed that due to the fermentation process, the antioxidant properties and phenolic content of tea were changed and also the tea brewing method was effective on these properties and the highest phenolic and flavonoid contents and antioxidant activity were determined in the rolling step on the microwave brewing method. While the lowest phenolic and flavonoid contents were observed in the withering step on microwave brewing method and the lowest antioxidant activity was related to the tea treatment under conventional brewing. Therefore, the microwave method with high extraction capability and reduced the processing time can be an alternative to the conventional methods in the food industry.

Today, consumption of milk and its products is one of the signs of development of human societies. Milk is a healthy, nutritious, delicious and thirsty drink that is consumed by a large group of people, especially children. Therefore, the aim of this study was using grape syrup as a flavoring in probiotic milk containing Bacillus coagulants and investigating effects of grape syrup on physicochemical and microbial properties of probiotic milk. For this purpose, two quantitative factors including grape syrup concentrations (0. 17, 1, 3, 5 and 5. 83 %) and storage time (0. 96, 2, 4. 5, 7 and 8. 04 days) in five levels were evaluated by using a central composite design. The results showed that different concentrations of grape syrup and storage time on pH, acidity, dry matter, fat and viability of B. coagulation of probiotic flavored milk were significant (P<0. 05). Optimum condition was obtained based on maximum pH and viability of B. coagulation and minimum acidity. The optimum condition was 1% grape syrup and 2 days’ storage time, which its total desirability was 95%.

Edible coatings application to the food prior to drying by infrared system is another potential pretreatment to drying. Edible coatings are thin layers of an edible material applied to the surface of the food and creating a selective barrier to the gas transport. The aim of this study was to investigate the color and area changes of coated apricot slices with xanthan and balangu seeds gums during drying in the infrared system. In this study, apricot slices in cylinder form with a thickness of 0. 5 cm were coated using xanthan and balangu seeds gum (concentration of 0. 6%) and then placed in an infrared dryer and the effect of radiation power (150, 250 and 375 W) on the appearance characteristics were examined. To examine the color and area changes of the samples, samples image were taken continuously during drying time. Color indexes including brightness (L*), redness (a*), yellowness (b*) and color changes (Δ E) as well as changes in the samples area during drying time were calculated. The calculated L* index for the drying process of apricot samples showed that the coated samples were brighter in terms of brightness and the coated apricots with balangu seed gum had higher L* values. In terms of color change index (Δ E), coated apricots with balangu seed gum showed the lowest color changes during drying time and the average values of Δ E for the control sample, coated with xanthan gum and coated with balangu seed gum were equal to 21. 30, 16. 89 and 13. 92, respectively. For modeling the color change index, the quadratic model had less error than the power model. The results showed that the coating with balangu seed gum maintained the appearance of the dried product and also the least area changes in the total drying time and at different irradiation powers were observed in these samples.

The present study, the effect of coating and osmotic dehydration on Physicochemical (texture, shrinkage, rehydration, pH, acidity and color parameters) and microbial characteristics of banana chips were investigated. The coating as the pretreatment was carried out in three concentrations (1, 3 and 5%) of basil seed gum (BSG) and samples were stabilized at 70 ° C for 5 min. for moisture content reduction to the acceptable level, dehydration was carried out with different concentrations of sekanjabin syrup (SS) (55 and 65%) for 4h and then in order to reach equilibrium moisture content the slices were dried at 65 ° C. decreasing the concentration of BSG and increasing the concentration of SS caused to decreasing in pH and increasing in acidity and shrinkage of dried banana chips. Results showed that increasing concentrations of BSG and SS significantly (p<0. 05) resulted in increase the hardness, respectively. In this study the highest L* index refers to samples treated with 5% BSG and 55% SS, and lowest L* index refers to samples produced with 5% BSG and 65% SS. the results from total count test of microorganisms microbial quality of the samples was in acceptable range.

Although one of the most suitable methods for natural fortification of bread is using fiber sources such as rice bran, due to its negative effect on the physical, textural, nutritional and sensory properties of bread, the addition of fiber has not yet been widespread. In this study, the effect of adding hydrothermaled rice bran to bread, as the dominant feed of the community, in optimal conditions and for amounts of 3%, 6% and 9% of wheat flour, was investigated. The results showed that by a slight increasing in the percentage of added hydrothermaled rice bran, the specific volume of bread was increased and the density was decreased. The highest crumb moisture content was observed for high amounts of added bran (6% and 9%). The ratio of crust to crumb also showed a direct relationship by increasing the percentage of bran. Textural changes also indicate that the degree of firmness and gumminess of bread has been significantly increased during storage days (first to fifth day) by increasing the amount of hydrothermaled rice bran. However, the cohesiveness of bread had a significant downward trend by increasing the amount of bran and also during the storage period. Also, among the added amounts of bran, the sample containing 3% bran significantly obtained higher scores in terms of sensory characteristics comparing with the control sample and other samples. Summing up, the results of this study showed that small quantities of hydrothermaled rice bran can be used to produce more useful bread with desirable sensory properties.

Chitosan based films have several disadvantages, such as poor mechanical properties and low moisture deterioration, which limits their use in food packaging. In this study, nanomaterials such as nanoclay (M) and nanosilver (Ag) were used to improve the properties of the film whilst applying electrical current during film drying. Nanocomposite films based on chitosan, were prepared by adding four levels 0, 1, 3 and 5% silver and clay, then heat and electricity with 0, 15, 30 and 60 Voltage were simultaneously applied to dry them, finally their characteristics like including WVP, O2P, physical and mechanical properties, and microstructure were studied. The presence of nanoparticles in nanocomposite films increased the moisture, thickness, opacity, WVP, O2P and improved mechanical properties, incomparison with pure chitosan film. On the other hand, the concentration of 3% in both treatments improve the permeability and mechanical properties of the 1 and 5% levels. The application of electrical current had no significant effect on moisture content, solubility and thickness. In contrast, the use of electric current with a voltage of 30, improved mechanical properties, turbidity and WVP and a voltage of 60, improved O2P in nanocomposites. The images produced by the SEM show that the pure chitosan film has a rough surface and multiple gaps and the film surface of the nanoclay is relatively smooth and compact, which allows for increased tensile strength and inhibitory properties. The film containing nanosilver also had a more turbulent structure with a gap, turbidity and mechanical properties, and less inhibitory properties than nanoclay.

Malva sylvestris belongs to Malvaceae familyThe biological active compounds of Malva sylvestris describe probably it’ s biological activities and therapeutic activity. The purpose of this study was to investigate the antibacterial effect of Malva sylvestris on some pathogenic bacteria “ in vitro” . In this study, the extraction was carried out by the maceration method. The pour plate method and disk diffusion method were adopted to determine the susceptibility of the pathogenic strains against Malva sylvestris extracts. The broth microdilution and fractional inhibitory concentration index (FICI) were employed to determine antimicrobial effect. The minimum bactericidal concentration was measured by pour plate method. The concentration 100 mg/ml of the ethanolic extract showed the best result on Streptococcus pyogenes and Staphylococcus aureus (p<0. 05). Enterobacter aeruginosa was resistant to most of the aqueous and ethanolic Malva sylvestris extracts. Minimum inhibitory concentration of the ethanolic extract of Malva sylvestris for Streptococcus pyogenes, Staphylococcus aureus, Escherichia coli and Enterobacter aeruginosa were 8, 8, 64 and 64 mg/ml, respectively and the aqueous extract were 16, 32, 128, and 128 mg/ml, respectively. The ethanolic extract of Malva sylvestris had more inhibitory effect than the aqueous extracts on pathogenic strains. Furthermore, aqueous and ethanolic Malva sylvestris extracts showed greater inhibitory effect on grampositive bacteria in comparison with gram-negative bacteria.

The effects of Aloe Vera gel based edible coating in combination with Thym essential oil on postharvest quality of strawberries (natively called Gilasi) were studied. Two concentrations of Aloe vera fresh gel (50 and 100% wt) and two concentrations of Thym essential oil (0. 5 and 1 ml/L) were used for preparation of coatings. The treatments stored at refrigerator for maximum 21 days. The results showed that by increasing the time of storage, the total soluble solids and titrable acidity increased. The Aloe vera gel based edible coating without thymol had inverse effect on decay of strawberries. The control samples had the highest weight loss during the storage. Incorporation of thymol seems to have no effect on weight loss reduction. . The texture firmness of strawberries with 100% aloe vera gel +1 ml/L thymol generally decreased with increasing the preservation time. The changes in the firmness of other treatments did not follow a logical pattern. Lightness parameter (L*) reduced during 14 days of storage. According to the sensorial results and purchase intention, in most cases, control took the highest score. The results of this study showed that Aloe vera gel coatings, on its own, could improve the properties (e. g. reducing weight loss) of strawberries during storage. Incorporation of thymol essential oil also had a remarkabely positive effect on strawberries storage time and reduction of decay. Among with these positive effects of these coatings, there were negative impacts of Aloe vera gel on storage time and acidity and negative impacts of thymol on sensory attributes.

The aim of this research is to evaluate the effects of Balangu Shirazi seed gum (BSSG) (0. 3, 0. 4, 0. 5 %) and whey protein concentrate (WPC) (0, 2. 5, 5 %) as fat replacers at different concentration levels on the textural, physical and sensory properties of nonfat ice cream (0. 4 % fat) in comparison with control sample (10 % fat). All samples exhibited typical shear thinning behavior. The removal of fat resulted in some defects which improved by using BSSG and WPC. By increasing the concentration of selected fat replacers, hardness (30. 93-98. 40 g), creaminess (2. 6-4. 6), and sensory acceptance (4. 3-5. 8) increased, and the melting rate (0. 61-1. 10 g/min) and coarseness (2. 6-6. 3) decreased.

The use of chemical compounds to prevent corruption and increase the shelf life of agricultural products, including grapes, has many applications. Due to the harmful effects of these compounds on human health and also the tendency of people to use organic products, today the use of low-risk and alternative methods has increased. The use of antimicrobial, antibacterial and antifungal compounds, such as natural essential oils, can be a good way to increase the shelf life of crops. In this study, the effect of thyme essential oil on increasing the shelf life of Fakhri cultivar grapes by two methods of immersion (direct contact) and fumigant (indirect contact) in concentrations (0, 150, 300 and 450 μ l / l) In the cold storage with a temperature of 1± 2° C and a relative humidity of 90% was tested for 60 days. Traits such as percentage of changes in fruit weight, titratable acidity, total soluble solids, sensory evaluation including fruit texture firmness, Smell and flavor, antioxidant capacity and browning of cluster wood were evaluated. The least percentage of changes in fruit weight and titratable acidity were observed at a concentration of 450 μ l /l of thyme essential oil. The control treatment had the highest amount of total soluble solids in fruits (25. 2 degrees Brix). Also, the results of sensory evaluation of fruit texture firmness showed that the fumigant method was better than the immersion method with gradual release of essential oil to maintain the firmness of fruit texture better. Sensory evaluation of grape fruit Smell and flavor and taste showed that at high concentrations of essential oil, the sensory evaluation index was lower. Antioxidant capacity was declining in the whole process and fumigant and immersion methods were not significantly different from each other. The results of evaluation of browning of cluster wood showed that the two methods of fumigant and immersion were not significantly different from each other in maintaining the green color of cluster wood, but showed better performance than the control treatment.

The aim of this study was to investigate the effect of bacteria strain (Lactobacillus rhamnosus and Lactobacillus plantarum) and encapsulation system (multilayer and simple emulsion) on physicochemical, stability and viability characteristics of bacteria. Particle size of LR-ME (Lactobacillus rhamnosus embedded in multilayer emulsion), LR-E (Lactobacillus rhamnosus embedded in simple emulsion), LP-ME (Lactobacillus plantarum embedded in multilayer emulsion) and LP-E (Lactobacillus plantarum embedded in simple emulsion) was measured as 10. 63, 3. 53, 10. 47 and 4. 19 μ m, respectively. Results showed that the multilayer emulsion samples had larger particle size than simple emulsion. But the bacteria strain had no effects on the particle size of the samples. Span showed that the simple emulsion samples had more dispersion than the multilayer emulsions. Zeta potential of LR-ME, LR-E, LP-ME and LP-E emulsion samples was measured-51. 26,-39. 35,-56. 65 and-30. 25 mV, respectively. Multilayer emulsion samples had lower negative zeta potential than simple emulsion, but the bacterial strain had no effect on the zeta potential of the samples. Multilayer emulsion samples had higher stability than simple emulsion, But bacterial strain had no effect on the stability of samples. The bacterial counts in LR (free Lactobacillus rhamnosus), LR-ME, LR-E, LP (free Lactobacillus plantarum), LP-ME and LP-E were measured 8. 49, 8. 48, 8. 51, 8. 41, 8. 37 and 8. 39 log cfu/g, respectively. The results showed that coating with multilayer emulsion is the best method for increasing the viability of probiotics.

In this research, the effect of different thermal processes of milk, pasteurization ( 63° C for 30 min, 74° C for 15 s, 95° C for 5 min) and sterilization (120° C for 15 min and 140° C for 2-4 s), on the selective physicochemical, sensory and microbial properties of probiotic yoghurt was investigated during cold storage for 21 days. Results showed that during storage time, syneresis decreased and acidity and redox potential increased (p<0. 01). By increasing the severity of thermal processing, the decline in syneresis and redox potential (p<0. 01) and the increase in acidity and viability of Lactobacillus acidophilus (p<0. 05) and Bifidobacterium lactis was observed (p>0. 05). Finally, regarding to the highest sensory evaluation and probiotic bacteria viability, the yoghurt sample produced from milk treated at 140° C for 2-4 s was selected as the best sample.

The gums extracted from different sources have different functional and rheological properties compared to each other, and the extraction conditions have significant effects on these properties. Therefore, the study on the method of extraction and optimization of new sources of gums, due to different gum behaviors towards each other, has become more important. In this study, the optimization of extraction conditions for glucomannan of Eremurus luteus powder (Serish) as a new source of hydrocolloid has been studied. For this purpose, the effect of temperature (30-80° C), water-to-solid ratio (50-100%) and time (1-4 hours) on the extraction yield, apparent viscosity, and solubility were optimized using the response surface methodology. The results showed that the quadratic model is the best model to describe the data. The optimized conditions were temperature of 79° C, water to solids ratio of 98. 3 to 1 and extraction time of 3 hours and 12 minutes. Under these conditions, the apparent viscosity of 250 mPa. s, solubility of 53. 99% and extraction yield of 72. 43% were obtained. The results of chemical composition analysis showed that the optimal sample based on dry weight had 86. 25% carbohydrates, 6. 22% (protein), 6. 13% (moisture) and 4. 17% (ash). The results of monosaccharide analysis showed that in Eremurus root gum, the ratio of glucose to mannose was 1. 1 to 1 and belonged to the glucomannan family.

Doogh is a fermented dairy drink that produced with mixing of pasteurized yogurt, water, essential oils and salt. Due to low pH, doogh is susceptible to spoilage with mold and yeast that is the main challenge for its shelf life. At the same time, the consistency is very important in quality and marketability of doogh. Nowadays, the interesting of consumers to natural antimicrobial substances rather than chemical preservatives has been progressively increased. Chitosan is a derivative of chitin, unlike synthetic polymer compounds, is non-toxic and biodegradable in nature. The aim of this study was investigation on the effect of chitosan on the qualitative features and shelf life of doogh. In this research, chitosan was added to the doogh in four levels (0. 05, 0. 1, 0. 2, 0. 3%) and qualitative characteristics of them were investigated by physico-chemical, microbiological and sensory analysis during 60 days. The results showed that, use of chitosan resulted decreasing of phase separation rate, acidity, mold and yeast, Streptococcus salivarius subspecies thermophilus and Lactobacillus delbrueckii subspecies bulgaricus counts and increasing of viscosity and pH. So that, samples containing 0. 3% chitosan had 97% decrease in phase separation rate, 24% decrease in acidity, 6% decrease in mold and yeast count, 19% decrease in Streptococcus salivarius count, 11% decrease in Lactobacillus delbrueckii count, 122% increase in viscosity and 15% increase in pH compared with control samples, at the last day of storage. In the case of sensory features, chitosan did not have any effect on the color and appearance of doogh, but had effect on the flavor and also consistency was improved.

Nowadays due to the role of nutrition in public health, low fat food production is one of the advantages of food industry. Therefore, the aim of this study is the feasibility of a new product in modern baking industry using inulin as substitute for fat in three level (20%, 45% and 70%) and using xanthan gum as a improver three level (0. 1%, 0. 2% and 0. 3%) in cupcake dough formulation and evaluation of physical, microbial and sensory characteristics in final product. The results showed significant increase in inulin substitution level in low-fat cupcake formulation causes a significant increase (P<0. 05) in volume index (up to 45% substituting), stiffness, browning of crust color and significant decrease in crust transparence, redness and yellowness index as well as shelf life and sensory characteristics in final product. Also, using xanthan gum showed significant increasing (P<0. 05) in porosity, stiffness index, , browning of crust color, shelf life and sensory characteristics in final product but showed significant decreasing in volume index, crust yellowness and redness. According to the results by response level statistical method, in the sample 45% of xanthan gum and 0. 2 % of inulin were evaluated as the optimal points to be applied in the final product.

Resistance of microbial strains to antibiotics and controlling food safety are two of greatest global problems. In this research phenolic content, flavonoids, antioxidant capacity and antibacterial properties of Sclerorhachisplatyrachisessential oil were evaluated. Phenolic content and flavonoids of Sclerorhachisplatyrachisessential oil were measured using Folinciocalteu method and aluminum chloride colorimetric method respectively. Antioxidant capacity evaluated using DPPH, ABTS and β-carotene bleaching assay. Agar well diffusion, agar disk diffusion, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were used to evaluate antibacterial activity of essential oil against some pathogens. Results showed that total phenolic content and flavonoid of Sclerorhachisplatyrachis were 55. 63 mg GAE/g and 62. 28 mg QE/g respectively. Antioxidant capacity using DPPH, ABTS and β-carotene bleaching assay were 52. 39, 68. 3 and 49. 95 percent respectively. In disk diffusion method the highest and lowest zones were 16. 2 and 9. 7 mm, belonged to Staphylococcus aureus and Enterobacter aerogenes respectively. In all strains MBC was higher than MIC and Gram-negative bacteria were more resistant to essential oil. Sclerorhachisplatyrachisessential oil showed favorable antibacterial and antioxidant capacity and its usage will inhibit growth of pathogenic bacteria.

The use of functional foods has grown rapidly in recent years. In the present study, the effect of honey (40, 45 and 50 g), apple vinegar (6, 9 and 12 ml), basil seeds (1. 5, 2. 25 and 3 g) and storage time (1, 16 and 31 days) on the physicochemical characteristics of the Sekanjabin were studied using response surface methodology. Total sugar content, pH, acidity, turbidity, antioxidant activity, total phenolic compounds content and total acceptance of the Sekanjabin were evaluated. The results showed that at constant concentration of basil seeds, the amount of pH decreased significantly with increasing honey content (p <0. 05). In constant concentrations of honey, with increasing basil seeds, the pH increased significantly (p <0. 05). with passing of storage time, acidity decreased and then increased. The turbidity first decreased and then increased by increasing the storage time, the vinegar and the basil seeds. The antioxidant activity increased and then decreased by increasing the storage time. The phenolic content decreased and increased with increasing honey content during storage time. According the results of numerical optimization, optimal conditions were obtained: 50 g of honey, 10. 6 ml of apple vinegar, 2. 06 g of basil egg and 8 days of storage time. In these conditions, the physicochemical properties were 1. 37 g/ml acidity, 10. 81% antioxidant activity, 22. 18% phenolic content, 30. 63 g/ml total sugar. The results of this study showed the possibility of producing Sekanjabin containing basil seeds as a functional drink.

Deep frying is one of the most common operations used in food processing. But it is necessary to use methods to reduce the oil uptake and prevent the formation of toxic substances such as acrylamide, while maintaining the desired features. Accordingly, in the present study, the effect of microwave pre-treatment with the power of 2 and 5W / g and in 15 and 10 minutes respectively, on the amount of oil uptake and the amount of acrylamide formation in fried carrot pieces was investigated at two temperatures of 150˚ C and 170˚ C and in 2 and 4 minutes duration. According to the results, at all temperatures, with increasing of the frying time, the amount of oil and the acrylamide formation increased in all samples, but at the same frying times, control samples had higher oil uptake and acrylamide formation compared to the pre-treated samples. According to the investigations, the highest oil uptake and the highest amount of acrylamide formation were respectively measured in the samples fried at 150˚ C in 4 min (6. 12%), and the fried samples at 170˚ C and in 4 min (18. 49 ppb). However, the lowest amount of oil uptake and acrylamide formation in microwave pre-treated samples (with 5W/g power in 10 minutes) and samples fried at 170˚ C in 2 minutes were respectively (3. 78%) and (<4. 67 ppb).

Marmalade is a processed product of some plant organs such as fruit, flower, fruit peel and tuber in which the plant parts used are small and well homogenized. Sugar is used as a sweetener in the preparation of marmalade. In this study, the use of date syrup as a substitute for sucrose used in marmalade formulation was studied. The constrained mixture design was used to achieve the optimal formulation and the effect of sugar substitution with date palm syrup on properties of marmalade was studied. The ingredients used in the formulation were plum paste (35-65%), sugar syrup (0-65%) and date syrup (0-65%). Ten formulas were produced based on the constrained mixture design and their physical, chemical and sensorial properties were investigated. The results showed that plum paste had the greatest effect on increasing the viscosity and total acidity of marmalade, while total soluble solids decreased with increasing the amount of plum paste in the formulation. The L* index of the samples decreased with increasing date syrup and plum paste and the redness of marmalade increased with increasing plum paste. Sensory evaluation of the produced formulations showed that the increase in plum paste increased the consistency, spreadability, color and overall acceptance, while the sweetness and taste and flavor were more affected by the increase in date syrup. Optimal formulation was obtained in the ratios of 58% plum paste, 12% sugar syrup and 30% date syrup and in the optimal formulation the total acidity, total phenolic compounds, and viscosity of marmalade at 20 ° C were equal to 2. 07 g citric acid/100 g, 112. 4 mg gallic acid/100 g, and 3961 cp, respectively.

Ghavoot is a traditional food product that is made from a combination of powders of several types of plant seeds mixed with sugar. It is traditionally used for its energogenic, analgesic, anti-inflammatory, and anti-anxiety properties. In this study, the effect of buckwheat, chia and quinoa on the physicochemical and antioxidant properties of ghavoot was investigated. The total phenolic content and antioxidant activity of ghavoot samples were measured using Folin-Ciocalteau and DPPH free radical (2, 2-diphenyl-1-picrylhydrazyl) methods, respectively. The results showed that there was a significant difference in terms of percentage of dry matter (91. 7-98. 8), brix (38. 83-77. 56), ash (1. 5-3. 41), total sugar (16. 73-57. 15) and fat (8-22. 6) among the studied ghavoot samples. The amount of phenolic compounds was in the range of 1248. 73 to 1329. 49 mg gallic acid equivalent/100 g sample, and the highest amount of phenolic compounds and antioxidant activity was related to the samples with chia seeds. The results of color indexes showed that the highest amount of L index was related to buck wheat ghavoot samples and the highest amount of a and b indexes were observed in chia samples. In general, the results of this study showed that buckwheat, quinoa and chia cereals as semi cereal can be used in the preparation of ghavoot and it is possible to use the nutritional and antioxidant properties of these compounds in the production of this traditional product.

In this study, the effect of WPC, MPC, Milk powder, wheat fiber, and mixer of wheat and psyllium fiber at two levels (1 and 2%) on the physicochemical, quality properties of low-fat yogurt during 21-day storage time investigated. The results of this research showed that the addition of a mixer of wheat and psyllium fiber caused decreasing in pH and increasing in acidity. Samples contain MPC had the least syneresis and the highest viscosity so that the difference among samples was significant. Samples contain WPC, had the most TSS. On the first day and 21st day, samples with WPC and milk powder had the most microbial growth, respectively. According to these results, the best effects on quality properties were included: decreasing syneresis, increasing viscosity especially for MPC samples, and a good influence on microbial growth for all samples. Overall, using fibers and protein concentrate compounds can improve quality properties and has a good potential for application in varied food products.

Iran is one of the largest producers of pomegranate fruit in the world. Plenty of pomegranates produced are freshly consumed; however, fresh pomegranate consumption is not easy due to its nature. Pomegranate seeds are never sold fresh as in other ready-to-eat fruit packages in stores. For this purpose, in the present study, fresh pomegranate seeds were packaged in polyethylenepolyamide packages under atmospheric conditions modified with carbon dioxide: oxygen: nitrogen in three compounds: 15: 10: 75, 30: 0: 70, 0: 0: 100 were packaged and kept in refrigerator for two weeks. Pomegranate seeds were evaluated for sensory properties, biochemical parameters and the growth rate of yeast, Enterobacteriaceae, psychrophilic and mesophilic microorganisms. The results showed that packed pomegranate seeds in the presence of the highest amount of carbon dioxide (30% carbon dioxide+ 70% nitrogen) were significantly different from the other treatments, had the longest shelf life and more score in terms of sensory properties. It was also found that high levels of carbon dioxide in packaging significantly reduced the growth of psychrophilic, mesophilic, Enterobacteriaceae and yeast microorganisms.

To avoid or postpone the spoilage of meat goods and their products, various chemical, physical and microbial methods such as the incorporation of antioxidants, using suitable antibacterial substances have been suggested. In this analysis, three ranges of essential oil concentrations (0. 25, 1. 125, and 2 percent) and three storage courses (1, 6, and 11 days) were used to analyze the impact of applying essence Stachys schtschegleevii to ground Minced calf meat at refrigerated temperature. The capacity to inhibit DPPH free radicals, regenerative power, meat myoglobin amount, peroxide number, pH, and microbial load of the samples were examined by gas chromatography fitted with mass spectrometers after recognizing chemical compounds. Additionally, Statistical analysis plus process optimization were also carried out by response surface method. The findings of this analysis revealed that sesquiterpene (24. 35 percent) was the highest composition of the essence. Based on the acquired results from the optimization Process it seems that the samples containing 1. 24 percent of Stachys schtschegleevii essence with 2 days of storage were the most suitable manner (0. 824). With having an insightful view of the obtained results of the experiment, it could be indicated that the nature of this plant can greatly minimize the spoilage of minced calf meat.

In this research, an antimicrobial bionanocomposites based on carboxymethyl chitosan biopolymer-montmorillonite nanoclay was synthesized in the presence of titanium oxide nanoparticles. Investigation of surface morphology images with scanning electron microscopy (SEM) shows the rough and heterogeneous surface of nanocomposites in comparison with pure carboxymethyl chitosan. The results of the XRD test showed that the diffusion of nanoclay in the presence of TiO2 nanoparticles changed from full sheets to between layers sheets. The addition of TiO2 nanoparticles caused a significant increase (p˂ 0. 05) in turbidity in nanocomposites. The effect of TiO2 nanoparticles on reducing the amount of Gram-positive bacteria of Staphylococcus aureus is more than the effect of TiO2 nanoparticles on reducing the amount of gram-negative bacteria of Escherichia coli. By increasing the percentage of TiO2 nanoparticles, its efficacy in removing colonies of both bacteria is increased. Water solubility and Vapor permeability of nanobiocomposite films decreased with increasing weight percentage of TiO2. The tensile strength of the film containing TiO2 nanoparticles is more than the tensile strength of neat carboxymethyl chitosan film, which is statistically significant (p˂ 0. 05). The study demonstrated the high potential of bionanocomposites in preventing the growth of pathogenic bacteria and showed that such packages could be used to increase the shelf-life of food.

One of the most popular snacks today are pastilles that contain gelatin, acid, dye, essential oil and other synthetic additives and have adverse effects on the consumer. The aim of this study was to investigate the feasibility of producing a pastilles based on dates puree and concentrated whey and optimizing its formulation. In order to optimize the production conditions of pastilles based dates and concentrated whey, responsesurface methodology was used. In this study, the conditions of production of pastilles product (concentration of xanthan gum (0. 1-0. 5%) and agar (0. 3-0. 9%) as well as concentration of whey (5-15%)) were optimized to achieve maximum protein and total acceptability and total color index. According to the results of the statistical analysis of the data, a linear model for moisture, water activity, pH and total color index and a quadratic model for total acceptability were selected. The results showed that the concentration of whey had a significant effect on all responses. Increased concentration of whey had a positive effect on moisture of the samples and had a reverse effect on water activity, pH and total color index. The overall acceptability index did not show a steady trend, with a 10% increase in concentrated whey increasing and then decreasing. As the xanthan gum and agar gum content increased, the moisture content of the samples increased, but water activity decreased. . The overall acceptability index also showed the highest value in average percentages for the two gums (as was the case for whey). The optimum operating conditions obtained for the jelly production process included xanthan gum concentration of 0. 36% (w / w), agar gum concentration of 0. 46% (w / w) and concentrated whey 13. 92% (w / w). The predicted responses under these conditions were 36. 62% moisture content, 0. 66% water activity, 3. 25 pH, 1. 17 protein content, overall acceptability score of 6. 56 and total color index of 45. 94%. After the evaluation, it was found that the actual results were very close to the model estimates, indicating accurate model prediction.

In this study, the effect of different amounts of skim milk powder (SMP) (5 to 11. 5%), milk protein concentrate (MPC) (1 to 5%) and soy flour (0 to 5%) on acidity, pH, viscosity and sensory characteristics (flavor, color and overall acceptance ofconcentrated yogurt were investigated using mixture design. The results of acidity and pH showed that increasing the MPC and SMP decreased the acidity and increased the pH of the sample significantly, while increasing soy flour increased the acidity and decreased the pH of the samples. The results of viscosity showed that only the linear effect of SMP and MPC on the viscosity of samples was significant and increasing of SMP and MPC increased the viscosity of samples but soy flour had non-significant effect on the viscosity of the samples. The results of sensory score also showed that with increasing SMP and MPC, flavor, color and overall acceptance of samples increased significantly, but increasing soy flour decreased the sensory score. The results of variable importance in projection in PLS regression also showed that SMP had the highest positive significance and soy flour had the highest negative significance in terms of pH, viscosity, flavor score, color score and overall acceptance. The optimum formulation was obtained using numerical optimization algorithm in Design Expert software were SMP 9. 8%, MPC 1. 72% and soy flour 1%.

Artemisia is an important medicinal plant which is widely used in the treatment of skin diseases and it has antimicrobial properties. This research was carried out with the aim of making nano-fibers with Artemisia sieberi Besser extract to study its antimicrobial properties against Pseudomonas aeruginosa and Staphylococcus aureus bacteria. Artemisia extract and electrospinning solution containing 0. 2 g of polyethylene oxide, 0. 05 g of chitosan and 1. 5 ml of acetic acid were prepared and then nanofibers were produced by electrospinning of the solutions. Artemisia Extract loading with 100 mg/ml extract had a significant effect on the diameter of fibers and the average fber diameter with Artemisia extract (218. 4 nm) compared to the fibers without extract (204. 8 nm) were higher. The tensile stress at the tear point of the nanofibers with Artemisia extract (3. 04 MPa) was lower than the fibers without the extract (3. 46 MPa) and elongation at break was higher (7. 6%). The nanofibers with the extract had more resistance temperature than non-extract fibers. This is due to the crystal state of Artemisia extract in the fibers. The nanofibers produced with Artemisia extract had inhibitory properties for both studied bacteria. Nanofibers with 100 mg/ml extract completely controlled the bacterial growth. Nanofibers with 20 and 50 mg/ml of extract had a better inhibitory effect on Pseudomonas aeruginosa than Staphylococcus aureus. The Addition of Artemisia extract improved the antimicrobial properties of chitosan nanofibers.

Nowadays, due to the spread of diseases and their complications as well as the high cost of treatment, the use of functional and healthy foods has been considered by scientists. In this context, more attention is paid to complications such as infection and disease development due to the spread of free radicals. One of the options currently considered in the prevention, treatment and reduction of disease complications is biologically active peptides extracted from plant and animal sources. In the present study, peptides derived from milk hydrolysis, including peptides derived from whey and lactoferrin combined with vanillin flavors, were investigated in the laboratory to reduce infection and increase the potency of the antioxidant system. Antimicrobial tests against Staphylococcus aureus and Escherichia coli were performed after preparing milk hydrolyzed proteins and food supplementation with vanillin flavoring. The antioxidant effects of these peptides individually and along with a mixture of supplements were also tested. The results showed that the peptides derived from lactoferrin and whey protein concentrate alone and in combination had antimicrobial effects at concentrations of 2000, 4000 and 1000 μ g / ml, respectively. Also, the results of antioxidant tests in DPPH, ABTS and reducing power system showed the appropriate ability of these components at 400 mg/ml concentration. The highest antioxidant activity was related to the hydrolyzed whey protein among the components participating in the supplement. Based on the results, it can be concluded that milk-derived peptides with vanillin can be used as an effective supplement to reduce the therapeutic effects in diseases, which will be complemented by animal and clinical studie.

The purpose of this study was to investigate the effects of injection of CO2 / N2 gases at different ratios and gas treatment duration on physicochemical and microbiological properties of raw milk using a combined design. In this research acidity, pH, freezing point, total count, total yeast and mold count andtotal coliform count were performedon 15 raw milk samples between 9 and 15 minutes after injections. Statistical analysis showed that the combined treatment of nitrogen and carbon dioxide had significant effect on the acidity and pH of raw milk (p˂ 0. 05), so that with increasing the amount of carbon dioxide to 100%, the pH decreased and acidity increased. The combined effect of both gases on the freezing point of raw milk was significant (p˂ 0. 05). Increasing the treatment time of raw milk from 9 to 15 minutes had significant effect (p˂ 0. 05) on reducing the microbial load, but no significant reduction was observed due to the combination of gases. According to ANOVA results, in 100% nitrogen and duration of 15 minutes, the best results in terms of microbiology and chemistry were obtained. The effect of milk treated with a mixture of CO2 and N2 gases on yogurt properties, as a food model, has also been investigated. Yogurt samples were investigated for chemical, microbial, and organoleptic properties during 22 days storage time. The results showed that the raw milk treated with gas mixture did not have an adverse significant effect on the sensory and physicochemical properties of yogurt (p> 0. 05). However, yogurt acidity, pH and synthesis were significantly affected during storage time (p˂ 0. 05). Therefore, the application of raw milk treatment with 100% nitrogen gas for 15 minutes can be considered as a bacteriostatic agent in the preservation of raw milk in industrial scale.

White button mushrooms (Agaricus Bisporus) have significant nutritional value, but due to high moisture content, they need special treatments to increase storage time. Drying increases, the shelf life of the product by reducing microbial activity, weight and volume of products and it causes to pack, transport and store of products easier. IN this study, using osmotic treatment, three types of sugars Liquorice, white sugar and red sugar in three concentrations of 40, 50 and 60% and three temperatures of 25, 32. 5 and 40 ° C to reduce heat damage to the index qualities such as samples color, reducing drying time and energy consumption and increasing process efficiency in supplementary dryingwhich has done by hot air. According to the findings, among the treatments, Liquorice had the highest rate of moisture loss (89. 24 in 132 minutes), solids adsorption (10. 38%) and discoloration ( = 388. 470) and the lowest rate of wrinkling (63. 51%). The highest rehydration rate was related to white sugar (at 25. C, 2. 91 gr / gr and 40% concentration was 2. 82 gr / gr). The microbial test did not show a significant effect on the overall counting of the colonies, and no mold or yeast was observed in any of the samples.