elham azadfar

Doogh is one of the native drinks of Iran and some other nations including Eastern Europe, the Middle East, Asia (Afghanistan, Azerbaijan, Armenia, Iraq, Syria, Georgia, and Turkey), and the Balkan Islands, whose consumption is It has a lot of history. According to the definition of Iran's national standard, simple doogh is a lactic drink obtained from milk fermentation, the dry matter of which is adjusted by diluting yogurt or milk in the doogh-making process. And due to the low pH, doogh is susceptible to contamination by molds and yeasts, and some bacteria, which causes the quality of doogh to decrease and its shelf life to decrease. Among the nutritional properties of doogh, we can mention the increase of vitamins and nutritious metabolites, the improvement of calcium absorption, and the digestibility compared to raw milk. Rheological behavior in macro and micro scales is one of the properties influencing the quality of food. Food flow behavior for a number of purposes such as quality control, as well as the final properties of the product such as stability, texture, and appearance, directly depends on the food microstructure. One of the major problems is the biphasic of doogh during storage, which is due to its low viscosity, low pH, and their effect on the precipitation of proteins. Types of stabilizers are used to increase the stability of the doogh product, which has satisfactory results. Hydrocolloids are widely used to create tissue stability in acid fermentation products. One of the significant issues in doogh is its consistency, which plays a very important role in its marketability. On the other hand, today, the desire of consumers to use natural antimicrobial substances such as chia seeds, which are considered a rich source of protein and dietary fiber, instead of chemical preservatives, has increased. Hydrocolloids are widely used to create texture stability in acid fermentation products. Chia seed with the scientific name Salvia hispanica L. is an annual summer plant belonging to the mint family. Chia seeds are considered as a rich source of protein (18-25%) and dietary fiber (20-37%). Also, chia seeds contain (21 to 33%) oil, of which (60 to 63%) is related to the essential fatty acid alpha-linolenic acid. These seeds also contain significant concentrations of natural antioxidants such as chlorogenic acid, caffeic acid, myristin, quercetin and kaempferol. Chia seeds contain large amounts of phytosterols that help prevent cardiovascular diseases and have anti-cancer, antioxidant, bactericidal and antifungal effects, which are excellent nutritional properties. The technological advantages of chia have led to its innovative use in food products. The concentration of mucilage, the amount of viscosity increases, and the highest and lowest levels of stability were observed in the samples containing 0.05% of mucilage (85%) and the control sample (52%), respectively.

An optimization method was used to extract the mucilage of chia seeds. After dissolving the mucilage in deionized water, salt was added so that the amount of salt in the final product was 7%. In the next step, 40% of the doogh formulation was added to the stabilizer and salt mixture to prepare the doogh samples. Then, the effect of chia seed mucilage on the stability of doogh during 28 days of storage at 5°C refrigerator temperature was investigated. Chia seed mucilage was considered in a completely randomized design with treatments including concentrations of 0.01, 0.1, 0.3, 0.5% added to doogh and doogh without gum as a control sample. Then viscosity, zeta potential value, stability, sensory and chemical properties of doogh were measured. In this research, analysis and analysis of the results were done in the form of a completely random design and all the tests were done in 3 repetitions. To compare the mean of the treatments, Duncan's test was used using one-way analysis of variance (ANOVA) and SPSS version 16 software at a significance level of 0.05, and graphs were drawn using Excel software version 2016.

Acidity and pH are one of the most important chemical factors in the stability and taste of doogh. The statistical analysis of the chemical analysis of doogh mixed with chia seed mucilage in comparison with the control sample after the preparation process shows that the Regarding the findings of this research, the acidity and pH of chia seed mucilage were investigated in the values of (0, 0.01, 0.1, 0.3 and 0.5 percent), the results show that the acidity of doogh samples is reduced with chia seed mucilage. But pH changes were not significant. The sample containing 0.5% chia mucilage had a higher apparent viscosity at low cutting rates than the control sample (without mucilage) and other samples. Also, this figure shows that the apparent viscosity of the doogh samples decreases with the increase of the shear speed, which in fact indicates non-Newtonian behavior (shear thinning). And in addition, it can be found that the degree of stability increased with the increase in mucilage concentration. Also, The evaluation of the obtained results does not show a significant difference between the sensory attributes of smell, taste, texture and mouthfeel (tenderness, uniformity or homogeneity, oral viscosity and mouth coating) and overall acceptance. The present study showed that in evaluating the mouth feel of doogh samples, no significant difference was observed between the samples and the control, because in addition to the oral viscosity, the uniformity and homogeneity of the samples were also considered. Therefore, it can be concluded that adding more than the appropriate amount of gum causes the samples to become undesired viscous and makes it unpleasant from the point of view of the consumer, because the presence of high amounts of hydrocolloid from the sample's psyche, which is one of the characteristics of desirability It reduces. In similar researches, the use of high amounts of hydrocolloids have been introduced as reducing the desirability and reported that depending on the type of hydrocolloid used, its appropriate amount to increase the consistency is different. The results also show that by increasing the concentration of chia seed gum compared to the control sample, the desirability of the consistency of the samples increases, but this effect decreases at a concentration of 0.5%. The results of the present study show that adding hydrocolloids to doogh causes the zeta potential of the doogh sample to become negative. Due to its anionic nature, chia seed gum has a negative zeta potential. Probably, chia seed mucilage as an anionic hydrocolloid has been absorbed on the surface of caseins and as a result, spatial and electrostatic repulsion has prevented the particles from approaching each other. Colloids containing particles with a low zeta potential (positive or negative), in the absence of other inhibiting factors such as high viscosity and spatial hindrance, will have a great ability to clot and aggregate. The larger numerical value of the zeta potential in the formulation containing gum means the presence of more repulsive force between the droplets and their less tendency to stick together, which in this case repels each other and makes the system stable. Therefore, by increasing the concentration of gum in the samples, the intensity of the charged ions of the samples increased. As a result, the spatial and electrostatic repulsion forces of these samples have shown an important role in stabilization. It could be obtained by increasing the concentration of mucilage, the amount of stability increased, so that there was a significant difference (P<0.05) between the samples and the control sample (without chia seed mucilage). The samples containing 0.3% and 0.5% concentration of chia seed mucilage resulted in 100% stability and the least stability (30%) related to the control treatment at the end of the 28th day. Our findings results are probably due to the polyelectrolyte nature of chia seed gum in 0.5% weight-volume solution; Because the chia seed gum polymer consists of carbohydrates with carboxyl and hydroxyl functional groups. It should also be added that chia seed mucilage did not change much in dry matter, fat and doogh protein content. And as the apparent viscosity of doogh samples containing chia seed mucilage shows, the sample containing 0.5% chia mucilage had a higher apparent viscosity than other samples, and the apparent viscosity of doogh samples decreased with increasing shear rate.

The results showed that the addition of chia seed mucilage up to a concentration of 0.1% on the 28th day of storage time resulted in a remarkable increase in the stability of doogh samples (62%), and concentrations of 0.3% and 0.5% resulted in complete stability of the samples. became The highest apparent viscosity in the samples containing chia seed mucilage is related to the concentration of 0.5 and then 0.3%. Since the highest consistency score in the sensory evaluation of doogh samples and its complete stability compared to the control sample was observed in the sample containing 0.3% chia seed mucilage, this concentration is suggested as the optimal concentration.

Raw milk is susceptible to environmental pollution and considered to be one of the most perishable food items. The prevailing mode of contamination arises from the consumption of milk with digestive system, mucous secretions, and skin. The bacteria have the capacity to endure in milk for a period of ten days. The contamination of dairy products  to polluted hand hygiene products is one of the contributing factors . The present study aimed to examine the effects of disinfectant solutions, specifically chlorine, with varying concentrations (1%, 2%, and 3%), on the contamination of personnel's hands. ANOVA, also known as one-way analysis of variance, was employed to assess the disparities in means. In order to compare the means at a significant level of 95%, Duncan's test was utilized. The findings exhibited that the presence of chlorine has a noteworthy impact on the abundance of microorganisms. Additionally, an investigation was conducted to assess the impact of MicroZ, alcohol at 68% and alcohol 96% on the reduction of Staphylococcus microbial population. By examining the central indicators and dispersion of the tested communities, the results showed that 68% alcohol has a greater effect on reducing the microbial population than microZ and 96% alcohol.

Effect of osmosis dehydration, ultrasonic and edible coating as the pretreatment before drying has been studied in order to improve the flavor of the product, reduce thermal damages, decrease interstitial water and ease of transferring mass. The response surface method was used to optimize the drying conditions of Pommelo slices by osmosis-hot air. The concentration of edible coating (0-2% w/v) and the time of applying ultrasound (0-30 min) and the concentration of sucrose (40-80% w/w) were evaluated as independent variables on the amount of moisture content, absorption of solids, weight loss and productivity coefficient of Pommelo slices as dependent variables. All process variables were linearly significant for all responses (P<0.01). The comparison of the optimization results of coated and uncoated Pommelo osmotic dehydration showed that at the optimal point, the maximum amount of carboxymethyl cellulose coating and the osmotic dehydration time and the concentration of the osmotic solution in the coated sample were calculated as 2%, 21.86 minutes and 57.75%, respectively. The highest values of water reduction, weight loss and efficiency coefficient were 0.09172 (g/100g of solid matter), 0.091% and 19.478 respectively in the coated sample, and the highest absorption of solids with a value of 0.0089 (g/100g of solids) was reported in the uncoated sample. The results showed that the use of coating reduces the absorption of solid.

Yogurt, a widely consumed dairy producton a global scale, is highly regarded for its outstanding nutritional composition, gastrointestinal advantages, prolonged storage capability, rapid digestibility and assimilation rates, economic importance, and therapeutic properties.  And It is shown in this research illustrates that yogurt with an increased quantity of alfalfa extract elevates the levels of phenolic compounds and antioxidant capabilities. In this study, alfalfa extract was incorporated into yogurt formulation at varying concentrations of 2, 4, 6, and 8 percent by weight. Following a storage period of 20 days, the assessment of antioxidant activity was conducted by measuring DPPH radical inhibition. Moreover, an analysis of phenolic compounds and an evaluation of yogurt quality attributes including pH, acidity, water content, and viscosity were carried out. Subsequently, a factorial experiment design was employed, utilizing a completely randomized design with three replications for statistical purposes. Statistical analysis involved the comparison of means at a significance level of 1% using SAS software version 9. The results showed that the presence of alfalfa extract led to an augmentation in the levels of water-soluble phenolic compounds as well as the antioxidant capacity of yogurt. So that, at the conclusion of a 10-day period, the highest antioxidant activity was associated with yogurt formulations incorporating 6% and 8% alfalfa extract. Furthermore, the yogurt sample containing 8% extract exhibited the lowest water content, a statistically significant variance compared to the remaining samples (p≤0.05). It should be noted that Considering the impact of dairy products on health and the need to increase per capita consumption of dairy products, more attention should be paid to the production of products that have more health benefits and high rheological properties. Hence, within this study, it was demonstrated that the inclusion of alfalfa extract resulted in an augmentation of the samples' antioxidant characteristics.

Edible oils and fats are an important part of human diet. Oxidation has an adverse effect on the storage of oils in two ways, including reduced shelf life and reduced nutritional value, which is due to the production of undesirable compounds and procarcinogen properties during high heating. There are several ways to prevent the oxidation of oils, one of them is the addition of synthetic antioxidants. Due to the fact that synthetic antioxidants have adverse effects, such as mutagenicity and procarcinogen, on the human body, research on natural antioxidant sources seems to be essential in order to replace synthetic compounds. At present, increasing attention is paid to natural antioxidants and preservatives, including plant extracts. The most important positive feature of natural antioxidants compared to synthetic antioxidants is their safety and high acceptance by consumers.

In this study, ethanolic extract of red bell pepper was extracted by ultrasound. Then the free radical scavenging power of the extracts at concentrations of 100, 200, 400, 800, 1600 ppm was measured by DPPH test. A completely randomized statistical design was used to evaluate the results. Data were analyzed using SAS statistical software and the means were compared using Duncan test at the probability level. Microsoft Excel 2016 software was used to draw the charts.

The results showed that as the concentration of the extract increased from 100 to 1600 ppm, the antioxidant property of the extract also increased. In addition, as the concentration of the extract in soybean oil increased, the free radical scavenging activity of the oil increased significantly. Moreover, there was a statistically significant difference between the concentrations of 100, 200, 400, 800, 1600 with the control sample at 0.01 level. The highest free radical scavenging power was observed at 1600 ppm and the lowest was observed in the control sample; so that at a concentration of 1600 ppm, the antioxidant properties increased.

The results of oil oxidative stability containing different concentrations showed that the sample containing 1600 ppm of red bell pepper extract had a greater effect on reducing the TBA index. Furthermore, it has a greater effect on increasing the oxidative stability index than other concentrations and also compared to the synthetic antioxidant BHT at a concentration of 200 ppm. Due to the presence of phenolic compounds and antioxidant activity in higher concentrations of bell pepper extract and a positive effect on maintaining oil quality, a decrease in oxidation during storage is evident in comparison of the control sample containing no antioxidants and the sample containing synthetic antioxidants. Therefore, The higher antioxidant capacity of 1600 ppm compared to other concentrations during the thermal process can be attributed to the residual amounts of most phenolic compounds in it at 65 ° C and also the high amount of these compounds in the extract.

The current research aims to compare the effect of green (enzymatic and ultrasoundic) and conventional (acidic and alkaline) extraction methods on the yield (total-dietary fiber (TDF), soluble-dietary fiber (SDF) and insoluble-dietary fiber (IDF)), chemical composition, and hydration properties of olive-pomace DF. The rheological properties of doughs containing different amounts (0, 5, 10, and 15%) of SDF were investigated. The yield of TDF was 74.79 (ultrasonic method)- 90.2% (enzymatic method) which 12.12 -21.68 % of them was SDF. The moisture content of SDF was higher than IDF. The ash and protein contents of IDF were higher than SDF. The extraction method had no significant effect on the moisture and ash content of SDF. The lowest protein content was observed in DF extracted by the enzymic method (P < 0.05). The highest and lowest swelling-power and solubility-index were obtained for the fiber extracted by the enzymic and ultrasonic methods, respectively due to the level water absorption of this fiber. The enrichment of wheat flour with SDF extracted by enzymatic method showed by increasing the fiber level to 10%, the dough-development, stability time and FQN increased, while the softening-degree decreased significantly. Replacing 15 % wheat-flour with SDF led to increasing resistance to extension and energy of doughs. The extensibility of the dough increased significantly with the addition of 5% fiber, while the addition of 10% fiber reduced this index to less than the control value. Overall, although the performance of the enzymatic method was significantly higher than other ones, this method was very time-consuming which limits its application in food-industry. Using a combination of green methods to accelerate enzymatic extraction can be a topic for future research. Furthermore, the replacement of ⁓10 % of wheat flour with SDF showed acceptable rheological properties which can meet the expectation for high-quality and nutritional value bread.

In this research,we first obtained methanol extracts of Ricinus communis Laef and identified their constituents.the total amount of phenolic compounds in the extract as well as its antioxidant activity were determined by investigating the inhibitory power of DPPH free radicals. The extracts were then added at various concentrations to purified antioxidant-free soya bean oil.The inhibition of the activity of the free radicals by the extracts and the oxidative stability of the oil at 65 degrees centigrade were studied for3 days by measuring the peroxide index,TBA and the Acidite index. Finally, the activities of the extracts were compared with those of the synthetic antioxidant BHT that, at the concentration of 200ppm,had been added to the purified soya bean oil. In general, results obtained showed that addition of 100 to600 ppm extracts to soya bean oil at a given storage time increased the oxidative stability index the quantities of polyphenolic compounds and the inhibition of the activities of the free radicals in the oil, but decreased the peroxide index,the acidite index diene.On the other hand,at a given concentration of the extracts, the peroxide index,the TBA index and the number of the DNA conjugates increased by increasing the storage period of the oil from one to three days,but the duration of induction decreased. Therefore, results obtained from investigating the oxidative stability of the oil extracts at the concentration of 600ppm,as compared with the other concentrations of extracts and the control sample, were more effective with respect to the oxidative stability of soya bean oil. were more effective than the BHT added at the concentration of 200 ppm to the oil. finally, it can be inferred that with regard to the gained results, extract including antimicrobial materials has had antibacterial effects but, it has less antifungoid effect.