مجله علوم غذایی و تغذیه
سال پانزدهم شماره 1 (زمستان 1396)

In the Northwest part of Iran, a traditional product with high popularity among consumers is produced and is named “Nehre Butter”. This study is concerned to evaluate and compare the nutritional characteristics of this product with the industrial products, with a particular emphasis on the risk factors for cardiovascular disease.
Industrial and traditional butter samples were prepared and fatty acid profile and cholesterol content were measured using gas chromatography and atherogenic and thrombogenic indexes were calculated. In order to investigate the effect of feeding prepared butters, 40 Wistar rats were randomly divided into four groups of ten, including one control group and three groups were treated with fermented cream butter, non-fermented cream butter and traditional butter respectively. The end of the sixty days treatment period, serum cholesterol, triglycerides, LDL-C and HDL-C were measured using colorimetric methods.
The most favourable thrombogenic and atherogenic indexes, hypercholesterolemic/ hypocholesterolemic ratio and cholesterol content were found in the traditional butter. The traditional butter also showed a high percentage of conjugated linoleic acid. In the case of the biological model survey, serum lipids were higher in the traditional butter fed rats as compared to the control, but lower than cream butter fed groups.
This study showed that the traditional butter due to its mild effects on health in comparison with the industrial ones is recommended, although moderate consumption is advised.

The application of new approaches for packaging valuable fruits such as strawberry has become an attractive research subject. These approaches are used to keep the fruits properties at high quality by increasing storage time.
In this study, two different packing methods (Modified Atmosphere Packaging (MAP) using gas mixture (10% O2, 15% CO2, 75% N2) and Nano Silver Particles were employed. The impact of using these methods on the validity of storage time has been studied. The strawberry packaging using Nano Sliver Particles has been analyzed during 16 days in the poly-ethylene covers with the thickness of 40 microns at the temperature of 50°C. The measures used in the experiments consisted of weigh loss, solid particles in solutions, acidity, pH, fruit tissue hardness, color and the weight percentage of the O2 and CO2 existed in the package.
The results of the two methods on the qualitative properties of strawberry at 5°C and at different time intervals (i.e. 4, 8, 12 and 16 days) indicated that both methods increased the shelf life of the fruit regards to improved sensory characteristics.
The experimental results illustrated that both introduced packaging approaches increased the storage time. The experimental data also indicated that the qualitative characteristics of strawberry, namely fruit color and tissue hardness have increased by using the presented approaches.

Technological performance of Bakery’s yeast is closely related to its viability. In order to predict the performance of baker's yeast, observations concerned with accurate and fast detection of viable and nonviable yeast in the fermentation environment is essential.
In this study, three samples of instant dry yeast were investigated by epifluorescence light microscopy (EFLM) using 0.02 % FDA and 0.1% Evans blue. Gasograph apparatus was employed to measure CO2 produced by the Saccharomyces cerevisiae during fermentation. Microbial tests were carried out in order to count the number of yeasts colonies formed. Bread volume and height were assessed after baking process.
Baker’s yeast (A) had the highest number of green cells (177.8±7.36) and baker’s yeast (C) had the lowest number of green cells (102.2±8.97). The number of yeast colonies formed in baker’s yeast (A) was the highest (15×1010 cfu/mg) while the bakery’s yeast (C) was the least (12×1010 cfu/mg). Gasograph test showed that baker’s yeast (A) produced the highest amount of CO2 (163.3± 1.9 ml CO2/3h) and bakery’s yeast (C) produced the lowest amount during fermentation process (139.67±1.6 ml CO2/3h). Bread (A) produced the highest volume (132.22±1.0 cm3) and height (4.72±0.35 cm) while bread (C) had the lowest volume (108.33±6.21 cm3) and height (3.81± 0.3 cm).
The tests concerned indicated that high survivability and bioactivity of bakery’s yeast leads to more production of CO2 and higher volume and height of bread. The results showed a direct correlation between the percentage of live yeasts and ability of CO2 production. Utilization of EFLM can help to predict the bakery yeast bioactivity without the need for baking tests.

Heavy metals are important elements in the oil quality and determine the freshness, shelf life, storage ability and also affect the human health nutritionally. Therefore determination of heavy metals due to their effect concerned with the rate of oxidation is quite essential.
In this study, concentrations of heavy metals including Lead, Cadmium, Mercury and Arsenic during different stages of soya bean oil refining were studied using atomic absorption spectrometry.
The results indicated that the most common stage in Arsenic reduction is the neutralization stage that eliminates 60% of the total Arsenic content. The main stage in Cadmium reduction is the deodorization that reduces 40% of the initial Cadmium. Major part of Mercury reduction is concerned with metal scavenger addition that is referred to chelating activity of citric acid that might be added during bleaching and deodorization stages. Neutralization has separation role and causes the reduction of lead as soap.
The results showed that neutralization and the addition of scavengers are the main parts in heavy metals reduction.

Researchers are always looking for ways to maintain the food quality. In this study the effects of two types of packing (Conventional and Vacuum) and additives that contain oregano extract and sodium tripolyphosphate (2%) individually and in combination, were investigated on the quality of rainbow trout fillets without skin during 6 months of storage at -18 ° C.
This survey consisted of five treatments. Sampling were performed at 0 and 1, 2, 3, 4, 5 and 6 months to determine some chemical (thiobarbituric acid, free fatty acid and water holding capacity), sensory and tissue analyses.
Chemical examination of the samples indicated that conventional packing containing sodium tripolyphosphate and additive mixture with oregano had better performance in reducing thiobarbituric acid as well as good effect concerned with vacuum packing in respect of free fatty acids reduction as compared to the control. Dripping in tripolyphosphate treatment was lower than additive mixture. Treatment concerned with sodium tripolyphosphate indicated better results regarding sensory characteristics as compared to the treatment with added oregano extract and control.
The application of polyphosphate as an additive in vacuum packaging might be regarded as an effective method to maintain the quality of rainbow trout fillets stored at -18°C for 6 months.

Garlic increases the antioxidant levels of the body. The antioxidant defensive system in the body can reduce the oxidative stress and reduces the damage to the cells. The aim of this study is to investigate the effects of short-term supplementation of garlic on the total anti-oxidative capacity, malondialdehyde serum in active men after eccentric exercise.
Twenty healthy athlete males (age of 24 ± 3 years, body mass index of 24.4±1.3 kg.m-2, and VO2 max of 49.1±3.2 ml/kg/min) were randomly assigned to two equal groups: experimental (daily intake of 700 mg garlic capsules) and control (placebo) groups who used dextrose capsules for four weeks. The blood samples were taken at baseline, after completing a four-week period supplementation and after eccentric exercise (45 minutes of running with 9 set of 5-minutes with 80% oxygen consumption and 10% with a negative slope between each set of 2 minute active recovery with zero slopes). The parameters were analyzed using repeated measure ANOVA, Bonferroni, with a significance level of a=0.05.
Garlic supplementation for four weeks increased the total antioxidant capacity in the pre exercise (P Garlic supplementation might reduce oxidative stress damage by increasing of TAC after eccentric exercise in active men.

Oak treescover a vast area of Zagros forests. Acorn has numbers of nutritional characteristics and might be regarded as a good source of nutrition. The aim of this study is to describe the nutritional characteristics and physicochemical properties of acorn oil.
This research was carried out in Chaharmahal and Bakhtiari province. Fourteen trees were selected randomly, in different diameter classes in two groups of single stem trees and coppice shoots. Thirty acorns were harvested from each tree and dried in an oven at 80 °C for 2 days. The nutritional elements of the seed were measured and the oil was extracted by light petroleum ether employing soxhlet aparatus.
The results indicated that nitrogen was present at high concentration followed by some elements namely Potassium, Calcium, Iron and Manganese in respective decreasing order. The oil concentration of the fruit accounted for 8.56% and the fatty acid profile of the fatty acid of the oil indicated that the predominant fatty acid was the monounsaturated fatty acid (Oleic 49.4%) followed by polyunsaturated and saturated fatty acids in respective decreasing order.
Acorn of Persian Oak is important nutritionally and the oil contains an appreciable concentration of unsaturated fatty acids. Therefore, good management concerned with acorn harvesting and oil production might be required and essential.

Antimicrobial packaging is a new trend among various active packaging strategies with greater research focus in recent years. The concomitant use of nanoparticles and antimicrobial materials in food packaging is a new approach. Therefore, this study aimed at making a biofilm based on nanocomposites containing starch and cellulose nanoparticles in addition to garlic extract, which combines degradability and antimicrobial activity.
Garlic extract was extracted from fresh raw garlic and nanoparticles of cellulose and starch were synthesized biochemically. Scanning electron microscopy was used for characterization of the nanoparticles of cellulose and starch. By adding a mixture of three above materials to polyethylene polymer, a biofilm was prepared and its antimicrobial activity against two species of bacteria, yeast and mold was evaluated alone and in the presence of milk up to 6 weeks. Data were compared using student t-test.
A P value of The biofilm showed its greatest antimicrobial effects on E. coli (With an inhibition diameter of approximately 8.5 cm around the biofilm). Antimicrobial properties of biofilm in the presence of contaminated milk (As the packaging model of milk) were significantly higher in comparison to the control without any biofilm.
It is possible to have a suitable antimicrobial biofilm by using nanoparticles of starch, cellulose and garlic extract. The findings of the current study suggest a new approach for food packaging industries toward the use of biodegradable active packagings which ultimately lead to quality improvement, food safety and decrease in the amount of waste.

Apple is a unique fruit with valuable nutritional and health effect properties and has been employed in various food products and formulations. The aim of this project is to optimize the concentration of apple juice in yogurt.
The effect of different concentrations of apple juice (0, 5, 10 and 15 percent) to the milk to be used for yogurt making with different concentrations of dry matter (10, 12, 14 percent) on physicochemical and sensory properties during fourteen days of maintenance were investigated.
The results indicated decreases in the pH with increasing acidity in all the cases during storage. Incorporation of apple juice had significant effect (p Among the treatments, the one with intermediate values of the two variables was selected as the best treatment with the highest sensory scores.

Regarding the nutritional need for Celiac patients to use gluten-free diet, studies concerned with production to improve gluten-free products have been increased. The application of some ingredient as hydrocolloids is necessary due to low volume and weak texture in gluten-free products such as rice cake. This study is concerned with the application of hydrocolloids and its effect on the viscoelastic behavior of gluten-free rice cake.
The effect of guar and xanthan gums on viscoelastic properties of gluten-free rice cake using stress relaxation test has been investigated followed by modeling and fitting the experimental date using tow Peleg- Normand and extended Maxwell models.
The results showed that F0, K1, K2 and Maxwell model parameters decreased by increasing guar and xanthan gums. Therefore by adding guar and xanthan gums, the initial decay rate was decreased. According to SSE and R2 models it might be stated that the Peleg- Normand model can justify the stress Viscoelastic behavior in gluten-free cake as versus the time.
The application of guar and xanthan gums has improved the gluten-free cake considerably.