The aim of this study was to investigate the effect of using portulaca oleracea as a source of plant antioxidants for feeding fattening male lambs, on carcass traits, meat quality, and oxidative stability. Twenty-one male lambs with an average weight of 24±1.5 kg and 150±15 days old were fed with one of the experimental rations included a diet without portulaca oleracea as control, a diet containing 7.5%, and a diet containing 15% portulaca oleracea, for 84 days. The muscle (Longissimus dorsi) samplewas used to determine pH, chemical composition, colorimetric properties, and oxidative stability of meat. Meat lipid oxidation was determined after 1, 7, and 30 days of refrigerated storage using thiobarbituric acid (TBARS). The use of portulaca oleracea in diets improved meat color characteristics such as L, chroma, and Hue. The highest ash concentration and the lowest meat moisture were observed in the treatment of 15% portulaca oleracea (P<0.05). Meat pH was the lowest in the first hour after slaughter but did not differ at 24 h. Compared to the control, in both treatment groups feeding the lambs with portulaca significantly reduced the concentration of Malondialdehyde in the meat of the lambs and increased the meat oxidative stability (P<0.05). The results of this experiment showed that feeding portulaca oleracea by improving properties such as color and increasing the meat oxidative stability improves meat quality, which may have lead to an increase in its nutritional value in terms of human health.

Oxidation of bread lipids during baking and storage reduces the nutritional value of the product and leads to the formation of off-flavors and off-odors. In this research, oxidative stability of rice bran, corn, canola, sunflower and soybean oils during Brotchen bread baking process and storage was evaluated. Baking process caused a significant increase in oxidative indices such as peroxide, anisidine, Totox and thiobarbitoric acid values and free fatty acid content. However, storage of breads for 6 days in room temperature did not affect the value of the indices. Generaly, the value of the indices in bread containing rice bran oil was lower than those of the other breads, which indicated the higher oxidative stability of rice bran oil in baking process and storage. Pure oils treated in simulated baking process and storage had an oxidative quality similar to that of breads. This means that bread ingridients may not have an effect on oil oxidative stability. Bread containing rice bran oil gained also higher scores in sensory evaluation, which of course were in agree with its better oxidative status.

IntroductionToday, many edible oils such as palms, corn, soybeans and sunflowers are used in food preparation. Essential oleic, linoleic and linolenic fatty acids, found abundantly in olive, sunflower and soybean oils, respectively, play an important role in maintaining health. Antioxidant compounds are used to increase the shelf life of oils, which are classified into two groups of natural and synthetic antioxidants based on the source of production. Phenolic acids are a subset of a large group of phenolic compounds that are used as natural antioxidants in industry. Gallic acid is much stronger than protocatchuic acid due to its three hydroxyl groups. However, the presence of more than three hydroxyl groups does not seem to increase the antioxidant effect in oily systems. The position of the hydroxyl group on the aromatic ring also affects the antioxidant activity, so that the replacement of the hydroxyl group in the ortho and para position increases the antioxidant activity of phenolic acids. Methyl gallate, which is widely found in plants and polyphenolic secondary metabolites, is a natural antioxidant. Despite efforts to date, no suitable natural antioxidant has been proposed to control the thermal oxidation of oils at high temperatures. Therefore, due to the widespread use of oils in food, the thermal stability of natural antioxidants gallic acid and methyl-gallate compared to the powerful but synthetic antioxidant TBHQ, depending on the degree of satiety of the lipid system (sunflower oil and olive oil) and 80 degrees Celsius will be evaluated in this study. Material and MethodsSamples of sunflower and olive oil were purchased from local stores. All chemicals and solvents were provided by Merck and Charlot. Sunflower and olive oil were purified by column chromatography to remove natural antioxidants. Oxidation of purified sunflower oil (1 g per oil) in the presence of a concentration level of gallic acid, methyl gallate and TBHQ (1.2 μmol/g) in glass bottles. The rate of progression of oxidative reactions and the evaluation of oil quality during temperature application is possible by measuring the peroxide number. The carbonyl number is determined using 2-propanol as solvent and 2,4 decodenal as standard and absorbance at 420 nm. The effect of antioxidants (InH) on the oxidation of the test samples can be measured based on the kinetic parameters. These parameters are stability factor F, ORR oxidation rate ratio, activity A and average consumption of WInH antioxidants. Results and DiscussionThe minimum and maximum induction times are related to the control sample and the sample containing the synthetic antioxidant TBHQ, respectively, which, considering the position of the two hydroxyl groups in the para position relative to each other in the TBHQ molecule, make this antioxidant stronger. Justifies. At 80 °C and in sunflower oil, the antioxidant methyl gallate shows a more effective stability factor (F) and antioxidant activity (A), indicating greater antioxidant power than gallic acid. Similarly, F-ORR-A values in methylgalate treatment have a significant effectiveness compared to other treatments. The higher oxidative stability of olive oil against sunflower oils can be attributed to the small amounts of oleic acid and especially the small amounts of linolenic acid in olives. Stability factor (F), is significantly higher for the TBHQ antioxidant than the values obtained for the other two. This factor is affected by the induction period of antioxidants and can be expected due to the effectiveness of antioxidants in increasing the duration of the induction period. The highest value obtained for the ORR oxidation rate parameter, is related to the antioxidant gallic acid. The parameter of antioxidant activity A, in TBHQ is higher than the other two antioxidants. Measurement of carbonyl compounds resulting from the decomposition of hydroperoxides is a good measure of the rate of development of oxidative reactions. In the treatment of gallic acid and TBHQ, the changes in the carbonyl number decrease at the end of the annealing, which is probably due to the decomposition of carbonyl compounds and the production of polymer compounds. Which cannot be measured by carbonyl number test. ConclusionBetter efficacy of gallic acid compared to methyl gallate in olive oil and better efficacy of methyl gallate compared to gallic acid in sunflower oil at 80 °C show the composition of fatty acids, the nature of lipid systems and the position of antioxidants in the reaction medium. Have a great effect on improving the performance of antioxidants. Determination of oxidative stability based on carbonyl number shows similar results to peroxide number .

Oil in foodstuff deep frying heated to a long time and effect of some factors (humidity, temperature and oxygen) cause different chemical and physical changes of the oil (such as hydrolysis, oxidation and polymerization) and degrade the quality of the oil and product. The results of these changes increase of the free fatty acids, peroxide value, polar compounds and trans isomers, and also decrease of the unsaturated fatty acids, oxidation induction time, levels of tochopherol and phenolic compounds, which all indicate a decline the oil quality. Studies shows that the chemical composition of oil and especially natural antioxidants are important parameters in predictive the behavior of oil in the frying process. Independently to the commercial category of olive oil, is clearly resistant against the deep frying. In this paper, the oxidative stability of oil during frying according to the source, the presence of natural bioactive compounds (antioxidants) and fatty acid composition have been compared with olive oil.

This paper presents a new composite index to analyze power system transient stability. Contingency ranking in power system transient stability is a complicated and time consuming task. To prevail over this difficulty, various indices are used. These indices are based on the concept of coherency, transient energy conversion between kinetic and potential energy and three dot products of the system variables. It is well known that some indices work better than others for a particular power system. This paper along with test results using two practical 230 kV Sistan and 400 kV Khorasan power system in Iran, and 9 bus IEEE test system demonstrates that combination of indices provides better ranking than a single one. In this paper two composite indices (CI) is presented and compared. One composite index is based on Least Mean Square algorithm (LMS) and other based on summing indices by equal weights. Numerical simulations of the developed index, demonstrate that composite index is more effective than other indices.      

Quinoa is known as a suitable plant in adverse environmental conditions due to its desirable nutritional value and high production potential such a country like Iran, which has a climate diversity, it will create food security, increase farmers'''' incomes and sustainable production. To study the genotype and environment interaction and determine the stability and adaptability of grain yield of quinoa genotypes in different regions of Iran, ten genotypes were evaluated in a randomized complete block design with three replications in four regions of Karaj, Shahrekord, Urmia, and Kashmar during 2017-2018 cropping season. The studied genotypes included Titicaca, Red Carina, Giza1, Q12, Q18, Q21, Q22, Q26, Q29, and Q31. The results of the combined analysis of variance showed that the effect of environment and the genotype and environment interaction on the grain yield were significant (p≤0.01). The highest grain yield in Karaj and Shahrekord (717 and 2196 kg.ha-1, respectively) was obtained by the Q26 genotype and in Urmia and Kashmar (1614 and 829 kg.ha-1, respectively) by the Q18 and Titicaca genotypes, respectively. According to the results of stability and compatibility analysis with different methods and indices (parametric and non-parametric), the Red Carina genotype was identified as a genotype with suitable and stable yield and compatible with the study areas, with 996 kg.ha-1 grain yield higher than the average yield of all genotypes (939 kg.ha-1), the highest rank of simultaneous selection index for yield and stability, the lowest mean rank (1.56), and the minimum standard deviation of rank (SD = 1.03).

This study was aimed to fabricate O/W emulsions of Descurainia Sophia seeds oil in order to be stabilized against oxidation. Response surface methodology (RSM) was used to optimizing the process in which the gum Arabic (GA), whey protein concentrate (WPC), and sonication time were selected as independent variables where the peroxide value (meq/kg oil) was considered as a response factor. The optimum point was obtained when the WPC, and GA, and ultrasound treatment time were as 19. 78%, 11. 08%, and 0. 1 s, respectively. In the associated optimum point, peroxide value was determined as 0. 59 meq/kg oil. The emulsion oil droplets varied dependently to ultrasound time and WPC concentration which both decreased the oil droplets sizes with more exposing and high concentration inclusion. Conversely, ultrasound applying resulted in higher peroxide values at the instantaneous determinations. The optimum emulsion indicated 916 nm with the-48 mV Zeta potential. The respective sample exhibited shear thinning behavior which more effectively attributed to WPC existence. Oxidation stability of the emulsion samples compared with crude oil and the oil treated with 30 s ultrasound. The results indicated that the GA and WPC effectively preserved the oil during 28 d at the intensifying circumstances (50 ° C) and the free oils were oxidized more intensively. GA due to steric repulsion structure forming in the vicinity of oil droplets and WPC due to electrostatic repulsion, produced a complex biopolymer structure which had potentially antioxidant and coating attributes.

Walnut (Juglans regia L. ) is a tree with significant economic value and usage for human health and various food industries. However, fresh walnut kernels are a less widespread product than the dried kernels. This study aimed to determine the fresh walnut kernel properties including, fatty acid composition, proximate composition, total phenolics (TPs), total antioxidant capacity (TAC), acidic, peroxide and saponification values of extracted oil and minerals of fresh walnuts kernels. Green walnut fruits were harvested on commercial maturity. The content of different fatty acids (%) was determined as 16: 0; 5. 91, 18: 1; 77. 7, 18. 2; 11. 13 and 18: 3; 2. 84. Also, the essential nutritional compounds such as protein content (16 ± 0. 67), ash (3± 0. 32), water (20 ± 0. 49), fat (40 ± 0. 22) and total carbohydrate (21 ± 0. 23) were quantified and reported in percentages. The energy content was 508 ± 0. 48 kcal. Acidic values, peroxide values and saponification values in walnut oil were 3 ± 0. 14, 0. 3 ± 0. 06 and 130 ± 0. 54 respectively. Furthermore, the average mineral contents were also determined. In general, it can be claimed that fresh walnuts have significant amounts of protein, oil and minerals, and higher water content in comparison with dry nuts. Nonetheless, our results in comparison with the information available about dry walnuts showed that fresh walnuts contained less oil content compared to dried fruits.