جستجوی مقالات مرتبط با کلیدواژه "oxidant activity" در نشریات گروه "پزشکی"

Recently, an increased demand for nondairy probiotic products comes from the popularity of vegetarianism, lactose intolerance, and high cholesterol content in dairy products. The objective of this study is evaluating the effect of refrigerated study on the viability of probiotics and some physicochemical characteristics in cornelian cherry juice. Cornelian cherry juice with natural and adjusted pH with sodium bicarbonate was inoculated with three industrial bacteria (L. rhamnosus, L. plantarom and L. casei) and two native probiotic bacteria (L. casei) (108 cfu/ml). Then the samples were placed in the refrigerator (4°C) immediately after inoculation. Next, the changes in chemical characteristics such as pH, acidity, phenolic compounds content, anthocyanin content, antioxidant activity, microbial characteristics (such as enumeration of live probiotic cells), and sensory properties were evaluated during 4 weeks with the time intervals of one week for the samples with adjusted pH. Significant differences between the averages of obtained data were checked by one way ANOVA test. Also differences between the averages of each treatment during the refrigerating time were examined by repeated measure test using SPSS software at the significant level of 0.05. Data analysis showed that treatment type, storage period and interaction effect of these two factors have significant effects on the changes of physicochemical characteristics and probiotic viability (P<0.05). The results revealed that native probiotic strain L. casei spp. T4 compared to other strains maintained its viability at 8.67 log cfu/ml after 4 weeks of refrigerated storage. Also there were the most changes in physicochemical characteristics in the cornelian cherry treatments containing this strain, which is a marker of fermentative activity during the refrigerated storage. The results showed that cornelian cherry juice because of low pH and presence of inhibitor phenolic compounds has negative effect on viability of probiotics, especially industrial strains during the refrigerated storage.

Anti-oxidant compounds prevent prevalence of chronic diseases and food spoiling. The aim of this study was to evaluate the total phenolic and flavonoid content and antioxidant activity of beech and oak barks.

In this experimental study، the skin of beech and oak trees were prepared and then acetone extraction was obtained using Soxhle method. At the beginning، total phenol and flavonoid of extracts were determined and the anti-oxidant properties of the extracts were then evaluated by three methods (methods Biphenyl Pykryl Hydrosol، regenerative power produced- and nitric oxide).

The amount of phenolic was higher in bark of beech trees، but flavonoids were higher in oaks. The result of test to trap free radicals of Biphenyl Pykryl Hydrazyl showed the inhibitory concentration 50% of acetone extract of the bark of beech and oak، were 92. 19 and 33. 7 mg/L respectively. Beech extracts had greater regenerative power than oak. In Nitric oxide trap test acetone extract inhibited 50% in bark of beech trees was 98/23 and the oak extract was 92/90 mg/L respectively.

Acetone extract of the bark in three models showed varying degrees of anti - oxidant activity. Beech extract had better antioxidant activity compared with oak extract.