جستجوی مقالات مرتبط با کلیدواژه « phenolic composition » در نشریات گروه « کشاورزی »

The medicinal plants are important sources of antioxidants. Natural antioxidants increase the antioxidant capacity of the plasma and reduce the risk of certain diseases such as cancer، heart diseases and stroke. Synthetic antioxidants commonly used in processed foods have side effects and are toxic. Therefore، there is a need for more effective، less toxic and cost effective antioxidants derived from medicinal plants. Saffron petal is a rich plant source of polyphenolic compounds. Hence، this research was conducted for studying the antioxidant properties and phenolic compositions of saffron petal. In this study، saffron petal extraction was prepared by ethanol، methanol (30، 70 and 90%) and water. The phenolic compositions were determined using Folin-ciocalteau method. In next step، antioxidant activity evaluated using generates free radical of DPPH. The results showed that the type and contents of solvent significantly affect the phenolic values and antioxidant activity. Also there was a significant relation between phenolic compound content and radical scavenging activity. Moreover، the antioxidant activity and phenolic compound concentration were increased by increasing solvent concentration. Finally، it was concluded that the ethanol extract could be considered as a effective solvent for the maximum extraction of phenolic compounds and antioxidant activity.

Alkaline treated raisin is one of the most important raisins produced from Bidaneh Sefid grape in large scale in Iran. In current research, effects of potassium carbonate on drying rate, antioxidant activity, total phenolics and color of raisin were investigated. Raisin was produced sun-dried (as control), cold and warm alkaline at four concentrations of 0.75, 1.5, 3 and 6 percent of potassium carbonate. Results indicated that by increasing concentration of potassium carbonate and using warm solution, drying time reduced. Furthermore, raisin pre-treatment highly affects on total phenolic content and antioxidant activity. The highest content of totol phenolic and antioxidant activity were observed in warm 6% potassium carbonate treated raisins. In addition, warm-alkaline treated raisin showed higher total phenolic and antioxidant activity in comparison to those of cold-alkaline treated raisins. Production method revealed a significant effect on color, drying rate and antioxidant properties of Bidaneh Sefid. It seems the higher speed of drying helped in marinating polyphenol content and higher antioxidant activity. Based on current result, pre-treatment of grape by warm potassium carbonate solutions at lower concentration is suggested for marinating phenolic compounds.