July 1/Food & Farm Week-- "To identify the potential of green leafy vegetables (GLV) as antioxidants, methanolic extracts of Amaranthus sp., Centella asiatica, Murraya koenigii and Trigonella foenum graecum were studied for their antioxidant activity in different systems at multiple concentrations. Total antioxidant activity assessed by phosphomolybdenum method, free radical scavenging activity by 1,1-diphenly-2-picryl hydrazyl (DPPH), reducing power and ferrous ion chelating activity were determined," scientists writing in the journalPlant Foods for Human Nutritionreport.
"The GLV were analyzed for ascorbic acid, total and beta-carotene and total polyphenol contents. The ascorbic acid, total carotene, beta-carotene and total phenolic content (tannic acid equivalents) of the GLV ranged between 15.18-101.36, 34.78-64.51, 4.23-8.84 and 150.0-387.50mg/100g GLV, respectively. The extracts were found to have significantly different levels of antioxidant activities in the systems tested. The total antioxidant activity was highest in Murraya koenigii (2,691.78 mu mol of ascorbic acid/g sample) and least in Centella asiatica (623.78 mu mol of ascorbic acid/g sample). The extract concentration causing 50% inhibition of DPPH (IC50) was determined (M. koenigii
The researchers concluded, "Multiple regression analysis showed that the relationship of total antioxidant activity, free radical scavenging activity, and reducing power with polyphenol and total and beta-carotene was highly significant."
Gupta and colleagues published their study in Plant Foods for Human Nutrition ("Studies on Indian Green Leafy Vegetables for Their Antioxidant Activity." Plant Foods for Human Nutrition, 2009;64(1):39-45).
Additional information can be obtained by contacting S. Gupta, University of Mysore, Dept. of Studies Food Science & Nutrition, Mysore 570006, Karnataka, India.
From the July 6, 2009, Prepared Foods E-dition