Comparison of the antioxidant activity of two Spanish onion varieties

Santas, J., Carbo, R., Gordon, M.H. and Almajano, M.P. (2008) Comparison of the antioxidant activity of two Spanish onion varieties. Food Chemistry, 107 (3). pp. 1210-1216. ISSN 0308-8146 doi: 10.1016/j.foodchem.2007.09.056

Abstract/Summary

Phenol content and antioxidant activity of two Spanish onion varieties, namely white onion and Calcot de Valls, have been studied. White onions contained higher phenol content than Calcot onions, with values which ranged from 2.57 +/- 0.51 to 6.53 +/- 0.16 mg gallic acid equivalents/g dry weight (GAE/g DW) and 0.51 +/- 0.22 to 2.58 +/- 0.16 mg GAE/g DW, respectively, depending on the solvent used. Higher phenol content was associated with higher antioxidant capacity. White onion extracts had the highest antioxidant activity at 86.6 +/- 2.97 and 29.9 +/- 2.49 mu mol Trolox/g DW for TEAC and FRAP assays, respectively, while the values for the Calcot variety were 17.5 +/- 0.46 and 16.1 +/- 0.10 mu mol Trolox/g DW. The antioxidant capacity of freeze dried powder from both onion varieties was also tested in sunflower oil-in-water emulsions, and hydroperoxide formation was monitored during storage at 40 degrees C. In accordance with differences in phenol content, Spanish white onions had better antioxidant activity.. while Calcot was only effective in the early stages of the oxidation process. (c) 2007 Elsevier Ltd. All rights reserved.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/13014
Item Type	Article
Refereed	Yes
Divisions	Life Sciences > School of Chemistry, Food and Pharmacy > Department of Food and Nutritional Sciences
Uncontrolled Keywords	white onion, Calcot, extraction, phenol content, antioxidant capacity, emulsion, peroxide value , RADICAL SCAVENGING ACTIVITY, RED ONIONS, EXTRACTS, FLAVONOIDS, VEGETABLES, CAPACITY, STORAGE, PLANTS, ASSAY, POWER
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