PUB - Publikationen an der Universität Bielefeld

The prevailing stigmatization of synthetic antioxidants and the inefficiency of endogenous antioxidants like tocopherols during high temperature processing of edible oils necessitate the search for effective natural antioxidants. Here, polyphenolic extracts from chokecherry and hawthorn fruits were screened for possible antioxidative application in fats/oils. Extracts were successively partitioned on sephadex columns and fractions were screened for radical scavenging activity using DPPH and beta-carotene assays. Furthermore, sunflower oil fortified with extracts was assessed for stability using accelerated storage at 65 degrees C, Rancimat at 120 degrees C. and frying at 180 degrees C. Phenolic extracts showed significantly high radical scavenging and antioxidant activity in the oil. At the end of storage, hydroperoxide formation in sunflower oil was reduced by up to 50%, and the induction period significantly increased in the presence of extracts. Similarly, a significantly high frying stability was observed for the fortified samples, suggesting that the phenolic extracts can offer effective natural alternative to synthetic antioxidants during frying. (C) 2014 Elsevier Ltd. All rights reserved.