Understanding antioxidant mechanisms in preventing oxidation in foods - Oxidation in Foods and Beverages and Antioxidant Applications - page 223

10
Understanding antioxidant mechanisms
in preventing oxidation in foods
E. A. Decker, B. Chen and A. Panya, University of Massachusetts,
USA and R. J. Elias, The Pennsylvania State University, USA
Abstract: Many foods are becoming more susceptible to oxidative rancidity
due to attempts to make foods healthier by increasing polyunsaturated fatty
acids, and more sustainable by introducing light weight oxygen-permeable
and light-penetrating packaging. Unfortunately, very few new food
antioxidants have been made available over the past several decades and the
use of synthetic antioxidants is disfavored by many consumers. Thus, in
order to make natural, more sustainable and healthier foods, the food
technologist must find ways to use existing antioxidants more effectively.
This requires a strong understanding of antioxidant chemistry. This chapter
reviews the chemistry of free radical scavengers, metal chelators, singlet
oxygen quenchers and antioxidant enzymes. Interactions between
antioxidants to enhance activity are also discussed.
Key words: antioxidants, free radical scavengers, chain breaking
antioxidants, metal chelators, singlet oxygen quenchers, synergistic
antioxidant activity, tocopherol, ascorbic acid, carotenoids, BHA, BHT,
TBHQ, propyl gallate, EDTA, polyphosphates, citric acid, antioxidant
interactions.
10.1 Introduction
The oxidative susceptibility of foods is increasing due to factors such as removal
of hydrogenated oils, use of light weight oxygen-permeable and light-
penetrating packaging and inclusion of bioactive polyunsaturated fatty acids.
Therefore, new antioxidant technologies are needed to make lipid-containing