Chemistry and Reaction of Singlet Oxygen in Foods

TLDR

Singlet oxygen is a highly reactive, nonradical species distinct from triplet oxygen that drives undesirable oxidation in foods during processing and storage, contributing to flavor changes and nutrient losses. The study seeks to deepen knowledge of singlet oxygen’s formation, reactions, quenching mechanisms, and kinetics to improve food quality by minimizing oxidation during processing and storage. Photosensitizers generate singlet oxygen from triplet oxygen under light, while food antioxidants such as carotenoids and tocopherols can mitigate its oxidation. Singlet oxygen reacts with foods at a much higher rate than triplet oxygen because of its low activation energy, leading to significant oxidation.

Abstract

ABSTRACT Singlet oxygen is a highly reactive, electrophilic, and nonradical molecule. It is different from diradical triplet oxygen in its electron arrangement. Photosensitizers can form singlet oxygen from triplet oxygen in the presence of light. The reaction rate of singlet oxygen with foods is much greater than that of triplet oxygen due to the low activation energy. Singlet oxygen oxidation produces undesirable compounds in foods during processing and storage. However, carotenoids and tocopherols in foods can minimize singlet oxygen oxidation. The in‐depth scientific knowledge on the formation, reactions, quenching mechanisms, and kinetics of singlet oxygen can greatly improve the quality of foods by minimizing the oxidation during processing and storage. The single oxygen oxidation of foods has contributed to the explanation of several important chemical reactions in the reversion flavor in soybean oil, sunlight flavor in milk products, and the rapid losses of vitamin D, riboflavin, and ascorbic acid in milk under light storage.