Correlation of antioxidants and antioxidant enzymes to oxygen radical scavenging activities in berries

Abstract

Berry fruits contain high levels of antioxidant compounds. In addition to the usual nutrients such as vitamins and minerals, berry fruits are also rich in flavonols, anthocyanidins, proanthocyanidins, catechins, flavones, and glycosides. These antioxidants are capable of performing a number of functions including free radical scavenging, peroxide decomposition, singlet and triplet oxygen quenching, enzyme inhibition, and synergism. Some antioxidants exhibit additive and synergistic effects; therefore, a single phytochemical alone usually is not a good index to reflect antioxidant activity. A positive correlation was found between antioxidant activity and antioxidant enzyme activity, and phenolic content and anthocyanin content. In general, antioxidant values are highly correlated with total phenol content, whereas a smaller linear correlation exists between antioxidant capacity and total anthocyanin content. Genotype variation, the degree of maturity at harvest, different parts of fruit tissues, preharvest conditions, and postharvest handling techniques could all affect the antioxidant profiles. This chapter discusses the factors affecting antioxidants, antioxidant enzymes, oxygen radical scavenging activities and their correlations in berry fruits. © 2011 Springer Science+Business Media, LLC.