Influence of Polyphenol and Ascorbate Oxidases during Cooking Process on the Radical-Scavenging Activity of Vegetables

Abstract

The influence of polyphenol oxidase and ascorbate oxidase on radical-scavenging activity and contents of total phenol, chlorogenic acid, and ascorbic acid in vegetables during the cooking process were investigated. In the case of burdock and lettuce, which have a high activity of polyphenol oxidase, the radical-scavenging activity and the content of total phenol and chlorogenic acid decreased drastically within 1 min. In the case of broccoli, however, only a small decrease of radical-scavenging activity was observed, and total phenol and chlorogenic acid decreased almost not at all. The decrease of the activity in broccoli depended on the oxidation of ascorbic acid by ascorbate oxidase. None of these compounds decreased after the enzymes had been inactivated by heating.

Improvement of Postharvest Keeping Quality of Bell Pepper (Capsicum annum L.) Fruits Treated with Different Chemicals following Cold Storage

“…The control fruits exhibited the lowest mean total phenol (37.75 mg/100 g). This decrease is probably due to the oxidation by polyphenol oxidase (PPO) (Yamaguchi et al, 2003). Similar results have been reported in "Nangau" pear (Cheng et al, 2012) and strawberry fruits (Jiang et al, 2001;Tian et al, 2000).…”

Effect of three cooking methods on nutrient components and antioxidant capacities of bamboo shoot (Phyllostachys praecox C.D. Chu et C.S. Chao)

“…On the one hand, heat treatment had a decomposition effect on phenolic compounds (Ranilla et al, 2010), which also may have been lost to the solution, in which the bamboo shoots were boiled; on the other hand, heat treatment could make the existed polyphenol oxidases inactive so that prevented polyphenols' decomposition (Yamaguchi et al, 2003), and heat treatment could promote dietary fiber-binding type polyphenols decomposition into free phenolic compounds and then made the detected value much higher (Stewart et al, 2000). In contrast with fresh bamboo shoots, the antioxidant capacity of boiled samples reduced apparently, steamed ones remained unchanged, and stirfried ones increased slightly (Fig.…”

Effect of various anti-browning agents on phenolic compounds profile of fresh lettuce (L. sativa)

“…The amount of AA could be decreased during oxidation due to this reason (Yamaguchi et al, 2003). As a consequence, the assuring stability of AA during storage has been a major problem for preventing browning and phenol destruction.…”