XING-CUN YAO, SHENG-JUN WU*
*Corresponding author
School of Marine Science and Technology, Huaihai Institute of Technology, 59 Cangwu Road, Xinpu, 222005, China

Abstract

Glutathione is an effective reducing agent, while chitooligosaccharide has antibacterial activity. In this study, the efficacy of glutathione in combination with chitooligosaccharides as a preservative for use on apple slices was investigated. Browning, firmness, microbial population, and sensory property of the apple slices treated with glutathione in combination with chitooligosaccharide were monitored during hypothermia storage. 0.8% glutathione in combination with 1% chitooligosacchrides significantly inhibited browning formation after 14 days of hypothermia storage compared with that of the control (P < 0.05). Additionally, the apple slices treated with glutathione in combination with chitooligosaccharide maintained the firmness and inhibited the growth of the microorganism. Results indicate that the treatment developed in this study is a promising way to preserve apple slices.

INTRODUCTION

Fresh-cut apples have emerged as popular products for consumers who demand healthy alternatives to conventional snack foods and have been approved for school lunch programs (1). However, enzymatic browning in apple slices during storage decreases the commercial value of them (2, 3). Enzymatic browning reactions in fruits are primarily catalyzed by polyphenol oxidase (PPO) in the presence of oxygen and reducing substances (4). 

Many researchers have been focused on control of browning in apple and several approaches to browning inhibition have been reported (2-6). Inhibitors of enzymatic browning can be divided into six groups according to their different modes of action: reducing agents, chelating agents, complexing agents, acidulants, enzyme inhibitors, and enzyme treatments (7). Glutathione is a strong antioxidant and chelating agent, which has the ability to inhibit the activity of PPO and reduce oxygen, while chitooligosacchride has antibacterial activity.
Therefore, in this study, glutathione in combination with chitooligosacchrides was used to preserve apple slices during antibacterial storage. The aim of this study w ...