Effect Of Pure Oxygen Atmosphere On Antioxidant Enzyme And Antioxidant Activity Of Harvested Litchi Fruit During Storage

FRIN-03358; No of Pages 7
Food Research International xxx (2010) xxx–xxx

Contents lists available at ScienceDirect

Food Research International
j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / f o o d r e s

Effect of pure oxygen atmosphere on antioxidant enzyme and antioxidant activity of harvested litchi fruit during storage
Xuewu Duan a,⁎, Ting Liu a,Dandan Zhang a, Xinguo Su a, Hetong Lin b, Yueming Jiang a
a b

Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, PR China College of Food Science, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China

a r t i c l e

i n f o

a b s t r a c t
The effects of pure oxygen onpericarp browning, reactive oxygen species (ROS) metabolism, antioxidant enzyme and antioxidant activity of harvested litchi fruit were investigated. Application of pure oxygen significantly prevented pericarp browning and delayed the increase in membrane permeability of litchi fruit during storage. Litchi fruit exposed to pure oxygen showed a lower level of lipid peroxides, compared to control fruit,with the delay in the increases of both H2O2 content and superoxide production rate. Furthermore, it was found that the treatment with pure oxygen induced the activities of superoxide dismutase (SOD), ascorbated peroxidase (APX) and catalase (CAT), which could be beneficial in scavenging of H2O2 and superoxide and alleviating lipid peroxidation. In addition, antioxidant ability (reducing power andfree-radical scavenging activity against DPPH radical, superoxide anions and hydroxyl radical) of methanol extracts from litchi fruit pericarp declined gradually, with decreasing contents of anthocyanins and phenolic compounds, as storage time of the fruit progressed. There was a linear relationship between the contents of either anthocyanins or phenolic compounds and antioxidant ability or freeradical scavenging activity. Treatment with pure oxygen markedly increased antioxidant ability, which was related to higher levels of anthocyanins and phenolic compounds, compared with those of control fruit. It is suggested that enhanced antioxidant activity and antioxidant enzyme induced by pure oxygen may contribute to alleviating lipid peroxidation and maintenance of membrane integrity, whichreduced decompartmentation of enzymes and substrates, resulting in enzymatic browning. © 2010 Elsevier Ltd. All rights reserved.

Article history: Received 11 September 2010 Accepted 17 October 2010 Available online xxxx Keywords: High oxygen Litchi fruit Pericarp browning Antioxidant

1. Introduction Litchi (Litchi chinensis Sonn.) is a non-climacteric subtropical fruit with high commercialvalue for its white translucent aril and attractive red peel color. However, harvested litchi fruit deteriorates rapidly due to pericarp browning, which leads to reduced market value (Jiang, Duan, Joyce, Zhang, & Li, 2004). Pericarp browning has mainly been attributed to degradation of red pigments and oxidation of phenolics by PPO (Jiang, Zauberman, & Fuchs, 1997; Lin et al., 1988; Zauberman etal., 1991; Zhang, Pang, Ji, & Jiang, 2001). Some reports have shown that lipid peroxidation, which reduced membrane fluidity and increased membrane permeability (Jiang et al., 2004; Lin et al., 1988; Liu, Jiang, Chen, Zhang, & Yi, 1991), might result in loss of compartmentalization between enzymes and their substrates and, thereby, may be responsible for enzymatic browning. Therefore, inhibiting lipidperoxidation could be an important method to delay pericarp browning and extend the storage life of litchi fruit.

⁎ Corresponding author. Tel.: +86 20 37252960; fax: +86 20 37252831. E-mail address: xwduan@scib.ac.cn (X. Duan). 0963-9969/$ – see front matter © 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.foodres.2010.10.027

Controlled atmosphere (CA) with low oxygen concentration...