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EFFECT OF METHYL JASMONATE ON PERICARP BROWNING OF POSTHARVEST LYCHEES
Author(s) -
YANG SHAOYU,
CHEN YULONG,
FENG LINYAN,
YANG EN,
SU XINGUO,
JIANG YUEMING
Publication year - 2011
Publication title -
journal of food processing and preservation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.511
H-Index - 48
eISSN - 1745-4549
pISSN - 0145-8892
DOI - 10.1111/j.1745-4549.2010.00483.x
Subject(s) - browning , polyphenol oxidase , chemistry , anthocyanin , postharvest , food science , methyl jasmonate , peroxidase , polyphenol , lipofuscin , phenylalanine , catechol oxidase , phenylalanine ammonia lyase , biochemistry , antioxidant , botany , enzyme , biology , gene , amino acid
The application of methyl jasmonate (MJ) for the control of pericarp browning of harvested lychees in relation to the levels of anthocyanins and (–)‐epicatechin was investigated. Lychees were dipped for 3 min in 0.6 µg/L MJ + 0.05% Sportak, 1 µg/L MJ + 0.05% Sportak, 5 µg/L MJ + 0.05% Sportak, 25 µg/L MJ + 0.05% Sportak or 0.05% Sportak (control). In this study, contents of anthocyanins (–)‐epicatechin and lipofuscin‐like substance, and browning index of harvested lychees during storage were determined. The activities of phenylalanine ammonia lyase (PAL), polyphenol oxidase and peroxidase were also measured. The treatment with MJ significantly maintained the contents of anthocyanins and (–)‐epicatechin, delayed the accumulation of lipofuscin‐like substance and extended the shelf life of lychees. Furthermore, MJ treatment increased PAL activity, which can account for the maintenance of anthocyanin or (–)‐epicatechin content. After these treatments, 1 µg/L MJ was effective in inhibiting pericarp browning and in maintaining the contents of anthocyanins and (–)‐epicatechin of lychees. Thus, it is suggested that maintenance of anthocyanin or (–)‐epicatechin contents could be an important factor for controlling pericarp browning of lychees during storage. PRACTICAL APPLICATIONS Lychees are highly perishable after harvest because of rapid skin browning as a result of anthocyanin degradation and (–)‐epicatechin oxidation by polyphenol oxidase or peroxidase in the presence of peroxides, and the subsequent accumulation of lipofuscin‐like substance, a final product of the autooxidation of lipid hydroperoxides, malondialdehydes and proteins of cells. This study exhibited that treatment with 1 µg/L methyl jasmonate (MJ) inhibited significantly the degradation of anthocyanins and the oxidation of (–)‐epicatechin, and delayed significantly the accumulation of lipofuscin‐like substance and pericarp browning of lychees. Therefore, application of MJ could be an important strategy to extend storage life and maintain the quality of harvested lychees based on the maintenance of anthocyanin or (–)‐epicatechin content.