Articles
RELATIVE HUMIDITY INFLUENCES PERICARP BROWNING OF LITCHI CV. ´HONG HUAY´
Article number
712_107
Pages
823 – 828
Language
English
Abstract
Pericarp browning of litchi fruit cv. Hong Huay at different relative humidities (RH) was investigated.
The fruit were stored 20°C with 50%, 70%, 80% or 90% RH. Browning of fruit pericarp occurred most rapidly at 50% RH and least at 90% RH. Severe browning developed after 3 days at 50% RH and 10 days at 90% RH. Fruits held at 70% or 80% RH had intermediate rates of browning development which became severe after 7 and 9 days storage, respectively.
Increases in hue and decreases in a* values corresponded to the browning response to RH. Similarly, increases in water and weight losses were most rapid at 50% RH and least at 90% RH. Anthocyanin and phenolics contents decreased with storage at a faster rate at lower RH than at higher RH. Polyphenol oxidase (PPO) showed a dramatic rise at 50% RH while at 90% RH, no distinct increase was noted.
At 70-80% RH, PPO activity manifested a slowly increasing trend.
On the other hand, phenylalanine ammonia lyase (PAL) activity decreased with storage.
However, fruits held at 50% RH showed higher PAL activity than that of fruits held at higher RH. The results suggest that both physical and biochemical processes regulated pericarp browning.
The fruit were stored 20°C with 50%, 70%, 80% or 90% RH. Browning of fruit pericarp occurred most rapidly at 50% RH and least at 90% RH. Severe browning developed after 3 days at 50% RH and 10 days at 90% RH. Fruits held at 70% or 80% RH had intermediate rates of browning development which became severe after 7 and 9 days storage, respectively.
Increases in hue and decreases in a* values corresponded to the browning response to RH. Similarly, increases in water and weight losses were most rapid at 50% RH and least at 90% RH. Anthocyanin and phenolics contents decreased with storage at a faster rate at lower RH than at higher RH. Polyphenol oxidase (PPO) showed a dramatic rise at 50% RH while at 90% RH, no distinct increase was noted.
At 70-80% RH, PPO activity manifested a slowly increasing trend.
On the other hand, phenylalanine ammonia lyase (PAL) activity decreased with storage.
However, fruits held at 50% RH showed higher PAL activity than that of fruits held at higher RH. The results suggest that both physical and biochemical processes regulated pericarp browning.
Authors
R. Kaewchana, W. Nivomlao, S. Kanlavanarat
Keywords
Litchi (Litchi chinensis Sonn.), high humidity storage, pericarp browning, phenolics metabolism
Online Articles (123)