Studies of the postharvest physiology, biochemistry and reductionof chilling injury by intermittent warming on peach
Shannuang Wang, Z. Huayun and P. Yuzhen
Proceedings of 26th International Horticultural Congress. Volume of Abstract . Toronto, Canada, 11-17 August, 2002. Abstract S09-P-135. pp. 257.
2002
บทคัดย่อ
If peaches are stored under low temperature for extended periods, they will develop chilling injury. Symptoms of chilling injury include: woolliness, loss of juice, browning, and insipid taste, which affect their commercial value. To prevent chilling injury, intermittent warming (W) was used where fruit were exposed for 24 hr at 20 0C following cold storage for 7 days, 14m days and 21 days. The results show that lW for 24 hr at 20 0C every seven days of storage can reduce chilling injury. However, the degree of fruit softening is high, which shortens the storage duration. Intermitten warming for 24 hr to 20 0C every 21 days does not reduce chilling injury. It appeared that chilling injury was irreversible if cold storage exceeded 14 days. In fruit with IW for 24 hr to 20 0C every fourteen days, during the period of storage, total soluble solids (TSS) increased over time. Titratable acidity (TA) decreased slowly and TSS: TA ratio was most similar with the optimal TSS: TA ratio. Water-soluble pectin increased, but protopectin and firmness of fruit decreased. These three physical indexes were linearly correlated. The activity of PE was inhibited, PG activity of PG did not change, and woolliness was not observed. The activity of perxidase and polyphenol oxidase increased slowly, and loss of polyphenols and browning of the flesh was observed. Lipid peroxidation, as measured by appearnce of MDA, and electrolyte leakage were lower in fruit with no chilling compared with chilling-injured fruit.