Effects of hot water treatment to alleviate chilling injury and enhance phenolic metabolism in eggplant fruit during low temperature storage

Eggplant (Solanum melongena L.) fruit is highly perishable vegetable due to rapid quality deterioration when stored under ambient temperature. The current handling and storage temperatures, below optimum storage temperature (<10 degrees C), extend the storage life, but chilling injury (CI) occurs after a longer storage. In this study, the effects of pre-storage hot water dipping at 45 degrees C hot water for 10 min on alleviation of CI and enhancement of phenolic metabolism in cold stored eggplant fruit for 15 d were investigated. Fruit stored at 10 degrees C showed no CI and maintained fruit quality, while non-treated fruits stored at 1 degrees C indicated severe CI. Hot water treatment alleviated CI incidence and inhibited the increases in malondialdehyde and hydrogen peroxide levels, and enhanced phenolic metabolism by increases of total phenolic levels and phenylalanine ammonia-lyase activities compared with the non-treated fruits during storage at 1 degrees C. These results indicate that the alleviation of CI in eggplant fruit by hot water treatment at 45 degrees C for 10 min might be due to the increase of antioxidant activity by enhancement in phenolic metabolism.