Effects of low temperature conditioning on chilling injury and quality of cold-stored juicy peach fruit

The effects of low temperature conditioning (LTC) in alleviating chilling injury of juicy peach fruit and its optimum conditions were investigated in this study. ‘Xiahui No.5’ peach fruit were pre-conditioned at temperatures of 4, 8 and 12℃ for 2, 4, 6, 8 and 10 days, respectively, and then transferred to 0℃ for 28 days followed by 3 days shelf life holding at 20℃. Fruit texture profile analysis and sensory evaluation were done and fruit quality parameters including surface color values, contents of soluble solids and titratable acids, internal browning index and percentage juice were also measured after 3 day shelf-life period. The results indicated that the control fruit directly stored at 0℃ without pre-conditioning developed chilling injury symptoms including flesh wooliness and internal browning after 28 days of storage. Fruit pre-conditioned at 4℃ also exhibited severe chilling injury manifested as flesh leatheriness. Severe internal browning was observed in fruit pre-conditioned at 8℃. LTC at 12℃ for 6 days was found most effective in inhibiting the development of flesh wooliness and internal browning and maintaining sensory quality. These results suggest that LTC at 12℃ for 6 days might be a useful technique to alleviate chilling injury and maintain peach fruit quality during cold storage.