Optimum conditions of hot air treatment for inducing chilling tolerance of Chinese olive fruits during cold storage

In order to develop technology for inducing chilling tolerance and alleviating chilling injury of Chinese olive （Canarium album (Lour.) Raeusch）fruits during cold storage, freshly harvested ‘Tanxiang’ Chinese olive（Canarium album (Lour.) Raeusch cv. Tanxiang）fruits were pre-treated with hot air at 30℃ for 45?minutes, 38℃ for 30 minutes, 40℃ for 30 minutes, 42℃ for 45 minutes, 50℃ for 15 minutes and 60℃ for 15 minutes, respectively, which were based on the preliminary studies of hot air conditions for alleviating chilling injury of cold-stored Chinese olive fruits, then the treated fruits stored at (2±1)℃ and 90% relative humidity for 100 days. During fruit storage, chilling injury index of fruit, browning index of pericarp, browning degree of pulp, content of pericarp chlorophyll, respiration rate and cell membrane relative leakage rate of fruit were determined. The results showed that pre-treated with hot air at 38℃ for 30 minutes could significantly decrease chilling injury of cold-stored Chinese olive fruits. There was a certain effect of alleviating chilling injury of cold-stored Chinese olive fruits when the fruit pre-treated with hot air at 30℃ for 45 minutes, while pre-treated with hot air at 30℃ for 45 minutes could accelerate the degradation of pericarp chlorophyll and promote the disruption of the integrity of cellular membrane structure of Chinese olive fruits during cold storage. Whereas, pre-treated with the other four kinds of hot air conditions could promote the occurrence of chilling injury of cold-stored Chinese olive fruits. From the results, it could conclude that pre-treated with hot air at 38℃ for 30 minutes could be used as the optimum conditions of hot air treatment for inducing chilling tolerance and alleviating chilling injury of Chinese olive fruits during storage at (2±1)℃ and 90% relative humidity.