不同处理对采后“南果梨”贮藏期间果皮钙形态及褐变的影响

Effect of Different Postharvest Treatments on Peel Calcium Fractions and Browning of‘Nan Guo'Pear Fruit

以“南果梨”为试材,研究2%氯化钙处理、0.2%壳聚糖涂膜处理及2%柠檬酸处理对果实贮藏期间果皮褐变及钙形态的影响。结果表明：贮藏期间,氯化钙处理、壳聚糖涂膜处理、柠檬酸处理与对照相比显著提高了果皮中总钙含量,延缓了总钙含量的下降;果胶酸钙是果皮中的主要钙形态,约占全钙的53.4%~75.1%;氯化钙处理、壳聚糖涂膜处理和柠檬酸处理显著抑制了果皮中水溶性钙、果胶酸钙下降,促进草酸钙的增加;贮藏末期,氯化钙处理“南果梨”果皮褐变指数为5.556%、壳聚糖涂膜处理果皮褐变指数为16.667%、柠檬酸处理果皮褐变指数为25.000%,对照果皮褐变指数高达88.889%。相关性分析表明,果皮褐变与水溶性钙、果胶酸钙和草酸钙呈显著负相关,与磷酸钙呈显著正相关;氯化钙处理、壳聚糖涂膜处理和柠檬酸处理等3种处理都能通过控制可溶性钙向难溶性钙转变,抑制了果皮褐变的发生,其中以氯化钙处理效果最好。

The effect of postharvest treatments of 2% CaCI2 treatment,0. 2% chitosan coating treatment, 2% citric acid treatment on peel calcium fractions and browning of ＇Nan Guo＇pear were studied during storage, soaking with water as control. The results showed that the total calcium contents of 2% CaCl2,0. 2% chitosan coating treatment and 2% citric acid treatment treated fruits were higher than those of control respectively and delayed the decrease of total calcium content;pectin calcium was the main form of calcium in fruit,its content of total calcium accounted for 53. 4 %-75.1% ; treatments with 2 % CaCl2 treatment,0. 2% chitosan coating treatment and 2 % citric acid treatment inhibited the declines in water soluble calcium and pectin calcium,promoted the increase of calcium oxalate. The end of storage,incidence rate of pears treated with 2% CaCl2 treatment was 5. 556% ;incidence rate of pears treated with 0. 2% chitosan coating treatment was 16. 667% ;incidence rate of pears treated with 2 % citric acid treatment was 25. 000% ,while incidence rate of control fruit was 88. 889%. Correlation analysis showed that the content of water soluble calcium, pectin calcium and calcium oxalate were significantly positive correlation with browning, while the content of calcium phosphate was significantly negative correlation with browning. Treatments with 2 % CaCl2 treatment,0. 2 % chitosan coating treatment and 2 % citric acid treatment delayed peel browning by inhibiting the transformation of soluble calcium to insoluble calcium,and pears treated with 2℃.aC12 were the best