黄冠梨采后1-MCP和CaCl2处理对品质和果皮褐斑发生的影响

 对采后黄冠梨进行1 000 nL · L^-1 1-MCP 熏蒸（1-MCP）、4% CaCl₂（Ca）浸泡和二者结合（1-MCP +Ca）处理，结果表明，与对照（未进行1-MCP、Ca 处理）相比，Ca、1-MCP 和1-MCP + Ca 各处理保持了冷藏期间黄冠梨果实较高的硬度、可滴定酸和叶绿素含量，降低了果皮褐斑指数，但对可溶性固形物和维生素C 含量影响较小，并不同程度降低了果实的乙烯释放速率峰值，还显著降低了果皮可溶性酚含量和多酚氧化酶（PPO）活性，抑制果皮细胞膜透性和H₂O₂ 含量的升高，但对呼吸速率的影响较小。Ca、1-MCP + Ca 处理显著提高了果皮和果肉中钙含量。综合看来，以1-MCP + Ca 处理对维持冷藏期间果实品质的效果最好。1-MCP 和Ca（主要是Ca）抑制果皮酚类物质生成和维持细胞膜结构的完整性是其明显减少黄冠梨果皮褐斑的重要原因。

Effects of Postharvest 1-MCP and Calcium Treatments on the Quality and Skin Browning Spot Incidence of Huangguan Pear Fruit

Treatments of 1 000 nL·L~(-1) 1-MCP fumigation(1-MCP),4%CaCl_2 dip(Ca)and the combination of 1-MCP and Ca(1-MCP+Ca)were applied to harvested Huangguan pear fruits.The results showed that compared with control(without 1-MCP or Ca treatment),treatments of Ca,1-MCP and1-MCP+Ca maintained the higher firmness,titratable acid(TA)and chlorophyll contents,reduced the skin browning spot index,had slight effect on contents of total soluble solid(TSS)and vitamin C of fruits,also decreased peak value of ethylene production rate more or less,reduced soluble polyphenol content and polyphenoloxidase(PPO)activity markedly,and suppressed the rise of cell membrane permeability and H2O2 content of peel.But it had no obvious effect on the respiratory rate of fruits.Treatments of Ca and 1-MCP+Ca significantly increased Ca content of peel and flesh of fruits.On the whole,1-MCP+Ca was the most effective way to keep fruit quality in all treatments.It indicated that inhibiting the productionof the polyphenol substances and keeping integrity of cell membrane structure should be an important cause for 1-MCP and Ca treatments,mainly Ca,to reduce the browning spot of peel in Huangguan pear fruits significantly.