热调和间隙加温对桃果实冷害和果胶酶的影响(英文)

Effect of heat conditioning and intermittent warming on chilling injury and pectolytic enzymes in peaches

白凤’桃果实在 0℃下贮藏 2 9d再在 2 0℃下完熟 4 d后 ,近 86%的果实会出现不同程度的絮败。果实在冷藏前先在 35℃中存放 4 8h(热调 ) ,或冷藏期间每隔 9d在 2 0℃中存放 2 4 h(间隙加温 ) ,均能有效地减缓果实的絮败 ,但是这些处理也会造成果实软化或品质降低。发生絮败的果肉颜色并未明显褐变 ,但果肉硬度却维持在较高的水平上 ,这成为果实絮败的一个典型特征。果实的出汁率与絮败发生率呈明显负相关。常规冷藏的果实 ,无论是在冷藏的过程中 ,还是在随后的完熟期间 ,其内切 PG的活性较低。热调和间隙加温处理均能提高 PE、内切 PG和外切 PG的活性 ,第二次间隙加温的效果尤为显著。上述结果证实 ,桃果实的冷害与内切 PG活性的下降有着密切的联系。

About 86% peach fruit ( Prunus persica , cv Baifeng) became woolly during a ripening period of 4 d at 20 ℃ following 29 d of cold storage at 0 ℃ Conditioning at 35 ℃ for 48 h prior to cold storage or warming at 20 ℃ for 24 h every 9 d of cold storage was highly effective in alleviating woolliness, although low sensory quality or flesh softening also occurred Browning was not always accompanied with the development of woolliness, but retention of flesh firmness was a typical woolliness symptom Extractable juice content was highly negatively correlated with the incidence of woolliness Endo PG activity in fruit cold stored immediately and continuously after harvest was low throughout storage and the subsequent ripening period Both heat conditioning and intermittent warming enhanced PE, endo PG and exo PG activities, with the second intermittent warming being the most effective Chilling injury development appeared to be associated with reduced endo PG activity