不同可溶性固形物含量玉露香梨冷藏期抗氧化能力的变化

Changes in Antioxidant Capacity of'Yuluxiang'Pear with Different Soluble Solid Content during Cold Storage

基于不同可溶性固形物含量(soluble solid content,SSC)玉露香梨冷藏过程中果心酚类物质含量及抗氧性的变化,探讨玉露香梨中长期贮藏品质的控制方法。利用近红外水果无损检测仪构建的模型分选出3组不同SSC的玉露香梨,置于0℃下贮藏,分析果实品质、果心酚类物质及抗氧化能力等相关指标的变化。结果表明:Ⅰ组(SSC<11.0%)的玉露香梨采后果心绿原酸、熊果苷含量较其他2组高,冷藏后期抗氧化能力较低,果心褐变指数较Ⅱ组(SSC:11.0%~13.0%)和Ⅲ组(SSC>13.0%)的玉露香梨高。冷藏240 d,Ⅱ组的玉露香梨果实硬度、可滴定酸含量较高,可延缓过氧化物酶活性的下降及过氧化氢酶活性峰值的出现;DPPH自由基清除率及铁离子还原能力较高,可延缓氧化的过程。综上,可溶性固形物含量为11.0%~13.0%的玉露香梨在冷藏中保持较好的果实品质及抗氧化性,果心褐变程度低,可作为中长期冷藏玉露香梨参考的采收品质指标之一。

Based on the changes in phenolic content and antioxidant resistance in the core of the'Yuluxiang'pear with different soluble solid content(SSC)during cold storage,the quality control of the'Yuluxiang'pear during medium and long⁃term storage was discussed.Three groups of'Yuluxiang'pear with different SSC were selected by the model built by the near⁃infrared fruit nondestructive detector.The pears were stored at 0℃to analyze the changes in fruit quality,phenolic substances,and antioxidant capacity.The results showed that the content of chlorogenic acid and arbutin in the fruit core of group I(SSC<11.0%)was higher than that of the other two groups after harvest.The antioxidant capacity was lower in the late cold storage period.The core browning index was higher than that of group II(SSC:11.0%-13.0%)and group III(SSC>13.0%).By com⁃parison,after 240⁃day cold storage,the fruits firmness and titratable acid of group II remained high,which de⁃layed the decline of peroxidase activity and the emergence of peak catalase activity.Higher DPPH free radical scavenging rate and FRAP antioxidant capacity delayed the process of oxidation.In conclusion,'Yuluxiang'pear with SSC ranging from 11.0%to 13.0%maintained good fruit quality and antioxidant activity during cold storage.With a lower degree of core browning,it can be used as one of the reference harvest quality indicators for medium and long⁃term cold storage of'Yuluxiang'pear.