不同贮藏温度对百香果果实糖酸组分变化的影响

Effect of Different Storage Temperatures on the Sugar and Acid Components of Passion Fruit

为研究不同贮藏温度对百香果果实采后贮藏过程中的糖酸组分变化及相关酶活性变化的影响,本研究以紫果1号百香果为试材,采后分别贮藏于不同温度(5、15和25℃),通过测定可溶性固形物(TSS)、可滴定酸(TA)、有机酸、可溶性糖和糖代谢相关酶活性指标,分析不同贮藏温度对百香果糖酸组分变化的影响。结果表明,贮藏8 d时,5℃下百香果果实中的苹果酸、α-酮戊二酸和抗坏血酸显著高于15和25℃(P<0.05),说明低温可以有效抑制苹果酸、α-酮戊二酸和抗坏血酸的降解,进而维持较高的TA含量;贮藏8 d时,5℃下百香果果实中的蔗糖含量显著高于15和25℃(P<0.05),说明低温可以有效抑制蔗糖的降解,进而维持较高的TSS含量。相关性和主成分分析表明,低温可通过显著影响酸性转化酶(AI)的活性(P<0.05)抑制蔗糖分解。由此推测,AI可调控百香果果实贮藏过程中蔗糖向葡萄糖和果糖的降解,进而起到维持百香果品质的作用。本试验结果可为进一步解析百香果果实糖酸代谢的机制研究提供理论依据。

To study the effects of storage temperatures on the changes of sugar and acid components and related enzyme activities of passion fruit during postharvest storage,passion fruit Ziguo No.1 was stored at different temperatures(5,15 and 25℃).Soluble solids(TSS),titratable acid(TA),organic acids,soluble sugar,and enzyme activities related to sugar metabolism were measured.Malic acid,α-ketoglutarate,and ascorbic acid in passion fruit were significantly higher than those stored at 15 and 25℃at 5℃after 8 days’storage(P<0.05),which indicated that low temperature could effectively inhibit the degradation of malic acid,α-ketoglutarate,and ascorbic acid,thus maintaining a high TA content.When stored for 8 days,the sucrose content in passion fruit at 5℃was significantly higher than those stored 15 and 25℃(P<0.05),indicating that low temperature could effectively inhibit sucrose degradation,leading to a high TSS content.Correlation and principal component analysis showed that low temperature could inhibit the decomposition of sucrose by significantly affecting the activity of acid invertase(AI)(P<0.05).Therefore,AI can regulate the degradation of sucrose to glucose and fructose during the storage of passion fruit and maintain the quality of passion fruit.The results of this experiment can provide the data basis for further analysis of the sugar and acid metabolism mechanism of passion fruit.