不同采收期对“贵长”猕猴桃贮藏期间果实品质的影响

Effects of Different Harvest Periods on Fruit Quality of “Guichang” Kiwifruit during Storage

以“贵长”猕猴桃为试验材料,对8个不同采收期(盛花后132、136、140、144、148、152、156和160d,采收Ⅰ~Ⅷ期)猕猴桃果实在室温贮藏过程中的生理生化指标进行了比较。结果表明,随着采收期的推迟,猕猴桃采收后硬度和可滴定酸含量逐渐降低,干物质含量、可溶性固形物、可溶性糖含量、固酸比、糖酸比和总黄酮含量逐渐升高,而果实中总酚含量呈现先下降后上升的趋势。采收Ⅳ、Ⅴ、Ⅵ、Ⅶ和Ⅷ期采收期猕猴桃的可溶性固形物含量在7.00%以上,干物质含量在17.22%以上;采收Ⅳ期、Ⅴ期果实采收时具有较高的VC含量,失重率低于其他采收期,出现腐烂的时间较晚。贮藏期间,采收Ⅳ期、Ⅴ期猕猴桃的干物质含量高于其他采收期,可溶性固形物含量和可溶性糖含量在采后16d后整体上高于其他采收期,VC含量在采后28d后仍高于其他采收期,总酚含量在采后12d后均高于其他采收期,失重率和腐烂率则低于其他采收期。由此可见,“贵长”猕猴桃适宜采收期为采收Ⅳ~Ⅴ期(即盛花后144~148d),此时可溶性固形物和干物质含量分别为7.0%~7.5%和17.22%~18.45%。

Taking“Guichang”kiwifruit as test materials,the physiological and biochemical indices of“Guichang”kiwifruit harvested in 8 different periods(132,136,140,144,148,152,156 and 160 days after peak flowering(periodⅠ-Ⅷ)during the storage period at room temperature were compared.The results showed that:with the delay of harvest period,the firmness and the titratable acid content of post-harvest kiwifruit gradually decreased,the dry matter content,soluble solid content,soluble sugar content,solid-acid ratio(SSC/TA),sugar-acid ratio and total flavonoids content gradually increased,the content of total phenols in kiwifruit fruits first decreased and then increased gradually.The content of soluble solids and dry matter in kiwifruit harvested in harvest periodⅣ,Ⅴ,Ⅵ,ⅦandⅧ,were over 7.00%and 17.22%respectively.The fruit harvested in periodⅣand periodⅤhave higher content of vitamin C,lower weight loss ratio and later rotting time than those in kiwifruit fruits harvested in other harvest periods.During storage period,the dry matter content in kiwifruit fruits harvested in periodⅣand periodⅤwas higher than that in other harvest periods,the soluble solids content and soluble sugar content were higher on the 16 th day after harvesting were higher than those in other harvest periods,V C content was still higher on the 28th day after harvesting than that in other harvest periods,total phenols content was higher on the 12 th day after harvesting than that in other harvest periods,the weight loss ratio and decay ratio were lower on the 12 th day after harvesting than those in other harvest periods.Therefore,the optimum harvest period of"Guichang"kiwifruit was periodⅣ-Ⅴ(144-148 d after peak flowering).During the periods,the contents of soluble solids and dry matter reached 7.0%-7.5%and 17.22%-18.45%respectively.