Comprehensively Analyzing the Effect of Harvest Maturity on Storage Quality of Jinsha Pomelo Based on PCA

Abstract

In order to select suitable harvesting maturity for long-term storage of Jinsha pomelo,the sensory quality and antioxidant indexes of fruits harvested at 195,206 and 216 d(maturityⅠ,Ⅱ and Ⅲ)after blossom and storaged for 180 d at room degree were assayed. And principal component analysis(PCA)was applied to comprehensively assess the effects of harvesting maturity on storage quality of Jinsha pomelo. The results of sensory quality test showed that the decay rate of maturity Ⅰ and Ⅲ was lower than that of maturity Ⅱ,and the weight loss rate of maturity Ⅱ and Ⅲ was lower than that of maturity Ⅰ. The CCI value of maturity Ⅱ were higher than those of maturity Ⅰ and Ⅲ,while the colour brightness(L* value)of maturity Ⅲ was highest. Soluble sugar,VC content and solid-acid ratio of maturity Ⅰ were higher than those of maturity Ⅱ and Ⅲ,but TA content was the opposite;TSS and VC of maturity Ⅱ were higher than those of maturity Ⅲ. The juice yield was not significant difference among the three. The antioxidant indexes showed that the total phenol content of maturity Ⅰ and Ⅱ was significantly higher than that of maturity Ⅲ within 180 d of storage,reaching the maximum at 180 d and 150 d respectively(197.68 and 201.08 μg/g). The content of total flavonoids in maturity Ⅰ and Ⅱ was higher than that in maturity Ⅲ. The DPPH scavenging rate of maturity Ⅱ and Ⅲ was higher than that of maturity Ⅰ in the first 30 d. The reductive power of FRAR at three maturities maintained about 0.35 OD value,and there was no significant difference among them. PCA analysis showed that the comprehensive score of maturity Ⅱ was the highest in 0~30 d. The comprehensive score of maturity Ⅰ was the highest in 60~180 d and reached the highest value of 0.59 score in 90 d. The overall score of maturity Ⅲ was the lowest. The results showed that fruits harvested at 206 d after blossom were suitable for short-term storage;fruits harvested at 195 d after blossom were suitable for long-term storage;and fruits harvested at 216 d after blossom were unsuitable for storage.