PCA综合分析采收成熟度对金沙柚贮藏品质的影响

为选择适宜金沙柚长期贮藏的采收成熟度,本试验以盛花后195、206和216 d(成熟度Ⅰ、Ⅱ和Ⅲ)采收的果实为对象,检测了常温贮藏180 d内果实感官品质以及抗氧化相关指标,并通过主成分分析法(PCA)综合评价不同采收成熟度对金沙柚贮藏品质的影响。感官品质检测结果表明:成熟度Ⅰ和Ⅲ的腐烂率低于成熟度Ⅱ;成熟度Ⅱ和Ⅲ失重率低于成熟度Ⅰ。成熟度Ⅱ CCI值高于成熟度Ⅰ和Ⅲ,成熟度Ⅲ亮度(L*)最高。成熟度Ⅰ可溶性糖、V_C含量和固酸比高于成熟度Ⅱ和Ⅲ,TA含量反之;成熟度Ⅱ的TSS和V_C高于成熟度Ⅲ。三者出汁率无明显差异。抗氧化性指标检测表明:成熟度Ⅰ和Ⅱ的总酚含量在贮藏180 d内显著高于成熟度Ⅲ,分别于180和150 d达到最大值(197.68和201.08 μg/g)。成熟度Ⅰ和Ⅱ总黄酮含量高于Ⅲ。成熟度Ⅱ和Ⅲ的DPPH清除率前30 d高于成熟度Ⅰ。三个成熟度FRAR还原力维持OD值0.35左右,无明显差异。PCA分析发现:0~30 d成熟度Ⅱ综合得分最高,在60~180 d成熟度Ⅰ综合得分最高并在90 d达最高值0.59分,成熟度Ⅲ整体得分最低。说明盛花后206 d采收的金沙柚贮藏30 d上市最好,最长贮藏不宜超过120 d;盛花后195 d采收的金沙柚贮藏90 d上市最好,最长贮藏不宜超过150 d;盛花后216 d采收的金沙柚不适合贮藏。

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

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,V_C 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 V_C 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.