氯化钙处理对采后百香果细胞壁物质代谢的影响

Effect of Calcium Chloride Treatment on Cell Wall Metabolism of Postharvest Passiflora edulia

为探究氯化钙(CaCl_(2))处理对常温贮藏百香果细胞壁物质代谢的影响,采用5%CaCl_(2)对新鲜采摘的百香果进行浸泡处理5 min,清水处理为对照,于(22±1)℃条件下贮藏8 d,定期测定果实硬度、色差、细胞壁组分及细胞壁代谢相关酶活性,并进行相关性分析和主成分分析。结果表明,5%CaCl_(2)处理能够控制采后百香果硬度、色泽的下降,抑制共价结合型果胶(covalently bound pectin,SCSP)、紧密型半纤维素(24KSF)的降解,降低水溶性果胶(water soluble pectin,WSP)、离子型果胶(ionic bound pectin,ISP)、松散型半纤维素(4KSF)的含量,延缓多聚半乳糖醛酸酶(polygalacturonase,PG)、果胶甲酯酶(pectin methylesterase,PME)活性的上升。相关性分析结果说明,果实硬度与色泽、WSP含量、ISP含量、24KSF含量、PG活性、PME活性极显著相关(P<0.01)。主成分分析结果表明,PC1、PC2、PC3代表了12个指标82.266%的信息,能综合反映百香果生理指标的大部分信息,且CaCl_(2)处理组综合得分始终高于对照组,说明氯化钙处理可通过调节细胞壁物质代谢来减缓百香果的软化速度,延长货架期。

This study aimed to explore the effect of calcium chloride(CaCl_(2))treatment on the cell wall metabolism of Passiflora edulia during room temperature storage.The collected P.edulia samples were soaked in 5%CaCl_(2)and purified water(control)for 5 min and stored at(22±1)℃for 8 d.The firmness,color,cell wall components,and enzyme activities related to cell wall metabolism were determined regularly,followed by correlation analysis and principal component analysis(PCA).The results showed that 5%CaCl_(2)treatment could control the decrease in firmness and color of P.edulia,inhibit the degradation of covalently bound pectin(SCSP)and 24%potassium hydroxide-soluble fraction(24KSF)content,reduce the content of water-soluble pectin(WSP),ionic(EDTA)-soluble pectin(ISP),and 4%potassium hydroxide-soluble fraction(4KSF),and slow down the increase in polygalacturonase(PG)and pectin methylesterase(PME)activities.The correlation analysis showed that fruit firmness was significantly correlated with color,WSP content,ISP content,24KSF content,PG activity,and PME activity(P<0.01).PCA showed that PC1,PC2,and PC3 could represent 82.266%of the information of 12 indexes and comprehensively reflect the overall information of physiological indexes of P.edulia.The comprehensive score of the CaCl_(2)treatment group was always higher than that of the control group,which indicated that CaCl_(2)treatment could slow down the softening speed and prolong the shelf life of P.edulia during storage by regulating the cell wall metabolism.