低温结合不同厚度保鲜膜对‘巨峰’葡萄贮藏品质的影响

Impact of low temperature combined with different thickness preservation bags on storage quality of‘Kyoho’grape

为探究不同厚度低密度聚乙烯保鲜膜对采后葡萄质构品质及贮藏特性的影响,以‘巨峰’葡萄为试材,分别用0(无包装组,CK)、0.02、0.03、0.04、0.05 mm和0.06 mm厚度的LDPE保鲜膜袋包装,于(1±1)℃低温下贮放42 d,每隔7 d测定其贮藏期质构品质及贮藏特性指标,进行相关性分析,并采用主成分分析法确定最佳保鲜膜厚度。结果表明:与CK组相比,不同厚度LDPE保鲜膜均能延缓葡萄掉粒率及失重率的上升,较好地保持葡萄色泽和亮度,同时能抑制水分、可溶性糖和可溶性蛋白含量的下降,延缓果皮和果肉硬度的降低。CK组、0.05 mm和0.06 mm LDPE组分别在贮藏28 d、35 d和35 d时失去商品价值,而0.02 mm、0.03 mm和0.04 mm LDPE组能将葡萄保鲜期延长至42 d。相关性分析显示,葡萄贮藏期间质构、感官和营养各指标之间密切相关。PCA结果显示,0.03 mm LDPE组置信圈较窄小,保鲜效果最好。综上,0.03 mm LDPE能较好地保持‘巨峰’葡萄的贮藏品质。

To investigate the effect of low-density polyethylene(LDPE)preservation film of different thicknesses on the texture quality and storage characteristics of post-harvest grapes during shelf life.‘Kyoho’grape were used as the test material,and five treated groups were packaged in LDPE preservation film of different thicknesses(0.02、0.03、0.04、0.05 mm and 0.06 mm),while the control group was unpackaged,then stored for 42 days at(1±1)℃,and texture,sensory and nutritional indexes were determined every 7 days.Meanwhile,the correlation analysis of these indicators was carried out.Finally,the optimal thickness of LDPE was determined by principal component analysis(PCA).The results indicated that compared with the control group,different thickness of LDPE preservation film reduced grain falling and weight loss of‘Kyoho’grape,maintained the color and L∗of the peel,inhibited the decline of nutrient content,including moisture,soluble sugar and soluble protein,and delayed the decrease of peel and pulp hardness.The control group,0.05 mm and 0.06 mm LDPE groups lost its commercial value on day 28,35,35 of storage,respectively.However,the 0.02 mm,0.03 mm and 0.04 mm LDPE groups which maintained better quality extend storage to 42 days.Correlation analysis showed that the texture,sensory and nutritional indexes were closely related.Additionally,PCA results indicated that 0.03 mm LDPE had the narrower confidence circle and the best preservation effect.Consequently,0.03 mm LDPE could better maintained the storage quality of‘Kyoho’grapes.