| 摘要: |
| 【目的】揭示黄瓜商品果采后品质与果皮色素变化及其相关性，为根据皮色变化来判断黄瓜品质提供依据。【方法】以果皮绿色和褪绿进程有差异的华北型黄瓜品种“39-1”（果皮绿色较浅，褪绿进程较快）和“39-2”为试材，采集其商品果，置于20 ℃、空气相对湿度85%的条件下保存，分别于采后0，3，6，9，12 d取样测定商品果硬度、失重率、瓜头直径、瓜尾直径及可溶性固形物、VC、亚硝酸盐含量和果皮叶绿素、类胡萝卜素含量，分析采后0~12 d黄瓜各品质指标与果皮色素含量的变化规律及其相关性。【结果】随着采后时间的延长，“39-1”果实外观的失水萎蔫、瓜头膨大、瓜尾皱缩现象较“39-2”严重。采后0~12 d，“39-1”和“39-2” 2个品种果实硬度分别降低16.6%和13.6%；失重率分别达4.9%和3.7%；可溶性固形物含量均呈先增加后降低趋势，降低率分别为17.4% 和1.9%；果实VC含量分别降低29.8%和24.6%;亚硝酸盐含量稍有上升。综合外观品质和内在品质，“39-2”比“39-1”外观变化小，营养损失少。两品种果皮叶绿素a、叶绿素b和总叶绿素含量呈降低趋势，类胡萝卜素含量逐渐升高；“39-2”的总叶绿素含量高于“39-1”，“39-1”的类胡萝卜素与总叶绿素含量比值高于“39-2”。总叶绿素含量与失重率呈显著负相关，与硬度、可溶性固形物含量呈极显著正相关；类胡萝卜素与总叶绿素含量的比值与失重率呈极显著正相关，与硬度、可溶性固形物含量、VC含量呈极显著负相关。【结论】采后12 d内，黄瓜商品果品质呈下降趋势，其品质变化与果皮色素含量变化有一定关系，果实皮色可作为判断果实品质的参考。 |
| 关键词: 黄瓜 果实品质 果皮色素 采后生理 |
| DOI： |
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| 基金项目:国家重点研发计划子课题（2016YFD0101705-6）;陕西省农业科技创新与攻关项目（2016NY-048） |
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| Changes in quality and pericarp pigment content of postharvest commercial cucumber fruit and their correlations |
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LIU Xuexue,CHENG Zhihui,MENG Huanwen
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| Abstract: |
| 【Objective】The changes in quality and pericarp pigments content of postharvest commercial cucumber fruit and their correlations were investigated to provide basis for judging fruit quality change according to skin color.【Method】North China type cucumber varieties “39-1” (lighter green skin and quicker chlorosis) and “39-2” with different pericarp greening and degreening processes were used.The commercial fruits were picked up and stored in a growth chamber with temperature of 20 ℃ and air relative humidity of 85%.Fruit hardness,rate of weight loss,fruit head swelling rate,fruit end shrinkage rate,soluble solids,VC,nitrite content,chlorophyll and carotenoid contents were measured 0,3,6,9 and 12 d after harvest and the changes in quality and pericarp pigments contents and their correlations were analyzed.【Result】With the extension of postharvest time, fruits lost water,the head expended,and the end shrunk,with severe conditions in “39-1” fruits compared to “39-2” fruits.Within 12 days postharvest,the hardness values of “39-1” and “39-2” fruits decreased by 16.6% and 13.6%,and the weight loss rates increased by 4.9% and 3.7%.The soluble solids content increased at the beginning and then decreased with overall reduction rates of 17.4% and 1.9%,respectively.The VC contents decreased by 29.8% and 24.6%,while nitrite contents increased slightly.Comprehensively considering appearance quality and intrinsic quality,“39-2” had smaller changes in appearance and less nutrient loss than “39-1”.The contents of chlorophyll a,chlorophyll b and total chlorophyll in cucumber pericarp of two cultivars decreased,while the content of carotenoid increased gradually.The chlorophyll content of “39-2” was significantly higher than that of “39-1”,and the ratio of carotenoid to chlorophyll of “39-1” was significantly higher than that of “39-2”.There was significant negative correlation between chlorophyll content and weight loss rate,and chlorophyll content had significant positive correlation with hardness and soluble solids.The ratio of carotenoid to chlorophyll content had significant positive correlation with weight loss rate,and had significant negative correlation with hardness,soluble solids,and vitamin C content.【Conclusion】Within 12 days postharvest,the quality of cucumber fruit decreased,and its quality change was related with the change of pigment content in pericarp.The color of fruit skin can be used as a reference for judging fruit quality. |
| Key words: cucumber fruit quality pericarp pigment post-harvest physiology |
