贮藏温度对核桃果实冷藏期青皮不同部位褐变、活性氧代谢和种仁品质的影响  

Effects of storage temperatures on browning and active oxygen metabolism of different green husk tissues and kernel quality of walnut fruit during cold storage

作　　者：钟紫璇 高梦璐 马文睿 闫金姣 马艳萍[1] 刘朝斌[1] ZHONG Zixuan;GAO Menglu;MA Wenrui;YAN Jinjiao;MA Yanping;LIU Chaobin(College of Forestry,Northwest A&F University,Yangling 712100,China)

机构地区：[1]西北农林科技大学林学院,陕西杨凌712100

出　　处：《食品与发酵工业》2024年第11期261-269,共9页Food and Fermentation Industries

基　　金：国家自然科学基金面上项目(32271926);新疆维吾尔自治区科技成果转化示范专项(2021NC062)。

摘　　要：核桃果实采后青皮极易发生褐变,目前有关不同温度贮藏核桃果实青皮不同部位的褐变差异及其原因未见报道。该文研究不同温度(0、2、5、8℃)贮藏对‘清香’核桃果实青皮不同部位外观、褐变指数、活性氧代谢及其种仁品质相关指标的影响。结果表明,贮藏期间核桃果实青皮的褐变程度随贮藏温度的升高而增加,0、2℃核桃果实青皮内部的褐变指数高于外部,5、8℃果实青皮内部的褐变指数低于外部;4种温度下果实青皮外部的过氧化物酶(peroxidase,POD)活性、多酚氧化酶(polyphenol oxidase,PPO)活性、总酚含量和过氧化氢(H2O2)含量均高于内部,超氧阴离子(·O2-)产生率和丙二醛(malondialdehyde,MDA)含量均低于内部;萼端褐变指数、·O2-产生率、可溶性总糖和游离脯氨酸含量高于梗端;0℃则更好地保持了果实的品质,延缓了种仁酸败,贮藏60 d时种仁的可溶性蛋白质和粗脂肪含量显著高于2℃果实。综合各项指标认为,核桃果实在0、2℃贮藏期为60 d,5、8℃贮藏期不足30 d;青皮的褐变可能是因其活性氧和MDA过量积累加重了膜脂过氧化作用所致。Green husks of walnut fruit are susceptible to browning after harvesting,however,the browning difference of different tissues under different storage temperatures and its possible causes were not reported at present.In this study,the effects of different storage temperatures(0,2,5,8℃)on the indicators related to the appearance,browning index,and active oxygen metabolism in different green husk tissues of‘Qingxiang’walnut fruit and their kernel quality were studied.Results showed that the browning degree of the green husks increased with the storage temperature,and the browning index of green husks inside at 0℃and 2℃was higher than those on the outside,but they were lower on the inside than the outside at 5℃and 8℃during storage.The activities of peroxidase(POD)and polyphenol oxidase(PPO),total phenol content and hydrogen peroxide(H 2O_(2))contents in the outer part were higher than those in the inner part,but their production rate of superoxide anion(·O_(2)-)and malondialdehyde(MDA)contents were lower than those in the inner part.The browning index,·O_(2)-production rate,soluble total sugar,and free proline contents in the calyx end were higher than those in the stem end at four temperatures.The fruit quality was better maintained and the kernel rancidity was delayed at 0℃,with significantly higher soluble protein and crude fat contents in kernels than those at 2℃on the 60th day.In conclusion,the walnut fruit could be stored for 60 days at 0℃and 2℃,but less than for 30 days at 5℃and 8℃.The browning of green husks may be due to the reason that excessive accumulation of reactive oxide species and MDA aggravate the membrane lipid peroxidation.

关 键 词：核桃果实 贮藏温度 褐变 不同部位 活性氧代谢 

分 类 号：TS255.3[轻工技术与工程—农产品加工及贮藏工程]