二氧化硫保鲜剂处理对‘阳光玫瑰’葡萄贮藏期褐变的影响

Effect of SO_(2) treatment on browning of‘Sunshine Rose’grape during storage

为研究SO_(2)保鲜剂处理对‘阳光玫瑰’葡萄在贮藏期间褐变的影响及机制,该实验分别使用SO_(2)粉剂、SO_(2)片剂和SO_(2)胶囊贴片3种形式的保鲜剂对其进行处理,分析贮藏过程中腐烂率、失水率、色泽参数、致褐变因子及抗氧化酶的变化。结果表明,SO_(2)保鲜剂处理均能有效减慢果实的腐烂及失水进程,减缓维生素C、总酚和还原糖含量在贮藏过程中的下降,降低丙二醛(malondialdehyde,MDA)含量,抑制脂氧合酶(lipoxygenase,LOX)和多酚氧化酶(polyphenol oxidase,PPO)活性,提高抗氧化相关酶[超氧化物歧化酶(superoxide dismutase,SOD)和过氧化物酶(peroxidase,POD)]活力,从而有效减轻‘阳光玫瑰’葡萄的褐变;3种SO_(2)处理褐变抑制效果依次为:对照组<粉剂组<片剂组<胶囊贴片组。结合主成分分析和相关性分析,色泽参数与维生素C含量、总酚含量、还原糖含量、MDA含量和LOX活性、PPO活性呈极显著相关(P<0.01),第一主成分中维生素C和总酚的载荷量最高,说明维生素C氧化和多酚自氧化对葡萄褐变的影响最大。另外,所有处理葡萄中残留SO_(2)均远低于国标,不存在残留量超标现象。

To study the effect and mechanism of SO_(2) preservative treatment on the browning of‘Sunshine Rose’grape during storage,this experiment used SO_(2) powder,SO_(2) tablet,and SO_(2) capsule patch to treat the grape respectively,and analyzed the changes in rotting rate,filtration rate,color parameters,browning factors,and antioxidant enzymes during storage.Results showed that SO_(2) preservative treatment could effectively slow down fruit decay and water loss process,reduce the contents of ascorbic acid,total phenol,and reduce sugar,reduce the content of malondialdehyde(MDA),and inhibit lipoxygenase during storage.Lipoxygenase(LOX)and polyphenol oxidase(PPO)activities increased antioxidant-related enzyme activities[superoxide dismutase(SOD)and peroxidase(POD)];thus,effectively reducing the browning of‘Sunshine Rose’grapes.The inhibitory effects of SO_(2) treatment on browning were as follows:control group<powder group<tablet group<capsule patch set.Combined with principal component analysis and correlation analysis,color parameters were significantly correlated with vitamin C content,total phenol content,reducing sugar content,MDA content,LOX activity,and PPO activity(P<0.01),the loading amounts of vitamin C and total phenol in the first principal component were the highest,indicating that ascorbic acid oxidation and polyphenol autooxidation had the greatest effect on grape browning.In addition,the residual SO_(2) in all treated grapes was far lower than the national standard,and there was no excessive residue phenomenon.