不同贮藏温度下鲜切紫甘薯褐变相关因素研究

为研究鲜切紫甘薯的褐变条件与机理,本文对不同贮藏温度下(4和12℃)的鲜切紫甘薯的褐变程度、褐变相关酶活力以及褐变底物酚类物质进行分析。结果表明,12℃贮藏组的鲜切紫甘薯褐变度始终显著高于4℃贮藏组(P<0.05)。贮藏期间,褐变重的鲜切紫甘薯多酚氧化酶(Polyphenol oxidase,PPO)和过氧化物酶(Peroxidase,POD)活性更高,丙二醛(Malondialdehyde,MDA)含量更多。2~8 d,不同贮藏温度下鲜切紫甘薯绿原酸和阿魏酸含量显著不同(P<0.05),因此推断褐变相关酶活性、膜脂过氧化程度以及酚类物质含量可能是引起鲜切紫甘薯褐变的关键因素。通过相关性分析,多酚氧化酶(PPO)和过氧化物酶(POD)是引起鲜切紫甘薯褐变的关键酶。绿原酸和阿魏酸是鲜切紫甘薯褐变的主要底物。

Browning Related Factors of Fresh-cut Purple Sweet Potato under Different Storage Temperatures

In order to study the browning conditions and mechanism of fresh-cut purple sweet potato,browning degree,browning-related enzyme activity and browning substrate phenol of fresh-cut purple sweet potato were investigated under different storage temperatures(4 and 12℃). The results showed that the browning degree of fresh-cut purple sweet potato in the 12℃ storage group was significantly higher than the 4℃ storage group(P<0.05). During storage,the activity of polyphenol oxidase(PPO)and peroxidase(POD)and the content of malondialdehyde(MDA)with heavy browning were much higher. The contents of chlorogenic acid and ferulic acid in fresh cut sweet potato were significantly different under various storage temperatures for 2~8 d storage(P<0.05).Thus,the activity of browning-related enzyme,the membrane lipid peroxidation and phenolic content might be the key factors causing browning of fresh-cut purple sweet potato. Polyphenol oxidase(PPO)and peroxidase(POD)were the key enzymes that caused browning of fresh-cut purple sweet potato,and chlorogenic acid and ferulic acid were the main substrates for browning of fresh-cut purple sweet potato through correlation analysis.