L-半胱氨酸对鲜切紫甘薯护色保鲜作用

Study on the preservation of fresh-cut purple sweet potato by L-cysteine

以鲜切紫甘薯为原料,用0.5、1.0、2.0、3.0、4.0 g/L,五种不同质量浓度的L-半胱氨酸(L-cysteine,Lcys)溶液分别对鲜切紫甘薯做浸泡15 min处理。通过对各项理化指标与营养成分的测定,结果表明,L-cys处理能维持鲜切紫甘薯原有的色泽,较好地保持花色苷的含量,延缓营养物质含量的下降,通过在一定程度上抑制丙二醛(malondialdehyde,MDA)的生成及过氧化物酶(peroxidase,POD)和多酚氧化酶(polyphenol oxidase,PPO)的活性,有效延缓鲜切紫甘薯的褐变程度。其中质量浓度为2.0 g/L的L-cys溶液效果最好,贮藏12 d后,褐变度抑制率可达62.5%。因此,L-cys处理可以作为一种简单合理的鲜切紫甘薯保鲜方法,延长其货架期,为鲜切紫甘薯产品的开发提供支持。

To study the regulation of L-cysteine(L-cys)on the browning control and color preservation of freshcut purple sweet potato,purple sweet potato was cut and soaked with different concentrations of L-cys solution(0.5,1,2,3,4 g/L)for 15 min.The physical and chemical indicators as well as the nutrients content of fresh-cut purple sweet potato were determined.The results showed that L-cys treatment maintained the original color and the anthocyanin content,and delayed the decline of nutrients content of fresh-cut purple sweet potato.Besides,the browning of fresh-cut purple sweet potato was effectively alleviated by L-cys through inhibiting the formation of malondialdehyde(MDA)and the activities of peroxidase(POD)and polyphenol oxidase(PPO).Among them,the browning inhibition rate of fresh-cut purple sweet potato reached 62.5%at the concentration of 2 g/L L-cysteine after 12 d of storage.Therefore,the L-cysteine solution can be used as a simple and reasonable fresh-cut purple sweet potato preservation method to extend its shelf life and provide support for the development of fresh-cut purple sweet potato products.