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酶促褐变是香蕉加工中拟解决的关键问题,非硫安全高效抑制剂的筛选是目前的研究热点。美拉德产物(Maillard reaction products,简称MRPs)展示了其良好的抑制酶促褐变的能力,然而美拉德产物分级组分的相关研究尚未见报道。通过透析处理得到大于和小于3 500 u的分级组分,比较其抑制香蕉酶促褐变的相关能力,并对抑制机理进行研究。结果显示:3种MRPs中,MW>3 500 u的MRPs具有较好的还原力,MW<3 500 u的MRPs具有较好的DPPH·清除率、螯合铜离子能力以及抑制多酚氧化酶酶活的能力。MW<3 500 u的MRPs对游离酶抑制常数(K I)和对酶-底物络合物的抑制常数(K IS)分别为0.198 mmol/L和1.508 mmol/L,抑制类型属于混合型抑制。
Enzymatic browning is a key problem to be solved in banana processing. Screening of non-sulfur safe and efficient inhibitors is the current research hotspot. Maillard reaction products (MRPs) demonstrate their good ability to inhibit enzymatic browning, however, no relevant studies on the fractionation components of Maillard products have been reported yet. The fractionated components above and below 3 500 u were obtained by dialysis, and their relative ability to inhibit browning of banana was compared. The mechanism of inhibition was also studied. The results showed that MRPs with MW> 3 500 u had better reducing power among the three MRPs. MRPs with MW <3 500 u had better DPPH · scavenging ability, chelation ability of copper ions and inhibition of polyphenol oxidase Live ability. The inhibitory constants of KI and KIS of MRPs with MW <3 500u were 0.198 mmol / L and 1.508 mmol / L, respectively. The inhibition types were mixed inhibition.