摘要
新鲜玛咖块茎中的黑芥子酶经提取、透析、凝胶过滤层析纯化后,对其酶学性质、酶动力学参数以及干燥加工前、后玛咖中的黑芥子酶酶活力及其酶解产物异硫氰酸苄酯(BITC)的变化进行研究。凝胶渗透色谱测得纯化后的玛咖黑芥子酶的分子质量为190.9 ku。酶学性质研究结果显示:该酶的最适温度40℃,最适pH 7.0,金属离子Fe^(3+)、Cu^(2+)、Al^(3+)、Mg^(2+)、Zn^(2+)、Ba^(2+)对其有显著的抑制作用。采用Lineweaver-Burk法测得玛咖黑芥子酶的动力学参数Vmax=0.2383(μmol/L)/min,Km=0.1425 mmol/L。玛咖鲜果中的黑芥子酶酶活力为0.7256 U/g,BITC含量为3.3190 mg/g。将玛咖鲜果样品切片后分别在温度为50,60,70,80℃下干燥处理,结果显示:随着干燥温度的上升,玛咖干片样品中的黑芥子酶酶活力显著下降,BITC含量呈下降趋势。本研究完善了玛咖黑芥子酶的理论研究,并提出采用60℃以上温度对玛咖进行干燥处理可有效抑制黑芥子酶酶活力,为玛咖的加工利用提供了参考。
After extraction,dialysis and gel filtration chromatography,the myrosinase in fresh maca tubers was purified.The enzymatic properties,kinetic parameters of myrosinase were studied.Moreover,the effect of drying on the myrosinase activity and benzyl isothiocyanate(BITC)content of maca was investigated.The molecular weight of purified myrosinase was 190.9 ku determined by gel permeation chromatography(GPC).The results of enzymatic properties showed that the optimum temperature of myrosinase was 40℃,and the optimum pH value was 7.0.The metal ions Fe^(3+),Cu^(2+),Al^(3+),Mg^(2+),Zn^(2+),Ba^(2+)had significant inhibitory effects on the myrosinase.The kinetic parameters Vmax=0.2383(μmol/L)/min,and Km=0.1425 mmol/L were determined by the method of Lineweaver-Burk.The myrosinase activity and BITC content of fresh maca were 0.7256 U/g and 3.3190 mg/g,respectively.The fresh maca samples were sliced and dried at the temperature of 50,60,70℃,and 80℃,respectively.As the drying temperature increased,the myrosinase activity in the maca sample significantly decreased,and the BITC content showed a decreasing trend.This study has improved the theoretical study of the myrosinase from maca.It is proposed that drying maca at temperatures above 60℃can effectively inhibit the myrosinase activity.These results may provide guidance for the processing and utilization of maca.
作者
李婧
杨成
牛立沙
于艳丽
Li Jing;Yang Cheng;Niu Lisha;Yu Yanli(Sanda University Shanghai,Shanghai 201209;School of Food Science and Technology,Jiangnan University,Wuxi 214122,Jiangsu;Hebei Food Inspection and Research Institute,Shijiazhuang 050091)
出处
《中国食品学报》
EI
CAS
CSCD
北大核心
2024年第4期247-255,共9页
Journal of Chinese Institute Of Food Science and Technology
基金
上海市“晨光计划”项目(18CGB02)。
关键词
黑芥子酶
玛咖
酶学性质
酶活力
异硫氰酸苄酯
myrosinase
maca
enzymatic property
myrosinase activity
benzyl isothiocyanate
作者简介
第一作者:李婧,女,博士,讲师;通信作者:于艳丽,E-mail:ylyusanda@sina.com。
