南极碱盐单胞菌来源的细菌漆酶LacHa蛋白对小麦面包品质的影响

Effect of a bacterial laccase LacHa protein from Halomonas alkaliantartica on the quality of wheat bread

以南极碱盐单胞菌中的漆酶为研究材料,将该漆酶基因在大肠杆菌中进行异源表达,获得重组漆酶的分子量为68.5 kDa,酶活为224.5 U/L.进一步将该漆酶用于小麦面包的制作,以不添加漆酶的空白组为对照,实验组漆酶添加量分别为1、2、3、4、5和6 U.研究结果表明,小麦面包的比容值在漆酶添加量为5 U时达到最大.在此条件下,小麦面包的硬度、黏着性、咀嚼性均有极显著下降的趋势(p<0.01).随着储藏天数的增加,小麦面包品质有所下降,但漆酶添加量为5 U的实验组在第3天的硬度、黏着性仍极显著优于对照组.可见,细菌漆酶作为一种面粉改良剂,在烘焙食品的制作中具有较大的开发潜力,在食品加工领域有着较为广阔的应用前景.

In this study,the laccase from Halomonas alkaliantartica was used as the research material.The laccase gene was heterolytically expressed in Escherichia coli;a recombinant laccase was obtained with a molecular weight of 68.5 kDa and an enzyme activity of 224.5 U/L.This enzyme was then used in the production of wheat bread,with a blank group of bread produced without laccase as the control.To create the various experimental groups,laccase was added in amounts of 1,2,3,4,5,or 6 U.Compared with the blank group,the specific volume of the wheat bread was the largest in the 5 U laccase group.Under this condition,the hardness,adhesion,and chewability of the wheat bread significantly decreased(p<0.01).As storage duration increased,the quality of the bread decreased,but the hardness and stickiness of the experimental bread(5 U laccase)were still better than those of the control group on the third day.This study shows that laccase,as a flour improver,has considerable potential for use in the preparation of baked foods and broad application prospects in the field of food processing.