米曲霉粗酶和商业蛋白酶对马氏珍珠贝肉酶解特性的比较

摘要

A crude protease （CP）was prepared from AspergiUus oryzae in this work. CP, four commercial proteases （Protamex,Papain, PTN6.0S, Flavorzyme）and nonprotease were employed to hydrolyze Pinctada martensi. CP was found to be more effective protease with protein recovery of 68.36% than the tested commercial proteases, just little lower than PTN6.0 （71.38%）. Moreover, CP produced the highest degree of hydrolysis （ DH, 64.27% ） than others. The test of molecular weight distribution indicated that CP hydrolysate was mainly consisted of 〈 3 ku fraction, especially 〈 1 ku fraction（84.65% ） was observed to be the highest of commercial hydrolysates. CP hydrolysate possessed a higher umami amino acid （38.27%） than other hydrolysates so the sensory taste evaluation showed that CP hydrolysate had better taste than other hydrolysates.%以麸皮为原料固体发酵制备种曲，通过磷酸盐缓冲液提取得到粗酶（CP）。采用粗酶、Protamex、Papain、PTN6．0S、Flavorzyme以及内源性蛋白酶水解马氏珍珠贝肉蛋白，比较了各种酶的酶解特性、酶解液风味、分子量分布规律及氨基酸组成，并探究了酶解液组成和呈味特征的关联。结果表明：内源性蛋白酶的蛋白质回收率、水解度均最低，麸皮成曲粗酶CP酶解液的蛋白质回收率达68．36％、水解度达64．27％，显著高于其余商业蛋白酶。各酶解液中，CP的酶解液分子质量主要集中在小于3000U，其中小于1000U的寡肽及游离氨基酸占84．65％，均显著高于其余商业蛋白酶；游离氨基酸释放量和鲜味氨基酸释放率达38．27％，均显著高于其余商业蛋白酶的酶解液。CP酶解液风味最佳，苦味、腥味减弱明显，与内源性蛋白酶酶解液相比，腥味值降为26％，且鲜味值提高至2．75倍。