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、Papa-in、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3 000 U,其中小于1 000 U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。

A crude protease(CP)was prepared from Aspergillus 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.