超滤分离对马氏珍珠贝肉蛋白酶解液特性的影响

研究了马氏珍珠贝肉蛋白酶解液在超滤过程中膜通量的变化及超滤前后感官评价、肽分子量分布以及氨基酸的变化,对超滤膜的选择性及分离效果进行了评价和分析.实验结果表明,马氏珍珠贝肉蛋白酶解液在超滤过程中,随着超滤时间的延长,膜通量不断减小,透过液的鲜味明显提高,腥味和苦味基本消失,透过液中含有分子量大于截留分子量（5000 Da）的多肽,超滤膜实际有效截留分子量约为7000 Da~8000 Da,分子量小于4500 Da左右的多肽在透过液中得到有效富集.超滤处理后,同一氨基酸在总氨基酸和游离氨基酸中含量的变化均不一致,透过液肽态氨基酸中鲜味氨基酸占总氨基酸比例高于原酶解液,而苦味氨基酸和疏水性氨基酸占总氨基酸的比例均低于原酶解液.

Effects of ultrafiltration separation on characteristics of Pinctada martensii protein enzymatic hydrolysates

Evolution of permeation flux during the ultrafiltration process and variations in sensory characteristics, peptide molecular weight distribution and amino acid composition of Pinctada martensii protein enzymatic hydrolysates before and after ultrafiltration treatment were evaluated in the present study. Moreover, effects of selectivity and separation of ultrafiltration were also studied.Results showed that permeation flux decreased gradually with increasing ultrafiltration time. The Umami flavor of permeation fraction was significantly increased, and its fishy odor and bitterness almost disappeared. Permeation fraction comprised mainly of peptides with molecular weight below 4500 Da and some of those with molecular weight over 5000 Da.. The changes in the level of individual amino acid in both total and free amino acids exhibited different behavior after ultrafiltration. Compared with enzymatic hydrolysates without ultrafiltration treatment, the proportions of umami amino acids in total amino acids in its permeation fraction increased, while bitter and hydrophobic amino acids in total amino acids in its permeation fraction decreased, respectively.