桑叶蛋白超声提取联合超滤纯化工艺优化及其营养评价

吴雅茹; 陈贵茹; 雷建都; 王璐莹

doi:10.13386/j.issn1002-0306.2022100206

桑叶蛋白超声提取联合超滤纯化工艺优化及其营养评价

Optimization of Ultrasonic Extraction Combined with Ultrafiltration for Purification of Mulberry Leaf Protein and Its Nutritional Evaluation

摘要

摘要: 以桑叶为原料研究了超声提取联合超滤法制备桑叶蛋白营养成分的工艺。采用响应面试验对超声辅助提取桑叶蛋白制备桑叶蛋白粗提液的工艺条件进行优化，桑叶蛋白粗提液通过超滤纯化、浓缩桑叶蛋白成分，并利用正交试验优化超滤工艺中膜通量。参考GB 5009.124-2016食品安全国家标准食品中方法测定超声提取联合超滤法制备固体粗蛋白的氨基酸组成成分，并进一步进行营养价值分析。结果表明，液料比为29:1 mL/g，360 W超声15 min，42 ℃水浴加热34 min为最适宜的提取条件，蛋白得率可达5.56%；采用超滤膜超滤处理桑叶蛋白粗提液，最优纯化条件为操作压力：0.6 MPa，粗提液稀释1倍，浓缩比4:1，在此条件下，膜通量为21.40 L/m²·h，所得固体蛋白纯度可达35%以上；超声提取联合超滤技术制备的固体桑叶蛋白总氨基酸含量为22.22 g/100 g，且必需氨基酸占总氨基酸的比值、必需氨基酸占非必需氨基酸的比值均高于粮农组织/世界卫生组织成人模式数值。超声提取联合超滤法可有效提取、纯化桑叶中的蛋白成分，所制取的桑叶蛋白具备良好的营养价值，可满足成人营养需求。

Abstract: This paper discussed the preparation of protein nutrients from mulberry leaves by ultrasonic extraction combined with ultrafiltration technology. In order to obtain the optimal conditions for ultrasonic assisted extraction of mulberry leaf protein, we used response surface methodology to optimize the preparation of crude extract of mulberry leaf protein. In addition, we used ultrafiltration technology to purify and concentrate the protein components in the crude protein extract of mulberry leaves, and optimized the ultrafiltration membrane flux by orthogonal test. The amino acid components of solid crude protein prepared by ultrasonic extraction coupled with ultrafiltration technology were determined by referring to the method in GB 5009.124-2016 National Standard for Food Safety and further analyzed its nutritional value. The results showed that the optimal extraction conditions were as follows: The ratio of liquid-material ratio was 29:1 mL/g, ultrasonic extraction at 360 W for 15 min, and heating in water bath at 42 ℃ for 34 min, and the protein yield was up to 5.56%. Using the ultrafiltration technology to purify and concentrate the protein components in the crude protein extract, the optimal purification conditions were as follows: Operating pressure 0.6 MPa, diluting the crude extract by 1 time, and concentration ratio: 4:1. Under these conditions, the membrane flux was 21.40 L/m²·h, and the purity of solid protein was over 35%. The total amino acid content of solid mulberry leaf protein prepared by ultrasonic extraction coupled with ultrafiltration technology was 22.22 g/100 g, and the ratio of essential amino acids to total amino acids and the ratio of essential amino acids to non-essential amino acids were higher than the FAO/WHO adult model values. It could effectively extract and purify protein components from mulberry leaves by ultrasonic extraction combined with ultrafiltration technology. The prepared mulberry leaf proteins have good nutritional value and might meet the nutritional requirements of adults.