State Key Laboratory of Biological Fermentation Engineering of Beer, Qingdao 266100, China.
National R&D Center for Se-Rich Agricultural Products Processing, Hubei Engineering Research Center for Deep Processing of Green Se-Rich Agricultural Products, School of Modern Industry for Selenium Science and Engineering, Wuhan Polytechnic University, Wuhan 430023, China.
Molecules. 2022 Oct 12;27(20):6825. doi: 10.3390/molecules27206825.
Repurposing of waste beer yeast (WBY) that a main by-product of brewing industry has attracted considerable attention in recent years. In this study, the protein and polypeptide were extracted by ultrasonic-assisted extraction and enzymatic hydrolysis with process optimization, which resulted in a maximum yield of 73.94% and 61.24%, respectively. Both protein and polypeptide of WBY were composed of 17 Amino acids (AA) that included seven essential amino acids (EAA), and typically rich in glutamic acid (Glu) (6.46% and 6.13%) and glycine (Gly) (5.26% and 6.02%). AA score (AAS) revealed that the threonine (Thr) and SAA (methionine + cysteine) were the limiting AA of WBY protein and polypeptide. Furthermore, the antioxidant activities of WBY polypeptide that lower than 10 kDa against hydroxyl radical, DPPH radical, and ABTS radical were 95.10%, 98.37%, and 69.41%, respectively, which was significantly higher than that of WBY protein (25-50 kDa). Therefore, the protein and polypeptide extracted from WBY can be a source of high-quality AA applying in food and feed industry. Due to small molecular weight, abundant AA, and great antioxidant activity, WBY polypeptide can be promisingly used as functional additives in the pharmaceutical and healthcare industry.
近年来，啤酒废酵母（WBY）作为酿造工业的主要副产物，引起了广泛关注。本研究采用超声辅助提取和酶解技术提取 WBY 的蛋白质和多肽，并对提取工艺进行了优化，得到了最高产率分别为 73.94%和 61.24%的蛋白质和多肽。WBY 的蛋白质和多肽均由 17 种氨基酸（AA）组成，其中包括 7 种必需氨基酸（EAA），并且通常富含谷氨酸（Glu）（6.46%和 6.13%）和甘氨酸（Gly）（5.26%和 6.02%）。氨基酸评分（AAS）表明，WBY 蛋白质和多肽中的苏氨酸（Thr）和 SAA（蛋氨酸+半胱氨酸）是限制氨基酸。此外，小于 10 kDa 的 WBY 多肽对羟基自由基、DPPH 自由基和 ABTS 自由基的抗氧化活性分别为 95.10%、98.37%和 69.41%，明显高于 WBY 蛋白质（25-50 kDa）。因此，从 WBY 中提取的蛋白质和多肽可以作为高质量 AA 的来源，应用于食品和饲料工业。由于其分子量小、AA 丰富、抗氧化活性高，WBY 多肽有望作为药物和保健行业的功能性添加剂使用。
