Min Ju Hyun, Istianah Nur, Jang Jeong Hwa, Jeon Hyeon Ji, Jung Young Hoon
School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Republic of Korea.
Department of Food Science and Biotechnology, Brawijaya University, Malang 65145, Indonesia.
J Microbiol Biotechnol. 2024 Dec 28;34(12):2596-2608. doi: 10.4014/jmb.2409.09062. Epub 2024 Nov 18.
Yeast protein, high-quality and high-content microbial protein, can serve as alternative sources of protein. This study examined the structural and functional characteristics of yeast protein through enzymatic treatment using different ratios of alcalase (endo-type) and prozyme 2000P (exo-type) including 2:1 (A2P1), 1:1 (A1P1), and 1:2 (A1P2). After enzymatic hydrolysis, a significant increase in protein solubility from less than 3.1% in untreated proteins to around 16%, particularly at pH 2 or pH 12. Furthermore, a maximum degree of hydrolysis of over 85% was achieved after enzyme treatment. Among them, the highest value of 87.73% was achieved at yeast protein treated by A1P2. Scanning electron microscopy images revealed varied surface morphologies, with exhibiting an increased surface area, particularly after treatment using A2P1. Next, yeast protein treated with A2P1 also demonstrated a superior emulsion stability index (3364.17). However, the antioxidant capacity was higher in proteins treated with A1P2 (78.30%). In addition, the elevated levels of certain amino acids, specifically leucine, lysine, phenylalanine, valine, and arginine, thereby indicating an enhanced amino acid profile was observed. Overall, yeast proteins treated with complex enzymes exhibited improved functionality and potential for diverse food applications.
酵母蛋白，一种高质量且高含量的微生物蛋白，可用作蛋白质的替代来源。本研究通过使用不同比例的碱性蛋白酶（内切型）和复合酶2000P（外切型）进行酶处理，研究了酵母蛋白的结构和功能特性，这些比例包括2:1（A2P1）、1:1（A1P1）和1:2（A1P2）。酶解后，蛋白质溶解度显著增加，从未经处理的蛋白质中低于3.1%增加到约16%，特别是在pH 2或pH 12时。此外，酶处理后实现了超过85%的最大水解度。其中，经A1P2处理的酵母蛋白达到了最高值87.73%。扫描电子显微镜图像显示了不同的表面形态，特别是在使用A2P1处理后表面积增加。接下来，用A2P1处理的酵母蛋白还表现出优异的乳化稳定性指数（3364.17）。然而，用A1P2处理的蛋白质的抗氧化能力更高（78.30%）。此外，观察到某些氨基酸水平升高，特别是亮氨酸、赖氨酸、苯丙氨酸、缬氨酸和精氨酸，从而表明氨基酸谱得到了改善。总体而言，用复合酶处理的酵母蛋白表现出改善的功能和在多种食品应用中的潜力。
