Leng Weijun, Li Ying, Liang Xin, Yuan Li, Li Xiuting, Gao Ruichang
School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China; Key Laboratory of Geriatric Nutrition and Health, Beijing Technology and Business University, Ministry of Education, Beijing 100048, China.
School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China; College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China.
Food Chem. 2025 Apr 15;471:142802. doi: 10.1016/j.foodchem.2025.142802. Epub 2025 Jan 6.
In this study, the absolute electrostatic charge of myofibrillar protein (MP) was substantially increased by protein-glutaminase (PG) treatment, which was a critical step for achieving the dissociation and solubility of MP under low salt condition. The PG-treated MP exhibited the capacity to form thermo-reversible gels that could be melted through heating and subsequently reformed into a stable gel structure upon refrigeration. The results of SDS-PAGE further revealed that the levels of soluble monomeric myosin and actin in the supernatant of deamidated MP (DMP) gels were markedly elevated, and confirmed the increased formation of intermolecular disulfide bond between myosin and actin. Additionally, moderate deamidation was beneficial for the improvements of MP gel properties, especially in terms of water-holding capacity and springiness. Electronic tongue and correlation analysis indicated that the umami perception of DMP was significantly enhanced because of the conversion of glutamine (Gln) to glutamate (Glu) residues that induced by PG deamidation.
在本研究中，通过蛋白谷氨酰胺酶（PG）处理，肌原纤维蛋白（MP）的绝对静电荷显著增加，这是在低盐条件下实现MP解离和溶解的关键步骤。经PG处理的MP表现出形成热可逆凝胶的能力，该凝胶可通过加热熔化，随后在冷藏时重新形成稳定的凝胶结构。SDS-PAGE结果进一步表明，脱酰胺MP（DMP）凝胶上清液中可溶性单体肌球蛋白和肌动蛋白的水平显著升高，并证实了肌球蛋白和肌动蛋白之间分子间二硫键形成增加。此外，适度脱酰胺有利于改善MP凝胶特性，特别是在持水能力和弹性方面。电子舌和相关性分析表明，由于PG脱酰胺诱导谷氨酰胺（Gln）向谷氨酸（Glu）残基的转化，DMP的鲜味感知显著增强。
