Liu Yanlong, Lei Yuqing, Kang Xu, Ouyang Hui, Li Xiuting, Yu Xiongwei, Gu Qianhui, Li Shugang
Key Laboratory of Fermentation Engineering, Ministry of Education, School of Food and Biological Engineering, Hubei University of Technology, Wuhan 430068, China.
Engineering Research Center of Bio-Process, Ministry of Education, Key Laboratory for Agricultural Products Processing of Anhui Province, School of Food and Biological Engineering, Hefei University of Technology, Hefei 230601, China.
Gels. 2023 Jan 20;9(2):91. doi: 10.3390/gels9020091.
Walnut protein is a kind of natural, high-quality plant protein resource. However, its high content of gluten, strong hydrophobicity and poor gelation ability have greatly limited its development and utilization in gel products. It was found in this experiment that ultrasonic power combined with transglutaminase (TGase) had a significant effect on the gel properties of the walnut protein isolate (WNPI)-κ-carrageenan (KC) complex. The results showed that the gel strength of the WNPI-KC complex first increased and then decreased with the increase in ultrasonic power (0-400 W). WNPI-KC composite gel had the best texture properties, rheological properties, water-holding capacity (99.41 ± 0.76%), swelling ratio (2.31 ± 0.29%) and thermal stability (83.22 °C) following 200 W ultrasonic pretreatment. At this time, the gel network was more uniform and much denser, and the water molecules were more tightly bound. Further, 200 W ultrasonic pretreatment could promote the transformation of α-helices to β-folds in protein molecules, improve the fluorescence intensity, increase the content of free sulfhydryl groups and enhance the intermolecular forces. The experimental results could provide technical support for the development of walnut protein gel food.
核桃蛋白是一种天然的优质植物蛋白资源。然而，其高含量的谷蛋白、较强的疏水性和较差的凝胶化能力极大地限制了它在凝胶产品中的开发利用。本实验发现，超声功率与转谷氨酰胺酶（TGase）联合使用对核桃分离蛋白（WNPI）-κ-卡拉胶（KC）复合物的凝胶特性有显著影响。结果表明，随着超声功率（0-400W）的增加，WNPI-KC复合物的凝胶强度先升高后降低。经过200W超声预处理后，WNPI-KC复合凝胶具有最佳的质地特性、流变学特性、持水能力（99.41±0.76%）、溶胀率（2.31±0.29%）和热稳定性（83.22℃）。此时，凝胶网络更加均匀且致密，水分子结合得更紧密。此外，200W超声预处理可促进蛋白质分子中α-螺旋向β-折叠的转变，提高荧光强度，增加游离巯基含量并增强分子间作用力。实验结果可为核桃蛋白凝胶食品的开发提供技术支持。
