Sun Yizhou, Chen Haiming, Chen Wenxue, Zhong Qiuping, Zhang Ming, Shen Yan
College of Food Science and Engineering, Hainan University, 58 Renmin Road, Haikou 570228, China.
Maritime Academy, Hainan Vocational University of Science and Technology, 18 Qiongshan Road, Haikou 571126, China.
Foods. 2022 Apr 4;11(7):1042. doi: 10.3390/foods11071042.
In the food industry, coconut milk has a unique flavor and rich nutritional value. However, the poor emulsifying properties of coconut proteins restrict its development. In this study, the effect of ultrasound combined with preheating on coconut globulin and coconut milk was evaluated by physicochemical properties and structural characteristics. The results showed that ultrasound and 90 °C preheating gave coconut protein better emulsifying and thermal properties, demonstrated by higher solubility (45.2% to 53.5%), fewer free sulfhydryl groups (33.24 to 28.05 μmol/g) and higher surface hydrophobicity (7658.6 to 10,815.1). Additionally, Fourier transform infrared spectroscopy and scanning electron microscopy showed obvious changes in the secondary structure. Furthermore, the change in the physicochemical properties of the protein brought a higher zeta potential (-11 to -23 mV), decreased the thermal aggregation rate (148.5% to 13.4%) and increased the viscosity (126.9 to 1103.0 m·Pa·s) of the coconut milk, which indicates that ultrasound combined with preheating treatment provided coconut milk with better thermal stability. In conclusion, ultrasound combined with preheating will have a better influence on modifying coconut globulin and increasing the thermal stability of coconut milk. This study provides evidence that ultrasound and other modification technologies can be combined to solve the problems encountered in the processing of coconut protein products.
在食品工业中，椰奶具有独特的风味和丰富的营养价值。然而，椰子蛋白较差的乳化性能限制了其发展。在本研究中，通过物理化学性质和结构特征评估了超声联合预热对椰子球蛋白和椰奶的影响。结果表明，超声和90℃预热使椰子蛋白具有更好的乳化和热性能，表现为更高的溶解度（45.2%至53.5%）、更少的游离巯基（33.24至28.05μmol/g）和更高的表面疏水性（7658.6至10815.1）。此外，傅里叶变换红外光谱和扫描电子显微镜显示二级结构有明显变化。此外，蛋白质物理化学性质的改变使椰奶具有更高的ζ电位（-11至-23mV），降低了热聚集率（148.5%至13.4%）并增加了粘度（126.9至1103.0m·Pa·s），这表明超声联合预热处理赋予了椰奶更好的热稳定性。总之，超声联合预热对改性椰子球蛋白和提高椰奶的热稳定性具有更好的影响。本研究证明超声与其他改性技术相结合可以解决椰子蛋白产品加工过程中遇到的问题。
