摘要

Microalgae oil is rich in polyunsaturated fatty acids, docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA), commonly added to liquid foods. However, microalgae oil is prone to oxidative deterioration during food processing, preservation, and digestion. In addition, it is difficult to add liposoluble microalgae oil to liquid foods. Therefore, improving the stability of microalgae oil is critical for its application in the food industry. Here, a microalgae oil-water emulsion was prepared using soybean protein isolate (SPI) and chitosan (CS) coacervate. Because the oxidative stability of emulsions depends greatly on their physical stability, the effects of cross-linking with microbial transglutaminase (mTGase) on the physical and oxidative stabilities of the microalgae oil-water emulsion were investigated. The results indicated that the optimum cross-linking effect of mTGase on SPI/CS coacervate was achieved under the following conditions: pH:6.0; Cs to SPI ratio: 0.1 g/g; mTGase concentration: 25 U/g SPI. Cross-linking with mTGase significantly improved the physical and oxidative stabilities of the microalgae oil-water emulsion, as well as the emulsifying efficiency of microalgae oil. The microalgae oil emulsion product prepared using this method can be added to soy milk and other liquid protein drinks, thus enhancing the health benefits from DHA.