Preparation of Torreya Seed Oil-EGCG Nanoemulsion and Its Effect on the Quality of Salad Dressing and Moon Cakes
The composite nanoemulsion of torreya oil and epigallocatechin gallate (EGCG) was successfully prepared by ultrasonic emulsification method. The stability of the emulsion with different oil/water ratio and EGCG content was analyzed under different storage temperature and time, and the effect of the nanoemulsion on the quality of salad dressing and moon cake was further studied. The results show that the prepared torreya oil-EGCG nanoemulsion had stable properties (particle size=160-180 nm, PDI<0.2, Zeta potential≈-60 mV), and the oil/water ratio and EGCG had no significant effects on stability (P>0.05). Refrigeration and 2.0% EGCG nanoemulsion could reduce the loss of EGCG and inhibit its browning. The sensory quality of salad dressing with 1/10 torreya oil-EGCG nanoemulsion and 0.2% NHDC was improved. The antibacterial and antioxidant activity was significantly increased for prolonged quality stability. The addition of torreya oil-EGCG nanoemulsion can slow down the accumulation of acrylamide and reduce the loss of representative unsaturated fatty acids in moon cake baking. The above results indicate that nanoemulsion has great significance and prospects for development and use in improving food quality.