关键词: 牦牛酥油, 微囊粉, 冷冻干燥, 喷雾干燥, 乳化剂

Abstract: It was dedicated to solve the problem that yak butter is not easy to store and has bad flavor due to fat oxidation, maltodextrin and sodium caseinate were used as wall materials, molecular distillation monoglyceride and sucrose ester were used as emulsifiers, guar gum was used as a stabilizer to encapsulate yak butter, and yak butter microcapsule powder was prepared by vacuum freeze-drying and spray drying methods. The basic physical and chemical properties (moisture content, solubility, rheology, surface oil, encapsulation rate, yield), microscopic structure characterization, and thermal stability of the two were compared. The results showed that the microcapsules prepared by the two methods were milky white, free of impurities and fragrant. Both of them had good embedding rates (94.09%±0.22 and 92.28%±0.60).The yield of freeze-dried microencapsulated powder(98.42%)was significantly higher than that of spray-dried microencapsulated powder(25.77%), and the average particle size(16.70 μm)was smaller than that of spray-dried powder(24.95 μm). The solubility and fluidity of spray-dried powder were superior to those of freeze-dried powder. Under the scanning electron microscope, the surface of microencapsulated powder was smooth, the spray-dried powder was spherical, and the freeze-dried powder was irregular. The thermal stability of the spray-dried powder determined by TGA and differential scanning calorimetry was better.

Key words: yak butter, microencapsulated powder, freeze drying, spray drying, emulsifier