Abstract: [Objective] In order to improve the added value of Yunnan dairy cake whey,a new type of whey powder with high nutritional value was obtained by spray drying technology. [Method] With whey liquid as raw material,solubility and sensory score as evaluation indexes,single factor combined with orthogonal test was used to determine the optimum technological conditions for preparation of whey powder. [Result] The results showed that when the dosage of sodium bicarbonate was 0.7%,the centrifugal condition was 3 600 r/min,the curd pH was 6.5,the inlet temperature of spray drying was 180 ℃,and the peristaltic pump value was 70 Hz,the protein, lactose,moisture and ash contents of the whey powder prepared were 13.9%,49.4%,3.3% and 6.8%,respectively. The solubility of the whey protein powder is 95.18 g/100 g,and the emulsification is 72.07%. The whey protein powder has an attractive milk flavor,no acid taste and peculiar smell,and the color is uniform and pale yellow. The taste is smooth and the rehydration is good. [Conclusion] The experimental study provided a way for the utilization of whey liquid as a by-product of dairy cake,and provided a certain theoretical basis and reference value for the further processing of whey powder.

Key words: milk cake by-product, whey powder, spray drying, physical and chemical indexes, microbial