Study On The Process And Stability Of Rice Milk Beverage Contained Cow Milk

Innovative milk beverage is a kind of product drawing much attention from dairy companies in China. As a double-protein beverage product, rice milk beverage contained cow milk joins nutritional value and social benefit value together.Effects to the stability and color of rice milk produced by different extracting methods were studied in this paper. The optimum extracting parameters were fixed on. It was found that rice milk extracted by enzymatic hydrolyzing method had better stability than that extracted by milling method, but appeared worse color due to stronger browning problem. The optimum extracting parameters for milling method were: at 75℃milling for 14min, the ratio of the rice to water added was 1:10. The optimum extracting parameters for enzymatic hydrolyzing method were: at 55℃, 70 U·g-1 riceα-amylase reacting for 1h, the ratio of the rice to water added was 1:8. Enzymatic hydrolyzing method was better than milling method through general evaluation.After that, the basic formula of the product was studied through sensory evaluation. Different homogenization and sterilizing parameters were also studied. The results were as follows: sugar adding quantity was 2.0%, whole milk 10%. The optimum homogenization temperature was 60℃, pressure 40+20MPa. The products produced under the above homogenization condition hold a 313.4nm particle diameter, which was less than 1μm, polydispersity index was 0.631< 1.05. Products sterilized by UHT showed better stability and less browning index than that sterilized by high temperature high pressure in-canned method. The sterilization formula for high temperature high pressure in-canned method was 115℃holding for 15min. The sterilization formula for UHT was 135℃holding for 5s. The product quality was assured using these sterilization formulas.At last, the optimum emulsifier and stabilizer formula was studied. The result was DMG: SE15=2:3(w/w), adding 0.08%, CMC 0.01%+XG 0.05%. The rice milk and milk beverage product showed high stability using the formula above after 3 months'storage. The particle diameter of the product was 579.9nm, PDI value 0.738< 1.05 after 3 weeks'storage, determined by particle dispersing chart using Nano-ZS90 particle size analyzer produced by Malvern Instruments Ltd., which meant the product was still a colloid and single dispersing system.