Enzymolysis Of Milk By Adding Lactase And The Production Of Low Lactose Milk Powder

People who lack of lactase in their small intestine will have abdominal distention, diarrhea and bellyache symptoms after they drink milk. In medicine, it is called Lactose Intolerance (LI), which is caused for lactose mal-absorption. It was said that almost 1/3-1/2 human beings in the world have more or less lactase deficiency. In china, 75%~95% han people have this problem, 76%~95.5% minority as well. LI heavily impacts people obtaining abundant nutrition from milk; it will be much sense to deal with this malady."We tried to add lactase to milk to decompose some lactose, so as to produce low-lactose milk. People who have LI can also absorb a little lactose. We have determined the adding quantity as 0.1% at 39℃, and keep the decomposing for 4 hours. The taste and flavor of the low lactose milk after enzymolysis have no difference though a little more sweet. The fatty acid constitute has slight change.Liquid t-S Newton character was also determined. It shows that: pure milk is non-Newton liquid with an average viscosity as 2.69cp; milk after adding lactase, the average viscosity is 2.56cp, which means that milk after enzymolysis is more likely to Newton Liquid.To low down the sweetness caused form the enzymolysis, we use the organic membrane to filtrate some lactose and glucose. We have chosen 30000 and 150 MW membranes filtrate directly and filtrate after diluting to a half concentration. It shows that filtrate directly is more effective, diluting before filtrate can accelerate the course. The fat has the highest retention as 98.37%, while the lactose has the lowest as 24.7%.We also adopt microencapsulation spray desiccation technology to produce low-lactose milk powder, in which vegetable oil is used as core material, casein and dextrin and soluble fiber as wall material simultaneously. The prime arts and crafts are 190℃ inlet temperature, 90℃ outlet temperature, feed-in velocity as 25mL/min at 0.10MPa airflow pressure. The ratio of soluble fiber and casein and dextrin is 1:3:35.