Effects of Different Sterilization Treatments on Bioactive Proteins in Camel Skim Milk and Cream
The fresh camel milk was divided into skim milk and cream.Skim milk was treated by microfiltration,ultraviolet-c radiation and pasteurization,and cream was treated by high temperature treatment.The effects of non-thermal and thermal treatments on removal of microorganism,retention of active protein,and oxidation of protein and lipid were studied.Compared with pasteurization,the results showed that microfiltration and ultraviolet-c irradiation could reduce the total bacterial count and the spores could be completely or partially removed.1.4 μm microfiltration and ultraviolet-c irradiation retained more lactoferrin and immunoglobulin G.The lactoperoxidase activity decreased to 1/6 after pasteurization.However,the lactoperoxidase activity was more than 95％after 1.4 μm microfiltration or ultraviolet-c irradiation.Polyamine oxidase was susceptible to ultraviolet-c irradiation.Insulin was completely retained after 1.4 μm microfiltration.The retention of native whey protein by microfiltration was higher than that by pasteurization.Compared with thermal treatment,there was no significant glycosylation in non-thermal treated skim milk.Compared with 0.8 μm microfiltration,the membrane flux and permeability of protein was higher than 1.4 μm microfiltration,and the permeability of whey protein and caseins was 95.5％and 74.1％,respectively.In the high temperature sterilization of mixed cream,the bacteria and spores could be killed at 125 ℃ for 5 s,and the degree of oxidation of protein and lipid was low.Firstly,the whole camel milk was divided into skim milk and cream,each part was sterilized and then mixed.This method could ensure the overall sterilizing efficiency and improve the overall retention of active components.
NETL
NSTL
万方数据
