Separation Process Of Goat Milk Based On Ceramic Membrane Technology

Membrane separation is a physical fractionation process based on the molecular weight of the feed components.Due to the characteristics of low operating temperature,energy saving,no chemical additions,simple equipment,and no phase change.The membrane separation technology is used to separate the dairy industry,which not only preserves the natural state of the components in goat milk.It does not affect the functional properties of each component.At present,membrane separation technology for cow's milk is increasingly mature and industrialized production has been achieved(Canada,New Zealand,etc.).However,the research on membrane separation technology of goat milk has not attracted enough attention and lacks systematic data,which is still in its infancy.To a certain extent,it restricts the development of the goat milk industry.In this experiment,the microfiltration process of goat milk was used as the main line.The comparative study on the effect of separating milk protein in skim goat milk with different membrane pore sizes and the separation effect of lactose and other components in whole goat milk with different membrane pore size were studied.It provides a theoretical and applied basis for the membrane separation process of goat milk,the development of functional goat milk base and lactose-free goat milk.The main findings are as follows:(1)The 0.05?m ceramic membrane was selected as the optimal membrane material for the separation of casein and other components in defatted goat milk,and the effect of separating the milk protein from ceramic membrane was quantified.The results showed that the average membrane flux of ceramic membrane was maintained at 96.89 L/(m~2·h),the whey protein removal rate was 96.17%,the lactose removal rate was 86.42%,the ash removal rate was 73.39%,and the calcium removal rate was at 34.90%,the phosphorus removal rate was 55%.The pure water flux attenuation coefficient of the membrane after dilution and filtration was 55.57%.After cleaning with a mass fraction of 2%sodium hydroxide and 1%nitric acid solution,the membrane flux recovery coefficient was99.21%,and the ceramic membrane was well recovered.(2)The retentate and permeate in(1)were separately concentrated to a solid content of35%and 30%.After spray drying,goat casein micelle powder with protein content higher than 84%and 7%goat whey powder were successfully prepared.The other indexes were in accordance with the requirements of GB 11674-2010 whey powder and whey protein powder and GB 31617-2014 casein.(3)The 0.1?m ceramic membrane was selected as the best membrane material for the separation of lactose and other components in whole goat milk.Compared with the 0.2?m ceramic membrane,the 0.1?m ceramic membrane permeate is transparent yellow-green.While the 0.2?m ceramic membrane permeate is white turbid yellow-green,indicating that 0.1?m ceramic membrane can completely retain casein and increase lactose-free sheep.Milk production.(4)Lactose-free goat milk was successfully prepared in this experiment.The lactose content is 0.18%,protein content is 9.95%,fat content is 10.44%,calcium content is 97.33mg/100 mL,solid content is 23.16%.All indicators meet the requirements of the guidelines for Claims of Food Nutrition and Functions of Nutritional Components issued by the National Health and Family Planning Commission of China.