Preparation,characterization And Lipid-lowering Function Of Whey Protein-diacylglycerol Emulsion

1,3-diacylglycerol have a variety of effects,such as reducing blood fat,inhibitting the body fat accumulation,lossing weight,alleviating diabetes,etc.There have been many studies on 1,3-diacylglycerol,but the highly oxidized nature of 1,3-diacylglycerol has limited its use in foods.In this study,whey protein was used as the wall material,and 1,3-diacylglycerol as the core material.On the basis of single factor experiments,response surface analysis was used to optimize the preparation process of the whey proteindiacylglycerol nanoemulsion which prepared by high-pressure homogenization method.The characterization and lipid-lowering fuction of the nanoemulsion were respectively studied to improve the stability and bioavailability of 1,3-diacylglycerol,which provided a theoretical basis for the application of whey protein-diacylglycerol nanoemulsion in foods.1.The preparation process optimization of whey protein-diacylglycerol nanoemulsionThe whey protein-diacylglycerol nanoemulsion was prepared by high pressure homogenization method.Using the particle size and embedding rate of the nanoemulsion as comprehensive index,the preparation conditions of the nanoemulsion was optimized by single factor experiments and response surface analytical methodology.The optimal conditions of the whey protein-diacylglycerol nanoemulsion were as follows: wall material concentration 15.83%,the ratio of wall material and core material 3.35?1,emulsifier amount 4.02%.2.Characterization of whey protein-diacylglycerol nanoemulsionThe type,surface properties,centrifugal stability,temperature stability,oxidation stability and storage stability of the nanoemulsion were respectively studied.The results showed that,the nanoemulsion was O/W type,negatively charged,uniform distributed,and had an obvious core-shell structure.The average particle size of the nanoemulsion was around 142 nm,and the embedding results of the nanoemulsion were good.The nanoemulsion with good stability at the temperature under 80?,and can effectively delay the oxidation of diacylglycerol.The best storage temperature of the nanoemulsion was 4 ?.3.Lipid-lowering function research of whey protein-diacylglycerol nanoemulsionThe mice high-fat model was set up by high fat diet induced.The high-fat model mice were fed with whey protein-diacylglycerol nanoemulsion.The effects of whey protein-diacylglycerol nanoemulsion on the body weight,viscera index,blood fat,fat index and lipid metabolism of high-fat model mice were studied.The results showed that,whey protein-diacylglycerol nanoemulsion could significantly decrease the weight,fat index and liver index of high-fat model mice(P < 0.05),and it had no toxic side effect on the organs of mice.Moreover,the nanoemulsion could significantly decrease the level of TG,TC,HDL-C,LDL-C,FBG,FFA in the serum of high-fat model mice(P < 0.05),and significantly increase the level of HDL-C(P < 0.05).The whey protein-diacylglycerol nanoemulsion also had a certain repair effect on liver fat lesions in high-fat model mice,and could reduce the abdominal adipose accumulation and the size of abdominal fat cells in mice.The expression levels of FABP1,ABCA1,PPAR? m RNA were significantly increased in the liver(P < 0.05),and the expression levels of DGAT1 m RNA were significantly decreased in the liver(P < 0.05).The bioavailability of 1,3-diacylglycerol was improved by the whey protein-diacylglycerol nanoemulsion.And the lipid-lowering function of whey protein-diacylglycerol nanoemulsion was better than 1,3-diacylglycerol.