Research On Preparation Of Nutritious Margarine With Lipase Catalyzed Interesterifation Of Lard And Peanut Oil

The margarine is a kind of foodstuff that widely consumed in modern life.Currently,most of the margarine in the market produced by the way of hydrogenation and fractionation with natural oils and fats is poor in nutrition, more saturated fatty acid (SFA) and trans fatty acid (TFA). Therefore,looking for a new method for the preparation of low trans fatty acid and high unsaturated fatty acid (UFA) margarine is meaningful.Interesterification is an important mean of grease modified,it can change the nature of the grease by changing the distribution of the fatty acid molecules in triglycerides of the oils and fats,especially the change of the crystallization and melting characteristics and there is no trans fatty acid.Lard has excellent shortening and fat plastic,peanut oil containing a large number of unsaturated fatty acids,with a high nutritional value.This subject intends to use the lard and peanut oil as raw materials,adjusting the mass ratio of them,preparing margarine binder oil which is feeding and no trans fatty acids.The content of palmitic acid in acidtriglycerides sn-2position of lard is76.71%,this the main reason that make the lard β crystal. This topic using the lipase catalyzed transesterification method,with the changes of content of palmitic in acidtriglycerides sn-2position as an indicator.The best technological numbers when lard:peanut oil=1:1(w/w) were obtained by orthogonal test as following:the reaction time4h,lipase add3%of the amount of substrate,the reaction temperature is60℃.Under this condition,the content of oil of palmitic acid in triglycerides sn-2position was decreased from39.36%to24.26%. Under this technological numbers,with solid fat index(SFI) as target,determination the solid characteristic change of the oils and fats with different mass ratio before and after interesterification.The results show that the plastic range of grease is increased.The reaction product is suitable for the preparation of nutritional margarine base material oil.Using the differential scanning calorimetry (DSC) and X-ray diffraction (X-ray) determination the thermal properties and crystal of grease before and after interesterification.The results show that the triglycerides species in the oils and fats is increased,the melting process is gentle,the miscibility among triglycerides is increasd,the crystal morphology of oil is changed,more β’crystal form after interesterification. by the whole fatty acid composition analysis,the content of unsaturated fatty acid in grease after interesterification is increased compared with commercial margarine,nutritional enhanced.It is suitable to be margarine base material oil.In order to make the margarine has the best consistency and plastic range,using SFI as target to coordinate fat with the pilot with fat after interesterification,palm stearin and soybean oil.The results show that Palm stearin:interesterification oil:Soybean oil (w/w/w)=16:80:4,8:88:4,4:88:8, SFI curve after coordinate is coincide with the SFI curve universal margarine, Soft and hard margarine,soft margarine.Determine the optimal formulation of emulsifiers,Lecithin:Sucrose esters of fatty acids (SE-11):Sucrose esters of fatty acids (SE-15)=0.2:0.6:0.2.Preparation of margarine under laboratory conditions,the results show that prepared margarine is better in application performance and be able to meet the requirements.