Preparation And Safety Evaluation Of 1,3-Diacylglycerol Pig Fat And Its Microencapsulation Application

Pig fat is a traditional edible oil in China,which is rich in resources and has a unique flavor.The modern nutritionists proposed that long-term consumption of a large number of animal fats,can lead to elevated blood lipids,easily lead to obesity,fatty liver,cardiovascular disease and other disease,adversely affect human health.With a variety of functions such as weight loss,Diacylglycerol(DG)is a recently launched a commercial healthy fat substitute.At present,pig fat was modified to obtain a high content of 1,3-diacylglycerol(1,3-DG)pig fat technology has not yet reported.Theoretically,enzymatic modification of 1,3-DG obtained from pig fat does not have a security risk,but it is necessary to carry out safety evaluation as a non natural food materials used in industrial promotion and utilization.In this study,according to the GB15193 of food safety toxicology evaluation procedures and methods of the standard system to evaluate the safety of modified 1,3-DG pig fat,in order to provide a safe basis for the application and development of new materials.In addition,1,3-DG rich oil has the problems of easy oxidation,poor liquidity,compared with ordinary oil.Therefore,it is of great significance to study the microencapsulation technology of new 1,3-DG pig fat by using the principle of microcapsule technology,which can prolong the storage period of 1,3-DG pig fat and expand its application in food industry.The main research contents are as follows:(1)The process of preparing 1,3-DG pig fat by lipase catalyzed hydrolysis in solvent free system was developed.The effects of enzyme dosage,molar ratio of alcohol to oil,reaction temperature and reaction time on the content of 1,3-DG in pig fat were studied.The results showed that the optimum technological parameters were as follows: the addition of enzyme was 9.6%,the mass ratio of alcohol to oil was23:50,the reaction time was 16 h,the reaction temperature was 55?,and the content of 1,3-DG in pig fat was about 45.5%.(2)The evaluation of enzymatic modified 1,3-DG pig fat provides scientific basis for its development and utilization.On the basis of procedures and methods for toxicological assessment on food safety,acute toxicity,genetic toxicity(Ames test,micronucleus test and dominant lethal test)and 28 d oral toxicity test were evaluated with KM mice and SD rats.(3)The acute toxicity test showed that there was no obvious abnormality,LD50>17g/kg,which was non-toxic in mice by oral gavage modified 1,3-DG pig fat.Further more,the results of three genetic toxicity tests were negative and showed no mutagenicity.Finally,28 d toxicity test results showed that each dose group of rats with normal clinical examination,body weight,food intake,food utilization,blood routine,blood biochemistry,organ body ratio and other indexes were in the normal range compared with the control group,and the difference was not significant(p >0.05).In addition,histopathological observation showed no pathological changes.This study was designed to reduce the oxidation of 1,3-DG pig fat and prolong the shelf life of the product.Using sodium alginate as wall material,1,3-DG pig fat as core material and sucrose ester as emulsifier,the microcapsules of 1,3-DG pig fat were prepared by microencapsulation.With the embedding rate as the index,the single factor test and response surface analysis were used to optimize the preparation process of 1,3-DG pig fat microcapsules.Then,the physical and chemical indexes,morphological characteristics,oxidation stability and storage stability were analyzed.The results show that the optimum conditions of microcapsule granulation instrument:coagulant concentration of Ca Cl2 was 100 mmol/L,granulation instrument frequency was 1000 Hz,the pressure was 600 mbar;the best formula of microcapsule material:wall material concentration was 1.4%,core wall ratio was 1:1.9,emulsifier dosage was 2.8%.Under these conditions,the encapsulation efficiency of microcapsules was85.2%,the water activity was about 0.227,the ash content was about 1.98%,and the particle size distribution was about 280 um.This study from the development of the preparation technology of 1,3-DG fat pig,food safety assessment,to study 1,3-DG pig fat preservation technology,has laid the foundation for the new industrialization to human health functional animal grease,1,3-DG pig fat,and realize the effective value of pig fat utilization.