The Condition Optimization Of Spray-Dried Embedding Dha And The Application Of DHA In Acidic Milk-Containing Beverage

The mixed acidic milk-containing beverage is moderate in sweetness and sour,smooth and delicious.It not only retains the special flavor of yogurt,but also possesses most of the nutrition and functions of yogurt.It is favored by consumers,especially children.It is a good carrier for human body to supplement nutrients.It can be considered to strengthen DHA in it.Docosahexaenoic acid,referred to as DHA,is essential for human growth and health.DHA can promote brain development and eye function development of infants,and improve the sensitivity of infants to the nervous system.DHA can also prevent cardiovascular diseases,prevent the formation of myocardial infarction,cerebral thrombosis and cerebral infarction,improve the function of arteries,improve the autonomic regulation of the heart,and reduce the occurrence of arrhythmia and atherosclerosis.DHA contains some "isolated double bond" structures and five active methylenes.It is prone to oxidation,rancidity,polymerization,double bond conjugation and other chemical reactions.It produces algae-fishy substances mainly composed of carbonyl compounds,which not only affects the flavor,but also affects the quality and safety.The main forms of DHA algae oil are oil and microcapsule powder at present.DHA algae oil in food not only requires stricter product characteristics and process,but also is easy to oxidize.The microcapsule of DHA avoids the defect of easy oxidation of DHA oils to a certain extent,it is still easy to oxidize under high temperature because of its solid form and incomplete embedding.Especially when it is applied to acidic liquid food,it is easy to oxidation,rancidity,fishy.And the problem of oxidation limits its application in food.Few studies have been done on the application of DHA in acidic milk drinks at present.Therefore,the stability of DHA algae oil microcapsule with different wall materials has been studied in this paper.Homogeneous pressure,inlet and outlet temperatures,as well as the feed concentration rarely studied,have been selected to obtain more stable DHA microcapsule powder and to further study the application of DHA microcapsules in acidic drinks.To provide some reference for the development of new DHA functional beverage.The main results are as follows:1?Among the four formulation groups,lactalbumin powder(wall material ?),sodium caseinate(wall material ?),modified starch(wall material ?)and maltodextrin(wall material ?)were used as main wall materials respectively,the emulsifying stability of wall material ? and wall material ?after two-stage homogenization reached 100%,and the surface oil content was significantly lower than that of other two-stage homogenization group and all one-stage homogenization group(p<0.05).The flavor of two-stage homogeneous DHA microcapsule powder was much better than that of one-stage homogeneous group.The peroxide value of two-stage DHA microcapsule powder 24 Days of Antioxidant accelerated test at 62? was no more than 8 meq/kg.Compared with the same formulation,the two-stage homogeneous DHA microcapsule powder was significantly lower than that of one-stage homogeneous group(p<0.05).Among them,the peroxide value of the second section of wall material ? was 2.94 meq/kg after 24 Days of Antioxidant accelerated test at 62?,which was significantly lower than that of the other groups(p<0.05).The results showed that wall material I had the best effect on DHA oil embedding.Two-stage homogenization process can make the small particles more uniformly dispersed in the system,which is more suitable for the production of conventional DHA powder.2?Through the single factor test of feed concentration,homogeneous pressure,air inlet temperature and air outlet temperature,then the orthogonal analysis of these four factors was carried out at three levels with microencapsulation efficiency as the index.Within the range of each factor level,the order of influence degree on microencapsulation efficiency of DHA grease powder was as follows:air inlet temperature>feed liquid concentration=homogeneous pressure>air outlet temperature,and air inlet temperature was the main factor.Important factors,feed concentration and homogeneous pressure are secondary factors,and outlet temperature has little influence in this research area.The optimum combination is:feed liquid concentration is 3:11,homogeneous pressure is 20 MPa,inlet temperature is 160?,outlet temperature is 80?.3?In acidic milk-containing beverage,the effect of DHA microcapsule powder after homogenization is better than DHA microcapsule powder before homogenization.The homogenization process can destroy the structure of DHA microencapsulation,resulting in the overflow of DHA oil and easy to be oxidized.4?The DHA microcapsule powder of sodium caseinate composite wall material is most suitable for acidic milk-containing beverage.It is suggested that the net DHA content in acidic milk-containing beverage should be less than 25 mg/100 g.In 180 Days,the taste was acceptable.