Characterization Of Compound N-3/n-6 PUFAs And PS Microcapsules And Their Application In Middle-aged Formula Milk Powder

The balance of n-3 and n-6 polyunsaturated fatty acids ratio is very important for maintaining the stability of human body environment,improving cognitive memory and preventing chronic diseases.However,there is no unified conclusion on the optimal dietary intake ratio of n-3 /n-6 PUFAs.Phosphatidylserine and polyunsaturated fatty acids are important nutrients in the brain,which play an important synergistic role in structure and function.They are often used in middle-aged and elderly formula milk powder.In this paper,the cognitive protective effect of compound n-3/n-6 unsaturated fatty acids on the aged mice was studied by animal experiments.The optimal proportion of twenty-two carbon six enoic acid(DHA)and peanut four fatty acid(AA)was obtained.Then,the n-3/n-6 unsaturated fatty acids and phosphatidylserine microcapsules were prepared by spray drying.The physical and chemical properties and application of microcapsules were studied.The main research contents and results are as follows:(1)With 12-month-old ICR mice as test animals,after 6 weeks of continuous gastric polyunsaturated fatty acid grease,Y maze and Morris water maze methods observed learning memory and cognitive differences,and monitored the changes of peroxidation levels,blood lipid levels and brain Aβ-40 amyloid levels in mice.The results found that the incubation period of some unsaturated fatty acid oil mice was shortened and increased(p<0.05),unsaturated fatty acid oil group decreased peroxide(p<0.05),and Aβ-40 amyloid level in the brain(p<0.05).Feed DHA algae oil / AA grease = 1: 1,mice performed best.(2)The functional composite microcapsules were prepared by spray drying method with composite wall materials.The orthogonal design was applied to optimize the process.The physicochemical properties of the microcapsules were characterized by means of electron microscopy,infrared spectroscopy and thermogravimetry.The results showed that the optimum conditions were core wall ratio 1:3,homogeneous pressure40 MPa,spray temperature 180 degree,wall material ratio 5:20.The microcapsule structure is regular and complete,the embedding rate is92.48%,the surface oil content is 2.53%,the moisture content is only3.24%,and the moisture resistance and fluidity are good.Infrared spectrum analysis showed that the chemical structure of the core material did not change during the microencapsulation process.Thermogravimetric analysis showed that the self-made microcapsules had good thermal stability below 190 ℃.After microencapsulation,the oxidation stability of oil was significantly improved,phosphatidylserine can inhibit lipid oxidation to some extent.(3)The middle-aged formula milk powder was prepared by dry process and wet process,respectively.The milk powder prepared has milky color,strong frankincense and good blending property.During the production process,the POV value of the milk powder did not change significantly,and the ingredients met the enterprise standard of middle-aged and elderly formula milk powder.Scanning electron microscopy showed that wet milk powder particles were more broken.At60℃ accelerated storage,it was found that the addition of oil microcapsules reduced the stability of milk powder,but the oxidation stability of dry milk powder was slightly better than that of wet milk powder.The deterioration of milk powder could be observed to some extent by color difference and electronic tongue analysis.