Optimization Of Detection Method And Stability Of Lutein In Infant Formula Milk Powder

Lutein is a kind of natural pigment,which is indispensable for infant's visual development.At present,the research on lutein is very extensive,but the research on Lutein in infant formula milk powder is not comprehensive enough,and the national standard for lutein detection is universal,which does not aim at infant formula milk powder,a special dietary food with complex matrix.Therefore,in-depth study of lutein in infant formula milk powder is of great significance for the healthy growth of infants and young children.In this study,the HPLC method for the determination of lutein in infant formula milk powder was optimized,and the stability of lutein was explored from the aspects of production process,background value of raw and auxiliary materials,representative nutritional additives and shelf life stability.Objective to provide practical basis for the content of lutein in infant formula milk powder.The main results are as follows:1.By adjusting the detection column temperature to 35?,adjusting the flow matching ratio to methanol/water(95+5,volume ratio,containing 0.1%)The national standard lutein detection method was optimized.The separation effect of lutein and impurities in milk powder was improved and the detection process was simplified.For the optimized method,the correlation coefficient was 0.9993,the detection limit was 2 ?g/100 g,the limit of quantification was 7?g/100 g,and the precision was less than 3.0%.The average recovery was 101.96% with RSD less than 2% in the linear range of 10%?90%.The measurement results were expressed as 260±8?g/100 g.The above data show that the method is feasible and accurate.2.Through the experimental analysis of lutein content in four stages of homogenization,high temperature sterilization,concentration and spray drying during the production process,the stability of lutein in the whole production stage was monitored.The results showed that the loss of lutein occurred mainly in the high temperature sterilization stage(t=19.494,p=0.000)and spray drying stage(t=10.210,p=0.000).Both of these production stages show a significance of 0.01 level,indicating that the two conditions had great influence on the results,while the homogeneous stage(t=2.977,p=0.031)and concentration stage(t=2.786,p=0.039).Both of these production stages show a significance of 0.05 level,indicating that the two conditions had influence on the results.By comparing the results of lutein content in different stages of the production process,the results showed that lutein loss was high spray drying stage > temperature sterilization stage > homogeneous stage > enrichment stage.3.The stability of lutein in finished infant formula milk powder was comprehensively investigated through the influence of characteristic nutrition fortifier(metal ions,vitamins),temperature and different packaging materials on lutein content.The results showed that the high content of metal ions and vitamins could accelerate the loss of lutein,while the low content of metal ions and vitamins had little effect on the loss of lutein.In the mixing process,temperatureand storage time are the main factors affecting the stability of lutein in milk powder.The higher the mixing temperature is,the higher the lutein loss rate is.When the mixing temperature should be controlled at 40?,the lutein content can be well maintained.In the temperature and packaging test,storage temperature is the most important factor.Under normal storage conditions,the retention rate of lutein can > PE aluminum foil soft packaging > paper bag packaging.