Determination Of Folic Acid Content In Milk Powder By Microplate Method

Vitamins are a type of organic matter necessary to maintain the normal physiological functions and metabolism of living organisms.It is very low in the body and needs to be obtained from food.The lack of a certain vitamin in a long period of time can cause the corresponding lack of symptoms in the body.Water-soluble vitamins contain vitamin C and B vitamins.B vitamins are an important part of coenzymes or prosthetic groups.They participate in the metabolic process in the body and cannot be stored or stored in the body for a long time.They are easily consumed and metabolized and need to be replenished every day.Folic acid is actually one of the B vitamins,it is an indispensable part of human health,so the daily folic acid intake of folic acid and the determination of folic acid and its toxicological effects are hot topics of research today.Moreover,the method of measuring folic acid is the basis and premise for studying these problems,so the detection method of folic acid becomes particularly important.How to accurately measure the content of folic acid is one of the important criteria for measuring the quality of detection methods.Microbiological method is a common method for the determination of folic acid,which can accurately detect the biochemically active folic acid.The result shows the folic acid content in the matrix,which is the biggest advantage of the microbiological method different from other detection methods.The method is difficult to achieve.Most international standards now use microbiological testing as the first standard for multivitamin testing.Folic acid in dairy products and infant formulas is still detected by microbiological methods in the national testing standards currently in force in China.Lactobacillus casei(ATCC 7469)has a strong specificity relative to folic acid.Folic acid is an essential growth factor for this bacterium,and in a certain growth environment,the rate of growth and proliferation of the bacterium is proportional to the content of folic acid in the system.Relationship,microbial law is based on this principle quantitative analysis of folic acid.The detection process of the microbiological method is generally divided into the following six detection steps: 1)preparation of the working bacterial suspension.2)Preparation of test samples and working standard curves.3)Preparation of the test medium,the finished medium can now be applied.4)Sterilization and inoculation and culture.5)Sample measurement,the main method is optical density method.6)Calculation.In this paper,based on the principle of microbial methods and basic analytical procedures,a microplate assay method was developed.By repeating five measurements on ten groups of unknown concentrations,the relative standard deviations of the samples were <2%;The determination of the concentration sample shows that the relative error of the experiment is <2%;the recovery rate of the experiment is 98%-106%;the linear correlation coefficient can also reach 0.9995 or more;the coefficient of variation between the parallel holes of the same experiment is also < 5%.Therefore,the microplate method can be used to accurately determine the content of folic acid in milk powder,and compared with the traditional test tube method,the operation time of the experiment can be shortened in a large amount,the difficulty of the experiment is reduced,and the experiment cost is saved.The advantages of the microplate method are low cost,high sensitivity,high sample size measurement and high operability.With the rapid development of modern technology,many instrument detection methods have been developed to detect low content.Folic acid food.The instrumental detection method only detects and analyzes the folic acid derivative and a certain structure of folic acid.However,when analyzing the folic acid of all structural forms,the difficulty and complexity of the experiment will be large,and the cost will increase accordingly.Therefore,when performing analytical tests,researchers can determine the method of measurement based on different research purposes.