Validation method of analysis of imunoglobulin G in skim milk powder using enzyme link immunosobent assay (ELISA).

Abstract

People take a more proactive approach to maintaining their wellness by looking for natural ways to stay healthy and maintain a balanced immune system such as functional food. Functional foods are foods, and in fact they are foods, that go beyond simple nutrition and have specific targeted actions. Various strategies have been adopted to develop functional foods. The last approach to developing functional foods is based on the addition of ingredients that are very specific and have a very targeted action, that are used to reduce the risk of disease. Milk-based products enriched with immunoglobulins are recently available in the market. The active ingredient, colostrum, is targetted at maintaining health and the natural microbiota. The product is claimed to be lactose-free and fat- free, to have benecifial effects on the immune system and to improve the health of muscles and joints. Immunoassay is development of food analysis which is antibody-based optical were used as to determine IgG because of their simplicity, sensitivity and spesificity. Immunoglobulin G (IgG) in skim milk powder were analyzed by Sandwich Enzyme Link Immunosorbent Assay using bovine IgG ELISA kit. However, before adoption analysis method as a routine method, it should be validated. Standard curves were constructed using IgG standard (stock solution is 125ng/ml), ELISA was linear within 0-125 ng/mL range. Therefore, the samples required a 1/500 dilution to approximately 12.8 ng/mL. ELISA was developed for determination of IgG in bovine milk and colostrum with either goat or rabbit antibovine IgG or protein G used as detecting molecule. Performance parameters validation included liniearity, showed a working range of 5,10 ng to 38,42 ng and correlation coefficient r: 0.99. Overall instrument response repeatability relative standard deviation (RSD) were of 3,87% , 9,67% and 4,86% for IgG over 7 analyses for 3 kind of samples and recovery was 111,24%. The technique was applied to the measurement of IgG content in milk powders, and a precision relative standard deviation values of 20%, acuracy of 85-115% and percent recovery of RSD 15%, and the method is specific.