Determination of pantothenic acid in foods: influence of the extraction method

The analysis of vitamin B-5 in foods requires the liberation of pantothenic acid present as bound forms such as CoA. Different methods are available to achieve this extraction. We have compared the influence of the extraction method on the quantification of pantothenic acid by both microbiological and immunological assays. Whatever the extraction method used, the two assays gave similar results and allow the quantification of pantothenic acid in foods. The equation of the regression curve between the immunological and microbiological assays was y = 0.309 + 0.936x and the correlation coefficient r = 0.969. Only alkaline phosphatase associated with pantetheinase contained in a pigeon liver extract realized the total liberation of pantothenic acid from pure CoA. This level of liberation was, respectively, 39.5 and 22.3% with mylase and papain associated with takadiastase. No hydrolysis was observed with buffer extraction without enzyme. Such a difference was not obtained from the extraction of foods. The quantity of pantothenic acid was only slightly modified by the extraction method used, either with supplemented or naturally vitamin rich foods. These results suggest the presence of endogenous enzymes that realize the whole or partly of the liberation of pantothenic acid if they are not destroyed by a heating treatment before the extraction procedure. (C) 1998 Elsevier Science Ltd. All rights reserved.