METHOD DEVELOPMENT AND VALIDATION FOR QUANTITATIVE ANALYSIS OF MILK SOLID CONTENT IN CHOCOLATE
Authors: Rahmat M. and Aftar Mizan A. B.
Journal Issue: Malaysian Cocoa Journal, Volume 13(2)/2021
Keywords: milk fat, butyric acid, measurement uncertainty, selectivity, linearity, GC-FID
Published On: 1/11/2021
Abstract
In this study, an efficient and rapid method for estimation of milk solid content in chocolate via quantification of butyric acid was developed and validated. The method was based on direct base-transesterification of chocolate sample without fat extraction prior to quantification using gas chromatography coupled with flame ionization detected (GC-FID). Good selectivity and sensitivity were obtained with LoD and LoQ at 1.41 ppm and 4.95 ppm respectively. The mean recovery for butyric acid was 90% with relative standard deviations of less than 10% and the expanded uncertainty measurements for elements were less than 25% (with a coverage factor of 2 with a confidence level of 95%). Finally, the developed method was successfully applied for routine analysis of milk chocolate and dark chocolate.