Glucoamylase Activity in Industrial Enzyme Preparations Using Colorimetric Enzymatic Method: Collaborative Study

Abstract

Abstract Fifteen laboratories participated in a collaborative study to validate a colorimetric assay for the determination of glucoamylase in industrial enzyme preparations. All laboratories received 12 samples as blind duplicates provided by 3 industrial producers. Each sample was analyzed once a day for 3 days. Results from one laboratory were excluded from the statistical analysis. Performance of the method was calculated according to the AOAC guidelines. For all 15 laboratories the repeatability relative standard deviation (RSDr) values ranged from 0.89 to 2.37%, and the reproducibility relative standard deviation (RSDR) values ranged from 7.92 to 9.86. After excluding outliers the RSDr values ranged from 0.74 to 2.24%, and RSDR values ranged from 3.46 to 8.92. The colorimetric enzymatic method for determination of glucoamylase activity in industrial enzyme preparations has been adopted first action by AOAC INTERNATIONAL.