GLUCOAMYLASE ACTIVITY IN INDUSTRIAL ENZYME PREPARATIONS USING COLORIMETRIC ENZYMATIC METHOD - COLLABORATIVE STUDY

Fifteen laboratories participated in a collaborative study to validate a colorimetric assay for the determination of glucoamylase in industr ial enzyme preparations. All laboratories received 12 samples as blind duplicates provided by 3 industrial producers. Each sample was analyz ed once a day for 3 days, Results from one laboratory were excluded fr om the statistical analysis, Performance of the method was calculated according to the AOAC guidelines, For all 15 laboratories the repeatab ility relative standard deviation (RSD(r)) values ranged from 0.89 to 2.37%, and the reproducibility relative standard deviation (RSD(R)) va lues ranged from 7.92 to 9.86. After excluding outliers the RSD(r) val ues ranged from 0.74 to 2.24%, and RSD(R) values ranged from 3.46 to 8 .92, The colorimetric enzymatic method for determination of glucoamyla se activity in industrial enzyme preparations has been adopted first a ction by AOAC INTERNATIONAL.