The invention relates to a method for determining α-arabinofuranosidase (abbreviated ABF) activity in a sample, referred to as the sample to be analyzed (p), of a product intended for
animal feed and containing an additive that exhibits ABF activity, the ABF activity to be determined being specific to the additive, the method comprising the following steps: on the one hand, a sample, referred to as the
control sample (c), of the product which is free of the additive, and, on the other hand, the sample to be analyzed (p), are provided; for each of the
control sample (c) and the sample to be analyzed (p), respectively, an
enzyme fraction exhibiting ABF activity is extracted under the same conditions, then the ABF activity of each of the extracts, respectively ABFc and ABFp, is measured; and ABFp - ABFc is calculated to obtain the specific ABF activity of the additive in the product; according to which method the ABF activity is measured by
fluorescence by means of a substrate for the
enzyme, 4-methylumbelliferyl-α-L-arabinofuranoside, which is hydrolyzable to fluorescent 4-
methylumbelliferone.