Reliable, rapid determn. of lipase activity in foodstuffs. - by colorimetric assay based on hydrolysis of substrate

摘要

Determn. is effected by (a) treating a sample of the foodstuff with an aq. buffer soln. (pH 5-10) contg. a nonionic detergent at 25-50 deg.C. for at least 30 min. to extract lipases; (b) opt. filtering the extract; (c) adding a lipase substrate and a colour indicator; (d) measuring the optical density at a wavelength depending on the indicator to obtd. a blank reading; (e) incubating the soln. at 25-50 deg.C. for at least 1 hr. to permit lipase-catalysed hydrolysis of the substrate; and (f) remeasuring the optical density. USE/ADVANTAGE - The process may be used to assess the storage stability of foodstuffs, e.g. herbs and spices, by measuring microbial lipase activity. The assay is faster, more reliable and less expensive to perform than fluorescence assays based on hydrolysis of methylumbelliferone