Patent ID: 6413779
Filing Date: 2002-07-02
Classification: G01N

Abstract:
A method for evaluating loss of nutritional quality of proteins contained in a nutrient subjected to a heat treatment comprising the following steps:a) collecting a sample of said nutrient subjected to said heat treatment and adding thereto an ionic strength buffer at appropriate pH to obtain, on the one hand, a precipitate of proteins denatured by said heat treatment and, on the other hand, a transparent supernatant containing proteins which are still soluble; b) analyzing tryptophan fluorescence in said supernatant as a measure of protein denaturation and tryptophan degradation consecutive to said heat treatment; c) analyzing fluorescent by-products derived from an advanced Maillard reaction in said supernatant; d) calculating the ratio between the fluorescence of Maillard products over the fluorescence of tryptophan; and (e) correlating said ratio between the fluorescence of Maillard products over the fluorescence of tryptophan to the amount of nutritional damage on lysine.