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A Simplified Method for Determination of Browning in Dairy Powders
Author(s) -
PALOMBO RAHAMIM,
GERTLER ARIEH,
SAGUY ISRAEL
Publication year - 1984
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1365-2621.1984.tb12855.x
Subject(s) - browning , pronase , repeatability , chemistry , chromatography , proteolysis , reproducibility , coefficient of variation , proteolytic enzymes , reagent , enzyme , food science , analytical chemistry (journal) , biochemistry , trypsin , organic chemistry
An improved method for the determination of nonenzymatic browning in dehydrated dairy powders is described. The method involves liberation of the brown pigments from the protein molecules by means of a proteolytic enzyme, pronase. For complete proteolysis, the pronase mixture (2.53 mg enzyme/U.lg dry powder) was incubated at 45°C for 2 hr. After clarification, the browning index (defined as the optical density difference measured at 420 nm and 550 nm) was determined spectrophotometrically. The suggested method proved to be straightforward, easy to employ, and showed high accuracy and reproducibility. The procedure is suitable for routine laboratory analyses and its repeatability, as expressed by the coefficient of variation, was below 3%.