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Kinetics of Ascorbic Acid Loss and Nonenzymatic Browning in Orange Juice Serum: Experimental Rate Constants
Author(s) -
JOHNSON JR.,
BRADDOCK R.J.,
CHEN C.S.
Publication year - 1995
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.1365-2621.1995.tb09812.x
Subject(s) - ascorbic acid , chemistry , browning , orange juice , reaction rate constant , kinetics , orange (colour) , nuclear chemistry , chromatography , food science , physics , quantum mechanics
The kinetics of ascorbic acid loss and nonenzymatic browning in clarified orange juice (serum) were investigated in an anaerobic environment from 70.3 to 97.6°C and from 11.7 to 80.6Brix. Data were fitted to firstorder kinetic models. Rate constants of ascorbic acid degradation in serum were not different from rate constants in whole juice. Activation energies were ±30 kcal/mol and largely independent of solids concentration. Rate constants of browning pigment formation were 30–50% greater in serum. Activation energies were 19–25 kcal/mol and increased slightly with solids concentration.