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Thermal Destruction of Pteroylglutamic Acid in Buffer and Model Food Systems
Author(s) -
MNKENI A. P.,
BEVERIDGE T.
Publication year - 1982
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.1365-2621.1982.tb12940.x
Subject(s) - chemistry , reaction rate constant , buffer solution , nuclear chemistry , kinetics , chromatography , quantum mechanics , physics
First order rate constants (k) and activation energies (Ea) of pteroylglutamic acid (PteGlu) were determined between 100 and 140°C in citrate buffer (pH 3–6) and model food systems. The rate constants (hr ‐1 ) in citrate buffer ranged from 0.145–2.36 at pH 3; 0.074–0.840 at pH 4.0; 0.021–0.207 at pH 5.0, and 0.015–0.133 at pH 6.0. Corresponding Ea values were 22.6, 19.5, 17.8, and 16.8 kcal/mole at pH 3, 4,5, and 6, respectively. In an apple juice model (pH 3.4), the rate constants ranged from 0.063–0.822 and in tomato juice model (pH 4.3), from 0.056–0.723. Ea values in apple juice an tomato juice were 20.0 and 19.7 kcal/mole, respectively.