Determination of photostability of monoammonium glycyrrhizinate
2001
Couteau, C. | Coiffard, L.J.M.
In a previous study, it was shown that monoammonium glycyrrhizinate was thermostable in the pH range 7.0-9.0. To establish the best storage conditions of this sweetener, we have determined the photodegradation of 6 x 10(-5) M aqueous solutions of monoammonium glycyrrhizinate (lambda(max):256 nm, epsilon = 10600 M(-1) cm(-1)). The photodegradation appeared to follow first-order kinetics and was found to be pH-dependent. The degradation rate constant was calculated to be 8.85 x 10(-4), 5.38 x 10(-4), 4.33 x 10(-4), 4.66 x 10(-4) and 5.12 x 10(-4) min(-1), respectively, at pH 2.0, 4.5, 6.0, 8.0 and 10.0.
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