ABSTRACTThe use of mathematical computer‐aided simulations of liquid food quality degradation during storage requires the prior knowledge of kinetics of the reaction rates. In this paper a procedure to obtain this type of information is discussed. The objectives of this study were (1) to determine the rates of ascorbic acid oxidation and oxygen uptake in infant formula and (2) to determine the influence of light intensity on rates of ascorbic acid oxidation and oxygen uptake during storage. The quality index studied in this research was reduced ascorbic acid. Infant formula was selected as the model system. The overall reaction of ascorbic acid degradation and oxygen uptake was assumed and confirmed to be a second‐order reaction under limited dissolved oxygen presence in the liquid. The second‐order rate constants were calculated for ascorbic acid degradation and dissolved oxygen uptake in infant formula samples exposed to light in 1‐cm deep exposure cells. These storage experiments were conducted at five light intensities (dark, 1071 lux, 2142 lux, 3213 lux and 4284 lux) and three initial dissolved oxygen concentrations (1.0 ppm, 4.86 ppm and 8.71 ppm). The results indicated that in samples exposed to light, an increase in initial dissolved oxygen content increased the second‐order rate
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