ISSN:
1750-3841
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Oxygen uptake of a model system containing β-carotene was measured by a method capable of determining headspace oxygen and entrapped oxygen, both at low concentrations. β-Carotene was determined colorimetrically at 460 nm. A first-order mechanism was found for this reaction with respect to β-carotene concentration as measured by color. The values of the rate constants were functions of the oxygen concentrations in the headspace of samples; they increased as these concentrations increased. Up to seven molecules of oxygen were consumed as each molecule of β-carotene was discolored. This high oxygen consumption was not related to the oxidized products. A mathematical model was developed, based on the experimental data, to predict β-carotene decoloration by measuring oxygen uptake or to determine oxygen uptake from decoloration. A computer program was developed to make these predictions. Samples with known histories had linear correlations between oxygen uptake and β-carotene decoloration. The results for 1% and 2% headspace oxygen concentrations agreed with experimental values, presenting a standard deviation compatible with the experimental methods used. An important corollary is the suitability of a simple colorimetric test for monitoring oxygen uptake in a dehydrated system.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2621.1981.tb15319.x
Permalink