CYCLODEXTRINS AS SECONDARY ANTIOXIDANTS - SYNERGISM WITH ASCORBIC-ACID

Citation
E. Nunezdelicado et al., CYCLODEXTRINS AS SECONDARY ANTIOXIDANTS - SYNERGISM WITH ASCORBIC-ACID, Journal of agricultural and food chemistry, 45(8), 1997, pp. 2830-2835
Citations number
43
Categorie Soggetti
Food Science & Tenology",Agriculture,"Chemistry Applied
ISSN journal
00218561
Volume
45
Issue
8
Year of publication
1997
Pages
2830 - 2835
Database
ISI
SICI code
0021-8561(1997)45:8<2830:CASA-S>2.0.ZU;2-P
Abstract
The preservation of the antioxidant capacity of ascorbic acid by 2-hyd roxypropyl-beta-cyclodextrins has been studied. For this, a model syst em consisting of ascorbic acid, H2O2, a phenolic compound, 2,2,5,7,8-p entamethylchroman-6-ol (PMC), and commercial soybean lipoxygenase was used. In this system, ascorbic acid was oxidized by PMC radicals gener ated by the hydroperoxidative activity of lipoxygenase, giving rise to a biphasic curve, in which the inflection point represents the time a t which all the ascorbic acid has been consumed (t .(ip)). This t .(ip ) depends on the enzyme, ascorbic acid, and PMC concentration. When 2- hydroxypropyl-beta-cyclodextrins were included in the system, the t .( ip), increased, indicating that these cyclodextrins were acting as sec ondary antioxidants, so preserving the antioxidant capacity of the sys tem. A mathematical model to explain the effect of cyclodextrins on as corbic acid oxidation in this experimental system is described, giving a constant, K-c, which represents the preservation capacity of a part icular antioxidant system produced by cyclodextrins.