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Influence of Surface Structure on Cholesterol Oxidation in Model Food Powders
Author(s) -
Granelli K,
Fäldt P,
Appelqvist LÅ,
Bergenståhl B
Publication year - 1996
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/(sici)1097-0010(199605)71:1<75::aid-jsfa551>3.0.co;2-j
Subject(s) - triolein , cholesterol , chemistry , composition (language) , food science , chromatography , organic chemistry , biochemistry , linguistics , philosophy , lipase , enzyme
Three milk‐resembling powders having different oil phases were prepared and stored for six months at room temperature. Samples were taken monthly for estimation of the surface composition by ‘electron spectroscopy for chemical analysis’ (ESCA) and analyses of the level of cholesterol oxides by gas chromatography. The highest fat coverage was obtained with technical tristearin as the oil phase. This preparation had around 75% of the powder surface covered by fat; during storage this coverage decreased. This powder also had the largest increase in cholesterol oxides during storage, the final level being 159 μg g −1 cholesterol. The powder containing high‐melting pure tristearin had a low surface coverage of fat, originally about 25%, which decreased during the storage period. Little increase in cholesterol oxides was observed, the final level being 52 μg g −1 cholesterol. The third powder containing liquid triolein as oil phase, had a surface coverage of about 50% throughout the storage period. The cholesterol oxidation rate was in between that of the two tristearin powders, the final level of oxides being 75 μg g −1 cholesterol. The results for the investigated powders indicate that the surface composition is of major importance for the oxidation of cholesterol. No correlation between cholesterol oxidation and solvent extractable fat (free fat) was found.