Influence of Surface Structure on Cholesterol Oxidation in Model Food Powders

✍ Scribed by Granelli, K; Fäldt, P; Appelqvist, L-Å; Bergenståhl, B

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 701 KB
• Volume: 71
• Category: Article
• ISSN: 0022-5142
• DOI: 10.1002/(sici)1097-0010(199605)71:1<75::aid-jsfa551>3.0.co;2-j

✦ Synopsis

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 pg g 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 pg g 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 levt:l of oxides being 75 pg g -' 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.