Dietary plants sterols (phytosterols) have been shown to lower plasma cholesterol level in humans. Since phytosterols may protect against coronary heart diseases, they are being incorporated into functional foods. However, phytosterols are susceptible to oxidative degradation. The purpose of this study was to evaluate the formation of phytosterols oxidation products (POPs) in oil-in-water emulsions and bulk corn oil. The extent of lipid oxidation was monitored by measuring the lipid hydroperoxides and hexanal, whereas 7-keto derivatives of phytosterols were determined by gas chromatography to follow sterol oxidation. A higher POPs level and formation rate was found in the oil-in-water (o/w) emulsion with respect to the bulk oil. Interfacial tension measurements showed that phytosterols had a high degree of surface activity, which would allow them to migrate to the oil-water interface of the emulsion droplets where oxidative stress is high.
Phytosterol Oxidation in Oil-in-Water Emulsions and Bulk Oil / L. Cercaci; M.T. Rodriguez-Estrada; G. Lercker; E.A. Decker.. - In: FOOD CHEMISTRY. - ISSN 0308-8146. - STAMPA. - 102:(2007), pp. 161-167. [10.1016/j.foodchem.2006.05.010]
Phytosterol Oxidation in Oil-in-Water Emulsions and Bulk Oil
CERCACI, LUISITO;RODRIGUEZ ESTRADA, MARIA TERESA;LERCKER, GIOVANNI;
2007
Abstract
Dietary plants sterols (phytosterols) have been shown to lower plasma cholesterol level in humans. Since phytosterols may protect against coronary heart diseases, they are being incorporated into functional foods. However, phytosterols are susceptible to oxidative degradation. The purpose of this study was to evaluate the formation of phytosterols oxidation products (POPs) in oil-in-water emulsions and bulk corn oil. The extent of lipid oxidation was monitored by measuring the lipid hydroperoxides and hexanal, whereas 7-keto derivatives of phytosterols were determined by gas chromatography to follow sterol oxidation. A higher POPs level and formation rate was found in the oil-in-water (o/w) emulsion with respect to the bulk oil. Interfacial tension measurements showed that phytosterols had a high degree of surface activity, which would allow them to migrate to the oil-water interface of the emulsion droplets where oxidative stress is high.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
