Sterol Oxidation in Ready-to-Eat Infant Foods During Storage

摘要

The effect of storage on sterol oxidation of ready-to-eat infant foods was evaluated.Two different liquid infant foods (honey or fruits flavors),prepared with milk and cereals,were stored for 0,2,4,7 and 9 months at 25 °C.Sterol oxidation products (SOP) were isolated by cold saponification,purified by silica solid-phase extraction,and analyzed by gas chromatography (GC) and GC-mass spectrometry.beta-Sitosterol was the most representative sterol,followed by cholesterol and campesterol.No significant differences in the total and single SOP content (0.8-1 mg/kg of product) were observed with respect to storage time and type of sample;the main SOP found was 7-ketositosterol (<0.2 mg/kg of product).The extent of stigmasterol oxidation (2.9%) was higher than that of cholesterol (1.9%) and beta-sitosterol (1.4%).The type and quality of raw materials,as well as the processing conditions,seem to greatly influence SOP formation and accumulation in infant foods.