Safe intake of a plant sterol-enriched beverage with milk fat globule membrane: Bioaccessibility of sterol oxides during storage

Sterols in foods are susceptible to oxidation to form oxysterols. It is interesting for consumer health to know real intake and the possible associated adverse effects associated to oxysterols. This study measured oxysterol formation and bioaccessibility (BA) in a plant sterol (PS)-enriched milk-based fruit beverage with milk fat globule membrane (MFGM) added at 0, 3 and 6 months of storage at room temperature. The same cholesterol (COPs) and phytosterol oxidation products (POPs) (exclusively from beta-sitosterol) (7 alpha/beta-hydroxy, alpha/beta-epoxy, triol and 7-keto) were detected in the beverage and its bioaccessible fraction. Total COPs and POPs contents were maintained during storage, and their BA ranged between 58 and 80% and 45-49%, respectively, without significant differences throughout storage. beta-Sitosterol showed a lower mean oxidation percentage (0.028%) than cholesterol (1.24%), but the estimated POPs intake (0.5 mg/day) was two-fold higher than that of COPs (0.25 mg/day) from 250 g of beverage. These results show that the presence of milk fat and MFGM in the formulation of this beverage did not imply an increase in the contents of oxysterols and their BA. Thus, the beverage is suitable as a PS-enriched food matrix for the length of its shelf-life, and its consumption appears to be safe for consumers.