OXYSTEROL FORMATION IN EGG POWDER AND RELATIONSHIP WITH OTHER QUALITY PARAMETERS

To determine whether the spray-drying temperature influences oxysterol formation in powdered egg, three temperature conditions were assayed. Moreover, the relationships between oxysterol formation and other parameters of alteration (egg fat absorption at 232, 270, and 303 nm; color loss; and Maillard browning intensity) were studied. Formation of 7 beta-hydroxycholesterol and 7-ketocholesterol during the spray-drying process was much greater than formation of cholesterol 5 alpha,6 alpha-epoxide, cholestanetriol, and 25-hydroxycholesterol. Formation of oxysterols at T-A (180-120 degrees C; inlet-outlet temperatures) and that at T-B (193-128 degrees C) were similar but lower than at T-C (231-142 degrees C). Thus, there is a critical temperature between T-B and T-C at which the oxysterol formation increases significantly. In addition, this formation is well correlated with the rest of the alteration parameters studied.