Effects of flavonoids dietary supplementation on egg yolk antioxidant capacity and cholesterol level

Abstract

An experiment was conducted to examine the effects of supplementing laying hen feed with different levels of hesperidin or naringin, bioflavonoids that are abundant and inexpensive by-products of citrus cultivation, on the yolk antioxidant capacity and cholesterol level. Seventy-two laying hens, approximately twelve months old, were assigned into 6 experimental groups of twelve hens each. One of the groups served as control (C) and was given a commercial basal diet, without bioflavonoid supplementation, whereas the other five groups were given the same diet further supplemented with hesperidin at low (750mg/kg of feed) (H1) or high (1500mg/kg) (H2) concentration or naringin at low (750mg/kg) (N1) or high (1500mg/kg) (N2) concentration or α-tocopheryl acetate (200mg/kg) (E). Measurements of yolk antioxidant capacity were performed on 8 eggs from each dietary group, at 0, 4, 7, 28 and 63 days after the beginning of the experiment. Yolk cholesterol level was determined on the final day (63th) of the experimental period. Oxidative stability of egg yolk, expressed as ng MDA/g yolk, was significantly improved in the hesperidin and naringin groups even from the first four days of the supplementation period (P<0.001). However, no flavonoids effect on yolk cholesterol level (mg/g) was observed. Antioxidant properties of flavonoids seem to be a promising natural agent for improving the health status and the shelf life of laying hens’ egg.