棉粕致鸡蛋变色机制研究

Mechanism of egg discolor caused by cottonseed meal

目的探讨棉籽粕饲料诱导鸡蛋变色的机制。方法在蛋鸡饲料中分别添加醋酸棉酚和环丙烯脂肪酸,测定蛋清蛋黄色泽变化,蛋黄膜的超微结构变化,冷藏后蛋清蛋黄的PH,钙、铁离子含量等相关指标的变化。结果棉籽粕中的环丙烯脂肪酸是引起蛋清冷藏后呈桃红色的主要原因,环丙烯脂肪酸引起蛋黄膜通透性增加,冷藏过程中蛋黄中的钙、铁元素外流到蛋清中与副卵蛋白结合呈桃红色。结论棉籽粕诱导的鸡蛋变色是化学、物理、生物学变化的综合现象。

Objective To explore the mechanism of the discoloration of eggs induced by cottonseed meal. Method Gossypol acetate and cyclopropane fatty acid were added in laying hens feed, the changes of ultrastructural changes of color in white and yolk and egg yolk membrane, the p H of egg yolk, calcium and iron ion content were determined. Result The cyclopropane fatty acids in cottonseed meal were main reasons for the pink color of egg whites after refrigeration. The permeability of yolk membrane was increased cause by cyclopropane fatty acid, and calcium and iron transferred from yolk into white, iron ions combined with deputy egg protein during refrigerated storage and the color of egg white became cherry. Conclusion The discoloration of eggs induced by cottonseed meal is a comprehensive phenomenon of chemical, physical and biological changes.