Dipartimento di Scienze degli Alimenti, Alma Mater Studiorum-Università di Bologna, 40127 Bologna, Italy.
J Agric Food Chem. 2009 Dec 23;57(24):11517-27. doi: 10.1021/jf901537r.
Lipid oxidation and antioxidant capacity of freeze-dried egg yolks produced with two rearing systems (battery cages and free-range) and two types of feedings (conventional and organic) were studied. Nine fresh egg yolks of each crossed treatment were pooled, frozen for a month, freeze-dried, vacuum-packed, and kept at -18 degrees C until analysis. No significant differences were observed in the lipid (58.0-62.1%) and total sterol contents (33.0-35.5 g/kg of lipids) of the freeze-dried egg yolks. Free rearing and conventional feeding systems resulted in significantly higher total tocopherol, alpha-tocopherol, and lutein contents, as compared to the battery cage and the organic feed, respectively. However, no significant differences were found in lipid oxidation (peroxide value = 0.7-0.9 mequiv of O(2)/kg of fat; thiobarbituric reactive substances = 1.0-1.3 mg of malonylaldehyde/kg of sample) and cholesterol oxidation (28.8-43.5 mg of cholesterol oxidation products/kg of lipids; 0.08-0.12% oxidized cholesterol) of freeze-dried egg yolks except for 7alpha-hydroxycholesterol, which was significantly lower in samples obtained with organic feed.
研究了两种饲养系统（笼养和散养）和两种饲养方式（常规饲养和有机饲养）生产的冻干蛋黄的脂质氧化和抗氧化能力。将每个交叉处理的 9 个新鲜蛋黄混合，冷冻一个月，冻干，真空包装，并在-18°C下保存，直到分析。冻干蛋黄的脂质（58.0-62.1%）和总固醇含量（33.0-35.5 g/kg 脂质）没有显著差异。与笼养和有机饲料相比，自由饲养和常规饲养系统导致总生育酚、α-生育酚和叶黄素含量显著增加。然而，除了有机饲料获得的样品中 7α-羟基胆固醇显著降低外，冻干蛋黄的脂质氧化（过氧化物值=0.7-0.9 mequiv O(2)/kg 脂肪；硫代巴比妥酸反应物质=1.0-1.3 mg 丙二醛/kg 样品）和胆固醇氧化（28.8-43.5 mg 胆固醇氧化产物/kg 脂质；0.08-0.12%氧化胆固醇）没有显著差异。
