Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, China.
School of food and biological engineering, Hubei University of Technology, Wuhan 430070, Hubei Province, China.
Poult Sci. 2019 Jan 1;98(1):381-392. doi: 10.3382/ps/pey359.
The aim of this study was to evaluate the effects of dietary non-gossypol cottonseed oil (CSO) or cottonseed meal (CSM) and their interactions on the texture properties, structure, nutritional composition, and edible safety of egg yolk. A total of 162 24-wk-old Hy-line Brown laying hens were randomly allocated into 9 diet treatments with 6 replicates of 3 hens per cage. A 3 × 3 factorial design using corn soybean meal-based diets supplemented with 0, 6, or 12% CSM and 0, 2, or 4% CSO in place of soybean meal and soybean oil, respectively, was utilized. The experiment lasted for 8 wk. Eggs obtained from the CSO groups had an egg yolk gel structure, and the hardness of egg yolk increased significantly (P < 0.001) after 4°C storaged for 2 wk; the texture properties of eggs storage at 25°C had opposite trend. There were no differences in texture properties of fresh egg yolk among the different groups (P > 0.05). The saturated fatty acid (SFA) content of egg yolk increased in a CSO dose-dependent manner, whereas opposite effects (P < 0.001) were found in the monounsaturated fatty acids (MUFA) and the omega-3/omega-6 fatty acid ratio. CSO-containing diets significantly reduced the cholesterol content (P < 0.05). No significant difference was observed among the different groups on the contents of moisture, crude protein, crude fat, phospholipid, potassium, or iron (P > 0.05) in the egg yolk. Total gossypol residues were increased with the increased amount of CSM (P < 0.05), and these changes were independent of time (P > 0.05). The total gossypol concentration in the yolk was 2.01 to 5.16 mg/kg. These results suggest that CSO has a key influence on egg yolk quality, reducing both its taste and nutritional value. Egg yolk gelation was significantly associated with the change of fatty acid composition caused by CSO and storage conditions. Free gossypol will remain in the egg yolk. Although the residue is low, the edible safety risk of eggs maybe exists.
本研究旨在评估日粮中非棉酚棉籽油（CSO）或棉籽粕（CSM）及其互作效应对蛋黄质地特性、结构、营养成分和食用安全性的影响。将 162 只 24 周龄海兰褐蛋鸡随机分配到 9 种日粮处理中，每个处理 6 个重复，每个重复 3 只鸡。采用玉米-豆粕基础日粮，分别用棉籽粕和 CSO 替代 0、6 或 12%的豆粕和 0、2 或 4%的大豆油，进行 3×3 析因设计。试验持续 8 周。CSO 组鸡蛋的蛋黄凝胶结构，在 4°C 储存 2 周后，蛋黄硬度显著增加（P＜0.001）；在 25°C 储存时，质地特性呈相反趋势。不同组之间新鲜蛋黄的质地特性没有差异（P＞0.05）。蛋黄中的饱和脂肪酸（SFA）含量随 CSO 剂量的增加而呈依赖性增加，而单不饱和脂肪酸（MUFA）和 ω-3/ω-6 脂肪酸比例则出现相反的效果（P＜0.001）。CSO 日粮显著降低胆固醇含量（P＜0.05）。不同组之间蛋黄中的水分、粗蛋白、粗脂肪、磷脂、钾或铁含量没有差异（P＞0.05）。棉酚总残留量随 CSM 用量的增加而增加（P＜0.05），且这些变化与时间无关（P＞0.05）。蛋黄中的总棉酚浓度为 2.01-5.16mg/kg。这些结果表明，CSO 对蛋黄质量有重要影响，降低了蛋黄的口感和营养价值。蛋黄凝胶化与 CSO 引起的脂肪酸组成变化和储存条件密切相关。游离棉酚将残留在蛋黄中。虽然残留量低，但鸡蛋的食用安全性风险可能存在。
