the National Engineering Laboratory for Animal Breeding, MOA Key Laboratory of Animal Genetics and Breeding, College of Animal Science and Technology, China Agricultural Univ., Beijing 100193, China.
The Instit. of Animal Science, Hubei Acad. of Agricultural Science, Wuhan 430072, Hubei Province, China.
J Food Sci. 2018 Jan;83(1):39-45. doi: 10.1111/1750-3841.13977. Epub 2017 Dec 6.
The differences between the trimethylamine (TMA) content levels in duck and chicken egg yolks under normal dietary conditions were compared. Moreover, the association between the polymorphisms of the duck FMO3 gene and TMA content levels in duck egg yolks was analyzed. Then, to detect the mutations associated with the fish-flavor trait, duck populations were selected for a high-choline diet experiment, which was followed by full-length sequencing of the FMO3 exons. The results showed that the TMA content levels in duck eggs (3.60 μg/g) were significantly higher than those in chicken eggs (2.35 μg/g) under normal dietary conditions (P < 0.01). With regard to the high-choline diet, the average TMA content levels in duck egg yolks (9.21 μg/g; P < 0.01) increased significantly. Furthermore, 5 SNPs reported in Ensembl database were detected in duck FMO3 exons. However, no mutation loci were found to be significantly associated with the TMA content levels in duck egg yolks. Besides, duck liver FMO3 mRNA expression levels were not associated with the TMA content levels. The results indicated that excessive TMA deposition in duck eggs is one of main factors causing the fishy odor in duck eggs, and the addition of choline in the ducks' diets was responsible for inducing an increase in the TMA content levels in duck eggs.
Our study can help to diminish the fishy taste in duck eggs by reducing the amount of supplemented choline. Furthermore, this study laid a solid foundation for revealing the genetic factors involved in the fishy odor in duck eggs.
比较了正常饮食条件下鸭蛋黄和鸡蛋黄中三甲胺（TMA）含量水平的差异。此外，还分析了鸭 FMO3 基因多态性与鸭蛋黄中 TMA 含量水平之间的关系。然后，为了检测与鱼腥味特征相关的突变，选择鸭群进行高胆碱饮食实验，随后对 FMO3 外显子进行全长测序。结果表明，在正常饮食条件下，鸭蛋中的 TMA 含量（3.60μg/g）明显高于鸡蛋中的 TMA 含量（2.35μg/g）（P<0.01）。关于高胆碱饮食，鸭蛋蛋黄中的平均 TMA 含量（9.21μg/g；P<0.01）显著增加。此外，在鸭 FMO3 外显子中检测到 Ensembl 数据库中报道的 5 个 SNP。然而，没有发现突变位与鸭蛋黄中的 TMA 含量水平显著相关。此外，鸭肝 FMO3 mRNA 表达水平与 TMA 含量水平无关。结果表明，鸭蛋黄中 TMA 的过度沉积是导致鸭蛋鱼腥味的主要因素之一，鸭饲料中添加胆碱是导致鸭蛋黄中 TMA 含量增加的原因。
我们的研究可以通过减少补充胆碱的量来减少鸭蛋的鱼腥味。此外，这项研究为揭示鸭蛋鱼腥味相关的遗传因素奠定了坚实的基础。
