Wageningen Food Safety Research, Wageningen University and Research, Akkermaalsbos 2, 6708 WB Wageningen, The Netherlands.
School of Science & Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, UK.
Molecules. 2022 May 17;27(10):3199. doi: 10.3390/molecules27103199.
Processed milk and milk products produced from bovine milk, commonly contain β-casein A1 (βCA1) and β-casein A2 (βCA2). Since the presence of βCA1 is linked to milk intolerance and digestion problems, A2A2 milk, which only contains βCA2, is proposed as a healthier alternative. To support this health claim, the purity of A2A2-milk has to be guaranteed. In the presented study, a multiplex immunoassay, able to distinguish between βCA2 and βCA1, was developed and real-life applicability was shown on raw milk samples from genotyped A1A1, A1A2 and A2A2 cows. Because of its ability to discriminate between βCA2 and βCA1, this newly developed method was able to detect the addition of common bovine A1A2 milk to A2A2 milk, as low as 1%. Besides the detection of A2A2 milk purity, the developed assay can also be implemented as a rapid phenotyping method at dairy farms to replace the more invasive DNA-based screening. Additionally, the developed method was capable of detecting the addition of common bovine milk up to 1% in sheep, goat, buffalo, horse and donkey milk, which conforms to EU recommendations. In conclusion, a newly developed multiplex method capable of reliably detecting the dilution of A2A2 milk of multiple species, with common bovine milk up to 1%, is presented.
经加工的牛奶和牛奶制品由牛奶制成，通常含有β-酪蛋白 A1（βCA1）和β-酪蛋白 A2（βCA2）。由于βCA1 的存在与牛奶不耐受和消化问题有关，因此只含有βCA2 的 A2A2 牛奶被提议作为更健康的选择。为了支持这一健康声明，必须保证 A2A2 牛奶的纯度。在本研究中，开发了一种能够区分βCA2 和βCA1 的多重免疫分析方法，并在来自基因型为 A1A1、A1A2 和 A2A2 的奶牛的生奶样本上展示了实际应用。由于其能够区分βCA2 和βCA1，这种新开发的方法能够检测到低至 1%的常见牛 A1A2 牛奶添加到 A2A2 牛奶中。除了检测 A2A2 牛奶的纯度外，开发的检测方法还可以作为一种快速表型检测方法在奶牛场实施，以替代更具侵入性的基于 DNA 的筛选。此外，该方法还能够检测到绵羊、山羊、水牛、马和驴奶中添加的常见牛奶，其浓度高达 1%，符合欧盟的建议。总之，本文提出了一种新的多重方法，能够可靠地检测多种物种的 A2A2 牛奶的稀释，其中包括常见的牛牛奶，浓度可达 1%。
