Thompson Christopher M, Gao Quanyin, Lu Zhengfei, Babajanian Silva, Chang Peter, Swanson Gary
Herbalife Manufacturing, LLC, 20481 Crescent Bay Dr, Lake Forest, CA 92630.
Herbalife Nutrition, 950 West 190th St, Torrance, CA 90502.
J AOAC Int. 2020 Jan 1;103(1):205-209. doi: 10.5740/jaoacint.19-0083.
Differentiation of proteins from multiple sources provides challenges in the accuracy using multiple and often disputed protein identification methods. The U.S. Pharmacopeia Food Chemical Codex does not include monographs for many protein sources, including milk proteins and soy protein isolate. Monographs that are included for proteins do not list a single comprehensive identification method but instead rely on a combined assessment of ash (total), fat, lactose, loss on drying, and protein content. A fast, inexpensive, and accurate protein source assay is tantamount to prevention of economic adulteration in protein powders.
This study describes the development of a novel method to identify and differentiate animal proteins (cow protein powders as milk protein and whey protein) and plant proteins (soy protein powders). These proteins powders are of high importance to the food and dietary supplement industries, as they encompass the highest grossing and fastest growing protein sources in the global protein powder market.
The developed method uses PCR amplification and gel electrophoresis of short chain DNA fragments found in processed protein powders to identify and differentiate the source of each powder. The original development was performed using reference materials of known identity and tested against an inclusivity panel of protein powders from commercial sources. Bands were identified using the Agilent Tapestation 4200 and Tapestation Analysis Software A.02.02 (SR1) using proprietary band analysis.
The developed method was found to be specific for the identification of each protein source, passing a computational (National Center for Biotechnology Information Basic Local Alignment Search Tool) exclusivity panel and an experimental inclusivity panel. The method was also able to detect multiple adulterants in concentrations as low as 1% (w/w).
The developed method is fast, inexpensive, and accurate (100%) for the supplemental identification of cow and soy proteins and able to detect adulteration as low as 1% (w/w).
A new method can identify cow and soy proteins, and detect low levels of adulteration using DM-PCR.
利用多种且常存在争议的蛋白质鉴定方法区分多种来源的蛋白质，在准确性方面存在挑战。美国药典食品化学法典未包含许多蛋白质来源的专论，包括乳蛋白和大豆分离蛋白。已有的蛋白质专论并未列出单一全面的鉴定方法，而是依赖于对灰分（总量）、脂肪、乳糖、干燥失重和蛋白质含量的综合评估。一种快速、廉价且准确的蛋白质来源检测方法对于防止蛋白粉中的经济掺假至关重要。
本研究描述了一种鉴定和区分动物蛋白（如牛奶蛋白和乳清蛋白的牛蛋白粉）和植物蛋白（大豆蛋白粉）的新方法。这些蛋白粉对食品和膳食补充剂行业非常重要，因为它们是全球蛋白粉市场中销售额最高且增长最快的蛋白质来源。
所开发的方法利用加工过的蛋白粉中发现的短链DNA片段进行PCR扩增和凝胶电泳，以鉴定和区分每种蛋白粉的来源。最初的开发使用已知身份的参考材料，并针对来自商业来源的蛋白粉包容性面板进行测试。使用安捷伦Tapestation 4200和Tapestation分析软件A.02.02（SR1）通过专有条带分析来识别条带。
所开发的方法被发现对每种蛋白质来源的鉴定具有特异性，通过了计算（美国国立生物技术信息中心基本局部比对搜索工具）排他性面板和实验包容性面板。该方法还能够检测低至1%（w/w）浓度的多种掺假物。
所开发的方法快速、廉价且准确（100%），可用于牛蛋白和大豆蛋白的补充鉴定，并能够检测低至1%（w/w）的掺假。
一种新方法可以鉴定牛蛋白和大豆蛋白，并使用DM-PCR检测低水平掺假。
