DNA-based qualitative and quantitative identification of bovine whey powder in goat dairy products

Abstract

As one of the main ingredients in some milk powders, whey powder is sometimes added to pure goat milk products, which can cause health risks, economic fraud, and unfair competition of food industries. This study is the first to explore qualitative and quantitative methods to identify adulteration of bovine whey powder in goat dairy products based on DNA. We extracted DNA from whey powder using a modified DNA extraction method; this exhibited good quality and integrity, with purity of 1.53 to 1.75 and concentration of 122 to 179 ng/μL. Conventional PCR and real-time PCR were compared for qualitative detection of bovine whey powder; real-time PCR demonstrated sensitivity of 0.01 ng/ μL, which was higher than the 0.05 ng/μL detected by the conventional PCR method. Furthermore, real-time PCR was conducted for DNA quantitative detection, with good linearity (R 2 = 0.9858) obtained for bovine whey powder contents from 0.1% to 30%. Relative error decreased with increase of the mixing proportion of whey powder; the coefficient of variation above 0.1% of the mixing ratio was close to or less than 5%; and the relative standard deviation of repeatability results was less than 5%. Considering the economic costs of testing, conventional PCR could be performed first, and samples with obvious intentional adulteration detected can be further accurately quantified by real-time PCR. Overall, this research provides a realistic and effective method for qualitative and quantitative identification of bovine whey powder in goat dairy products, thus laying a good foundation for verification of goat dairy product label claims and industrial control.

Detection of Soybean-Derived Components in Dairy Products Using Proofreading Enzyme-Mediated Probe Cleavage Coupled with Ladder-Shape Melting Temperature Isothermal Amplification (Proofman–LMTIA)

“…Dairy products are one of the important sources of nutrition for the human body. However, fraud—driven by profits—often occurs, such as shoddy and adulterated dairy products with high value [ 4 , 5 , 6 ]. Therefore, the development of selective and sensitive detection techniques is a key challenge for the detection of authentic food, especially dairy products.…”

“…Driven by profits, fraud such as shoddy and adulterated dairy products with high value often occurs [ 4 , 5 , 6 ]. At present, the main adulterants in dairy products are nitrogen-containing compounds, vegetable proteins (such as soy protein) and animal proteins.…”

Quality of liquid goat whey affected by heat treatment of milk and coagulation type: case study of the Serbian market

“…Together with a growing demand and popularity of goat dairy products in general (Zhang et al, 2022), a growing demand for liquid goat whey has also been observed in Serbia. Liquid whey that appeared on the market recently, originated from both farm and industry cheese production.…”