Comparison of PCR Techniques in Adulteration Identification of Dairy Products

Abstract

Economic profit-driven food adulteration has become widespread in the dairy industry. One of the most common forms of dairy adulteration is the substitution of low-priced milk for high-priced milk. This has prompted regulatory authorities to focus on various means of authenticity testing. So far, many methods have been developed. Since milk adulteration has been upgraded, which has forced the testing methods to meet the needs of detection, which include DNA-based PCR methods. PCR and PCR-derived methods exhibit multiple advantages for authenticity testing, such as high stability, fast speed, and high efficiency, which meet the needs of modern testing. Therefore, it is important to develop rapid, reliable, and inexpensive PCR-based assays for dairy adulteration identification. In order to provide perspectives for improving adulteration identification methods, this review first summarizes the DNA extraction methods, then compares the advantages and disadvantages of various PCR authenticity testing methods, and finally proposes the directions for improving dairy product adulteration identification methods.

Application of Microsatellites to Trace the Dairy Products Back to the Farm of Origin

“…The difference in DNA quantity and purity could explain the slight differences in the number of alleles detected among the GO and the respective BM and CHE [16,22,32]. The descriptive statistics showed good gene variability of the two GOs, with average levels of differentiation between the two groups (Table 2).…”

“…The traceability of dairy products with PDO or PGI labels has become an important issue for authentication because they have high commercial and nutritional value and the breeds and geographical origins from which these products are derived have been used as market symbols and have encouraged rural development and breed conservation [16]. DNA-based techniques, metabolomics approaches, and chromatographic methods have also been used for the verification of PDO or PGI products [2,[14][15][16]22].…”

“…The difficulty in extracting DNA of good quality from ripened dairy products is known, and indeed, the extraction yield was higher for milk than for cheese. Ripening can reduce the integrity of DNA, thereby affecting DNA amplification detection [16,22]. Rentsch et al verified that long periods of cheese ripening result in losses of amplifiable DNA compared to fresh cheeses, probably because of DNA degradation [16,32].…”

“…While several molecular methods have already been developed for species/breed detection in dairy products [6,[16][17][18][19][20][21][22], the application of these methods for the traceability of the origin (farm or producer) in traditional dairy products has not been investigated due to technical process conditions.…”

“…The genetic traceability of dairy products poses some technical challenges as cheese comes from bulk milk (BM), which contains DNA from different cows of the farm and from different lactation periods and undergoes consistent changes during manufacturing processes, such as ripening, that may compromise the quality and quantity of the extracted DNA, making it unsuitable for subsequent analyses [22].…”