RAPD and SCAR markers as potential tools for detection of milk origin in dairy products: Adulterant sheep breeds in Serra da Estrela cheese production

Abstract

Serra da Estrela Protected Designation of Origin (PDO) cheese is the most famous Portuguese cheese and has a high commercial value. However, the adulteration of production with cheaper/lower-quality milks from non-autochthones ovine breeds compromises the quality of the final product and undervalues the original PDO cheese. A Randomly Amplified Polymorphic DNA (RAPD) method was developed for efficient detection of adulterant breeds in milk mixtures used for fraudulent production of this cheese. Furthermore, Sequence Characterized Amplified Region (SCAR) markers were designed envisioning the detection of milk adulteration in processed dairy foods. The RAPD-SCAR technique is here described, for the first time, to be potentially useful for detection of milk origin in dairy products. In this sense, our findings will play an important role on the valorization of Serra da Estrela cheese, as well as on other high-quality dairy products prone to adulteration, contributing to the further development of the dairy industry.

Evaluation of colour in Serra da Estrella cheese produced in different dairies along the milking season

“…Furthermore, the results indicate that the differences in lightness explained almost 90% of the variance observed, which is very much relevant. 3 Values with the same superscript in the same column are not significantly different (p<5%).…”

“…The values obtained for Hue in the present work are near 180º, meaning they correspond the transition between green and cyan. 3 Values with the same superscript in the same column are not significantly different (p<5%).…”

“…Nevertheless, some less conscious producers might use a mixture of Bordaleira Serra da Estrela ewe's milk with cheaper and / or low-quality milk from other more productive breeds, leading to increase cheese yield and lower products costs. This is why the certification of the producers is so important and allows controlling quality of the products along the entire chain, from raw-materials to the final cheese, also guarantying traceability (Cunha et al, 2016). This Portuguese delicacy is the most famous cheese produced in the country, being also much appreciated worldwide, with exports rising by the year.…”

Serra da Estrela cheese: A review

“…Starting with innovation associated with raw ewe's milk: Due to its high economic value, some producers can adulterate the milk or use milk from different ewes’ races, which results in fraudulent Serra da Estrela cheese production. To avoid this situation, analytical techniques were recently adapted and proposed to screen the milk origin (Cunha et al, ), like random amplified polymorphic DNA (RAPD) for the detection of adulterant breeds in milk mixtures and sequence characterized amplified regions (SCAR) markers for breed identification in processed dairy food. The combination of these methods, RAPD‐SCAR can be used to prevent fraudulent Serra da Estrela PDO cheese production and be implemented as a quality control.…”

Assessing Serra da Estrela PDO cheeses’ origin-production date using fatty acids profiles

“…Similarly, Serra da Estrela cheese, is a dairy traditional product highly prone to different forms of adulteration, namely, the use of milk of non-allowed sheep breeds for the fraudulent production of this artisanal cheese. To detect this fraudulent practice, a randomly amplified polymorphic DNA method was recently developed [19]. However, to the authors' best knowledge, the possibility of using the fatty acids profile coupled with chemometric tools for discriminating among Serra da Estrela cheese producers, geographical origin within the limited PDO region or the cheese production date was never evaluated.…”