Metagenomics to assess authenticity and traceability of Asturian Gamonéu PDO cheese: A multi-omic study.

Cheese is one of the most widely consumed fermented foods in Europe. The Principality of Asturias (northern Spain) has a broad tradition in cheese making including four cheeses under Protected Designation of Origin (PDO) status (Cabrales, Gamonéu, Casín and Afuega'l Pitu). The added value of PDO food products increases the risk of fraudulently copied cheeses reaching the market. The aim of this work was to develop a novel microbiome-based method contributing to the assessment of the authenticity of Gamonéu PDO cheese. For this purpose, cheese metagenomes and volatile organic compounds (VOCs) profiles were integrated using machine learning (ML) algorithms. Computational models accurately discriminated between samples from 9 Gamonéu PDO cheese producers, as well as between cheeses ripened in different natural caves. Furthermore, they allowed distinguishing PDO and non-PDO Gamonéu-like cheeses produced in the same area. Potential microbial markers of the geographical origin of Gamonéu PDO cheese included Debaryomyces hansenii, Lacticaseibacillus paracasei and Penicillium roqueforti (more abundant in non-PDO cheeses), and Brachybacterium faecium (more abundant in PDO cheeses). Computational models presented in this work may contribute to improving existing traceability methods in the field of fermented foods and may be applied to a wide range of cheese varieties.