Variations in organic acids during the ripening of artisanal and industrial Manchego cheeses

Five organic acids (citric, lactic, pyruvic, propionic and acetic acid) from 10 Manchego cheeses of Appellation of Origin (5 artisanal cheeses and 5 industrial cheeses) with different ripening time, were analysed by high performance liquid chromatography. The evolution of organic acids was different in cheeses made with raw milk (artisanal cheeses) from that in those made with pasteurized milk (industrial cheeses), as a consequence of the number and metabolic activity of the microorganisms developed in both types of cheeses. Moreover, the total concentration of the organic acids during ripening time differed: at the end of the ripening time, it decreased in the industrial cheeses, whereas the artisanal cheeses presented the highest concentration. Lactic acid was the main product of fermentation of sugars by lactic acid bacteria, and hence was the principal organic acid found in both types of cheese. Principal Components Analysis (PCA) applied to the data of both types of cheese, showed that citric acid, acetic acid and pyruvic acid were the organic acids contributing the most to differentiate them.Peer Reviewe