Vol. 3 núm. 2 - Sociedad Española de Microbiología

The analysis of Table 4 (pooled samples of Manchego and Burgos cheeses) indicatesthat the first component, accounting for the 42.1% of the variability, is an index of the«stage of ripening». As shown in the above table, this component was positivelycorrelated with fat and salt contents and negatively correlated with pH, moisture, a^ andlevels of coliforms and psychrotrophs. The second component, correlated with microbialgroups, was considered as an index of «microbiological quality». The third componentwas a measure of «thermonuclease» content.97TABLE 4EIGENVECTORS OF THE FIRST THREE COMPONENTS OF THE TOTAL CHEESES VARIABLESVariables1Components23pHFatNaClMoistureThermonuclease^wColiformsEnterococciLactic acid bacteriaMesophilesPsychrotrophsMolds & YeastsStaphylococciProportion of variability-53.7972.6466.28-85.401.32-77.71-65.541.12-0.16-35.38-68.08-7.16-13.3042.14-5.669.170.93-3.834.45-2.970.4466.8338.5530.673.7837.3437.2418.610.97-1.97-0.200.2379.44-0.013.682.934.60-5.20-0.19-16.19-0.118.87Fig. 3 shows the distribution of the 72 samples (Manchego and Burgos cheeses) onthe plane represented by the components first and second. This diagram clearly showsthe separation between Manchego (ripened) in quadrants I and II, and Burgos (fresh) inquadrants III and IV. The only anomalous position was that of a Manchego cheesesample which had characteristics of Burgos cheese (low salt content and high aw).Although the numbers of samples showing faulty microbiological quality was higher inBurgos (quadrant IV) than in Manchego cheeses (quadrant I), no important differencescould be detected.