CHARACTERIZATION OF YEASTS ASSOCIATED WITH PORTUGUESE PORK-BASED PRODUCTS

Yeasts from pork-based products, such as country-cured hams and severa l types of bacon, were studied. Contamination levels ranged from 10(3) -10(9) CFU/g of fat. Identification using a simplified method (SIM) sh owed that the predominant species were Debaryomyces hansenii, Cryptoco ccus laurentii, Cryptococcus humicolus, Debaryomyces polymorphus and P ichia guilliermondii. Lipolytic activity was observed in 24 out of 29 of the isolated strains and was not a determinant for attaining high l evels of contamination. The analysis of yeast long-chain fatty acid co mposition for most isolated strains showed a predominance of the acid C18:1 followed by decreasing proportions of the acids C16:0, C18:2, C1 8:3, C18:0 and C16:1. The fatty acid profiles were roughly similar for all yeasts analyzed suggesting that in these types of pork-based prod ucts the yeast lipid composition may have an ecological significance. (C) 1997 Elsevier Science B.V.