Actual healthy trends produce changes in the sensory characteristics of dry fermented sausages therefore, new strategies are needed to enhance their aroma. In particular, a reduction in the aroma characteristics was observed in reduced fat and salt dry sausages. In terms of aroma enhancing, generally coagulase-negative cocci were selected as the most important group from the endogenous microbiota in the production of flavour compounds. Among the volatile compounds analysed in dry sausages, ester compounds contribute to fruity aroma notes associated with high acceptance of traditional dry sausages. However, the origin of ester compounds in traditional dry sausages can be due to other microorganisms as lactic acid bacteria, yeast and moulds. Yeast contribution in dry fermented sausages was investigated with opposite results attributed to low yeast survival or low activity during processing. Generally, they affect sausage colour and flavour by their oxygen-scavenging and lipolytic activities in addition to, their ability to catabolize fermentation products such as lactate increasing the pH and contributing to less tangy and more aromatic sausages. Recently, the isolation and characterization of yeast from traditional dry fermented sausages made possible the selection of those with ability to produce aroma active compounds. Molecular methods were used for genetic typing of the isolated yeasts whereas their ability to produce aroma compounds was tested in different systems such as in culture media, in model systems and finally on dry fermented sausages. The results revealed that the appropriate selection of yeast strains with aroma potential may be used to improve the sensory characteristics of reformulated fermented sausages.

11Debaryomyces hansenii strains, M4 and P2, isolated from natural fermented 12 sausages were inoculated in slow fermented sausages to study their effect on

The ability of seven Debaryomyces hansenii strains to generate aroma compounds in a fermented sausage model system was evaluated. The presence of the yeast, in the inoculated models, was confirmed by PCR amplification of M13 minisatellite. Volatile compounds production was analysed using Solid Phase Micro-Extraction and gas chromatography/mass spectrometry. Forty volatile compounds were detected, quantified and their odour activity values (OAVs) calculated. All volatile compounds increased during time in the inoculated models although significant differences were found amongst them. Ester and sulphur production was strongly dependent on the strain inoculated. D. hansenii P2 and M6 strains were the highest producers of sulphur compounds where dimethyl disulphide and dimethyl trisulfide were the most prominent aroma components identified by their OAVs whereas, M4 showed the highest OAVs for ester compounds followed by the P2 strain. The meat model system has been useful to show the real ability of yeast strains to produce aroma compounds.

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