Isolation and identification of peptides generated during ripening of dry fermented sausages

LÓPEZ CONSTANZA MARÍA .; VIGNOLO GRACIELA; FADDA SILVINA

Tucumán, Argentina

Simposio; III Simposio Internacional de Bacterias Lácticas. Segundo encuentro Red Bal Argentina; 2009

CERELA-CONICET-MINCYT

  Lactic Acid Bacteria (LAB) are widely distributed in meat products such as dry fermented sausages. They play an important role on the hygienic quality of these products exerting a control on pathogen and spoilage microflora development. Moreover, species such as Lactobacillus plantarum, Lactobacillus curvatus and Lactobacillus sakei are used as starter culture in industrial manufacture in order to standardize flavor improving the shelf life. During the fermentation and ripening, LAB produce various metabolites involved in the typical flavor, specifically peptides and free amino acids generated by protein degradation with impact on final sausage taste. Recent investigations have been focused in peptides and amino acids patterns as quality markers of fresh meat. Hypothetically, high quality fermented sausages may be identified or differentiated based on their protein breakdown pattern. The aims of this work were i) to analyze the proteolytic product profiles of different commercial fermented sausages focusing on peptides generated during fermentation and ripening and ii) to identify compounds that can characterize different quality products. Ten commercial dry fermented sausages were analyzed by electrophoresis (SDS-PAGE). The analysis of fresh meat was also included. All fermented products exhibit higher protein degradation than fresh meat. The two fuet type sausages presented a different proteolytic pattern when compared with other analyzed ones. Since this sausage type is recognized to have a high quality standard, a relationship between its protein profile and meat quality/production technology can be establish. To isolate peptides of potential technological interest, fresh meat and five commercial fermented sausages with different qualities were selected. Separation of low molecular weight peptides was carried out by ultrafiltration, sequentially applying filter units with a nominal molecular mass limit of 10 kDa and 3 kDa. Fractions of 3-10 kDa and less than 3 kDa from each sausages and fresh meat were obtained and analyzed by RP-HPLC. Results showed a richer peptide profile for fermented sausages than for fresh meat. Fuet type, considered as “high quality” sausages, presented similar profiles with the absence of hydrophobic peptides (recognized to give bitter taste products). In addition, they shared a peak in the chromatograms absent in “lower quality” sausages. Some of these peptides were isolated in order to identify their sequence to determine their contribution to the flavor of dry fermented sausages. These results may allow establishing a fingerprint for such a high quality sausages.