Peptidomic characterization of a fermented sausage model using a functional meat starter culture.

LOPEZ, C; SENTANDREU, MA; G. VIGNOLO,; FADDA S

Simposio; IV Simposio Internacional de Bacterias Lácticas-SIBAL CERELA- CONICET.; 2013

CERELA CONICET

PEPTIDOMIC CHARACTERIZATION OF A FERMENTED SAUSAGE MODEL USING A FUNCTIONAL MEAT STARTER CULTURE C. M. Lopez1, M.A. Sentandreu2, G. M. Vignolo1 and S.G. Fadda1 1Centro de Referencia para Lactobacilos (CERELA-CONICET). Chacabuco 145. (4000) San Miguel de Tucumàn- Tucumàn- Argentina. sfadda@cerela.org.ar 2 Instituto de Agroquímica y Tecnología de Alimentos (IATA) del Consejo Superior de Investigaciones Científicas (CSIC) (46100) Burjassot- Valencia- España.   Lactic acid bacteria (LAB) and Coagulase negative Gram positive Cocci (CGC) such as Staphylococcus and Kocuria, are the two main groups involved in fermentation of dry cured sausages. Although, it is still unknown which bacterial group play the major role in the desirable aroma development, two major reactions occur: pH decrease due to the acidogenic metabolism of LAB and nitrates reduction by CGC. The characteristic taste and aroma of fermented sausage are due to many different non-volatile and volatile compounds, some of them originated from added spices while others are products derived from carbohydrates, proteins and lipids degradation by bacteria during ripening. Meat proteolysis has been widely studied and the contribution of some peptide fractions from the degradation of meat proteins to flavour was generally accepted. Food peptidómico is a new emerging science area which can contribute to reveal the sequences of the complex mixture of peptides (peptidome) of sausages which remain unexplored up to now. This work aimed at the characterization of the peptidome resulting from of a beaker sausage model (BS) fermentation, inoculated with an autochthonous well characterized meat starter culture containing Lactobacillus curvatus CRL705 and Staphylococcus vitulinus GV318.The role of muscle enzymes, L. curvatus and starter culture in peptidogenesis was distinguished. Mass spectrometry (MS) analysis of the low molecular weight (LMW) peptide fraction were performed at two incubation times (t=0 and t=10 days) in both BS + L. curvatus and BS + starter culture, as well as, BS control (sterile model with antibiotic addition) was included. Proteolysis was evidenced by an intense generation and breakdown of LMW peptides in each model through ripening and revealed the action of LAB and the starter culture by an increased diversity of peptides. In fact, the major peptide diversity underlay on the proteolysis of sarcoplasmic proteins, while a lower contribution of myofibrillar proteins was observed. The origin of proteolytic activity (muscle or bacterial) was stated by the analysis of cleavage sites of known muscle enzymes. L. curvatus (single culture) and starter culture (mixed culture) promoted the hydrolysis of some myofibrillar proteins due to their own peptidases. Also an improved proteolysis by muscle enzymes was evidenced when LAB were present, maybe due to the acidic environment which may activate endogenous enzymes. These results establish the baseline to find out the role of peptides on fermented sausage flavor and clearly provide new data about the role of starter cultures on meat proteolysis. Also, certain sets of peptides may be used as biomarkers indicating the presence of these efficient functional cultures which could constitute a technological application of MS for authentication studies of these products.