SIHUFE Guillermo Adrian
congresos y reuniones científicas
Use of an Exogenous Carboxypeptidase to Accelerate the Proteolysis of Reggianito Cheese
SIHUFE G.A.; CERUTI R.J.; PIROLA M.B.; RAMOS E.; ROBERT L.; RUBIOLO A.C.; ZORRILLA S.E.
Simposio; 2012 IDF Cheese Ripening & Technology Simposium; 2012
The use of an exogenous carboxypeptidase was evaluated to accelerate the proteolysis during Reggianito cheese ripening. Enzymes were added to milk prior to cheesemaking, and cheeses were manufactured using 4 different concentrations of enzyme: 0, 5, 10, and 20 g /100 L milk. After manufacturing, cheeses (with cylindrical shape and approximately 8 kg weight, 24 cm diameter, and 12 cm height) were salted by immersion in a saturated NaCl solution at 12 °C during 8 days and ripened at 13 °C and 85% RH. Samples were obtained at 0, 60, 90, 120, 150, 180 and 210 days of ripening and analysed to determine pH, moisture content, and proteolysis assesment (by the determination of nitrogen content in different extracts, by urea-PAGE analysis, and by RP-HPLC analysis of peptides and amino acids). Major casein fractions (as1-, as1-I- and b-casein) were significantly affected by the amount of enzyme added and the ripening time. An important degradation of β-casein was observed during the first 2 months in those cheeses manufactured with the highest enzyme contents. The regular chromatographic peptide profile of Reggianito cheese was not modified by the carboxypeptidase action. Moreover, a higher concentration of free amino acids was observed at 60 days of ripening in cheeses manufactured with exogenous enzymes, Lys, Glu, Leu, and Val being the amino acids with the highest concentrations in all the cheeses analysed. Principal component analysis showed that cheeses manufactured with the exogenous enzyme had a slight increase in the rate of formation and/or degradation of proteolysis products. The use of exogenous enzymes appears to be an interesting alternative to accelerate ripening of Reggianito cheese. This study provides useful information regarding to enzyme amount selection, which may help in future studies related to enzyme addition to accelerate the ripening of different hard cheeses.