Evaluation of Serpa cheese proteolysis by nitrogen content and capillary zone electrophoresis

Roseiro, L.B., Garcia-Risco, M., Barbosa, M., Ames, J.M. and Wilbey, R.A. (2003) Evaluation of Serpa cheese proteolysis by nitrogen content and capillary zone electrophoresis. International Journal of Dairy Technology, 56 (2). pp. 99-104. ISSN 1364-727X doi: 10.1046/j.1471-0307.2003.00079.x

Abstract/Summary

Proteolysis of Serpa cheese produced traditionally (B) and semi-industrially (C) was evaluated for the first time by determination of nitrogen content and capillary zone electrophoresis (CZE). A citrate dispersion of cheese was fractionated to determine the nitrogen in pH 4.4, trichloroacetic and phosphotungstic acid soluble fractions (pH 4.4-SN, TCA-SN and PTA-SN, respectively). The pH 4.4-SN was significantly higher for B ( P < 0.001), while TCA-SN was significantly higher for C ( P < 0.001). PTA-SN was also higher for C but at 60 days ripening no significant difference was found between B and C. Degradation of alpha(s1) - and beta-caseins evaluated by CZE was in good agreement with the maturation index (pH 4.4-SN/TN).