Changes in organic acids during ripening of Port Salut Argentino cheese

Abstract

Nine organic acids (formic, pyruvic, orotic, uric, lactic, acetic, citric, propionic and butyric) from 24 Port Salut Argentino cheese samples of different ages were analysed by high performance liquid chromatography. The level of total organic acids showed little change during the first 31 days, but it then increased rapidly up to the end of ripening. Lactic acid accounted for about 90% of the total organic acids content up to 31 days. Afterwards, the rapid increase in butyric acid level was responsible for the rise in total organic acids concentration. Each organic acid presented a characteristic pattern of change during ripening. Stepwise discriminant analysis classified cheeses according to their age. Discriminant functions were calculated for classifying unknown samples from their organic acids contents. Stepwise regression analysis allowed estimation of the ripening time of samples according to their organic acid levels.