Development of mathematical model to describe the acidification occurring during the ripening of dry fermented sausage

Abstract

To describe the evolution of pH values during the ripening process of fermented sausages, the use of a mathematical model is proposed. The model is both easy to use and statistically adequate. It can be employed to distinguish the different stages in the acidification process associated with the fermentation of sausages. It can be successfully used in the control of the manufacture of sausages when this is carried out in temperature-controlled chambers equipped with a microprocessor to continuously record pH values. The mathematical development of the function shows that the most rapid decline in pH occurs on the second day of ripening, coinciding with the highest levels of microbial development; on the 9th hour of the third day a stationary phase begins, which undergoes a slight increase from the 14th day. In order to better interpret the process, various parameters involved in the proton concentration of the sausage mixture were determined: water activity, fermentative microbial population ( Lactobacillaceae, Micrococcaceae) and metabolites derived from fermentative enzyme activity (lactic acid, acetic acid, total free fatty acids, total free amino acids).