Photoacoustic Monitoring of the Time Course of Ammonia Formation During the Spoilage of Inoculated Beef at Room Temperature

The natural aerobic spoilage of meat and that of meat inoculated with pure cultures is a complex process caused by microbial growth associated with the onset of various energy metabolisms. Chemical changes characterizing the end phase of bacterial activity at each of the distinct stages of their growth lead to the production of a well-defined sequence of volatiles [1]. In microbiology, determination of the microbial count number (number of bacteria per unit surface of meat) by elaborate plate counting techniques has become the common way to follow the growth and establish spoilage criteria. In principle predictions of the shelf-life of various meat products can be made if the relationship between the microbial count and the concentration of a specific volatile as the indicator of product deterioration can be found.