Microbiological quality and its relation to useful life in fresh cheeses expended in three markets of Trujillo. August – October, 2014

Abstract

The objective of this research was to evaluate the microbiological quality and its relation to useful life in fresh cheeses expended in three markets of Trujillo during the months of August to October 2014. Three 25g-samples of cheese were taken from 15 stalls. The microbiological quality was evaluated by counting the total of Coliforms, E. coli, Staphylococcus aureus and presence of Salmonella. The microbial load of all samples from the stalls of the three markets: Mayorista, Hermelinda and Central Market (Mercado Central) was found to be above the limits allowed by the Peruvian Technical Standard 2008 for the various microorganisms or groups of microorganisms: total Coliforms (100% of the samples), E. coli (100%) and S. aureus (100%). Salmonella was not found in any of the samples. These results indicate a risk to consumers' health. In order to determine the useful lifespan in fresh cheeses, they were kept at constant temperature of 25°C, subjected to sensory evaluation daily (appearance, taste, aroma, texture) carried out by 10 people until the day when one of the characteristics was rejected. It was found that all fresh cheeses expended in the above-mentioned markets have a short useful lifespan of less than 4 days. A highly significant correlation between the microbial load of microorganisms Staphylococcus aureus and E.coli with the useful lifespan of fresh cheeses was found, whereas for coliforms and salmonella it could not be found because the microbial load ratio was the same for all samples, finding no variation. Therefore, it is concluded that the higher microbial load, the lower the useful lifespan of fresh cheeses expended in the three markets of Trujillo evaluated in the present study.