Estudo da qualidade microbiológica de produtos de charcutaria

Abstract

The study of shelf life in food products has a vital role in the development and supply of safe and good quality products for consumption. The waste of food products that are safe and meet the quality standards and the financial loss that this represents on a food company, was one of the reasons for carrying out the present study. The aim of this report was to evaluate the shelf life of two charcuterie products: fresh goat cheese and dry cured pork ham after slicing and during their stay at the charcuterie section. The studies developed on these products were made considering their durability in the respective retail section of 24-hours. The experimental work was made by replicating the opening conditions of the 2 products and two storage temperatures were used: 4 ºC as the recommended temperature and 10 ºC as the abuse temperature. The determination of the life span of the products was based on the results of microbiological (Enterobacteriaceae, Lactic Acid Bacteria and Listeria monocytogenes), sensory and physical-chemical (aw and pH) analyzes during a period of 72 hours and storage at 4ºC and 10ºC. A challenge test was also carried out by inoculation of Listeria monocytogenes in both products, in order to evaluate its behavior for 72 hours. It was also tested if the presence of lactic acid bacteria isolated from both products could provide some sort of inhibition mechanism against L. monoyctogenes growth. The sensory analysis results showed that the products do not show any change in their organoleptic characteristics after 24 hours of storage. However, after 72 hours in the samples stored at 10 ºC, an acidic smell was detected in both products. In the samples of dry cured ham stored at 10 ºC and after 72 hours, the release of serum surrounding the the product was detected. Regarding the physical and chemical determinations, there were no changes in the pH and aw parameters in the products after 24 hours. The data collected from the microbiological analyzes indicated that there was no evidence of growth of L. monocytogenes in the products. Regarding the results of the remaining microbiological analyzes, it was also found that fresh goat cheese surpasses the limits of Enterobacteriaceae counts defined by the quality department in charge. In the experiment performed with Lactic Acid Bacteria isolated from the two products, it was determined that the presence of these microorganisms does not have a role in the inhibition of growth of L. monocytogenes. With this study, it was found that the extension of the self-life of 72 hours for dry cured pork ham is a possibility, however, in the case of fresh goat cheese, it was determined that the product does not comply with the established microbiological requirements, on the first day of analysis, which prevents the evaluation of this extension of shelf life.

Date of Award	25 Feb 2021
Original language	Portuguese
Awarding Institution	Universidade Católica Portuguesa
Supervisor	Paula Teixeira (Supervisor) & Sara Silva Bernardes (Co-Supervisor)