Comparación cualitativa en queso semi-maduro elaborado con bacterias termófilas y mesófilas

Abstract

This study aims to compare two bacterial strains for producing semi-ripe cheese using thermophilic and mesophilic bacteria for this study. These bacteria play a crucial role in the lactic fermentation process of cheese, offering the possibility of obtaining significant changes in its sensory properties, including flavor, texture, aroma, and nutritional composition. The research was conducted through the elaboration of cheeses by using pasteurized milk coagulated with enzymatic liquid rennet. These cheeses were subjected to a controlled maturation period of around 30 days. During the laboratory experimental phase, samples of each cheese were taken weekly for five weeks. These samples were subjected to a serial dilution of 10 to minus 7 to obtain manageable concentrations for analysis. During the first week of sampling, 12 cheese samples were obtained, and three lots were selected for grouping and subsequently composed into a combined sample. From this combined sample, 10 grams were taken to prepare a stock solution necessary for subsequent analyses. This solution was grown on nutrient agar to determine the Colony Forming Units (CFU). Various culture media were also used to detect pathogenic bacteria in cheese, including MacConkey, blood agar, MRS (for lactobacilli), and Salmonella-Shigella. The results provided vital information on the microbiological and sensory quality of the final product, highlighting the notable differences between the use of thermophilic and mesophilic bacteria in its production. Keywords. Semi-ripe cheese, thermophilic bacteria, mesophilic bacteria, Colony Forming Units.