M.A. Thesis:

omparison of microbial, physicochemical and sensory properties of some of the most important produced cheeses (brine white cheese, lactic cheese, UF cheese) in Iran

Abstract In this study, Three cheese samples (brine white cheese, lactic cheese and UF) were prepared from Golpayegan factory and then compared in terms of physicochemical, sensory and microbial properties at different times (0, 1 and 2 months). All samples had a significant difference in terms of physicochemical properties at the beginning of entering the cold storage (time 0) (p <0.05). After two months of refrigeration, the pH, dry matter and fat decreased, but their acidity, moisture and salt percentage increased. Of course, the rate of change was different in each sample. In terms of microbial load; No contamination was observed in the UF samples stored in the refrigerator. But both lactic cheese and brine white cheese contained pathogenic microorganisms. In terms of coliforms, Escherichia coli, mold and yeast were positive. However, keeping the samples in the refrigerator reduced the microbial load in them. In addition, Staphylococcus aureus and Salmonella were not found in any of the samples. In terms of sensory characteristics; the evaluators believed that UF cheese had the least aroma, taste and flavor, and have a soft texture. For this reason, they enjoyed the lowest overall acceptance. Although white cheese and lactic cheese was saltier, but they enjoyed better aroma, tastier taste, better texture, and ultimately higher overall acceptance. UF cheese is good in terms of health but poor in terms of sensory properties. Brine white cheese and lactic cheese, although contaminated at the beginning of production and refrigeration, but at the end of the maintenance period and control the storage temperature causes t o reduce their microbial load and sensory properties are more desirable. Keywords: brine white cheese - lactic cheese - UF cheese - Chemical Properties - Microbial Load

Keywords: Keywords: brine white cheese - lactic cheese - UF cheese - Chemical Properties - Microbial Load