Investigation of Some Properties and Late Blowing Defect of Model White Cheeses Contaminated with Clostridium sporogenes Strains

The aim of this study was to investigate the growth of C. sporogenes in model white cheese stored under cold conditions (4°C) and in vacuum packaging and its effect on quality parameters. For this purpose, two different cheeses were produced, contaminated (CMBP) and not (MBP) with C. sporogenes 73 and C. sporogenes 97 strains, and physicochemical, microbiological and volatile component analyses were performed every 15 days during the 60-day storage period of the cheeses. No significant difference was detected in dry matter (%), fat in dry matter (%), and protein (%) contents of cheeses during storage. As an important finding, C. sporogenes did not affect the acidity values (pH and % acidity). The pH and % acidity values of the cheeses were found to be 4.79±0.03 – 4.98±0.05 and 2.04±0.06 – 2.16±0.06, respectively. When the microbiological results were examined, the total mesophilic aerobic bacteria (TMAB), lactococci and lactobacilli counts of the cheeses decreased during storage, while the yeast-mold counts did not change. There was no change in CMBP cheese with an initial C. sporogenes spore count of 4.62±0.11 during storage. When the color parameters of the cheeses were examined, a difference was detected in the L* value and was lower in CMBP. At the end of storage, there was no change in the a* values of the cheeses, while the b* values decreased. It was determined that there were differences in the aromatic compounds of the cheeses and while the contents of acetic acid, butyric acid and acetoin, which are LBD indicators, were found to be 32.34%, 17.17% and 17.82% in CMBP cheese, butyric acid was not detected in MBP cheese. The results showed that C. sporogenes survived for a long time in white cheeses stored at pH values below 5 and at low temperatures and could cause the LBD on its own.