Occurrence, populations, diversity, and growth potential of spore-forming bacteria in “requeijão cremoso”

Abstract

The aim of this study was to determine the occurrence, counts, and diversity of spore-forming bacteria in three types (full fat, low fat, and flavored full fat) of “requeijão cremoso”. In addition, the growth potential (δ) of three prevalent species of spore-forming bacteria was determined in samples stored at three different temperatures. The occurrence of mesophilic aerobic spore-forming bacteria, mesophilic anaerobic spore-forming bacteria and blowing clostridia was around 30%, while only 1.38% of samples was contaminated with psychrotrophic aerobic spore-forming bacteria. The mean counts of psychrotrophic aerobic spore-forming bacteria, mesophilic anaerobic spore-forming bacteria, blowing clostridia and mesophilic aerobic spore-forming bacteria were 0.11 log CFU/g, 0.33 log MPN/g, 0.45 log MPN/g, and 0.46 log CFU/g, respectively. Paenibacillus sanguinis, P. brassicae, Bacillus thuringiensis, B. circulans, B. licheniformis, and B. pumilus were the most prevalent aerobic spore-forming bacteria species. On the other hand, C. sporogenes was the anaerobic mesophilic spore-forming bacteria species identified. P. sanguinis 2301083, B. thuringiensis bt407 and C. sporogenes JCM1416 may grow in full-fat, low-fat, and flavored full-fat “requeijão cremoso”, reaching δ values > 4 throughout the shelf life (>60 days), even when stored at low temperatures such as 4 °C.