High pressure inactivation ofClostridium botulinumtype E endospores in model emulsion systems

Abstract

Clostridium botulinum type E is a cold-tolerant, neurotoxigenic, endospore-forming organism, primarily associated with aquatic environments. High pressure thermal (HPT) processing presents a promising tool to enhance food safety and stability. The effect of fat on HPT inactivation of C. botulinum type E spores was investigated using an emulsion model system. The distribution of spores in oil-in-water (O/W) emulsions and their HPT (300-750 MPa, 45-75°C, 10 min) inactivation was determined as a function of emulsion fat content (30-70% (v/v) soybean oil in buffer). Approximately 26% and 74% of the spores were located at the oil-buffer interface and the continuous phase, respectively. Spore inactivation in emulsion systems decreased with increasing oil contents, which suggests that the fat content of food plays an important role in the protection of C. botulinum type E endospores against HPT treatments. These results can be helpful for future safety considerations.

Non-linear pressure/temperature-dependence of high pressure thermal inactivation of proteolytic Clostridium botulinum type B in foods

“…To date, few studies investigated the HPT inactivation of spores from the important food intoxicating organism, C . botulinum , in food matrices and food model systems [ 7 – 10 , 14 ]. Moreover, the comparison of inactivation data is not only difficult due to varying process parameters but also because of different thermodynamic properties of HPT units, in particular controlling and monitoring adiabatic heating effects.…”

“…For spores of non-proteolytic C . botulinum type E, it has been shown that increasing fat content can result in reduced HPT and thermal inactivation [ 14 , 15 ]. Both GPH and SS have a higher fat content than BV (braised veal) and VS (vegetable soup), namely 12.8% and 8.6%, respectively.…”

“…Such tailing effects appear to be significantly less pronounced for C . botulinum strains belonging to the non-proteolytic group II [ 14 , 17 ]. Most importantly, this demonstrates that it can be difficult to completely inactivate spores from proteolytic C .…”