Detection of heat resistance properties of Bacillus spores isolated from cocoa powder

In this research, the growth and colony forming characteristics of Bacillus species which are isolated from 5 different cocoa powder and the heat resistant characteristics of their spores were detected. The isolated cultures were kept in frozen vials to prevent mutations and contaminations. Frozen cultures were prepared using mesophilic and thermophilic strains. These frozen vials used for making frozen stock cultures. By this way they could be preserved without any mutation and contamination.The isolated Bacillus strains were identified by API 50CHB isolation system. Six Bacillus strains detected with higher survival and spore forming abilities at higher temperature and they were used in further research. Four of them are Bacillus subtilis (strain 81, 101, 125, 162A ), one is Bacillus licheniformis (strain 49) and the other one has not been identified (Strain 64).Strain 162A was identified as most heat resistant bacterium from high temperature (at 95-130?C for 0.25-12 min.) applied experiments. This strain was exposed to heat treatment at 130?C for 1 minute to inactivating all the spores.For evaluating the inactivation results two different mathematical methods, Weibull model and First order model were used.