The effect of heat stress on freeze-drying and conservation of Lactococcus

The accelerated shelf life testing (ASLT) method was used to study the effect of heat stress on conservation of Lactococcus. The bacterium was stored at four different temperatures of 4, 15, 25 and 37 °C. Lactococcus cell kinetic behaviour suggested a first order reaction, and the effect of storage temperature was quantified by determination of the half-life period and the activation energy. The beneficial effect of heat stress is clearly associated with a half-life period of 86 days for SLT6T and only 48 days four SLT6NT stored at 4 °C.