Method of preparing a composition containing lyophilised lactic acid bacteria has viability and bacterial activity improved during storage at room temperature and composition obtained

摘要

The invention concerns a method for preparing a freeze-dried composition comprising the following steps: a) preparing a concentrate of lactic acid bacteria in a liquid medium, said liquid medium comprising: (i) a water-soluble antioxidant compound or a combination of water-soluble antioxidant compounds, and (ii) a compound or a combination of compounds for increasing the glass transition temperature of the freeze-dried product; b) freeze-drying the lipoprotected lactic acid bacteria prepared at step a), in accordance with the following freeze-drying steps: b1) freezing the concentrate of bacteria, b2) primary drying, preferably in mild operating conditions, b3) secondary drying until obtaining a freeze-dried composition having a water activity of about 0.1 and whereof the glass transition temperature (Tg) is higher by at least 20 DEG C than the predetermined storage temperature (Ts). The invention is applicable to biological and food industries.