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US 10,093,894 B2Granted
Method for optimizing a process for freeze drying a bacteria-containing concentrate
AssigneeChr. Hansen A/S
InventorsBirgitte Yde, Tania Ivanova Georgieva, Anders Clausen, Susanne Abrahamsen
Life of this patent
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Abstract
The present invention relates to a process for optimizing the storage stability of a freeze dried bacteria-containing product obtained from a bacteria-containing concentrate, wherein the process is carried out at a pressure which will provide a sublimation temperature which is at least 10° C. above the melting point of the frozen bacteria-containing concentrate. Further, the present invention relates to the freeze dried concentrates per se.
Claims16
A process for obtaining a freeze-dried bacteria-containing concentrate, comprising:
- (i) preparing a frozen sample of a bacteria-containing concentrate and measuring its melting point,
- (ii) calculating a freeze-drying pressure range that provides a sublimation temperature that is from 10° C. to 20° C. above the melting point of the frozen bacteria-containing concentrate with reference to a saturated steam table, wherein the freeze-drying pressure range is from (a) a pressure corresponding to the sublimation temperature that is 10° C. above the melting point of the frozen bacteria-containing concentrate, as determined with reference to a saturated steam table, to (b) a pressure corresponding to the sublimation temperature that is 20° C. above the melting point of the frozen bacteria-containing concentrate, as determined with reference to a saturated steam table, and
- (iii) freeze-drying the frozen bacteria-containing concentrate at a pressure that is within the calculated freeze-drying pressure range until a freeze-dried bacteria-containing product having a water activity (aw) of no more than 0.2 is obtained, wherein the frozen bacteria-containing concentrate undergoes local melting during freeze-drying.
Dependencies are inferred from the claim text.