Stability of microbial composition, and manufacturing methods therefore
The present invention relates to encapsulation of microbial cultures to improve the robustness and stability upon storage. In particular, the present invention relates to dry preparations of microbial cultures, such as lactic acid bacteria (LAB), coated by a fat-matrix that increase survivability and mitigate post-acidification upon storage at ambient temperature for extended periods of time.
1 . A method for the preparation of a composition comprising a microencapsulated microbial culture, said method comprising the steps of:
a) obtaining a concentrated cell mass of the microbial culture;
b) adding a protective compound to the concentrated cell mass of (a) to obtain a mixture;
c) drying the mixture of (b) to obtain a dried mixture;
d) optionally grinding the dried mixture of (c) to obtain a powder;
e) coating the dried mixture of (c) or powder of (d); and
f) mixing the coated dried mixture or powder of (e) with an excipient;
wherein the protective compound is a cryoprotectant and/or lyoprotectant with a bulk density between 150 and 600 kg/m 3 .
2 . The method of claim 1 , wherein the protective compound is a cryoprotectant and/or lyoprotectant with a bulk density between 150 and 225 kg/m 3 .
3 . The method of claim 1 , wherein the protective compound is a cryoprotectant and/or lyoprotectant with a bulk density of about 180 kg/m 3 .
4 . The method of claim 1 , wherein the method comprises step f) and further comprises the step of:
g) adjusting the water activity (aw) of the excipient mixture of f) to about 0.35.
5 . The method of claim 1 , wherein said protective compound is a cryoprotectant and/or lyoprotectant comprising at least one ingredient selected from the group consisting of maltodextrin, oligofructose, pectin, xanthan gum, OSA starch and sodium ascorbate.
6 . The method of claim 1 , wherein said excipient is calcium carbonate.