Stability of beta-carotene in spray dried preparation of Rhodotorula glutinis mutant 32.
OBJECTIVE
To obtain beta-carotene-rich dry cell preparation from mutant 32 of Rhodotorula glutinis and determination of its pigment stability.


RESULTS
The mutant 32 of R. glutinis was grown in a 14 l stirred tank fermenter. Cell mass was concentrated 10-fold by cross-flow microfiltration and then spray dried. Butylated hydroxy toluene (BHT) and d-tocopherol were used as protecting agents. A two-level, three-variable, factorial optimization was performed to achieve moisture-free, non-viable and beta-carotene-rich feed additive.


CONCLUSIONS
The beta-carotene and cell mass in stirred tank fermenter were found to be 54 +/- 5 mg l-1 and 12.8 +/- 2 g l-1, respectively. In the presence of BHT, 97 +/- 3% (w/w) beta-carotene was recovered for all the inlet temperatures studied. The best beta-carotene and yeast powder recoveries were obtained at 160 degrees C, 11.6% (w/v) cell mass concentration and 1 g l-1 BHT. The pigments inside dried yeast powder were stable in dark and cold condition for at least 10 weeks. The purified beta-carotene got almost totally denatured, under similar conditions of storage, within 76 h.


CONCLUSIONS
Spray dried and stable preparation of beta-carotene-rich yeast, R. glutinis can provide alternative source of beta-carotene for use in animal nutrition.
Bhosale
P
P
Chemical Engineering Division, National Chemical Laboratory, Pune, India.
Jogdand
V V
VV
Gadre
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RV
D000821:Animal Feed; D000818:Animals; D003890:Desiccation / Q000379:methods; D004355:Drug Stability; D005285:Fermentation; D005503:Food Additives / Q000737:chemistry; D007218:Industrial Microbiology / Q000379:methods*; D009154:Mutation; D012248:Rhodotorula / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D014462:Ultrafiltration / Q000379:methods; D019207:beta Carotene / Q000096:biosynthesis* / Q000737:chemistry
D005503:Food Additives; D019207:beta Carotene