A novel method for double encapsulation of C-phycocyanin using aqueous two phase systems for extension of shelf life.

Spirulina platensis is having high nutritive value
due to pigments such as chlorophyll-a, phycobiliproteins
(especially phycocyanins) and carotenoids. In our present
work, C-phycocyanin (C-PC) was extracted from dry biomass of Spirulina platensis. C-PC being heat sensitive,
reiterates the need for additional protection during drying
(micro encapsulation). Accordingly, a novel method
employing aqueous two phase systems (ATPSs) as carrier
materials to achieve double encapsulation was studied for
the first time. PEG 4000/Potassium phosphate and PEG
6000/Dextran were used at already standardized tie line
length, at different volume ratios (by varying the total
phase composition). ATPS at each volume ratio acted as
different carrier materials offering varied degree of heat
protection during double encapsulation while maltodextrin,
being the conventional carrier material, was used for
comparison. The best results of spray dried powders using
PEG (4% w/w)/Potassium phosphate salt (18%, w/w) and
PEG (6%)/Dextran (10%, w/w) phase systems as carrier
materials were compared with conventional encapsulation
(MDX as a carrier material) and freeze dying as control.
PEG/Dextran as a carrier material with volume ratio of
0.25 resulted in the highest retention of blue colour (b*-
value), purity (0.43) as well as yield (YEP) of 94.99% w/w
of C-PC, which could be stored for 6 months without much
reduction from initial powder characteristics. From the
overall results, it can be concluded that ATPS can be used
as an effective carrier material for double encapsulation of
biomolecules such as C-PC with additional benefit of
enhancing the purity.