Yadav and Prabha

solution showed maximum stability at neutral pH than under acidic and

alkaline conditions.

Similarly Kaur et al., (2009)ȱ studiedȱ theȱ effectȱ ofȱ pHȱ ofȱ theȱ methanolicȱ

solution of the extracted intracellular pigment of Rhodotorula rubra

mtcc1446obtainedfromMYEB:coconutwater(50:50)mediumbyadjusting

to 5, 6 and 7 using 0.1N NaOH and HCl. This pigment solution showed

its stability till 1h at pH 5, pH 6 and pH 7. At pH 7 it showed maximum

stability with no change in absorbance till 48h (0.705 OD/ml to 0.702 OD/

ml) as 99% residual colour remained in the solution. Maximum decrease

was observed at pH 5 (0.705 OD/ml to 0.439 OD/ml) with 62% residual

colour in the solution. They concluded that this pigment solution is having

maximum stability at neutral pH than under acidic conditions.

Effect of different temperatures on extra and intracellular pigment of

Rhodotorula minuta RAI ₃ from sterile MYEB, coconut water and rice

It was interesting to know that, intensity of pigment decrease was more

rapid in intracellular at laboratory pasteurization A ₅₂₀

(0.310 to 0.178)

followed by boiling A ₅₂₀

(0.140 to 0.096) and sterilization temperatures A ₅₂₀

(0.071 to 0.064 ). The decrease in the intensity of extracellular pigment was

slightly lesser compared to intracellular pigment at lab pasteurization A ₅₂₀

(0.148 to 0.126), boiling A ₅₂₀

(0.083 to 0.073) and sterilization temperature

A ₅₂₀ ȱ(0.051ȱtoȱ0.046).ȱTheȱmediaȱhadȱnoȱeffectȱonȱheatȱstabilityȱofȱpigment.ȱ

Heatȱtreatmentȱhadȱnegativeȱeffectȱonȱintensityȱofȱintracellularȱpigmentȱ

compared to extracellular pigment (Fig.1).

On par with the present study present study, Kaur et al., (2009) subjected

alcoholic extracted pigment solution of Rhodotorula rubra to heat treatment

from 700-1000C for 15 minutes and measured by taking OD at 360 nm. It

was shown that colour decrease was more rapid in intracellular (0.705 OD/

ml to 0.36 0D/ml) pigment extracted from submerged fermentation than

in intracellular pigment (0.41 OD/ml to 0.16 0D/ml) extracted by solid-

state fermentation than extracellular pigment extracted in submerged

fermentation (0.28OD/ml to 0.090D/ml).

References

Aksu,-Z., Eren,-A-T 2007. Production of carotenoids by the isolated yeast of Rhodotorula

glutinis. Biochemical Engineering Journal , 35 :107–11.

CostaȱHL,ȱMartelliȱdaȱsilvaȱIMȱandȱPomeroyȱD.ȱ2005.Productionȱofȱβ-caroteneȱbyȱ

a Rhodotorula strain. Biotechnol Lett , 9 : 373-375.

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