Optimization of Microbial Biopigment Production from Rhodotorula sp. MTCC 1446 Utilizing Potato Waste Based Media.

Standardization of the growth conditions for Rhodotorula sp. MTCC 1446 for microbial biopigment production utilizing the horticultural wastes was conducted to replace the use of synthetic food colors by optimizing cheap media formulation. Screening of different horticultural wastes revealed potato waste based media 5% (w/v) showed maximum biomass growth and biopigment production. Cultural conditions viz. incubation temperature, pH, incubation time and DAHP supplementation were statistically optimized using Response Surface Methodology results revealed that incubation temperature of 30 °C, pH 7, incubation time 66 h and 362.5 mg/100 ml DAHP supplementation as optimized cultural conditions for the biopigment production. Temperature and pH were the most significant facorts to determine microbial biomass growth and biopigment production. Identification studies revealed the presence of carotenoids viz. β-carotene, torulene and torularhodin in the biopigment later confirmed by HPLC analysis also. Utilization of dried purified biopigment form in pear nectar and pear bar resulted in the increase in their phenolic content along with increase in the sensory score of both products in terms of appearance, flavor and overall acceptability. Hence, the biopigment produced on potato waste based media under optimized cultural conditions using Rhodotorula sp. can be serve as a nutritive alternative to synthetic food colors for food industries. [ABSTRACT FROM AUTHOR]