Extraction, purification and application study of R-Phycoerythrin from Gracilaria corticata (J. Agardh) J. Agardh var. corticata

Abstract

Red seaweeds, such as Gracilaria corticata (J. Agardh) J. Agardh var. corticata rich in polysaccharides and found abundantly in Indian waters throughout the seasons, have a considerable amount of phycobiliproteins, especially phycoerythrin which has recently found applications in food and beverage industry as a natural coloring agent. Extraction of phycobiliproteins was carried out using phosphate buffer (0.1M), precipitated in 65 % ammonium sulphate saturation, dialyzed overnight using distilled water and phycoerythrin was separated using DEAE cellulose-52 column chromatography. The purity and yield obtained after purification of R-phycoerythrin was 1.10 and 0.024 % (w/w), respectively where as crude phycobiliproteins yielded 0.078 % (w/w). This could be preserved for a period of 100 days in the presence of 5 % NaCl at 0±5 ^oC with a color loss of only 37.5 %. Dialyzed and lyophilized phycobiliprotein was used for application in commercially available carbonated drinks such as Lehar soda, 7up and TATA mineral water. Among the three drinks, 7up retained the color for more than 30 days at room temperature with 50 % loss where as in other drinks color retention was only for 3 days. The present study concludes that phycoerythrin can be used as a natural colorant in cool, sweetened and carbonated drinks.