Extraction of phycoerythrin from Kappaphycus alvarezii seaweed using ultrasonication

Kappaphycus alvarezii is type of red seaweed that widely cultivated in Indonesia. K. alvarezii contains phycobiliproteins mainly phycoerythrin which is commonly used as natural dyes in food and cosmetics, fluorescent, and analytical reagents. Phycoerythrin is generally extracted from red seaweed using buffer phosphate with freeze thawing process. The purpose of this study was to determine the effect of extraction time using ultrasonic waves on the characteristics of phycoerythrin. The maximum absorbance was formed at a wavelength of 499, 534, and 564 nm. Ultrasonic extraction treatment for 30 min and precipitation 60% ammonium sulfate were the best treatments, which had a pigment concentration of 1.9102 mg/mL, purity index 0.8311, and protein concentration of 0.5206 mg/mL. The antioxidant activity possessed by the phycoerythrin pigment is categorized as strong to very strong.