Optimization of cell wall degradation, extraction buffer concentration and evaluation of functional properties of phycoerythrin pigment from Caspian red macroalgae, Osmundea caspica (Rhodomelaceae, Rhodophyta)

Phycoerythrin (PE) is a naturally produced colorant with great fluorescent and antioxidant properties, which has an important potential in food pharmaceutical industries. This study was conducted by randomly experimental design in order to optimize the phycoerythrin extraction under different independent variable (biomass: buffer ratio, buffer ionic strength and cellular disruption method) from Caspian Sea red macroalgae (Osmundea caspica). Purity and concentrations of PE changed significantly under different treatments (P<0.05). The highest PE purity and concentrations was obtained in 100Mm sodium phosphate buffer and 1:20 biomass: buffer ratio. Therefore, the positive correlation has been observed between increasing levels of buffer ionic strength with PE purity and concentrations while lowest PE purity and highest PE concentrations (mg/gr fresh algae) were obtained with increasing level of biomass: buffer ratio. Antioxidant activity of extracted PE was evaluated by measuring the free radical scavenging ability using DPPH. PE was found to have better free radical scavenging activity at highest concentration with dose-dependent manner. Therefore, the obtained phycoerythrin in 100mM buffer in the extraction process approximatlly with a purity of one can be introduced with the aim of application in the food industry.