Method for extracting, with high yield, phycobiliproteins from cyanobacterial and/or algal biomass, obtaining aqueous extracts characterized by high concentration of pigments (4-5 mg/mL) and a purity, at least equal to food/cosmetic grade (P≥2). The process is characterized by a first step in which the cyanobacterial/algal cells are broken by ultrasonication in an ammonium sulphate solution, with simultaneous extraction of water-soluble compounds other than phycobiliproteins, and a second step in which phycobiliproteins are extracted using water or aqueous solutions. The method allowed to extract up to 95-98% of the phycobiliprotein content from Spirulina biomass obtaining bright blue crude extracts with P>3 and concentration up to 4-5 mg/mL. Bright fuchsia crude extracts of Porphyridium cruentum (principally containing B-phycoerythrin) were also obtained with P=4 and concentration of about 1 mg/mL.
The method, which incorporates cell rupture and purification of the product in a single step, applies an inverse logic to the traditional one, as first it aims to eliminate the contaminating molecules (thus contributing to purification) and only after it aims to extract the compounds of interest (the phycobiliproteins) from the biomass. Production times are reduced (one day, biomass harvesting included), to the advantage of the product quality. Since both the chemical-physical and organoleptic characteristics (e.g., no unpleasant smells develop) are preserved.
Furthermore, it is possible to use any extracting solution deemed appropriate, obtaining very concentrated bright coloured extracts (a few mg/mL), with purity grade P > 2, without applying downstream purification processes.
These characteristics reduce production costs and make the method an excellent candidate for industrial-scale use.
Italy; Europe