Kinetics of high pressure homogenization assisted protein extraction from Chlorella pyrenoidosa

Protein extraction kinetics from microalga Chlorella pyrenoidosa by applying High Pressure Homogenization pretreatment was studied. Untreated and treated (400–800 bar, 1 and 4 passes) aqueous microalgal suspensions were incubated at 20–40 °C for up to 24 h. A four-pass treatment at 800 bar caused maximization of carbohydrate (103 mg carbohydrates/g dry biomass immediately after treatment) and protein recovery (382.0 mg proteins/g dry biomass after extraction at 40 °C for 24 h). Protein characteristic extraction time was significantly dependent on pretreatment conditions and extraction temperature (5.16 h for untreated sample at 20 °C vs. 1.34 h for 800 bar/4 passes treated biomass at 40 °C). A combination of a two-hour ethanolic extraction at 60 °C prior to a six-hour aqueous extraction from biomass treated at 800 bar/4 passes maximized chlorophyll separation (16.3 mg chlorophylls/g dry biomass) and led to aqueous extracts of high protein content (764.7 mg proteins/g dry extract).