Extraction of biomolecules from Coelastrella sp. LRF1 biomass using Ohmic Heating technology

Abstract

Ohmic heating (OH) allows a natural synergy between thermal and electrical effects, appearing as an efficient approach to the thermal extraction of biocompounds. Different electrical field intensities (e.g., 12 and 217 V/cm), treatment temperatures (from 50 to 100 °C) and heating strategies (continuous and pulsed heating) were combined to enhance for the first time the extraction of nutrients from microalgae Coelastrella sp. LFR1, which is highly adapted to extreme survival conditions. Results showed that OH applied at 217 V/cm, through a fast and single heating pulse (OHP), and at maximum peak temperature of approximately 100 °C (with <1 s of holding time), resulted in the maximum recovery of 50% of chlorophyll a (e.g., 1.02 mg/gDW) and 20.4% of proteins (29.4 mg/gDW) from biomass; lipids and carbohydrates were equally extracted resulting on extraction of 40 and 52%, respectively. OHP allowed to obtain nutrient rich extracts from Coelastrella sp. LFR1 with a significant radical scavenging activity ranging from 20 to 60%.