Utilizing lipid-extracted microalgae biomass residues for maltodextrin production

• Recovering valuable carbohydrate compounds from microalgae biomass residues.
• Optimization of hydrolysis conditions to obtain low-molecular-weight maltodextrin.
• Maltodextrin obtained was resistant to enzymatic hydrolysis.
• Maltodextrin obtained was found similar as commercial-grade maltodextrin.

Cultivation of microalgae biomass for biodiesel production has been placed as one of the forefront research fields that gained wide interest from researchers across the world. Nevertheless, after extracting the lipid from the microalgae biomass, little attention is given on the possibility to convert the microalgae biomass residues to other value-added co-products. In the present study, the microalgae biomass residues were utilized by recovering valuable carbohydrate compound remaining in the biomass after lipid extraction. Parametric study on the carbohydrate hydrolysis conditions was performed to obtain low-molecular-weight maltodextrin from the microalgae carbohydrate. It was found that the highest maltodextrin yield (90%) could be attained by using 3 vol.% of H2SO4 (or 0.56 M) at operating temperature of 90 °C after 1 h of hydrolysis time. In addition, the maltodextrin obtained from the microalgae biomass residues was resistant to enzymatic hydrolysis, in which this form of maltodextrin is usually denoted as resistant maltodextrin.