Optimising Extraction Methods for Enhanced Lipid Recovery from Macroalgae

Biodiesel feedstocks have evolved from the use of food-grade vegetable oils to lipids from microalgae and microorganisms. The challenges faced in the production of biodiesel from this third-generation lipids lie in the efficient extraction techniques and production costs. This study aimed to optimise extraction techniques to enhance lipid recovery from macroalgae. Six macroalgal species from the northwest coast of Aceh, Indonesia, were initially screened to evaluate their lipid yields using the Soxhlet extraction (S) method. Caulerpa taxifolia was selected for further optimisation based on its high lipid yield and favourable fatty acid profile, consisting of 85.8 % palmitic acid (C16:0) and 14.2 % myristic acid (C14:0). Various extraction methods were tested, including ultrasonication (S), enzymatic extraction (E), and combinations of ultrasonication-Soxhlet extraction (US), enzymatic-ultrasonication (EU), enzymatic-Soxhlet extraction (ES), and enzymatic-ultrasonication-Soxhlet extraction (EUS). The ES method produced the highest lipid yield of 21.5 %, a 15-fold increase compared to that of the S method alone. Physicochemical analysis of the extracted lipids showed properties suitable for biodiesel production, although further refinement is required to fully meet the quality standards. This study demonstrates the potential of optimised extraction techniques to significantly enhance lipid recovery from macroalgae, thereby contributing to the development of sustainable marine-biofuel resources. Further research is required to refine these methods and explore their large-scale applicability in the field.