Optimal Phenolic Production from Microalgae Chlorella: A Review

Chlorella sp. is regarded as a functional food and a significant source of nutrients across all domains due to its prevalence and beneficial health effects. Numerous studies have been conducted on the optimization of phenolic extraction from Chlorella, a significant secondary metabolite for medicinal or cosmetic applications. This study aims to explore the potential for developing upstream, midstream, and downstream processes from Chlorella to optimize phenol production, providing insights into strain selection, cultivation conditions, harvesting and drying techniques, ideal extraction methods, and their applications across various industries. Results indicate the presence of potential compounds in Chlorella, with production contingent upon species and cultivation strain, cultivation stage, harvesting time, cultivation medium, nutrient supplementation, lighting conditions, harvesting and post-harvesting treatment, and extraction process. It is essential to identify upstream processes, specifically data regarding cultivation strains, cultivation stages, and ideal growing conditions for study on phenolic production using Chlorella. Furthermore, studies utilizing cell disruption techniques provide higher total phenolic content compared to conventional extraction methods. Additional research is necessary, namely to compare the phenolics generated by various Chlorella species and to optimize the combination of parameters in both growth conditions and extraction processes to achieve maximum phenolic yield.