Bioprocessing to Preserve and Improve Microalgae Nutritional and Functional Potential: Novel Insight and Perspectives

This narrative review examines bioprocessing methods to improve the nutritional and functional potential of microalgae, primarily *Arthrospira* and *Chlorella*, for human food applications. The background emphasizes the need for sustainable, plant-based protein sources to feed a growing global population. The methods summarized are strategies for cultivation, harvesting, and processing, including extraction, enzymatic treatments, fermentation, and microencapsulation, aimed at enhancing bioactive compounds (antioxidants, peptides) and mitigating sensory issues like unpleasant taste and color. Key results indicate that bioprocessing can enrich microalgae-derived substrates with compounds showing antioxidant, antimicrobial, and anti-hypertensive properties in vitro, and can improve properties like dough workability and nutrient digestibility in food models. For example, fermentation with lactic acid bacteria can increase phenolic content and radical scavenging activity. Limitations include the frequent technological and sensory challenges of incorporating whole biomass into foods (e.g., reduced bread volume, altered texture), variable effects on protein digestibility depending on processing, and the need for safety assessments for many species. The implications are that while microalgae are promising sustainable ingredients, further research is needed on cost-effective whole-biomass bioprocessing, in vivo digestibility, and safety to realize their full potential as future foods.