Chemical, rheological, and volatile profiling of microalgae Arthrospira, Isochrysis, Nannochloropsis, and Tetraselmis species

Microalgae are increasingly regarded as a sustainable source of novel food and functional products due to their nutritional composition. This study aimed to conduct an in-depth analysis of the chemical, microstructural and rheological, and volatile-flavour related properties of Arthrospira, Isochrysis, Nannochloropsis, and Tetraselmis species. Chemometric data analysis was employed to integrate the multivariate data, investigate the classification among the four species, and identify discriminating and distinct features. Arthrospira is high in protein content, and Nannochloropsis is lipid-rich with dominantly polyunsaturated fatty acids. Isochrysis is rich in carotenoids and total phenolics, while Tetraselmis is high in carbohydrates. Key discriminant volatile markers encompass aldehydes, terpenes, and hydrocarbons for Arthrospira; ketones and alcohols for Nannochloropsis; aldehydes, ketones, and sulfur-containing compounds for Tetraselmis; and furans and aldehydes for Isochrysis. Moreover, Arthrospira and Isochrysis demonstrate elevated viscosity and notable thickening potential. In summary, the different microalgal biomass studied in this study showcase unique compositional, rheological, and volatile properties, highlighting their potential as functional ingredients for diverse applications in the food and pharmaceutical industries.