Impact of fermentation on the antioxidant activity and color of haematococcus pluvialis and porphyridium cruentum

Microalgae are emerging as a promising ingredient for the food industry due to their sustainable cultivation and production of a variety of bioactive compounds, including proteins, lipids, carbohydrates, antioxidant compounds, and pigments [1]. Among the many cataloged species of microalgae, two stand out in research due to their powerful applications in the pharmaceutical, nutraceutical, cosmetic, and food and beverage industries. The first is Haematococcus pluvialis, a unicellular microalga known for its high content of astaxanthin (3,3-dihydroxy-β, β-carotene-4,4- dione), one of the most important natural antioxidants [2]. The second is Porphyridium cruentum, a red marine microalgae that serves as a reservoir of high-value compounds such as carotenoids, sulfated exopolysaccharides (EPSs), β-phycoerythrin (PE), and lipids [3]. Carotenoids and astaxanthins are well-known antioxidants with numerous applications in the food and pharmaceutical industries. However, the application of microalgae in food faces challenges related to their intense flavour and odour. Fermentation of microalgae biomass with bacteria has emerged as a promising strategy to mitigate these problems [4]. However, the fermentation process can modify other characteristics of the biomass.