What this work is about, in plain words
How does spirulina respond to drying out? The authors studied how dehydration, temperature and irradiation affect its yellow-orange pigments, the xanthophylls, and developed a way to isolate them.
Besides the blue pigment phycocyanin, the cyanobacterium Arthrospira platensis (spirulina) contains carotenoids. Among them are xanthophylls, yellow-orange pigments that protect the cell from oxidative damage. The authors studied how their formation is affected by dehydration, the stress spirulina experiences when it dries out.
The biomass was dried at different temperatures and irradiated with near-ultraviolet or blue light. The pigments were then extracted and their spectra studied.
According to the authors, a method was developed for extracting and purifying the two main xanthophylls of spirulina: myxoxanthophyll (63 % of the total) and oscillaxanthin (27 %). Irradiation with near-ultraviolet light at 38 °C enhanced their synthesis, while at low temperature there was no such effect.
The work shows that drying and irradiation conditions affect the pigment composition of the biomass. This is worth considering when choosing how to process the raw material.
Limitations. This is a laboratory physicochemical study on one strain. The biological activity of the pigments was not studied in the work.