What this work is about, in plain words
A brief methods note: a simple way to measure the absorption spectrum of dried spirulina — powder or tablets.
The absorption spectrum can be used to assess the biochemical composition of spirulina, above all its pigments. But for dry biomass, such as powder or tablets, obtaining such a spectrum is difficult: expensive instruments are needed. The authors set out to develop a simple method for an ordinary laboratory spectrophotometer.
The note describes sample preparation. Dry spirulina is mixed, and tablets or "flakes" are first ground in a mortar so that the sample is uniform. Its water content is determined separately. A weighed portion is then gently ground in a small amount of warm water into a uniform suspension, and its attenuation spectrum is measured.
In the authors' assessment, the method makes it possible to obtain the spectrum of dried spirulina without special expensive equipment.
The work may be useful for quick pigment checks of dry spirulina raw material.
Limitations. This is a brief methods note without statistical testing on a large number of samples.