The increasing importance of natural beta-carotene in fighting xerophthalmia and cancer has given special importance to algal sources of beta-carotene. The susceptibility to quick degradation of this valuable nutrient in an oxygen atmosphere, light or heat calls for specific attention to processing and storage practices.
In the case of Spirulina powder, it was found that initial losses of beta-carotene on spray drying were between 7 and 10%. On storage in colored bottles containing air, more than 50% was lost in less than 45 days. The particle size of the dried material seems to have an influence.
Flakes (about 20 mesh+) retained 52% of the original beta-carotene level while the spray-dried fine powder (100 mesh-), retained only 34% of the original level. This is explainable in terms of surface area available for the active reaction which is higher in the powder than in flakes. This questions the suitability of using spray drying for Spirulina drying.
Luckily you can avoid this by consuming only Raw Living Spirulina.