Spirulina: A source of dietary gamma‐linolenic acid?

Spirulina powders obtained from different commercial sources contained 23.6–38.0 mg g −1 DM as long‐chain fatty acids and 3.4–6.0 mg g −1 DM as y‐linolenic acid (6, 9, 12‐octadecatrienoic acid). However, γ‐linolenic acid constituted up to 40% of the total fatty acids within the isolated galactolipids. Unesterified fatty acids accounted for 8.4–66.9% of the fatty acids recovered from the different samples; the remaining fatty acids were in glycerolipids. There was also a wide variation in the contents of photosynthetic pigments among the different preparations. Spirulina was four‐fold more expensive than evening primrose oil as a source of a‐linolenic acid to supplement human diets. Since α‐linolenic acid (9, 12, 15‐octadecatrienoic acid), (E)‐3 hexa‐decenoate, 3‐sn‐phosphatidylcholineand 3‐sn‐phosphatidyl ethanol‐amine were not detected in the lipid extracts, none of the samples was significantly adulterated by eucaryotic algae. From an analysis of the extracted lipids it was possible to make some predictions both about the manner in which the cells were cultured and the post‐harvest treatment of the preparations.