Physicochemical properties of wild and cultivated Saccharina latissima macroalgae harvested in the Canadian boreal-subarctic transition zone

Saccharina latissima is a brown seaweed used as a food ingredient. The aim of this work was to study possible differences between S. latissima chemical composition, color, mode of cultivation, harvesting period and site and its environmental conditions. Water temperature, salinity, radiation, and fluorescence were monitored in each harvesting site. Chemical composition of S. latissima varied greatly with period and site, with a high content of carbohydrates and ash. Crude protein content varied from 3.7 % to 12.8 %, with a higher concentration observed in wild samples harvested in Bas-St. Laurent (11.1–12.8 %). Cultivated seaweed also presented a high crude protein (12.2 %) and ash (52 % against 27 % in wild samples) concentrations, but crude fiber and carbohydrates concentrations were lower, reaching up to 2.7 and 1.9-fold, respectively, than those in wild seaweeds. S. latissima presented a more intense yellow color in June. A trend of darker and more green-colored seaweeds when cultivated in the end of summer was confirmed. Our results suggest that variations in chemical components and chromaticity of this species are probably affected by complex interactions of environmental conditions.

Mots clés

• Seaweed biomass
• Macroalgae color
• Photosynthetically active radiation
• Brown macroalgae
• Saint-Lawrence Basin