Alginate stability during high salt preservation of Ascophyllum nodosum

Formaldehyde is usually added to brown algae to avoid microbial growth during storage and to fix polyphenols in the algae before alginate extraction. Since formaldehyde is toxic, allergenic and possibly carcinogenic, dry salting of Ascophyllum nodosum was tested as an alternative. The seaweeds, harvested at locations with a salinity of about 30‰ from late autumn to early spring, were stored at 22±2 °C under compost-like conditions. Untreated samples of seaweed lost their quality as a raw material for alginate production within 14 days. Salted (20–22%) as well as formaldehyde treated seaweed was preserved for at least 46 days. Due to the reduced water activity and oxygen saturation in the dry salted seaweed, microbial growth and brown colouring reactions were suppressed. Economic factors must also be taken into account before large-scale applications are considered. This revised version was published online in June 2006 with corrections to the Cover Date.