Processing of sugar kelp: Effects on mass balance, nutrient composition, and color

The European production of seaweed, including kelp species, is increasing, but efficient processing schemes for complete biomass valorization are still lacking. In this study, we investigated the effect of combining pulsed electric field (PEF) processing and soaking/blanching treatments (10, 45, and 60 °C) on the chemical composition of sugar kelp. Furthermore, we suggest applications for the various fractions resulting from the different pre-processing steps. More dry matter was extracted from the biomass with increasing degree of processing. Combining PEF and blanching gave the highest extraction yield (˜60 %) compared to only using one of the steps (˜40 %). The extracted compounds contained ash (including iodine), polyphenols, and mannitol. Proteins, heavy metals, other sugars, and (presumably) fiber were concentrated in the solid fractions. Based on the composition, applications within food, feed, agriculture, nutraceuticals, and cosmeceuticals are suggested for the fractions and extracts. These results can be relevant to researchers investigating novel technologies, processing seaweed, and food safety, as well as to the seaweed industry, for the selection of processing technologies and product applications.