Bioextracting Polyphenols from the Brown Seaweed Ascophyllum nodosum from Québec's North Shore Coastline

Abstract

Developing innovative industries in rural communities requires researching valuable finished products using local natural resources and feasible equipment and technology. Resources like seaweed are popular in today's global cosmetic ingredient and biotechnology market and are commonly found growing in remote communities, making it an ideal opportunity for rural economic development. This study focuses on the antioxidant-rich polyphenol compounds found in the seaweed species Ascophyllum nodosum, local to Québec's North Shore coastline. Different processing technologies were compared to optimize polyphenol yields, including different preservation methods as well as bioextraction techniques that are applicable and accessible to remote regions. Analyses of extracts were performed using different colorimetric assays to measure total polyphenols and phlorotannins, as well as to estimate antioxidant activity. Results from the study found that the samples immediately frozen displayed higher polyphenol concentration and the highest antioxidant activity. Analysis also showed that a microwave-assisted extraction method improved polyphenol yield efficiency for water extractions. However, the conventional solvent extraction method using 75% (v/v aq.) 1,3-propanediol solvent resulted in the highest phenolic content, totalling 9.8% (w/w) of its dry weight, and the optimal antioxidant activity.