Hoang Chinh Nguyen, Colin J. Barrow
School of Life and Environmental Sciences, Deakin University, Geelong, Victoria 3216, Australia
Seaweeds have attracted great attention for industrial applications as they contain various valuable bioactive compounds. Particularly, brown seaweeds are a rich source of phenolics and polysaccharides (e.g., alginate and fucoidan) with unique properties and biological activities. This study aimed to develop a novel enzymatic method for simultaneously extracting phenolics and polysaccharides from brown seaweed and evaluate antioxidant activity of the extracts. The ability of several enzymes (cellulase and protease in individual and combination) to extract phenolics and polysaccharides was examined. Among the tested enzymes, cellulase demonstrated the highest extraction efficiency. The cellulase-assisted extraction was then optimized using response surface methodology to maximize the content of phenolic and polysaccharides. Under the optimal extraction conditions, the highest phenolic and polysaccharide contents were obtained. The polysaccharides were further fractionated to obtain alginate and fucoidan. The phenolic, alginate, and fucoidan fractions showed potential antioxidant activities. This study suggested that cellulase-assisted extraction is a green and efficient method for simultaneous extraction of phenolic and polysaccharides from brown seaweed and the phenolic, alginate, and fucoidan fractions are a promising antioxidant agent for future applications.