Abstract
In the southern area of Hokkaido, Makombu (Saccharina japonica) is mainly farmed. During the winter season (from January to March), dulse (Devaleraea inkyuleei), a type of red algae, naturally grows on the ropes used for Makombu farming. Fishermen were removing the overgrown dulse as an obstruction. Therefore, we have recently begun exploring the health benefits of dulse to advance its use as a functional food material. As a result, we found that Hokkaido dulse is rich in protein and carbohydrate (about 40％ per dry weight, respectively). The major component of protein was phycoerythrin (PE), and then we determined the primary structure and 3D structure of it. In addition, we determined the entire structure of chloroplast DNA, in which the gene of PE is encoded. Furthermore, we found that dulse PE has hypotensive, antioxidant, anti-inflammatory, and brain function-improving effects. On the other hand, the major component of carbohydrate was xylan of polysaccharide. Therefore, we prepared oligosaccharides by enzymatic degradation of the dulse xylan. From this oligosaccharide, we isolated β - (1→3)/β - (1→4)-xylotriose (DX3), which has a β - (1→3) bond at the non-reducing end and a β - (1→4) bond at the reducing end. Furthermore, we clarified that DX3 selectively promotes the growth of Bifidobacterium adolescentis. Based on these findings, we believe that detailed investigation of the biochemical properties of Hokkaido dulse will contribute to the development of protein sources for future food shortages and to the development of food materials that make people healthier, and we are continuing our research.
https://ror.org/02e16g702 
