Apios ( Apios americana Medikus), also called the potato bean, Indian potato, or groundnut, belongs to the legume family, and is widely distributed across eastern North America. Apios starch was hydroxypropylated, and its physicochemical and structural characteristics were investigated in this study. The starch was extracted by alkali precipitation method, and hydroxypropylated apios starch (HPAS) was prepared using propylene oxide at concentrations of 2.5, 5, 7.5, and 10% (v/w). X-ray diffraction of native apios starch and HPAS revealed the presence of the typical ‘A’ type of cereal starch. Additionally, the hydroxypropylation affects the relative crystallinity of the starch. The swelling power and solubility of apios starch increased after hydroxypropylation. Gelatinization parameters were obtained using differential scanning calorimetry. The gelatinization temperature of native starch is 69°C, whereas that of HPAS-10% is 52.94°C. This suggests that HPAS is suitable for preparing food items requiring enhanced gelatinization.

In this study, in order to verify the use of mycelium as a new functional material, Rhynchosia nulubilis was cultivated with Ganoderma lucidum mycelium, and the biological activity of the culture extract was evaluated. Measurements of the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radical scavenging activity showed that the ethanol extract from Rhynchosia nulubilis cultivated with Ganoderma lucidum mycelium (RNGM) had significantly higher radical scavenging activity compared to the ethanol extract from Rhynchosia nulubilis (RN). The growth inhibition rate of RNGM against HeLa cells was 93.93% at 400 μg/mL in the 3-(4,5-dimethylthiazol-2-yl)-2,5-dimethyl tetrazolium assay. RNGM effectively decreased nitric oxide production in lipopolysaccharide-treated RAW264.7 macrophage cells. The total polyphenol, total flavonoid, and the β-glucan contents of RNGM were higher than those of RN. These results demonstrated that increased total polyphenols, flavonoids, and β-glucan of Rhynchosia nulubilis during cultivation with the Ganoderma lucidum mycelium could increase the antioxidant and anti-inflammatory activity and cytotoxicity of cancer cells.