Physicochemical and emulsifying properties of pectin from Ottelia acuminata inflorescence

The pectin extracted from Ottelia acuminata inflorescence was investigated for its physicochemical and emulsifying properties. Ottelia acuminata inflorescence pectin (OAIP), with a yield of 8.73 g/100 g, contained 2.39 g/100 g of moisture, 0.84 g/100 g of total ash and 1.83 g/100 g of protein. The results revealed that OAIP was low methylated carrying negative charges. The charge density and molecular morphology of the pectin changed significantly with pH variation. A formula for the relation of dynamic viscosity with temperature and concentration was established: η= 0.01683 exp (16.3283 exp (0.0262 C)/RT) (C)−1.5816. At OAIP concentration of 2.0 g/100 mL, a stable emulsion containing fifty percent oil fraction (v/v) can be achieved. At 1.0 g/100 mL OAIP concentration, the emulsion containing fifty percent oil fraction was stable within 7 days, after which remarkable emulsion layer separation was observed for all emulsions at different pH values, Na+ and Ca2+ concentrations. •A formula on dynamic viscosity was developed: η= 0.01683 exp (16.3283 exp (0.0262 C)/RT) (C)−1.5816.•The emulsifying activity of the OAIP varied with the pectin concentration, pH, Na+ and Ca2+.•The microstructure observations were carried out to reflect the droplet sizes.