Composition and Properties of Starch from Golden Crown Bean

In order to clarify the basic properties of Golden Crown Bean starch, the Golden Crown Bean seed residues after extraction of salt soluble protein were used as raw materials, of which the starch was obtained by water extraction. The morphology of starch particles was observed, and the composition, particle size, physicochemical properties and in vitro anti-digestibility of the starch were determined. The results showed that the content of amylose and amylopectin in the starch of Golden Crown bean seeds was 47.39% and 52.07%, respectively. The morphology of the starch particles was similar to that of pea starch, with an oval or spherical shape. The surface of the particles was smooth and complete, with a particle size of 75.10 μm. The peak viscosity (212.20 RVU) and attenuation value (68.50 RVU) of Golden Crown Bean starch were lower, but the retrogradation value (96.80 RVU) was higher than that of corn starch; the starting temperature (T₀), peak temperature (T_p) of starch gelatinization in Golden Crown Beans were significantly higher than those of pea starch (P<0.05). The retrogradation value of Golden Crown Bean starch was close to 80% at 90 min, the retrogradation speed was significantly higher than that of corn starch. The transmittance of Golden Crown Bean starch was between pea starch and corn starch. The water holding capacity (WHC) and oil holding capacity (OHC) were 1.08 and 1.00 g/g respectively, the gel hardness was small, belonging to easy retrogradation starch. The content of resistant starch (RS) was 68.43%, which was higher than that of corn starch and pea starch (P<0.05), exhibiting an excellent anti-digestibility feature.