Isolation and characterization of starches from chestnuts cultivated in three regions of Korea

Chestnut starches were isolated from chestnuts cultivated in three different regions of Korea (Gongju-si (GJ), Gwangyang-si (GY), and Hadong-gun (HD)), and their physicochemical properties were investigated to assess further potential commercial uses of chestnuts. GJ and HD had higher protein and fat content than GY. GJ had the highest amylose content (20.37%). Chestnut starch granules were shaped as rounded triangles or irregular ovals, 2-10 mu m in size, with B-type X-ray diffraction patterns. HD showed the highest solubility and swelling power at 90 degrees C. DSC analysis revealed that the thermal properties of the three starches were not significantly different (p < 0.05). In RVA, chestnut starches displayed relatively lower pasting temperatures and higher peak viscosity and breakdown values than corn starch. It is very interesting to note that chestnut starches formed gels at relatively low concentrations (5%), and their gels had much higher freeze-thaw stability than corn starch.