Abstract:

Sixteen Chinese chestnut (Castanea mollissima) varieties collected from different areas of China were used to study the effects of starch-surface-lipid on pasting property of chestnut starch. RVA-pasting viscosity of chestnut starch with de-fatting treatment gradually increased, and reached a peak during the whole warming period at 50 ℃ for 1 min. However, the RVA-pasting viscosity declined to the lowest when starch was warmed at 95 ℃. A following cooling at 12 ℃ brought, the RVA-pasting viscosity to slowly increased again until the whole process ended. Moreover, curves of the RVA-pasting viscosity in chestnut starch, expressed four types in terms of their shapes. The de-fatting treatment did not change shape of curve, but modified the characteristic values of the RVA-pasting viscosity quite largely. The three characteristic values ‘PEAK’, ‘THROUGH’ and ‘FINAL’ increased while the characteristic value ‘PASTING TEMPERATURE’ decreased after the chestnut starch lost its fat. De-fatting of chestnut starch did not affect the ‘PEAK TIME’ of the RVA-pasting viscosity, but interfered the ‘BREAKDOWN’ and ‘SETBACK’ of the RVA-pasting viscosity, depending on chestnut cultivars. When the starch-surface-lipid content was in a range 0.96% to 4.50% the pasting property of chestnut starch was obviously affected regarding to ‘PEAK’, ‘THROUGH’, ‘FINAL’ and ‘BREAKDOWN’ in the characteristic values of the RVA-pasting viscosity.

Key words: chestnut, starch, starch-surface-lipid, pasting property