Effect on Physicochemical and Thermal Properties of Buckwheat (Fagopyrum esculentum) Starch by Acid Hydrolysis Combined with Heat Moisture Treatment

Starch extracted from buckwheat was modified by acid hydrolysis combined with heat moisture treatment (AH-HMT) and evaluated for physicochemical and thermal properties. A three-level, five-factor central composite design was used to study the individual and combined effects of pH (2 to 4), moisture content (25 to 35%) and temperature (90 to 110C). After modification swelling power and oil binding capacity decreased, whereas solubility, amylose content and water-binding capacity increased. Textural properties were found to be largely affected by modification. Post AH-HMT, a decline in peak viscosity (PV) was noticed while trough and final viscosity were increased. It was also observed that AH-HMT increased onset (To), peak (Tp) and conclusion (Tc) temperature to 87.04C, 93.60C and 95.88C, respectively. However, a significant decrease in enthalpy (ΔH) from 1.046 to 0.211 J/g was observed. Practical Applications The present study deals with the combined effect of two modifications on functionality of buckwheat starch. Native starch possesses some inherent properties which limits their application in food industry. The combined effect of both the modification could improve the properties and reduce the side effect of one another. A better understanding of the effect of combined modification on the properties of buckwheat starch can lead to the development of tailor-made starches for specific applications opening the avenues for better exploitation for this cheaply available crop.