Background: The effect of high-pressure homogenization (HPH) on the rheological and thermal properties, water retention capacity (WRC), morphology and in vitro digestion of wheat starch was evaluated. Starch suspensions (50 g kg-1 , w/w) were treated at increasing pressures (up to 100 MPa) and numbers of cycles (up to 5) to generate a wide range of energy densities (70-500 MJ m-3 ) delivered to the sample during processing.
Results: High-pressure homogenization induced a partial starch gelatinization confirmed by higher digestibility. Gelatinization degree (GD) was between 13% and 83%, causing a wide range of functional properties. High-pressure homogenization-treated starch samples showed WRC values of 810-1910 g kg-1 . Storage modulus (G') and complex viscosity (η* ) of starch dispersions were almost two and three times higher than the control at 13% and 83% GD, respectively. Positive linear relationships between GD (R = 0.98, P < 0.001), WRC (R = 0.87, P < 0.05), or rheological parameters (R = 0.89÷0.90, P < 0.01) and energy density of HPH treatments were found.
Conclusion: High-pressure homogenization treatment represents a promising technology to obtain wheat starch with tailored rheological properties and digestibility, which allows the texture and glycemic response of food products to be adjusted. © 2020 Society of Chemical Industry.
Keywords: functional properties; gelatinization; high pressure; homogenization; rheology; wheat starch.
© 2020 Society of Chemical Industry.