Effect of thermal and high-pressure processing on the thermo-rheological and functional properties of common bean (Phaseolus vulgaris L.) flours

The effect of hydrothermal (HT) (boiling for 15 or 120 min) and high-hydrostatic pressure (HHP) (150, 300, 450, and 600 MPa for 5, 10 or 15 min) processing on the rheological, pasting, thermal and functional properties of bean flours was investigated. HT and HHP treatments differently affected these properties. HT120 led to maximum values of elastic and viscous moduli (G′, G″), and gel strength of bean flours. HHP enhanced G′, G″ and gel strength as the pressure and holding time increased. The viscoelastic properties of HT120 and HHP600/5-treated bean flours correlated with the increased viscosity of these samples. The pasting profiles and thermograms indicated a full, partial, and limited starch gelatinization in HT120, HHP600/5 and HHP ≤450 MPa samples, respectively. Enthalpy values showed that HT120 caused a higher degree of protein denaturation than HHP, with protein denaturation increasing as pressurization and time increased. This had an impact on protein solubility and emulsifying activity of flours which were significantly diminished by HT15/HT120, but maintained or slightly decreased by HHP. Nevertheless, HHP-treated samples showed enhanced emulsifying stability with increased pressure and holding time. These results demonstrate that HHP has the technological potential to manufacture bean flours with a range of functionalities into diverse food products. •HT and HHP induced varied degree of starch gelatinization and protein denaturation.•HHP improved the pasting properties and resistance to shear-thinning of bean flours.•Severe heating and the highest-pressure level increased the gel strength of flours.•The emulsifying activity of flours was reduced by HT and retained by low pressures.•HHP enhanced the emulsifying stability of flours with increasing pressure and time.