Legume Seeds Treated by High Hydrostatic Pressure: Effect on Functional Properties of Flours

Pigeon pea (PP), cowpea (CU), dolichos bean (DB), and jack bean (JB) are legumes that constitute the daily diet in many countries. Legumes are a good source of proteins, carbohydrates, and minerals. Considering that legumes present potentials to be used as ingredients for food formulation, the study of functional and physicochemical properties of flours obtained from legume seeds treated by high hydrostatic pressure treatment (HHPT) (200, 400, 600 MPa) was conducted. Flours were evaluated for polypeptide composition (SDS-PAGE), fluorescence spectroscopy, color, protein solubility (PS), water-holding capacity (WHC), oil-holding capacity (OHC), emulsion activity (EA), emulsion stability (ES), foaming capacity (FC), foaming stability (FS), and least gelation concentration (LGC). PS of PP, CU, and DB diminished with the increase of pressure and only CU showed an increase of PS (7–40%) at the isoelectric point. WHC of PP, CU, and DB varied with the pressure applied; however, WHC of JB was not modified by HHPT as we observed in lambda max fluorescence-emission values and PS. Only PP showed an increment of OHC at 400 and 600 MPa. EA of PP was not affected by HPPT, while DB and JB showed a decrease. ES of CU, DB, and JB was not affected by HHPT. FC of PP, DB, and JB diminished with the increase of pressure. FS of DB and CU (400 MPa) was improved and continued for 120 min. LGC values and the equilibrium moisture content of flours were not influenced by HHPT, but the last decreased with the increase of temperature. Moisture sorption isotherms of flours fitted adequately to H-H equation covering the practical range of water activity (0.10–0.90) at the three temperatures tested. High pressure processed flours of PP, CU, DB, and JB showed functional properties that could be useful for food formulation.