Assessment of the physicochemical, functional and structural characteristics of a defatted flour from guamuchil (Pithecellobium dulce (Roxb.) seeds

Abstract

Guamuchil tree is native of México and its fruits, which belong to Leguminosae family, contain seeds that are wasted. In this work, the physicochemical, functional and structural characterization of a defatted flour obtained from guamuchil seeds (DGuSF) was carried out. DGuSF had a low moisture (5.44 %) and lipid (2.91 %) contents and high protein (33.18 %) and carbohydrate (55.54 %) contents. Functional properties were highly dependence of pH, showing the highest values of 4.71 g H2O/g, 50 %, 84 %, 56 %, and 79 % for water binding capacity (WBCa), emulsifying capacity (EmA), emulsifying stability (EmS), foaming capacity (FoC), and foaming stability (FoS), respectively, at a value of 10. In the case of least gelling concentration (LGCo) the better value of 8 % was at pH 4, being obtained at this same condition the highest apparent viscosity (ηa) of 290.8 Pa·s. Values of 72.3 % and 40.5 % for in vitro protein enzymatic digestibility (IVPED) and in vitro antioxidant activity (IVVA), respectively, were also obtained for DGuSF, while their protein fractions presented molecular masses in the scale of ∼13–150 kDa. According to these results, guamuchil seeds could represent an alternative for the elaboration of DGuSF, to be applied as a food constituent because of its good compositional and functional characteristics.