The yellow yam ( Dioscorea cayenensis ) is a tuber that has local importance and some agroindustrial potential, but it is still limited because there are few studies that characterize it well. This research was aimed at evaluating the effect of combined pretreatments (immersion in 1.5% citric acid for 10 min, blanching at 50°C for 3 min, and soaking in sodium bicarbonate for 24 h) on the physicochemical, functional, thermal, and rheological properties of the flours obtained. Two samples were compared: one control (DC0) and one pretreated (DC1). The DC1 flour showed smaller particles than the DC0. The pretreatments increased the starch content (from 80.40% to 85.32%) and amylose (from 15.45% to 21.51%), as well as functional properties like swelling power, solubility, emulsion activity, and stability index. In the DSC analysis, DC1 showed higher gelatinization temperatures (To: 76.03°C; Tp: 81.56°C; Tc: 92.86°C) and lower enthalpy ( Δ H : 12.44 J/g) compared to DC0 (To: 74.84°C; Tp: 78.93°C; Tc: 89.74°C; Δ H : 13.22 J/g). Rheologically, DC1 had higher apparent viscosity (2.26 vs. 0.27 Pa·s) and yield stress (4.09 vs. 1.14 Pa), showing a more cohesive matrix. The pasting curves showed a reduction in the maximum viscosity (from 15308.42 to 4478.33 cP), probably because of a partial reorganization of amylose chains. The results of this study show that the pretreatments changed the structure and the functionality of D. cayenensis flour, improving its thermal stability and its potential use in food formulations that need specific texture and heat resistance.
Montero-Castillo et al. (Thu,) studied this question.