Production of resistant starch by enzymatic debranching in legume flours

•Resistant starch was produced by enzymatic hydrolysis of legume flour.•Legumes employed were lentil, chickpea, faba bean, kidney bean and red kidney bean.•Hydrolysis was carried out with pullulanase for 24h at 50°C and pH 5.•At the end of the hydrolysis, a maximum RS of 7.47% was obtained for chickpeas.•Hydrolysis curves were successfully modeled by a kinetic equation. Resistant starch (RS) was produced by enzymatic hydrolysis of flours from five different legumes: lentil, chickpea, faba bean, kidney bean and red kidney bean. Each legume was firstly treated thermally, then hydrolyzed with pullulanase for 24h at 50°C and pH 5 and lyophilized. At the end of each hydrolysis reaction, the RS amount ranged from 4.7% for red kidney beans to 7.5% for chickpeas. With respect to the curves of RS against hydrolysis time, a linear increase was observed initially and a plateau was generally achieved by the end of reaction. These curves were successfully modeled by a kinetic equation including three parameters: initial RS, RS at long operation time and a kinetic constant (k). Furthermore, the relative increase in hydrolysis, calculated using the kinetic parameters, was successfully correlated to the percentage of amylose.