Investigating the Canning Quality of Red Kidney Bean (Phaseolus vulgaris) Using Empirical High Temperature/High-Pressure Rheology
The pasting profile (PP) of starchy tissues is conventionally measured by recording the apparent viscosity (ɳ) in heating/cooling cycles. However, conventional rheometers show critical limitations when the starch is embedded in compact cotyledon tissues, as is the case with pulses. In this work, the PP of 13 different red kidney beans (Phaseolus vulgaris) from different growing regions were investigated using a novel empirical rheometer that can perform heating/cooling cycles at higher temperature/pressure. It was hypothesized that the continuous measure of ɳ at these conditions of bean flours would correlate to their texture after canning, as determined by the mini-Kramer cell. Furthermore, mechanistic answers were obtained by investigating their compositional (starch, protein, pectin, and ash content) and physical (water holding capacity, seed ratio, volume and weight) properties. Interestingly, PP parameters, including high temperature/high pressure-setback, -trough and -final viscosity, correlated with firmness, starch, and protein content of beans when cooking brine was incorporated.