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Abstract In the present study, three varieties of kidney beans (Red Rajma (RR), Rajma Chitra (RC), and Rajma Sharmili (RS)) were physically characterized and the effect of pre-gelatinization by microwave and hot water on functional and pasting properties of flour were studied. A significant difference was observed in the physical properties of all the kidney beans, indicating that they can be easily characterized and identified based on physical properties. Pre-gelatinization treatment led to variation in color, functional and pasting properties of flours. Color parameters L*, b*, chroma, and hue values reduced with the treatment, whereas a* and total color difference ( $$\Delta$$ Δ E) values increased. Water absorption capacity (WAC) and oil absorption capacity (OAC) varied in the range of 1.15–1.91% and 1.25–1.75% for microwave and hot water treatment, respectively. The highest value of WAC and OAC was observed for microwave-treated RC and hot water-treated RR, respectively. WAC increases with both treatments, whereas OAC increases only with water bath cooking. Functional group analysis (FTIR) showed no major peaks shifting in water bath treatment, whereas a slight deflation of certain peaks was observed in the case of microwave treatment. Pasting curves showed a significant reduction in peak and final viscosity after pre-gelatinization treatment; however, none of the samples showed any breakdown during cooking. Graphical Abstract

The present study evaluated the effect of various pre-treatments (Potassium metabisulphite (KMS), KMS+Ultrasonication (KMSUS), KMS+Microwave (KMSMW), KMS+Hot water (KMSHWB) followed by infrared drying on the quality of Elephant Foot Yam (EFY). KMSMW-treated samples showed the fastest drying rate and highest moisture diffusivity, whereas the KMS-treated sample had the highest weight gain (171.57 %) in rehydration (80 °C). KMSMW and KMSHWB-treated samples exhibited softer textures in rehydration compared to control. Pre-treated samples had higher water absorption capacity and lower oil absorption capacity compared to the control. Pre-treatments also influenced the amylose content and the highest amylose content was observed for KMSUS (21.25 %). Pre-treatments positively influenced the retention of bioactive compounds and reduced the calcium oxalate (117.37 mg/g to 64.09 mg/g). Among all the pre-treatments, KMSHWB showed higher retention of bioactive compounds viz., TPC (297.67 mg GAE/100 g), TFC (922.22 mg QE/100 g), DPPH scavenging activity (57.91 %), ABTS (1.42 mmol TE/100 g) and lowest calcium oxalate (64.09 mg/100 g).