Effect of pin to plate atmospheric cold plasma on physicochemical and functional properties of elephant foot yam (Amorphophallus paeoniifolius) starch

Abstract

This study investigated the effect of atmospheric pressure pin-to-plate cold plasma on physicochemical and functional properties of elephant foot yam starch (EFYS). The isolated EFYS was subjected to the plasma treatment at varying voltages (190 V, 210, V and 230 V) for 5, 10 and 15 min of exposure. The control and treated starches were analysed for pH, amylose content, carboxyl group, paste clarity, water and oil binding property, pasting property, DSC, FTIR, XRD and SEM. There has been a significant reduction (p < 0.05) in pH values of starch from 7.22 to 4.92 and also reduction in turbidity values by 32.48 %. Plasma treatment improved paste clarity and storage stability. However, a significant increase was observed in the oil (1.26–3.80 g/g) and water binding capacity (1.47–1.91 g/g) of the starch. The structural modification, including surface etching, has been confirmed by FTIR and SEM analysis. Plasma treatment significantly increased starch crystallinity, which correlated with higher gelatinization enthalpy, indicating enhanced thermal stability due to plasma induced crosslinking. FTIR data confirmed that cross-linking takes place in samples treated at lower voltages (190Vand 210 V) followed by depolymerization occurring in harshly treated plasma samples (230 V for 15 min).