Influence of plasma-activated water on the morphological, functional, and digestibility characteristics of hydrothermally modified non-conventional talipot starch

The starch isolated by the alkali method from talipot palm ( Corypha umbraculifera L . ) stem pith is a non-conventional starch with a high yield (76%). Talipot starch was subjected to hydrothermal treatments, heat-moisture treatment (HMT) and annealing (ANN) with plasma-activated water (PAW). HMT and ANN with PAW created fissures and surface degradation and significantly increased (p ≤ 0.05) the relative crystallinity of talipot starch from 16.91% to 26.96%. The increased crystalline perfection of modified starch significantly decreased (p ≤ 0.05) the swelling power and increased the pasting temperature, gelatinization temperature, and gelatinization enthalpy. The significant decrease (p ≤ 0.05) in peak and breakdown viscosities and enhancement in storage and loss moduli indicates improved shear and thermal stability of modified starch gels. PAW with acidic nature decreased the starch digestibility and increased the resistant starch content to 51.03% and 52.11% after HMT and ANN treatments, respectively. The reactive species present in the PAW reduced the retrogradation tendency by reducing the setback and final viscosities and improving the paste clarity of modified starches. PAW modified starch gel possessing enhanced paste clarity is suitable for the preparation of pie fillings, soups and sauces. Hydrothermal treatments with PAW can be regarded as a novel technique to modify starch without enzymes, acids, or cross-linking agents to improve the functionality, reduce retrogradation tendency and increase resistant starch content. • Heat-moisture treatment (HMT) and annealing (ANN) were done on talipot starch. • HMT and ANN with plasma-activated water (PAW) increased starch crystallinity. • Hydrothermal treatment with PAW enhanced the thermal stability of talipot starch. • HMT and ANN with PAW showed reduced retrogradation tendency in talipot starch. • Hydrothermal treatment with PAW increased the resistant starch content.