Insights into the physicochemical, crystalline, multistructural, thermal and digestibility behavior of taro starch (Colocasia esculenta) modified by cold plasma treatment with high voltage dielectric barrier discharge (HVDBD): An alternative technique for chemical modification of starch and environmental sustainability

Cold plasma is a non-thermal, effective, environmentally friendly and promising technique for modifying starch. In the current study, the effect of different voltages (15–25 kV) and exposure times (2–10 min) of HVDBDA cold plasma treatment (CPT) on the crystalline, multistructural, thermal, physicochemical and digestibility behavior of modified taro starch was investigated. The results showed that HVDBD-CPT increased the percentage amylose content (12.86–17.49%), water binding capacity (1.26–1.60 g/g), oil binding capacity (1.71–2.03 g/g), lightness value (92.38–97.42) and bulk density as well as tap density, while pH (6.07–5.04), percent turbidity (73.82–53.01%) and percent crystallinity (41.77–33.11%) decreased significantly with increasing tension and exposure time. However, the native and modified starch exhibited A and B type starch associated with the presence of nanocrystals with orthorhombic and hexagonal structures. However, the accumulation of aggregates and increased surface roughness of the modified starch were also observed in SEM and AFM analysis. Furthermore, FTIR analysis revealed significant differences in the functional groups of the modified starch. In addition, all modified starch a decrease in molecular weight (peak 1: 131.75 × 105 g/mol to 111.55 × 105 g/mol; peak 2: 6.78 × 104 g/mol to 1.44 × 104 g/mol), enthalpy and pasting properties, while the gelatinization temperature increased. Nevertheless, the digestibility behavior (% RDS and % RS) of the modified starch increased with increasing tension and exposure time, while the % SDS decreased. Thus, the plasma treatment changed the properties of the starch due to the depolymerization and etching effect. Consequently, cold plasma modification has shown a top-notch potential to modify starch with unique properties and increase the versatility of taro starch in the food industry. [Display omitted] • CPT improved the morphology, surface roughness and powder flow properties of taro starch. • PH, enthalpy and Mw of taro starch were reduced in the modified starch. • Water and oil binding capacity, RDS and RS of taro starch were increased after CPT. • A-type and B-type starch showed nanocrystals with orthorhombic and hexagonal structure. • Starch properties changed due to the depolymerization and etching effects of CPT. [ABSTRACT FROM AUTHOR]