Effect of nonthermal plasma on physico-chemical, amino acid composition, pasting and protein characteristics of short and long grain rice flour

• Rice of both types showed increased behavior in physicochemical properties with nonthermal plasma (NTP) treatment.
• Higher peak viscosity of flour reflected higher swelling capacity of starch granules in presence of lower amylose.
• With NTP treatment higher blue value and λmax was observed due to the large branching of chains in amylose and amylopectin.
• Amino acids composition was observed to be increased with NTP treatment.
• Protein profiling did not showed effect on rice storage proteins with NTP treatment.

Nonthermal plasma (NTP) is a novel technology with potential applications in food property and functionality modification. In this study, short and long grain rice flours were exposed to different plasma intensities and resulting ozone concentrations, and their physicochemical, amino acid composition, X-ray diffraction, pasting properties and protein profile were evaluated. The L*, b*, blue value, λmax, pH, transmittance, swelling power, and syneresis of both rice types increased with NTP treatment while a* decreased. X-ray diffraction revealed a decrease in crystallinity with NTP treatment. Long grain rice showed higher peak viscosity, breakdown viscosity and lower pasting temperature as compared to short grain rice due to higher amylose content. Glutamic acid, asparagine, serine histidine, threonine, γ-aminobutyric acid, tryptophan, isoleucine, phenylalanine and proline content increased with NTP treatment in both rice types. SDS page analysis did not reveal any effect of NTP treatment on banding pattern of total protein of both rice types.