Effect of low-pressure plasma on physico–chemical and functional properties of parboiled rice flour

• Plasma treatment improved the gel and flour hydration properties of parboiled rice flour.
• Changes in crystalline structure of parboiled rice flour.
• Decrease in endothermic enthalpy.
• Modification of flour by plasma treatment.

The present research was conducted to study the efficacy of low pressure plasma treatment in modification of parboiled rice flour. Parboiled rice samples were taken and plasma treated at varying power of 30 W, 40 W and 50 W for duration of 5, 10 and 15 min. After treatment, the parboiled rice was ground for examining physico–chemical and functional properties of the flour. From the analysis, it was found that plasma treatment could improve the flour hydration and gel hydration properties of the flour. Plasma treatment induced cross-linking of flour. On the contrary, the plasma treatment reduced the amylose content from 30.34 ± 0.13 to 27.89 ± 0.09%, which in turn caused a decline in the amylose to amylopectin ratio. This observed result could be due to depolymerization of starch, which is proved to happen during plasma treatment. Other changes that were observed after treatment are increase in gelatinization temperature. Plasma induced changes resulted, decline in endothermic enthalpies from 7.90 ± 0.21 to 7.47 ± 0.21 and changes in % crystallinity of flour from 28.25 ± 0.07 to 24.36 ± 0.48. Further, the phenolic content and antioxidant properties of treated flour samples were also influenced after treatment. It can be concluded that cold plasma treatment can be promising technology for improving functionality of flour.