Impact of cold plasma on pearl and barnyard millets' microbial quality, antioxidant status, and nutritional composition

Abstract

In the quest for sustainable and innovative food processing technologies, cold plasma treatment has emerged as a promising approach with the potential to enhance grains' nutritional and functional properties. This study investigates the impact of cold plasma treatment on two millet varieties, namely pearl millet (Pennisetum glaucum) and barnyard millet (Echinochloa spp.). This study analyzed the effect of Cold plasma on the proximate composition, vitamin content, physiochemical property, anti-nutrient factor, bioactive compounds, antioxidant activity and microbial count of millets. Pearl millet (RP) and Barnyard millet (RB) (native), cold plasma treated Pearl (CP) and Barnyard (CB) (2 kV, 5 min) were characterized. A noticeable change was found in fat, vitamin B-complex content and antioxidant activity. Furthermore, the microbial count analysis revealed that cold plasma treatment induced substantial reductions in bacterial and yeast populations, underscoring the technology's effectiveness in enhancing the safety and extending the shelf-life of millet grains. Treatments of samples led to a reduction of phytic acid and tannin. In pearl millet, tannin content decreased by 18%, and phytic acid content was reduced by 57%. In barnyard millet, there was a substantial (24%) reduction in tannin content and a 61% decrease in phytic acid. Total Flavonoid content (TFC) and Total Phenolic content (TPC) also decreased after treatment. But this treatment led to an increase in fat content by 43% and 87% in CP and CB, respectively. These alterations offer new insights into the potential of cold plasma treatment as a means to enhance the nutritional quality and safety of millets. The results of this study contribute to the growing body of knowledge on innovative food processing techniques for improving the nutritional value of grains.