Abstract:
Millets, a group of small-seeded grasses, are widely cultivated as staple food
sources due to their nutritional richness. Finger millet (Eleusine coracana), a widely
cultivated and nutritionally rich cereal, is gaining attention for its health benefits.
However, its consumption is often limited due to the presence of antinutritional
factors such as tannins and phytic acid, which impede nutrient bioavailability and
protein digestibility. This study explored the application of atmospheric pressure
cold plasma (CP) as a novel, green processing technology to mitigate these
antinutritional factors and enhance the functional and nutritional properties of full
grain, dehusked, and flour of finger millet. Using a Box-Behnken design, the CP
process parameters—voltage (10–20 kV), treatment time (10–20 min), and
electrode distance (8–10 cm)—were optimized with tannin and phytic acid
reductions as target responses. The optimized conditions were determined for full grain millet (20 kV, 18 min, 10 cm), dehusked millet (20 kV, 19 min, 10 cm), and
flour (20 kV, 20 min, 9 cm), achieving tannin and phytic acid reductions of 24.4%
and 30%, 15.37% and 19.39%, and 27% and 43%, respectively. Characterization
of the CP-treated samples revealed significant improvements in functional
properties, including enhanced water solubility, oil and water absorption capacities,
emulsifying capacity, and foaming properties. FTIR analysis confirmed alterations
in functional group concentrations, while SEM imaging demonstrated
morphological changes, such as surface cracking, indicative of improved reactivity.
Furthermore, CP treatment effectively reduced microbial loads, achieving over a 4-
log reduction in bacterial count and a 3-log reduction in yeast and mold, enhancing
the microbiological safety of the product. Storage studies conducted over 18 weeks
at room temperature (28±3°C) showed that CP-treated samples stored in laminated
pouches retained quality better than those stored in LDPE packets. These findings
underscore the potential of CP technology to improve the nutritional and functional
quality of finger millet while extending its shelf life. The study highlights CP as a
sustainable and efficient alternative for processing finger millet, paving the way for
its broader industrial and consumer applications
