Effect of Germination, Drying, Milling and Sieving on the Nutritional Quality of Foxtail Millet (Setaria italica)

Aims: The study aimed to evaluate the effect of germination, drying, milling and sieving on the protein and phytate content of foxtail millet

Study Design: This was an experimental, laboratory-based study.

Place and Duration of Study: The study was conducted at the Department of Dairy Microbiology, Dairy Science College, Hebbal, Bengaluru, Karnataka, India, between January 2024 and October 2024.

Methodology: Soaked foxtail millet (Setaria italica) was germinated at different time-temperature combinations (20, 25 and 30°C for 24, 48 and 72 hours). Germination was optimized based on its effects on reducing phytate content and enhancing protein content. Post-germination, the millet was dried at 20°C, 25°C, and 30°C to a final moisture content of 5–7%, ensuring uniform moisture reduction while preserving nutritional quality. The optimum drying temperature was selected based on its influence on protein and phytate levels. The dried millet was milled into fine flour and sieved through a 150-micron sieve to achieve uniform particle size. The protein content was determined using the micro-Kjeldahl method, while phytate content was estimated via titration with ferric chloride. Statistical analysis was performed using ANOVA, with a critical difference (CD) at a 5% significance level used to determine significance among treatments.

Results: Germination at 30°C for 48 hours resulted in the highest protein content (14.76%) and significantly reduced phytate levels (1.59 mol/kg). Drying at 30°C for 48 hours achieved a moisture content of 6.32%, with protein content increasing to 15.10% and phytate content slightly rising to 1.65 mol/kg. Milling and sieving further reduced both protein (13.23%) and phytate content (1.40 mol/kg), with a statistically significant reduction observed only in phytate levels.

Conclusion: Germination at 30°C for 48 hours significantly enhanced protein content and reduced phytate levels in foxtail millet, while drying and sieving processes further optimized nutritional quality. These findings highlight the potential of tailored processing techniques to improve the functional and nutritional value of millet-based products.