NUTRITIONAL PROFILING OF RAW AND GERMINATED FOXTAIL MILLET (SETARIA ITALICA L.): CHANGES IN NUTRITIONAL COMPOSITION, DIGESTIBILITY, MINERAL CONTENT AND PHYTOCHEMICAL CHARACTERISTICS

Abstract

Foxtail millet (Setaria italica L.) is a nutrient-rich minor cereal receiving increasing attention because of its superior nutritional quality, low glycaemic index and suitability for functional food development. Germination is a simple, cost-effective bioprocess that enhances nutrient bioavailability and improves the functional characteristics of cereal grains. The present study evaluated the influence of germination on the nutritional profile, carbohydrate fractions, digestibility, amino acid composition, fatty acid profile, mineral composition and phytochemical characteristics of foxtail millet by comparing raw foxtail millet (RFM) with germinated foxtail millet (TFM). The crude fibre content increased significantly from 3.77 ± 0.01% in RFM to 6.86 ± 0.01% in TFM, while total dietary fibre increased from 11.10 ± 0.00% to 15.00 ± 0.00%. Total sugars increased marginally from 9.56 ± 0.06% to 11.00 ± 0.00%, whereas reducing sugars decreased from 0.54 ± 0.01% to 0.41 ± 0.00% and non-reducing sugars increased from 9.02 ± 0.06% to 10.58 ± 0.00%. Total starch content increased from 56.70 ± 0.32% in RFM to 60.90 ± 0.89% in TFM. Amylose content increased markedly from 18.67 ± 0.35% to 52.40 ± 0.23%, whereas amylopectin decreased from 38.03 ± 0.65% to 8.50 ± 0.74%. Statistically significant differences (p ≤ 0.05) were observed for reducing sugars, amylose and amylopectin, while differences in total sugars, non-reducing sugars and total starch were not significant. The samples exhibited dose-dependent inhibition of In vitro α-amylase activity, with IC50 values of 76.99 ± 0.01 μg/mL and 65.33 ± 0.01 μg/mL for RFM and TFM, respectively. Germination substantially enhanced in vitro protein digestibility from 55.30 ± 0.27% to 148.27 ± 4.09%, accompanied by an improvement in amino acid content. Linolenic and oleic acids remained the predominant fatty acids in both samples with only minor variations following germination. Mineral analysis demonstrated significant enhancement of calcium (41.05 ± 1.45 mg/100 g) and iron (5.50 ± 0.08 mg/100 g) in germinated millet (p ≤ 0.05), although magnesium, manganese, zinc and phosphorus decreased slightly after germination. Qualitative phytochemical screening revealed the strong presence of carbohydrates and alkaloids in both samples. Proteins were more intensely detected after germination, while amino acids were observed only in germinated millet. Fixed oils, fats, terpenoids and cardiac glycosides were detected in both samples, whereas flavonoids, steroids, saponins, tannins, phlobatannins, phenols and quinones were absent. The findings demonstrate that germination significantly improves the nutritional quality, dietary fibre, protein digestibility, amino acid availability and selected mineral contents of foxtail millet while modifying carbohydrate characteristics. These improvements support the utilization of germinated foxtail millet as a functional ingredient for the development of health-promoting foods targeting metabolic disorders and improved nutritional security.