Multivariate assessment of nutrient and antinutrient modulation during traditional germination of diverse millet species using principal component analysis
摘要
Traditional germination is rediscovered as an eco-friendly biological process that has the potential to modify the structure of grains and increase nutritional value through enzyme activation. In this study, we studied the effect of traditional germination on pearl, sorghum, finger and buckwheat millet flours using multivariate analysis to understand the relationship between nutrients, antinutrients, functional and phytochemical properties. The process led to a significant reduction in dry substances (23.5–30.1%) but resulted in a remarkable increase in the intensity of germination (82.2–98%). There was an improvement in functional properties, with water absorption capacity increasing to 2.01 g/g and the swelling index increasing as high as 22.72%. There was a remarkable decrease in antinutrients, with a reduction in tannins to 9.50 mg/g from 35.25 mg/g, oxalic acid to 0.49 mg/100 g from 0.97 mg/100 g and phytic acid to 0.34 mg/100 g from 1.33 mg/100 g, indicating an improvement in mineral bioavailability. Among these flours, the mineral content was higher for germinated finger and buckwheat millet, reaching levels of calcium at 1445 mg/100 g, zinc at 25.11 mg/100 g and magnesium at 367.47 mg/100 g. Fourier Transform Infrared Spectroscopy analysis revealed molecular changes attributed to the germination process, including increased hydroxyl bonds, alterations in amide bands and a decrease in starch bands, indicating enzymatic modification of starch protein matrices. Principal component analysis demonstrated 59.10% of the total variation and differentiated the germination process. This study, therefore, highlights that traditional germination is an effective way to improve the nutritional properties of millets.