Table 2.

Changes in millets nutritional properties with respect to processing methods.

Processing Methods	Millets	Experimental Condition	Inference/Study Outcome	References
Germination	Foxtail	Germinated for 46.5 h (optimized)	Increased protein content (13.75 g/100 g) as compared to raw seeds (10.60 g/100 g). Increased dietary fiber by 5.2%. Elevated the levels of minerals such as Fe, Mg, Ca, and Na. Free, bound, and total phenolics and flavonoids content is increased. Decreased fat content from 3.86 to 2.78 g/100 g.	[39,40]
		Germination at room temp with tap water	Increased protein (by 29.72%) total dietary fiber (58.02%) and total phenolic content (77.42%). Increased level of DPPH radical scavenging was observed.	[20,35]
	Kodo	38.75 °C for 36 h	Elevation in mineral content. Protein and dietary fiber content increased. Total carbohydrates reduced.	[41]
	Pearl Var; Kalukombu (K) and Maharashtra Rabi Bajra (MRB)	Sprouting at room temperature for 72 h	Protein content reduced in MRB variety, while K variety had no significant effect. Fat and ash content reduced. Iron and calcium content significantly increased after germination.	[42]
	Proso	Sprouting for 96 h	Protein and minerals become more biologically accessible.	[43]
Malting	Pearl Var; Ex-Borno	Steeping at 25 °C for 24 h, Germinated at different time intervals, kilned (hot-air oven) at 55 °C for 18 h	Protein content increased from 7.52% (control) to 9.19% (96 h) malted millet flour. Crude fiber increased with an increasing malting period (i.e., 0.77% for control to 1.38% for 96 h malted sample). Decrease in carbohydrate content due to starch hydrolyzed into simple sugars by enzymes such as α- and β-amylase. Fat level was found to be lowest for 96 h of malted samples, which affects energy values of millet flour, but ensures increased shelf life. Kilning and steeping process decreases the level of amino acids (tyrosine, isoleucine, methionine, glycine, cysteine and glutamic acid).	[44]
	Pearl	Alkaline steeping of malted flour (2% Ca (OH2) and (2% ash solution))	Both the steeping methods increase the protein level of flour samples. Lime steeped millet flour had increased fiber content as compared to ash steeped and control flours. Lime steeping lowered the levels of crude lipid in millet flour. Ca, Mg, and K levels increased while phosphorus and zinc levels decreased as steeping duration progressed.	[45]
Soaking	Pearl	Soaking for 24 h	Protein content increased due to the mobilization of stored nitrogen of grains. Fat content and crude fiber increases with sprouting The utilization of energy sources results in reduced carbohydrates.Sprouting reduced minerals (Co, Cr, Mn, Cu, Zn, Fe, Na, and K) due to leaching, but Ca content increased due to degradation of phytic acid.	[46]
	Foxtail Var; white	High-pressure soaking (600 MPa, 60 °C and 120 min)	Protein level decreased from 13.65% (native) to 13.11% (treated sample) due to the formation of protein–starch complex.	[40]
Fermentation	Pearl Var; Sosart 1	Pure cultures of Lactobacillus plantarum	Increase in protein content after 96 h fermentation from 8.7% in unfermented sample to 20.54% in starter culture fermented sample and 20.21% in naturally fermented sample. Lipid content decreased from 10.34 to 0.34 (starter culture sample) and 0.74 (naturally fermented). Carbohydrates decreased with a parallel increase in soluble sugar.	[47]
	Foxtail	Fermentation followed by heat moisture treatment	Increased crude protein content. Decreased the total carbohydrate level. Enhanced the nutritional quality of starch.	[20]
		Fermentation using L. paracasei Fn032 strain	Crude protein content increased by 20.51% in the fermented sample. Total carbohydrate decreased to 74.02%.	[48]
Cooking/ Boiling/ Roasting	Pearl	Roasting (150 °C for 5 min)	Increased the percentage bio-accessibility of total polyphenols from 73.2% in native grains to 78.1% in roasted samples. Bio-accessible flavonoid content increased.	[49,50]
		Pressure cooking (15 psi in triple distilled water for 15 to 20 min)	Total polyphenol content decreased by 29%.
		Blanching 98 °C for 10–20 s	Lowered the percentage of free fatty acids, acid value and fat acidity.
		Microwave heating	Reduced bio-accessibility of phenolic content.
	Foxtail	Soaking followed by cooking	Maximum decrease in protein, Fe, and Zn. Increased the bioavailability of soluble Zn and ionizable Fe.	[20]
	Kodo	Boiling at 95–100 °C for 25 min	Increased porosity and water absorption capacity. Reduced starch yield.	[38]
		Pressure cooking at 9.8 × 104 Pa for 20 min	High level of resistant starch observed. Enhanced oil absorption capacity.
		Puffing 230 °C for 3 min	Increased carbohydrate content from 68.35% to 74.38%. Increased protein content from 7.92% to 8.12%. Decreased crude fiber and fat content. Calcium level reduced from 27 to 18 mg/100 g.	[51]
	Proso	Pan and microwave cooking	Increased level of DPPH and FRAP radical scavenging activity. Increased carbohydrate content but decreased fat content. Protein content increased in pan cooking but decreased in microwave cooking.	[35,52]
	Little	Pan and microwave cooking	Carbohydrate content increased, while fat content decreased. Protein content increased in microwave cooking but decreased in pan cooking.	[52]