Table 3.

The effect of processing on the bioavailability of iron in millets and its potential to meet the physiological requirement of iron.

Process	Mean iron content (mg/100 g)	Bioavailability (%)	Bioavailable iron (mg/100 g)	Contribution to the physiological requirement of iron (%) (ICMR, 2020)
				1–3 yrs	4–6 yrs	7–9 yrs	10–12 yrs girls	13–15 yrs girls	16–17 yrs girls	Adult men	Adult women
In vivo human study
Boiled/baked meal	6.3 ± 3.1	6.0 ± 1.9	0.4 ± 0.3	105	82	66	31	29	27	44	33
Boiled/baked meal	12.6 ± 6.9	8.3 ± 1.1	1.0 ± 0.4	263	204	164	79	72	68	110	83
In vitro method
Raw/unprocessed grain	5.4 ± 2.9	9.8 ± 6.8	0.5 ± 0.3	124	96	77	37	34	32	52	39
Boiled meal	23.2 ± 17.2	19.1 ± 20.3	2.2 ± 0.9	570	442	355	171	156	148	238	181
Decorticated grain	4.2 ± 3.2	24.8 ± 15.7	1.3 ± 1.4	332	257	207	99	91	86	139	105
Dephytinized grain	3.3 ± 1.7	24.6 ± 8.7	0.7 ± 0.2	190	148	119	57	52	50	79	60
Fermented grain	14.6 ± 13.8	15.4 ± 13	1.7 ± 1.3	452	351	282	135	124	118	189	143
Germinated grain	5.2 ± 1.0	22.0 ± 8.2	1.1 ± 0.5	300	233	187	90	82	78	125	95
Malted flour	2.9 ± 1.4	28.0 ± 3.5	0.8 ± 0.2	215	167	134	64	59	56	90	68
Popped grain	12.7 ± 0.21	13.4*	1.73 ± 0.0	455	353	284	136	124	118	190	144
Expanded grain	5.5 ± 0.4	49.1*	2.7 ± 0.2	711	551	443	213	194	185	297	225
Soaked grain	4.9 ± 0.7	11.6 ± 6.1	0.5 ± 0.2	140	109	87	42	38	36	58	44

^*SD values not available. All in vitro studies are based on 100 g of grain, whereas in vivo studies, they varied from 84 g to 300 g (44, 45, 47–50, 53–55, 57, 58). The quantity required to be consumed can be adjusted to meet 100% of the physiological requirement.