Effect of dephytinization on bioavailability of iron, calcium and zinc from infant cereals assessed in the Caco-2 cell model

Table 1 Mineral content (per 100 g), phytate (IP₅ + IP₆) content (per 100 g) and molar ratios of phytate to iron, calcium and zinc, and phytate × calcium/zinc of commercial infant cereals

Infant cereal	Fe (mg)	Ca (mg)	Zn (mg)	Phytate (mg)	Phytate/Fe	Phytate/Ca	Phytate/Zn	Phytate × Ca/Zn
Eight cereals-honey	8.3 ± 0.4	137.3 ± 5.6	0.6 ± 0.3	319.6 ± 3.1	3.8	0.16	53.1	182.3
Rice cream	8.8 ± 0.1	283.1 ± 27.7	1.2 ± 0.2	167.1 ± 27.5	1.6	0.11	14.4	101.9
Multicereals	8.7 ± 0.2	174.4 ± 21.0	1.5 ± 0.4	143.5 ± 10.6	1.4	0.07	9.8	42.7
Gluten-free cereals	7.5 ± 1.0	154.4 ± 38.9	1.0 ± 0.3	299.8 ± 16.9	3.5	0.18	31.8	122.7

Table 2 Iron retention, transport and uptake from infant cereals by Caco-2 cells

	Infant cereal	Iron added (&mgr;g)	Solubility (%)	Retention (&mgr;g)	Retention (%)	Transport (&mgr;g)	Transport efficiency (%)	Uptake (&mgr;g)	Uptake efficiency (%)
- phytase	A	12.51	17.42 ± 6.1a	1 ± 0.1	7.99 ± 2.2b	1.59 ± 0.6	2.21 ± 1a	2.59 ± 0.8	3.6 ± 0.9b
	B	13.08	8.72 ± 2.7b	0.79 ± 0.4	6.04 ± 0.6b	0.21 ± 0	0.14 ± 0.03c	1 ± 0.2	0.66 ± 0.2d
	C	13.13	24.21 ± 1.9ª	2.19 ± 0.1	16.68 ± 3.8ª	1.09 ± 0.7	2.01 ± 0.8ª	3.28 ± 1.1	6.05 ± 2.2ª
	D	11.18	20.93 ± 4.8ª	0.78 ± 0.2	6.98 ± 0.8b	0.18 ± 0.04	0.33 ± 0.1b	0.96 ± 0.2	1.8 ± 0.3c
+ phytase	A	12.51	34.53 ± 8.61	2.52 ± 0.3	20.14 ± 3.91	2.18 ± 0.9	6.02 ± 1.31	4.7 ± 0.9	13 ± 2.51
	B	13.08	21.1 ± 1.81	2.1 ± 0.2	16.28 ± 2.11	2.49 ± 0.9	4.01 ± 0.81	4.62 ± 1.6	7.45 ± 3.91
	C	13.13	19.19 ± 31	2.41 ± 0.3	18.35 ± 3.4	1.66 ± 0.6	2.43 ± 0.6	4.0 ± 1.2	5.95 ± 1.1
	D	11.18	16.64 ± 6.2	1.65 ± 0.2	14.75 ± 1.31	0.99 ± 0.2	1.47 ± 0.31	2.64 ± 0.8	3.93 ± 0.71

A: Eight cereals honey; B: Multicereals; C: Rice cream; D: Gluten-free cereals. mean ± SD, n = 5. Different letter (a-d) denotes significant differences (P < 0.05) between commercial infant cereals (without phytase treatment) to assess the effect of different phytate content.

¹P vs the same infant cereal dephytinized or not.

Table 3 Calcium retention, transport and uptake from infant cereals by Caco-2 cells

	Infant cereal	Calcium added (&mgr;g)	Solubility (%)	Retention (&mgr;g)	Retention (%)	Transport (&mgr;g)	Transport efficiency (%)	Uptake (&mgr;g)	Uptake efficiency (%)
- phytase	A	206	38.9 ± 11.1a,1	5.72 ± 0.3	2.78 ± 1a,1	25.99 ± 8	4.9 ± 1.2a	31.71 ± 4.9	5.99 ± 2a
	B	261.6	15.2 ± 1.8b1	7.33 ± 0.2	2.8 ± 0.6ª	16.1 ± 3.9	0.94 ± 0.1b,1	23.43 ± 3.6	0.66 ± 0.2b
	C	424.7	2.8 ± 1c	2.18 ± 0.3	0.51 ± 0.2b	33.1 ± 6.1	0.22 ± 0.02d	35.28 ± 7.2	0.23 ± 0.2c
	D	231.6	4.53 ± 1.3c	4.45 ± 0.2	1.92 ± 0.3ª	15.64 ± 4.4	0.31 ± 0.08c	20.09 ± 1.8	0.39 ± 0.1c
+ phytase	A	206	22.5 ± 2.3	0.7 ± 0.2	0.34 ± 0.09	29.59 ± 7.2	3.24 ± 1	30.29 ± 6.8	3.31 ± 0.9
	B	261.6	8.03 ± 2.7	7.33 ± 1.4	2.8 ± 0.6	23.08 ± 2.1	0.71 ± 0.04	30.41 ± 2.2	0.93 ± 0.2
	C	424.7	3.72 ± 1.9	5.5 ± 0.1	1.3 ± 0.7	28.1 ± 4.4	0.25 ± 0.07	33.6 ± 7.1	0.43 ± 0.09
	D	231.6	8.31 ± 1.21	2.98 ± 0.7	1.29 ± 0.9	66.16 ± 10.8	2.38 ± 0.11	69.14 ± 8.2	2.48 ± 0.31

Table 4 Zinc retention, transport and uptake from infant cereals by Caco-2 cells

	Infant cereal	Zinc added (&mgr;g)	Solubility (%)	Retention (&mgr;g)	Retention (%)	Transport (&mgr;g)	Transport efficiency (%)	Uptake (&mgr;g)	Uptake efficiency (%)
- phytase	A	2.12	36.4 ± 7.1a	0.18 ± 0.08	8.5 ± 2b	1.88 ± 0.6	32.3 ± 3a,1	2.06 ± 0.8	35.4 ± 4.1a
	B	2.22	18.9 ± 3.8b	0.09 ± 0.01	4.05 ± 2c	0.5 ± 0.08	4.25 ± 1.1c	0.59 ± 0.6	5 ± 0.9d
	C	2.63	17 ± 1.9b	0.54 ± 0.1	20.53 ± 3.8a	0.62 ± 0.1	4 ± 0.8c	1.16 ± 0.4	7.5 ± 0.2c
	D	1.63	37.8 ± 6.2a,1	0.09 ± 0.01	5.5 ± 1.6c	0.71 ± 0.2	16.5 ± 0.3b	0.8 ± 0.4	18.6 ± 1.2b
+ phytase	A	2.12	46.9 ± 6.6	0.84 ± 0.2	22.2 ± 2.71	1.04 ± 0.5	23 ± 3.6	1.88 ± 0.9	41.6 ± 6.5
	B	2.22	18.92 ± 2.7	0.42 ± 0.1	18.92 ± 2.81	0.44 ± 0.2	3.74 ± 0.3	0.86 ± 0.2	7.3 ± 0.21
	C	2.63	27.3 ± 61	0.38 ± 0.1	14.45 ± 3.4	1.59 ± 0.6	16.5 ± 2.61	1.97 ± 0.8	20.4 ± 2.11
	D	1.63	21 ± 4.3	0.18 ± 0.03	61.3 ± 9.91	1.43 ± 0.4	18.4 ± 4.1	1.61 ± 0.2	20.7 ± 0.61