Distribution of nutrients, bioactive compounds, and antioxidant properties of grain-based milling fractions of Glycine max L

Figures & data

Figure 1. Flow diagram for milling and separation of soybean-milled fractions.

Table 1. Proximate composition of whole soybean grain and their milling fractions (% DW).

Sample	Protein	Moisture	Ash	Fat	Total dietary fibre	Carbohydrate	Energy (Kcal/100 g,DW)
Whole	39.02 ± 0.24^b	8.42 ± 0.05^b	6.10 ± 0.02^a	19.04 ± 0.16^b	24.30 ± 0.26^b	11.55 ± 0.54^e	422.22 ± 0.38^b
Cotyledon	47.15 ± 0.15^a	9.73 ± 0.05^a	5.54 ± 0.09^b	22.14 ± 0.17^a	4.32 ± 0.21^e	20.85 ± 0.23^d	479.91 ± 0.46^a
Germ	35.37 ± 0.38^bc	9.93 ± 0.05^a	4.68 ± 0.08^c	10.39 ± 0.33^d	3.10 ± 0.02^e	46.45 ± 0.79^b	427.02 ± 0.81^b
Seed coat	4.80 ± 0.10^d	4.85 ± 0.02^c	5.72 ± 0.06^b	1.89 ± 0.21^e	74.53 ± 0.13^a	13.06 ± 0.23^e	237.52 ± 0.68^d
Plumule fraction	4.61 ± 0.05^d	10.12 ± 0.04^a	3.26 ± 0.16^d	2.16 ± 0.06^e	18.28 ± 0.05^c	71.71 ± 0.15^a	361.22 ± 0.43^c
ALESC*	34.20 ± 0.11^c	9.92 ± 0.04^a	4.15 ± 0.06^c	16.59 ± 0.21^c	14.27 ± 0.05^d	30.80 ± 0.41^c	737.81 ± 0.43^b

Results are means ± SE of three independent triplicate analysis.

For each row, means with different letters (a–d) are significantly different (p > .05).

*ALESC, aleurone layer enriched in seed coat.

Table 2. Mineral elements’ composition of whole-soybean grain and their milling fractions (n = 3).

	Whole	Cotyledon	Germ	Seed coat	Plumule	ALESC*
Macronutrient mineral (% DW)
Ca	0.31 ± 0.02^b	0.35 ± 0.03^b	0.29 ± 0.01^bc	0.41 ± 0.01^a	.24 ± 0.01c	0.34 ± 0.02^b
Mg	0.03 ± 0.01^c	0.06 ± 0.03^a	0.04 ± 0.02^b	0.06 ± 0.02^a	.02 ± 0.01d	0.06 ± 0.02^a
Na	0.33 ± 0.03^a	0.28 ± 0.03^bc	0.32 ± 0.04^a	0.30 ± 0.03^a	.25 ± 0.03b	0.25 ± 0.03^b
K	1.64 ± 0.02^b	2.23 ± 0.01^a	2.1 ± 1.25^a	0.83 ± 0.03^c	1.07 ± 0.08b	1.47 ± 0.01^b
P	0.58 ± 0.03^b	0.73 ± 0.01^a	0.68 ± 0.03^a	0.52 ± 0.04^b	.48 ± 0.03c	0.59 ± 0.07^bc
Microelement mineral (% DW)
Fe	61.04 ± 0.72^c	66.27 ± 1.31^a	57.04 ± 1.05^d	47.49 ± 0.44^f	64.93 ± 0.42b	54.82 ± 0.60^e
Cu	16.49 ± 0.67^a	15.52 ± 0.52^a	11.66 ± 0.39^b	8.53 ± 0.41^c	14.34 ± 0.65b	13.68 ± 0.44^b
Mn	30.59 ± 0.61^a	36.72 ± 1.51^a	27.37 ± 0.55^b	26.71 ± 0.35^b	29.32 ± 0.88b	24.01 ± 0.86^c
Zn	39.68 ± 0.83^c	51.87 ± 0.39^a	42.70 ± 0.41^b	21.63 ± 0.32^d	36.70 ± 0.44c	29.52 ± 0.87^d

Results are means ± SE of three independent triplicate analyses.

For each row, means with different letters (a–d) are significantly different (p > .05).

*ALESC, Aleurone layer enriched in seed coat.

DW, Dry weight basis.

Table 3. Amino acid composition of whole-soybean grain and their milling fractions (g/100 g DW, n = 3).

Amino acid	Whole	Cotyledon	Germ	Seed coat	Plumule	ALESC*
Essential amino acids (EAA)
Arginine	2.6 ± 0.19^ab	2.74 ± 0.03^ab	3.29 ± 0.67^a	0.35 ± 0.01^c	2.16 ± 0.12^b	0.75 ± 0.02^b
Leucine	2.82 ± 0.25^a	2.94 ± 0.03^a	2.79 ± 0.58^ab	0.45 ± 0.01^b	2.54 ± 0.14^a	0.88 ± 0.03^a
Lysine	2.41 ± 0.15^ab	2.55 ± 0.03^bc	2.97 ± 0.64^ab	0.59 ± 0.02^a	1.94 ± 0.32^bc	0.92 ± 0.03^a
Isoleucine	2.26 ± 0.70^bc	2.32 ± 0.53^c	2.25 ± 0.47^bc	0.31 ± 0.01^d	1.69 ± 0.12^cd	0.70 ± 0.09^bc
Phenylalanine	1.86 ± 0.14^c	1.96 ± 0.02^d	1.74 ± 0.36^cd	0.31 ± 0.01^d	1.67 ± 0.10^d	0.60 ± 0.02^c
Threonine	1.29 ± 0.09^d	1.37 ± 0.01^e	1.52 ± 0.32^cd	0.24 ± 0.01^e	1.16 ± 0.07^e	0.43 ± 0.02^d
Histidine	0.97 ± 0.07^d	1.01 ± 0.01^f	1.08 ± 0.24^de	0.24 ± 0.01^e	0.79 ± 0.11^f	0.38 ± 0.01^d
Methionine	0.40 ± 0.05^e	0.42 ± 0.01^g	0.52 ± 0.11^e	0.06 ± 0.01^f	0.30 ± 0.05^g	0.11 ± 0.01^e
Non-essential amino acids (NEAA)
Glutamic acid	6.82 ± 0.43^a	7.47 ± 0.13^a	5.65 ± 1.26^a	0.80 ± 0.01^a	5.87 ± 0.32^a	1.96 ± 0.10^a
Aspartic acid	4.35 ± 0.24^b	5.02 ± 0.06^b	4.26 ± 0.85^b	0.68 ± 0.02^b	3.50 ± 0.24^b	1.43 ± 0.11^b
Valine	2.05 ± 0.15^c	2.15 ± 0.02^c	2.24 ± 0.47^c	0.43 ± 0.01^c	1.86 ± 0.12^c	0.73 ± 0.04^d
Serine	1.48 ± 0.14^d	1.56 ± 0.02^e	1.46 ± 0.32^cd	0.36 ± 0.01^d	1.24 ± 0.09^de	0.54 ± 0.07^de
Alanine	1.56 ± 0.09^d	1.65 ± 0.01^e	1.93 ± 0.39^cd	0.37 ± 0.01^d	1.41 ± 0.07^d	0.59 ± 0.03^de
Glycine	1.60 ± 0.10^d	1.65 ± 0.02^e	1.90 ± 0.34^cd	0.81 ± 0.02^a	1.40 ± 0.09^d	0.95 ± 0.05^c
Proline	1.77 ± 0.12^cd	1.86 ± 0.04^d	1.53 ± 0.26^cd	0.44 ± 0.03^c	1.29 ± 0.58^de	0.63 ± 0.03^d
Tyrosine	0.98 ± 0.09^e	1.01 ± 0.01^f	1.08 ± 0.19^de	0.32 ± 0.01^e	0.87 ± 0.05^e	0.43 ± 0.01^e
Cystine	0.22 ± 0.02^f	0.24 ± 0.01^g	0.25 ± 0.06^e	0.03 ± 0.02^f	0.17 ± 0.01^f	0.20 ± 0.25^f
∑EAA	14.61 ± 1.64	15.31 ± 0.66	16.16 ± 3.39	2.55 ± 0.09	12.25 ± 1.03	4.75 ± 0.24
∑NEAA	20.28 ± 1.38	22.63 ± 0.32	20.3 ± 4.15	4.24 ± 0.14	17.60 ± 1.59	7.45 ± 0.70
∑EAA/NEAA	0.72 ± 1.19	0.68 ± 2.06	0.80 ± 0.82	0.60 ± 0.64	0.70 ± 0.65	0.64 ± 0.34
Total	34.9	37.9	36.5	6.8	29.9	12.2

Results are means ± SE of three independent triplicate analyses.

For each row, means with different letters (a–f) are significantly different (p > .05).

*ALESC, Aleurone layer enriched in seed coat.

Table 4. Essential amino acid composition of milling fractions compared with the FAO/WHO pattern (g/16 N g = grams of amino acid per 100 g protein).

Amino acid	Whole g/16Ng	Cotyledon g/16Ng	Germ g/16Ng	Seed coat g/16Ng	Plumule g/16Ng	ALESC* g/16Ng	FAO/WHO pattern	Whole (%)	Cotyledon (%)	Germ %	Seed coat (%)	Plumule %	ALESC* (%)
Isoleucine	22.6	23.2	22.5	3.1	42.25	7	4	565	580	563	78	1056	175
Leucine	28.2	29.4	27.9	4.5	36.29	8.8	7	403	420	399	64	518	126
Lysine	24.1	25.5	29.7	5.9	35.27	9.2	5.5	438	464	540	107	641	167
Methionine + Cystine	6.2	6.6	7.7	0.9	13.43	3.1	3.5	177	189	220	26	384	89
Phenylalanine	28.4	29.7	28.2	6.3	42.33	10.3	6	473	495	470	105	706	172
+Tyrosine
Threonine	12.9	13.7	15.2	2.4	29	4.3	4	323	343	380	60	725	108
Valine	20.5	21.5	22.4	4.3	37.2	7.3	5	410	430	448	86	744	146

*ALESC, aleurone layer enriched in seed coat.

Table 5. Isoflavones content of whole-soybean grains and their milling fractions (mg/g).

Isoflavone	Whole	Cotyledon	Germ	Seed coat	Plumule	ALESC*
Aglycones
Genistein	0.128 ± 0.01^c	0.120 ± 0.01^c	0.070 ± 0.04^d	0.040 ± 0.01^f	0.051 ± 0.00^h	0.013 ± 0.00^h
Daidzein	0.374 ± 0.01^b	0.123 ± 0.05^c	0.066 ± 0.05^d	0.051 ± 0.00^e	0.031 ± 0.00^g	0.032 ± 0.01^g
Glycitein	0.609 ± 0.02^a	0.156 ± 0.01^c	0.065 ± 0.05^d	0.031 ± 0.01^g	0.016 ± 0.00^h	0.951 ± 0.01^c
Sub-total	1.111	0.399	0.201	0.122	0.098	0.996
7-O-β-Glucosides
Daidzin	1.102 ± 0.11^a	0.714 ± 0.03^b	0.318 ± 0.02^c	0.022 ± 0.01^f	0.138 ± 0.01^e	0.213 ± 0.02^d
Glycitein	0.322 ± 0.04^a	0.209 ± 0.01^b	0.215 ± 0.01^b	0.014 ± 0.00^d	0.125 ± 0.02^c	0.035 ± 0.01^d
Genistin	1.150 ± 0.05^a	1.070 ± 0.06^a	0.032 ± 0.02^c	0.022 ± 0.01^c	0.071 ± 0.01^c	0.109 ± 0.02^b
Sub-total	2.574	1.993	0.565	0.058	0.334	0.357

Results are means ± SE of three independent triplicate analyses.

For each row, means with different letters (a–h) are significantly different (p > .05).

*ALESC, Aleurone layer enriched in seed coat.

Table 6. Phenolic acid contents in whole soybean grains and their milling fractions (g/100 g).

Phenolic acids		Gallic acid	Protocatechuic acid	Chlorogenic acid	Hydroxybenzoic acid	Vanillic acid	Caffeic acid	Coumaric acid	Sinapic acid
Whole	Free	4.6 ± 1.1 (78.0)	22.9 ± 0.1 (96)	76.2 ± 5.5 (90.3)	2.1 ± 0.2 (37.5)	16.1 ± 0.1 (100)	3.9 ± 0.0 (78)	8.2 ± 0.7 (83.7)	5.2 ± 0.1 (52.5)
	Bound	1.3 ± 0.1 (22)	1.1 ± 0.3 (4)	8.2 ± 0.2 (9.7)	3.5 ± 0.1 (62.5)	Nd	1.1 ± 0.01 (22)	1.6 ± 0.3 (16.3)	4.7 ± 0.1 (47.5)
	Total	5.9 ± 0.2	24 ± 0.3	84.4 ± 1.3	5.6 ± 0.4	16.1 ± 1.2	5.0 ± 0.6	9.8 ± 0.3	9.9 ± 1.4
Cotyledon	Free	4.6 ± 4.1 (79.3)	7.5 ± 0.2 (90.4)	10.1 ± 0.4 (63.5)	4.9 ± 0.0 (100)	5.8 ± 0.4 (100)	3.8 ± 0.1 (61.3)	3.1 ± 0.1 (42.5)	8.1 ± 0.2 (72.3)
	Bound	1.2 ± 0.1 (20.7)	0.8 ± 0.0 (9.6)	5.8 ± 1.2 (36.5)	Nd	Nd	2.4 ± 0.2 (38.7)	4.2 ± 0.9 (57.5)	3.1 ± 0.1 (27.7)
	Total	5.8 ± 0.5	8.3 ± 0.3	15.9 ± 1.2	4.9 ± 0.1	5.8 ± 0.4	6.2 ± 0.8	7.3 ± 0.3	11.2 ± 0.7
Germ	Free	1.9 ± 0.1 (73.4)	11.4 ± 0.1 (90.5)	9.6 ± 0.4 (100)	14.2 ± 1.0 (100)	11.9 ± 0.3 (97.9)	15.1 ± 0.1 (98.1)	2.5 ± 0.0 (100)	7.4 ± 0.1 (100)
	Bound	0.70 ± 0.4 (26.6)	1.22 ± 0.2 (9.5)	Nd	Nd	0.28 ± 0.1 (2.1)	0.27 ± 0.1 (1.9)	Nd	Nd
	Total	2.59 ± 0.3	12.6 ± 0.5	9.6 ± 0.2	14.2 ± 1.1	12.2 ± 0.8	15.4 ± 1.3	2.5 ± 0.4	7.4 ± 0.2
Seed coat	Free	0.3 ± 0.1 (100)	0.5 ± 0.2 (10.2)	1.0 ± 0.2 (100)	22.6 ± 0.0 (100)	0.8 ± 0.0 (100)	0.5 ± 0.0 (100)	0.4 ± 0.1 (12.4)	2.5 ± 0.2 (100)
	Bound	Nd	4.4 ± 0.8 (90.2)	Nd	Nd	Nd	Nd	2.9 ± 0.4 (87.6)	Nd
	Total	0.3 ± 0.1	4.9 ± 0.4	1.0 ± 0.1	22.6 ± 1.7	0.8 ± 0.2	0.5 ± 0.1	3.2 ± 0.5	2.5 ± 0.2
ALESC*	Free	0.8 ± 0.0 (14.8)	9.7 ± 1.1 (27)	1.4 ± 0.2 (100)	1.9 ± 0.01 (100)	0.8 ± 0.0 (35)	Nd	1.7 ± 0.1 (68)	4.5 ± 1.2 (100)
	Bound	4.6 ± 0.9 (85.2)	26.6 ± 1.8 (73)	Nd	Nd	1.5 ± 0.1 (65)	Nd	0.7 ± 0.2 (28)	Nd
	Total	5.4 ± 0.4	36.2 ± 2.4	1.4 ± 0.6	1.9 ± 0.3	2.3 ± 0.4	0.0 ± 0.0	2.5 ± 0.3	4.5 ± 0.1
Plumule	Free	0.5 ± 0.1 (100)	2.2 ± 0.2 (15.6)	0.3 ± 0.0 (100)	1.7 ± 0.3 (100)	1.3 ± 0.2 (100)	0.4 ± 0.1 (100)	6.1 ± 1.2 (90.4)	6.2 ± 0.8 (100)
	Bound	Nd	11.9 ± 1.8 (84.4)	Nd	Nd	Nd	Nd	0.8 ± 0.2 (9.6)	Nd
	Total	0.5 ± 0.1	14.1 ± 1.6	0.0 ± 0.0	1.7 ± 0.2	1.3 ± 0.4	0.4 ± 0.1	6.8 ± 0.6	6.2 ± 0.4

Results are means ± SE of three independent triplicate analysis.

Nd = not detected.

*ALESC, Aleurone layer enriched in seed coat.

Figure 2. TPCs (a), TFCs (b), ABTS (c) and FRAP (d) values for free and bound phenolic and antioxidant of soybean seed fractions. Results were expressed in mg GAE, μmol TE 100 g⁻¹ of for ABTS and FRAP. Different letters indicate significant differences (p < .05).