The influence of Bambara groundnut (Vigna subterranean) flour on the nutritional, physical and antioxidant properties of steamed bread

Figures & data

Table 1. Formulation of different steamed bread fortified with Bambara groundnut flour.

Tabla 1. Formulación de diferentes panes al vapor enriquecidos con harina de frijol de bambara.

Ingredients	Control	BGN5	BGN10	BGN15	BGN20
WF (g)	300	285	270	255	240
BGN flour (g)	0	15	30	45	60
Sugar (g)	25	25	25	25	25
Instant yeast (g)	2.5	2.5	2.5	2.5	2.5
Baking powder (g)	1.4	1.4	1.4	1.4	1.4
Shortening (margarine) (g)	4.5	4.5	4.5	4.5	4.5
Salt (g)	2	2	2	2	2
Water (mL)	154	154	154	154	154

Control = steamed bread without Bambara groundnut flour; BGN5–BGN20 = steamed bread with 5%, 10%, 15% and 20% Bambara groundnut flour. WF = wheat flour, BGN = Bambara groundnut.

Control = pan al vapor sin harina de frijol de bambara; BGN5-BGN20 = pan al vapor con 5, 10, 15 y 20% de harina de frijol de bambara. WF = harina de trigo, BGN = frijol de bambara.

Figure 1. Water and oil absorption capacity of the flour. Means ± SD with different superscripts are significantly different (p < 0.05). Control = flour without Bambara groundnut flour; BGN5–BGN20 = flour with 5, 10, 15 and 20% Bambara groundnut flour.

Figura 1. Capacidad de absorción de agua y aceite de la harina. Las medias ± DE con superíndices diferentes son significativamente diferentes (p < 0,05). Control = harina sin harina de frijol de bambara; BGN5-BGN20 = harina con 5, 10. 15 y 20% de harina de frijol de bambara.

Table 2. The pH and total titratable acidity of dough samples during storage.

Tabla 2. El pH y la acidez total valorable de las muestras de masa durante el almacenamiento.

	0 min		30 min		60 min		90 min
Sample	pH	Acidity %	pH	Acidity %	pH	Acidity %	pH	Acidity %
Control	5.71 ± 0.08^a	5.58 ± 0.12^a	5.57 ± 0.15^a	5.28 ± 0.24^a	5.48 ± 0.09^a	4.80 ± 0.26^a	5.45 ± 0.11^a	3.98 ± 0.52^a
BGN5	5.68 ± 0.03^a	6.95 ± 0.52^b	5.51 ± 0.07^a	6.32 ± 0.41^b	5.46 ± 0.03^a	5.99 ± 0.27^b	5.40 ± 0.04^a	5.50 ± 0.50^b
BGN10	5.60 ± 0.05^b	8.25 ± 0.70^c	5.40 ± 0.08^b	7.75 ± 0.50^c	5.36 ± 0.04^b	7.48 ± 0.32^c	5.32 ± 0.04^b	7.05 ± 0.42^c
BGN15	5.58 ± 0.05^b	8.50 ± 0.93^cd	5.37 ± 0.02^b	8.65 ± 0.10^d	5.20 ± 0.02^c	8.73 ± 0.66^d	5.10 ± 0.03^c	8.90 ± 0.57^d
BGN20	5.40 ± 0.05^c	9.56 ± 0.78^d	5.22 ± 0.02^c	9.80 ± 0.32^e	5.16 ± 0.07^c	10.22 ± 0.78^e	5.06 ± 0.26^c	10.33 ± 1.04^e

Means ± SD with different letters within same column are significantly different (p < 0.05). Control = dough without Bambara groundnut flour; BG5–BGN20 = dough with 5%, 10%, 15% and 20% Bambara groundnut flour.

Las medias ± DE con letras diferentes dentro de la misma columna son significativamente diferentes (p < 0,05). Control = masa sin harina de frijol de bambara; BG5-BGN20 = masa con 5, 10, 15 y 20% de harina de frijol de bambara.

Figure 2. Leavening capacity of dough samples at different storage periods. Means ± SD with different superscripts are significantly different (p < 0.05). Control = dough without Bambara groundnut flour; BGN5–BGN20 = dough with 5, 10, 15 and 20% Bambara groundnut flour.

Figura 2. Capacidad de fermentación de las muestras de masa en diferentes periodos de almacenamiento. Las medias ± DE con diferentes superíndices son significativamente diferentes (p < 0,05). Control = masa sin harina de frijol de bambara; BGN5-BGN20 = masa con 5, 10. 15 y 20% de harina de frijol de bambara.

Table 3. Proximate compositions of fortified flour blends and steamed breads (dry basis).

Tabla 3. Composiciones proximales de las mezclas de harina fortificada y de los panes al vapor (base seca).

Sample		Moisture (%)	Ash (%)	Protein (%)	Fibre (%)	Fat (%)	Carbohydrate
Flours	Control	12.48 ± 2.58^a	1.01 ± 0.01^a	3.98 ± 0.13^a	0.97 ± 0.09^a	1.77 ± 0.02^a	79.77 ± 2.41^d
	BGN5	14.11 ± 0.99^b	1.13 ± 0.07^ab	4.18 ± 0.29^a	1.52 ± 0.01^b	1.85 ± 0.04^a	77.20 ± 0.75^d
	BGN10	14.68 ± 1.50^c	1.93 ± 0.33^c	5.27 ± 0.82^b	1.99 ± 0.01^c	2.13 ± 0.07^b	73.99 ± 1.38^c
	BGN15	15.56 ± 1.63^d	2.73 ± 0.5^d	6.82 ± 0.55^c	2.10 ± 0.01^d	2.28 ± 0.02^c	70.50 ± 1.99^b
	BGN20	20.01 ± 1.50^e	4.24 ± 0.7^e	7.37 ± 0.26^d	2.34 ± 0.01^e	2.48 ± 0.08^d	63.56 ± 1.37^a
Steamed bread	Control	19.69 ± 1.99^a	1.16 ± 0.10^a	3.53 ± 0.09^a	1.15 ± 0.05^a	1.75 ± 0.04^a	72.72 ± 2.21^e
	BGN5	24.28 ± 2.99^b	1.69 ± 0.18^b	3.93 ± 0.40^b	2.03 ± 0.01^b	1.85 ± 0.04^b	66.20 ± 3.49^d
	BGN10	27.89 ± 1.73^c	1.86 ± 0.21^bc	4.33 ± 0.27^c	1.99 ± 0.73^b	2.17 ± 0.05^c	61.75 ± 1.32^c
	BGN15	31.92 ± 1.45^d	2.05 ± 0.12^c	4.94 ± 0.05^d	2.51 ± 0.01^c	2.27 ± 0.03^d	56.29 ± 1.39^b
	BGN20	34.24 ± 0.79^e	2.11 ± 0.15^d	5.67 ± 0.24^e	2.99 ± 0.02^d	2.47 ± 0.08^e	52.51 ± 1.13^a

Means ± SD with different superscripts within the same column are significantly different (p < 0.05). Control = flour and steamed bread without Bambara groundnut flour; BGN5–BGN20 = flour and steamed bread with 5%, 10%, 15% and 20% Bambara groundnut flour.

Las medias ± DE con superíndices diferentes dentro de la misma columna son significativamente diferentes (p < 0,05). Control = harina y pan al vapor sin harina de frijol de bambara; BGN5-BGN20 = harina y pan al vapor con 5, 10, 15 y 20% de harina de frijol de bambara.

Table 4. Colour of flours, crust and crumb of steamed breads fortified with BGN flour.

Tabla 4. Color de las harinas, la corteza y la miga de los panes al vapor enriquecidos con harina BGN.

Sample		L*	a*	b*	Chroma	∆E
Flours	Control	91.39 ± 0.01^e	0.68 ± 0.02^d	10.29 ± 0.04^a	10.32 ± 0.04^a
	BGN5	91.00 ± 0.01^d	0.67 ± 0.01^c	10.41 ± 0.03^b	10.44 ± 0.03^b	0.41 ± 0.01^b
	BGN10	90.98 ± 0.01^c	0.64 ± 0.02^b	10.42 ± 0.01^b	10.43 ± 0.01^b	0.14 ± 0.03^a
	BGN15	90.76 ± 0.01^b	0.55 ± 0.01^a	10.68 ± 0.01^c	10.70 ± 0.01^c	0.85 ± 0.07^d
	BGN20	90.50 ± 0.00^a	0.54 ± 0.01^a	11.11 ± 0.01^d	11.13 ± 0.01^d	0.52 ± 0.02^c
Steamed bread
Crust	Control	74.88 ± 0.04^e	4.33 ± 0.06^d	28.25 ± 0.82^a	28.58 ± 0.09^a
	BGN5	74.61 ± 0.06^d	4.19 ± 0.02^c	28.89 ± 0.01^b	29.12 ± 0.13^b	0.70 ± 0.07^a
	BGN10	74.11 ± 0.00^c	3.88 ± 0.01^b	29.35 ± 0.45^c	29.60 ± 0.44^c	0.80 ± 0.25^a
	BGN15	72.73 ± 0.03^b	3.59 ± 0.01^a	29.93 ± 0.03^d	30.14 ± 0.03^d	1.56 ± 0.10^b
	BGN20	71.21 ± 0.05^a	3.58 ± 0.02^a	31.60 ± 0.06^e	30.80 ± 0.05^e	2.26 ± 0.03^c
Crumb	Control	76.27 ± 0.09^d	3.15 ± 0.01^d	23.19 ± 0.02^a	23.40 ± 0.02^a
	BGN5	76.18 ± 0.03^c	2.64 ± 0.01^c	23.72 ± 0.05^b	23.87 ± 0.05^b	0.70 ± 0.01^a
	BGN10	75.02 ± 0.03^b	2.64 ± 0.02^c	24.40 ± 0.03^c	24.54 ± 0.03^c	1.33 ± 0.06^b
	BGN15	74.56 ± 0.07^a	2.44 ± 0.01^b	24.65 ± 0.01^d	24.77 ± 0.01^d	0.58 ± 0.28^a
	BGN20	74.36 ± 0.05^a	2.23 ± 0.01^a	25.15 ± 0.01^e	25.25 ± 0.01^e	0.61 ± 0.01^a

Means ± SD with different letters in the same column are significantly different (p < 0.05). Control = flour and steamed bread without Bambara groundnut flour; BGN5–BGN20 = flour and steamed bread with 5%, 10%, 15% and 20% Bambara groundnut flour.

Las medias ± DE con letras diferentes en la misma columna son significativamente diferentes (p < 0,05). Control = harina y pan al vapor sin harina de frijol de bambara; BGN5-BGN20 = harina y pan al vapor con 5, 10, 15 y 20% de harina de frijol de bambara.

Table 5. Total phenolic and flavonoid contents and antioxidant activity of fortified flours and steamed breads.

Tabla 5. Contenido total de fenoles, flavonoides y actividad antioxidante de las harinas fortificadas y los panes cocidos al vapor.

Sample		TPC (mg GAE/g)	TFC (mg CE/g)	FRAP (mg GAE/g)	DPPH (%)
Flours	Control	32.72 ± 1.10^a	9.57 ± 0.67^a	1.95 ± 0.02^a	17.25 ± 4.39^a
	BGN5	39.89 ± 1.00^b	12.69 ± 0.28^b	2.11 ± 0.04^b	26.58 ± 0.16^b
	BGN10	51.05 ± 0.45^c	15.69 ± 1.62^c	2.22 ± 0.05^c	28.11 ± 0.24^b
	BGN15	64.91 ± 0.36^d	17.62 ± 0.47^d	2.28 ± 0.03^c	28.48 ± 0.88^b
	BGN20	71.79 ± 5.67^e	22.25 ± 0.41^e	2.38 ± 0.06^d	37.92 ± 0.18^c
Steamed bread	Control	37.18 ± 1.69^a	11.45 ± 0.21^a	1.91 ± 0.05^a	41.03 ± 0.39^a
	BGN5	49.76 ± 1.14^b	13.73 ± 0.11^b	2.01 ± 0.09^ab	74.10 ± 0.33^b
	BGN10	65.06 ± 0.19^c	16.93 ± 1.12^c	2.05 ± 0.10^c	79.05 ± 0.39^c
	BGN15	76.23 ± 0.42^d	18.57 ± 0.07^d	2.08 ± 0.08c	80.48 ± 0.18^d
	BGN20	79.88 ± 0.13^e	23.39 ± 0.28^e	2.35 ± 0.01^d	80.96 ± 0.18^d

Means ± SD with different superscripts in the same column are significantly different (p < 0.05). Control = flour and steamed bread without Bambara groundnut flour; BGN5–BGN20 = flour and steamed bread with 5%, 10%, 15% and 20% Bambara groundnut flour. TPC = total phenolic content; TFC = total flavonoid content.

Las medias ± DE con diferentes superíndices en la misma columna son significativamente diferentes (p < 0,05). Control = harina y pan al vapor sin harina de frijol de bambara; BGN5-BGN20 = harina y pan al vapor con 5, 10, 15 y 20% de harina de frijol de bambara. TPC = contenido fenólico total; TFC = contenido total de flavonoides.

Table 6. Physical characteristics of steamed breads fortified with BGN flour.

Tabla 6. Características físicas de los panes al vapor enriquecidos con harina de BGN.

Sample	Weight (g)	Volume (ml)	Specific volume (cm^3)	Diameter (cm)	Height (cm)	Spread ratio
Control	468.63 ± 0.25^a	636.67 ± 3.51^b	1.36 ± 0.01^d	14.03 ± 0.15^a	6.70 ± 0.20^d	2.09 ± 0.07^a
BGN5	469.27 ± 0.25^a	622.67 ± 5.69^a	1.33 ± 0.03^d	14.67 ± 0.15^b	6.43 ± 0.11^c	2.28 ± 0.02^b
BGN10	469.70 ± 0.20^ab	582.33 ± 14.57^e	1.24 ± 0.09^c	15.37 ± 0.25^c	5.90 ± 0.10^b	2.60 ± 0.01^c
BGN15	471.60 ± 1.67^b	477.33 ± 44.09^d	1.01 ± 0.03^b	15.83 ± 0.12^d	5.83 ± 0.06^b	2.71 ± 0.02^c
BGN20	474.30 ± 1.61^c	414.67 ± 14.50^c	0.87 ± 0.19^a	16.03 ± 0.15^e	5.40 ± 0.30^a	2.97 ± 0.15^d

Means ± SD with different letters in the same column are significantly different (p < 0.05). Control = steamed bread without Bambara groundnut flour; BGN5–BGN20 = steamed bread with 5%, 10%, 15% and 20% Bambara groundnut flour.

Las medias ± DE con letras diferentes en la misma columna son significativamente diferentes (p < 0,05). Control = pan al vapor sin harina de frijol de bambara; BGN5-BGN20 = pan al vapor con 5, 10, 15 y 20% de harina de frijol de bambara.

Table 7. Textural parameters of fortified steamed breads.

Tabla 7. Parámetros de textura de los panes al vapor fortificados.

Sample	Hardness (N)	Springiness (mm)	Cohesiveness	Adhesiveness (N.s)
Control	49.27 ± 6.36^c	0.13 ± 0.00^a	0.91 ± 0.01^a	−8.35 ± 5.77^a
BGN5	45.98 ± 3.83^bc	0.13 ± 0.01^ab	0.90 ± 0.01^ab	−12.43 ± 2.3.00^a
BGN10	37.10 ± 0.50^c	0.10 ± 0.03^a	0.89 ± 0.01^ab	−11.31 ± 167.51^a
BGN15	36.34 ± 10.73^b	0.09 ± 0.01^b	0.89 ± 0.01^ab	−7.28 ± 6.49^a
BGN20	25.09 ± 0.65^a	0.09 ± 0.02^b	0.88 ± 0.01^c	−6.28 ± 0.95^a

Means ± SD with different superscripts in the same column are significantly different (p < 0.05). Control = steamed bread without Bambara groundnut flour; BGN5–BGN20 = steamed bread with 5%, 10%, 15% and 20% Bambara groundnut flour.

Las medias ± DE con diferentes superíndices en la misma columna son significativamente diferentes (p < 0,05). Control = pan al vapor sin harina de frijol de bambara; BGN5-BGN20 = pan al vapor con 5, 10, 15 y 20% de harina de frijol de bambara.