The in-vitro starch digestibility, pasting and antioxidant properties of the composite flour from cassava root and tigernut seed

Figures & data

Table 1. Proximate composition of composite flour from tigernut and fermented cassava flour.

Flour Sample (%)	Moisture (%)	Crude protein (%)	Crude fat (%)	Crude fiber (%)	Ash (%)	Carbohydrate (%)
Tigernut (100)	8.53^cd ± 0.19	10.70^g ± 0.39	6.66^g ± 0.26	7.31^g ± 0.09	5.10^e ± 0.29	62.52^a ± 0.11
Cassava (100)	7.16^a ± 0.13	1.53^a ± 0.06	0.23^a ± 0.02	1.20^a ± 0.02	1.10^a ± 0.02	88.80^g ± 0.10
Cassava: Tigernut (90:10)	7.43^ab ± 0.21	2.48^b ± 0.03	0.81^b ± 0.02	1.74^b ± 0.07	1.51^a ± 0.03	86.04^f ± 0.06
Cassava: Tigernut (80:20)	7.96^bc ± 0.23	3 .61^c ± 0.06	1.49^c ± 0.03	2.42^c ± 0.06	1.97^b ± 0.02	82.56^e ± 0.40
Cassava: Tigernut (70:30)	8.76^d ± 0.11	4.63^d ± 0.06	2.29^d ± 0.03	3.12^d ± 0.04	2.49^c ± 0.02	78.73^d ± 0.19
Cassava: Tigernut (60:40)	8.91^d ± 0.18	5.66^e ± 0.04	3.00^e ± 0.02	3.92^e ± 0.04	2.90^c ± 0.04	75.92^c ± 0.33
Cassava: Tigernut (50:50)	9.93^e ± 0.08	6.79^f ± 0.05	3.64^f ± 0.02	4.86^f ± 0.09	3.37^d ± 0.03	71.88^b ± 0.05

The values presented are the mean ± standard deviation. Mean values in the same column with different superscript letters are significantly different (p < 0.05).

Table 2. Functional properties of composite flour from tigernut and fermented cassava flour.

Flour Sample (%)	Bulk density g/ml	WAC (%)	Swelling capacity (g/g)	Water solubility index (%)
Tigernut (100)	0.618^a ± 0.005	132.01^a± 0.14	3.98^a ± 0.09	15.80^a ± 0.17
Cassava (100)	0.759^f ± 0.003	168.21^g ± 0.32	9.97^f ± 0.10	20.44^f ± 0.46
Cassava: Tigernut (90:10)	0.745^f ± 0.005	164.53^f ± 0.50	9.08^f ± 0.06	19.87^e ± 0.12
Cassava: Tigernut (80:20)	0.739^e ± 0.001	158.49^e ± 0.20	8.41^e ± 0.00	18.89^e ± 0.13
Cassava: Tigernut (70:30)	0.717^d ± 0.003	154.35^d ± 0.35	6.17^d ± 0.02	17.67^d ± 0.08
Cassava: Tigernut (60:40)	0.703^c ± 0.002	149.98^c ± 0.52	5.19^c ± 0.05	17.10^c ± 0.03
Cassava: Tigernut (50:50)	0.684^b ± 0.002	142.07^b ± 1.11	4.22^b ± 0.02	16.84^b ± 0.17

The values presented are the mean ± standard deviation. Mean values in the same column with different superscript letters are significantly different (p < 0.05).

Table 3. Pasting properties of composite flour from tigernut and fermented cassava flour.

Flour Sample (%)	Peak Viscosity (RVU)	Trough Viscosity (RVU)	Breakdown Viscosity (RVU)	Freeze-Thaw Viscosity (RVU)	Setback Viscosity (RVU)	Peak Time (mins)	Pasting Temp (^oC)
Tigernut (100)	197.50^a ± 2.12	184.00^a ± 1.41	13.50^a ± 0.71	314.50^a ± 4.95	131.50^a ± 2.12	5.44^c ± 0.05	81.58^c ± 0.04
Cassava (100)	5693.00^g ± 5.66	3100.50^g ± 6.36	2599.50^g ± 2.12	4358.00^g ± 5.66	1262.50^g ± 4.95	4.84^a ± 0.05	75.90^a ± 0.07
Cassava: Tigernut (90:10)	4441.50^f ± 3.54	2455.50^f ± 0.71	2044.00^f ± 2.83	3465.00^f ± 1.41	1007.00^f ± 1.41	4.80^a ± 0.00	75.88^a ± 0.04
Cassava: Tigernut (80:20)	3690.00^e ± 1.41	2176.50^e ± 2.12	1586.50^e ± 0.71	3217.50^e ± 3.54	936.00^e ± 1.89	4.80^a ± 0.10	75.83^a ± 0.04
Cassava: Tigernut (70:30)	2491.50^d ± 0.71	1834.00^d ± 1.41	1139.50^d ± 3.54	2747.00^d ± 2.83	866.50^d ± 2.19	4.87^a ± 0.00	76.30^a ± 0.57
Cassava: Tigernut (60:40)	2051.50^c ± 2.12	1396.50^c ± 2.12	656.00^c ± 1.41	2017.00^c ± 2.87	622.00^c ± 2.88	4.90^a ± 0.04	77.53^ab ± 1.09
Cassava: Tigernut (50:50)	1750.50^b ± 2.12	1264.00^b ± 2.83	487.50^b ± 2.12	1884.00^b ± 1.41	514.50^b ± 3.54	5.13^b ± 0.00	78.23^b ± 0.11

The values presented are the mean ± standard deviation. Mean values in the same column with different superscript letters are significantly different (p < 0.05).

Figure 1. Effect of tigernut flour addition on the in vitro starch digestibility of cassava flour. RDS, rapidly digestible starch; SDS, slowly digestible starch; RS, resistant starch. Different letters along the sample period are significantly different (p < 0.05).

Table 4. Total phenolic content and radical scavenging activity of composite flour from tigernut and cassava flour.

Flour Sample (%)	TPC (mg GAE/g)	ABTS (µmol TE/g)	DPPH (µmol TE/g)	FRAP (µmol TE/g)
Tigernut (100)	6.14^g ± 0.06	34.49^g ± 0.71	22.92^g ± 0.35	27.76^g ± 1.13
Cassava (100)	0.42^a ± 0.04	7.04^a ± 0.21	6.38^a ± 0.67	6.59^a ± 0.57
Cassava: Tigernut (90:10)	0.99^b ± 0.04	13.67^b ± 0.42	9.10^b ± 0.14	10.86^b ± 0.97
Cassava: Tigernut (80:20)	1.88^c ± 0.05	20.14^c ± 0.71	13.70^c ± 0.28	18.38^c ± 0.86
Cassava: Tigernut (70:30)	2.26^d ± 0.02	25.01^d ± 0.71	16.53^d ± 0.54	22.34^d ± 0.64
Cassava: Tigernut (60:40)	2.81^e ± 0.06	29.59^e ± 0.86	18.69^e ± 1.23	26.32^e ± 0.46
Cassava: Tigernut (50:50)	4.03^f ± 0.04	31.34^f ± 0.97	21.53^f ± 1.66	28.24^f ± 0.50

The values presented are the mean ± standard deviation. Mean values in the same column with different superscript letters are significantly different (p < 0.05).

Data availability statement

The data supporting this study’s findings are available on request from the corresponding.