**3.1 Content of total phenolics and condensed tannins**

The content of total phenolics in the extracts was determined using the Folin– Ciocalteu's phenol reagent. The results were expressed as (+)-catechin equivalents per g of the extract or 100 g seeds. The results are reported in **Tables 2** and **3**. The content of total phenolics ranged from 40.7 (FAB 219) to 66.1 mg/g extract (FAB 187) and from 326 (FAB 219) to 574 mg/100 g seeds (FAB 5019).

The content of condensed tannins in the extracts was determined using the vanillin/HCl colorimetric method. The results ranged from 2.40 (FAB 297) to 49.9 mg/g extract (FAB 225) and from 22.2 (FAB 297) to 441 mg/100 seeds (FAB 5019) (**Tables 1** and **3**).

The results obtained in this research confirm the fact that faba bean is a rich source of phenolic compounds as well as condensed tannins. A lower content of total phenolic compounds was previously reported for extracts of pea [28], white bean [29], broad bean [23, 30] lupin [31], and grass pea [32]. A similarly high content of total phenolic compounds was previously reported for red lentil [33], green lentil [34], red bean [35], and adzuki bean [36].

The presence of condensed tannins in faba bean seeds determined with the vanillin method was reported by Amarowicz et al. [37], Baginsky et al. [38], Amarowicz and Shahidi [39], and Zduńczyk et al. [17]. In a research conducted by


*b Catechin equivalents.*

#### **Table 2.**

*Contents of total phenolic compounds and condensed tannins and antioxidant activity of faba bean extracts. Results are reported per g of extract.*

**45**

**3.2 Antioxidant activity**

*Antioxidant Activity of Faba Bean Extracts DOI: http://dx.doi.org/10.5772/intechopen.85534*

**(mg/100 g seeds)**

561 ± 13 486 ± 14 **Condensed tanninsb (mg/100 g seeds)**

> 451 ± 13 265 ± 12

 421 ± 14 217 ± 12 6.56 ± 0.13 5.34 ± 0.08 626 ± 18 308 ± 13 9.81 ± 0.14 7.90 ± 0.12 418 ± 9 126 ± 7 5.52 ± 0.09 6.28 ± 0.09 482 ± 17 471 ± 23 6.85 ± 0.09 6.66 ± 0.15 464 ± 6 326 ± 14 6.01 ± 0.10 6.60 ± 0.07 602 ± 17 365 ± 10 8.20 ± 0.14 7.40 ± 0.10

 484 ± 4 247 ± 6 6.16 ± 0.13 6.32 ± 0.13 421 ± 10 109 ± 19 5.50 ± 0.16 5.35 ± 0.10 524 ± 5 222 ± 12 7.37 ± 0.09 7.78 ± 0.10 574 ± 22 441 ± 12 7.80 ± 0.20 6.88 ± 0.08 509 ± 13 362 ± 15 6.51 ± 0.20 6.23 ± 0.09 425 ± 2 192 ± 9 5.82 ± 0.07 5.66 ± 0.13 539 ± 6 447 ± 6 7.94 ± 0.15 6.40 ± 0.13 378 ± 7 22.2 ± 1.0 5.72 ± 0.15 4.61 ± 0.10 395 ± 4 82.8 ± 9.9 6.31 ± 0.13 6.01 ± 0.08 326 ± 11 34.5 ± 7.5 5.28 ± 0.10 4.82 ± 0.13 373 ± 2 34.0 ± 4.9 4.85 ± 0.09 5.34 ± 0.11 475 ± 13 191 ± 14 7.13 ± 0.19 6.34 ± 0.10 559 ± 9 201 ± 14 7.63 ± 0.19 7.64 ± 0.10 410 ± 9 309 ± 18 6.04 ± 0.03 5.85 ± 0.12

**TEAC (mmol TE/100 g seeds)**

> 7.75 ± 0.16 7.91 ± 0.22

**FRAP (mmol Fe2+/100 g seeds)**

> 7.57 ± 0.11 6.61 ± 0.08

**No Total phenolicsa**

15 16

*a*

*b*

**Table 3.**

*Catechin equivalents.*

*Catechin equivalents.*

*Results are reported per 100 g of seeds.*

Luo et al. [40], the content of condensed tannins in faba bean extracts ranged from 0.9 to 1.9 g of gallic acid equivalents/100 g extract. In this research, the authors used the Folin-Ciocalteu's phenol reagent to determine the content of tannins precipitated from the extract by using polypyrrolidone (PVPP). Amarowicz and Shahidi [39] identified gallate procyanidin dimer and three gallate procyanidins in faba bean extract by using HPLC-DAD-MS. The content of the abovementioned compounds was 689, 89.8, 28.6, and 18.3 μg/g extract. Five procyanidin dimmers and three procyanidin trimers were determined in faba bean extract using an UHPLC-ESI-QTOF-MS method [41]. The presence of procyanidin B1, B2, B3, B4,

*Contents of total phenolic compounds and condensed tannins and antioxidant activity of faba bean seeds.* 

Antioxidant properties of the extracts were investigated using ABTS and FRAP assays. The extracts and seeds were characterized by the Trolox equivalent antioxidant capacity (TEAC) values ranging from 0.550 (FAB 443) to 1.030 mmol Trolox/g extract (FAB 187) and from 4.85 (FAB 318) to 9.81 mmol Trolox/100 g

C1, and C2 has been reported by De Pascual-Teresa et al. [42].

*Antioxidant Activity of Faba Bean Extracts DOI: http://dx.doi.org/10.5772/intechopen.85534*


*Plant Extracts*

5019) (**Tables 1** and **3**).

**No Total phenolicsa**

**(mg/g extract)**

per g of the extract or 100 g seeds. The results are reported in **Tables 2** and **3**. The content of total phenolics ranged from 40.7 (FAB 219) to 66.1 mg/g extract (FAB

The content of condensed tannins in the extracts was determined using the vanillin/HCl colorimetric method. The results ranged from 2.40 (FAB 297) to 49.9 mg/g extract (FAB 225) and from 22.2 (FAB 297) to 441 mg/100 seeds (FAB

The results obtained in this research confirm the fact that faba bean is a rich source of phenolic compounds as well as condensed tannins. A lower content of total phenolic compounds was previously reported for extracts of pea [28], white bean [29], broad bean [23, 30] lupin [31], and grass pea [32]. A similarly high content of total phenolic compounds was previously reported for red lentil [33], green

The presence of condensed tannins in faba bean seeds determined with the vanillin method was reported by Amarowicz et al. [37], Baginsky et al. [38], Amarowicz and Shahidi [39], and Zduńczyk et al. [17]. In a research conducted by

 51.5 ± 0.4 26.4 ± 0.7 0.656 ± 0.014 0.673 ± 0.014 42.1 ± 1.0 10.9 ± 0.9 0.550 ± 0.016 0.535 ± 0.010 61.2 ± 0.5 25.9 ± 1.4 0.860 ± 0.011 0.908 ± 0.012 62.8 ± 2.4 48.2 ± 1.3 0.854 ± 0.022 0.753 ± 0.008 60.5 ± 1.6 43.2 ± 1.8 0.775 ± 0.023 0.742 ± 0.011 47.6 ± 0.2 21.5 ± 1.1 0.563 ± 0.008 0.634 ± 014 60.2 ± 0.7 49.9 ± 0.7 0.886 ± 0.017 0.715 ± 0.015 46.9 ± 0.9 2.40 ± 0.72 0.710 ± 0.018 0.572 ± 0.013 41.8 ± 0.4 8.77 ± 1.06 0.669 ± 0.014 0.636 ± 0.009 40.7 ± 1.4 4.32 ± 0.78 0.661 ± 0.012 0.603 ± 0.016 45.5 ± 0.3 4.15 ± 0.69 0.592 ± 0.011 0.651 ± 0.014 55.0 ± 1.6 22.1 ± 1.6 0.826 ± 0.022 0.734 ± 0.012 59.1 ± 1.1 21.3 ± 1.5 0.806 ± 0.020 0.807 ± 0.011 46.8 ± 1.0 35.3 ± 2.1 0.691 ± 0.004 0.671 ± 0.011 61.1 ± 1.4 49.1 ± 1.4 0.844 ± 0.017 0.824 ± 0.014 51.7 ± 1.5 28.2 ± 1.3 0.841 ± 0.024 0.703 ± 0.012 46.3 ± 1.5 23.8 ± 1.4 0.721 ± 0.014 0.588 ± 0.008 66.1 ± 1.9 32.5 ± 1.3 1.035 ± 0.014 0.833 ± 0.009 47.9 ± 1.0 14.4 ± 0.8 0.631 ± 0.011 0.718 ± 0.013 48.8 ± 1.7 47.8 ± 2.3 0.694 ± 0.009 0.675 ± 0.010 48.7 ± 0.6 34.2 ± 1.5 0.631 ± 0.010 0.694 ± 0.015 65.7 ± 1.9 39.9 ± 1.1 0.894 ± 0.015 0.807 ± 0.007

*Contents of total phenolic compounds and condensed tannins and antioxidant activity of faba bean extracts.* 

**TEAC (mmol TE/g extract)**

**FRAP (mmol Fe2+/g extract)**

**Condensed tanninsb (mg/g extract)**

187) and from 326 (FAB 219) to 574 mg/100 g seeds (FAB 5019).

lentil [34], red bean [35], and adzuki bean [36].

**44**

*a*

*b*

**Table 2.**

*Catechin equivalents.*

*Catechin equivalents.*

*Results are reported per g of extract.*

#### **Table 3.**

*Contents of total phenolic compounds and condensed tannins and antioxidant activity of faba bean seeds. Results are reported per 100 g of seeds.*

Luo et al. [40], the content of condensed tannins in faba bean extracts ranged from 0.9 to 1.9 g of gallic acid equivalents/100 g extract. In this research, the authors used the Folin-Ciocalteu's phenol reagent to determine the content of tannins precipitated from the extract by using polypyrrolidone (PVPP). Amarowicz and Shahidi [39] identified gallate procyanidin dimer and three gallate procyanidins in faba bean extract by using HPLC-DAD-MS. The content of the abovementioned compounds was 689, 89.8, 28.6, and 18.3 μg/g extract. Five procyanidin dimmers and three procyanidin trimers were determined in faba bean extract using an UHPLC-ESI-QTOF-MS method [41]. The presence of procyanidin B1, B2, B3, B4, C1, and C2 has been reported by De Pascual-Teresa et al. [42].
