**2.2 Chemicals**

Ferrous chloride, sodium persulfate, ferrous chloride, 2,4,6-tri(2-pyridyl) *s*-triazine (TPTZ), 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS),


**43**

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

(Gliwice, Poland).

**2.3 Extraction**

6-hydroxy-2,5,7,8-tetramethyl-chroman-2-carboxylic acid (Trolox), Folin–

**2.4 Determination of total phenolic compound contents**

echin equivalents per g of the extract and per 100 g of seeds.

**2.5 Determination of condensed tannins content**

equivalents per g extract and 100 g of seeds.

mmol Fe2+ equivalents per g extract and 100 g of seeds.

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

per g extract and 100 g of seeds.

**2.6 ABTS assay**

**2.7 FRAP assay**

**2.8 Statistical analysis**

**3. Results and discussion**

Ciocalteu's phenol reagent, and (+)-catechin were purchased from Sigma (Poznań, Poland). Methanol, acetone, and hexane were obtained from P.O.Ch. Company

Phenolic compounds were extracted from grounded and defatted with hexane faba bean seed by using 80% acetone (v/v) at a solid to solvent ratio of 1:10 (w/v), for 15 min at 50°C [23]. Extraction was carried out in flasks placed in a shaking water bath (Elpan 357, Wrocław, Poland). Acetone from the combined extract was evaporated using a Büchi rotary evaporator. The sample was then freeze-dried.

The content of total phenolic compounds in the extracts was determined using the Folin–Ciocalteu's phenol reagent [24]. The results were expressed as (+)-cat-

The content of condensed tannins was determined using a vanillin/HCl colorimetric method [25]. The results obtained were reported as mg catechin equivalent

The Trolox equivalent antioxidant capacity (TEAC) was determined using the method of Re et al. [26]. The results obtained were reported as mmol Trolox

The ferric-reducing antioxidant power (FRAP) assay was performed as previously described by Benzie and Strain [27]. The results obtained were reported as

The results are reported as a mean value of three determinations ± standard deviation. The Pearson correlation was used to determine the relation between results of total phenolics, condensed tannins, TEAC, and FRAP values. Moreover the principal component analysis (PCA) and hierarchical cluster analysis (HCA) with Ward's method using Euclidean distances were conducted. Statistical and chemometric analyses of data

The content of total phenolics in the extracts was determined using the Folin– Ciocalteu's phenol reagent. The results were expressed as (+)-catechin equivalents

were performed using the Statistica software (Windows software package 8.0).

**Table 1.** *Description of faba bean seeds.* 6-hydroxy-2,5,7,8-tetramethyl-chroman-2-carboxylic acid (Trolox), Folin– Ciocalteu's phenol reagent, and (+)-catechin were purchased from Sigma (Poznań, Poland). Methanol, acetone, and hexane were obtained from P.O.Ch. Company (Gliwice, Poland).
