## 2 Materials and Methods
### Chemical and Nutritional Characteristics  
Protein content in extruded samples was determined by using the Kjeldahl method [26]. Fibre determinations were conducted in three replications for the contents of neutral-detergent fibre (NDF) in extrudate samples according to the [PERSON] et al. [27] method using filtration bags and Ankom apparatus (Ankom220, Macedon, NY, USA). The NDF content was determined using a solution of neutral detergent (sodium-lauryl sulfate, ethylenediamine tetra acetic discodium salt, sodium borate, di-basic sodium phosphate, triethylene glycol), alpha-amylase (17,400 liquid units/mL, FAA Ankom Technology) and sodium sulfite (FSS Ankom Technology). Reducing sugar content was determined using the standard dinitrosalicylic acid (DNSA) method [28]. The contents of free reducing sugars and sucrose were determined as follows: the samples were dispersed in a sodium acetate buffer (pH 5.0) and then treated with 200 \(\upmu\)L (10 mg in 1 mL of 0.4 M sodium acetate buffer, pH 5.0) of invertase (EC 3.2.1.26; 300 U mg\({}^{-1}\)) at 37 \({}^{\circ}\)C for 30 min. After centrifugation, reducing sugars were analysed in the supernatants using the DNSA reagent. Extrudate extracts were prepared to evaluate phenolics content and antioxidant activity following the methodology proposed by [PERSON] et al. [29]. Ground extrudates were extracted with a mixture of acetone, water and hydrochloric acid (70:29:1; \(v/v/v\)). Afterwards, the samples were centrifuged for 10 min and the resultant supernatant was collected and used for further analyses. The content of total phenols was determined with the method of [PERSON] and [PERSON] [30] by using the Folin-Ciocalteau reagent. The absorbance of the samples was measured with a UV-vis spectrophotometer at the wavelength of 725 nm. Results was computed and expressed as gallic acid equivalents (GAE) in mg per g of dry matter (DM). The content of anthocyanins in extruded beans was determined according to the method provided by [PERSON] and [PERSON] [31]. Determinations were carried out using solutions of potassium chloride and sodium acetate at two pH values, i.e., 1.0 and 4.5. The solutions were mixed with extrudate extract in a ratio of 20:1 (\(v/v\)). After 15 min, absorbance of the samples was measured at two wavelengths (520 nm and 700 nm). After absorbance value correction for various pH values, the content of anthocyanins was expressed in mg of cyanidin 3-glucoside equivalents (Cy3-GE) per g of dry matter (DM). The total content of flavonoids was determined according to the method used by [PERSON] et al. [32]. The prepared bean extract was mixed with a methanolic solution of AlCl\({}_{3}\times\) 6H\({}_{2}\)O. After incubation, absorbance was measured with a UV-vis spectrophotometer at the wavelength of 430 nm. The total flavonoid content was expressed as quercetin equivalents (QE) in mg per g DM. The antiradical activity of extrudate extracts was determined according to the method of [PERSON] et al. [33] with some modifications. A Trolox calibration solution (0, 25, 50, 75, 100, 150, 200, 300 \(\upmu\)M/mL) was prepared in the extraction mixture. An ABTS\({}^{+}\) solution with the final concentration of 2.45 mM potassium persulfate and 7 mM ABTS\({}^{+}\) was diluted with an acetone solution to ensure the absorbance of 0.7 \(\pm\) 0.02 at 734 nm. Then, 280 \(\upmu\)L of ABTS\({}^{+}\) were transferred to a 96-well microplate and mixed with 20 \(\upmu\)L of the sample. The result obtained was expressed as Trolox equivalent. Reducing power was measured by following the method provided by [PERSON] et al. [34]. The extrudate extract was mixed with a phosphate buffer (200 mM, pH 6.6) and 1% solution of K\({}_{3}\)[Fe(CN\({}_{6}\))]. Next, the samples were incubated at 50 \({}^{\circ}\)C for 20 min. The reaction was stopped with trichloroacetic acid, and the samples were centrifuged (6800\(\times\) g, 10 min). The resultant supernatant was mixed with distilled water and FeCl\({}_{3}\). Then absorbance was measured at the wavelength of 700 nm.