## 2 Materials and Methods
### Physico-Chemical Analyses  
To perform the biochemical analysis, samples were taken from the homogenates corresponding to each cooking method. The following indicators were determined: dry matter content, major nutrients (carbohydrates, proteins, and lipids), total nitrogen content, non-protein nitrogen content, crude protein broken down by pepsin in hydrochloric acid, fatty acid content, and hydro-soluble (thiamine, riboflavin, and niacin) and fat-soluble (retinol,tocopherol, and F) vitamins. The dry matter was determined through drying in a vacuum oven at 102 \(\pm\) 2 \({}^{\circ}\)C, according to ISO 1442:2023 [24]. The result is expressed in DM% or DM (g/100 g of analyzed product). The carbohydrate content was determined according to the specifications of AOAC 923.09 [25]. An alkaline solution of cupric salt is reduced under heat with the help of the reducing sugar from the sample to be analyzed. The excess copper sulfate is treated with potassium iodide in an acidic medium, and the released iodine is titrated with a sodium thiosulfate solution. The result is expressed in reducing sugar, %. The lipid content was determined by means of the ether-hydrochloric extraction method in accordance with SR ISO 1443:2008 [26]. The protein substances and carbohydrates in the sample to be analyzed are hydrolyzed with hot hydrochloric acid, the insoluble part is separated via filtration, and the fat is extracted with ethyl alcohol in a Soxhlet installation. In determining the protein content (P = 6.25(NT \(-\) NPN), the Kjeldhal method was used, specifically by assessing the total nitrogen content (NT) (according to ISO 5983-1:2005 [27]), and the determination of non-protein nitrogen (NPN) was based on the method of protein precipitation with trichloroacetic acid (according to ISO 8968-4:2016 [28]), thus determining the non-protein nitrogen in the filtrate using the same method. Toevaluate the digestibility of proteins in the analyzed products, the content of crude protein decomposed with pepsin and hydrochloric acid solution was determined. The action of the enzyme (2 U/mg pepsin) on the sample heated for 48 h at 40 \({}^{\circ}\)C simulates the process of human protein digestion. The suspension was filtered, and the nitrogen content of the filtrate was established in accordance with the method for determining crude protein. Digestibility is expressed in %, as the ratio between the amount of digested protein and the initial amount of crude protein in the analyzed samples (in vitro digestibility (%) = digestible protein/initial protein \(\times\) 100) [29]. The fatty acid content was determined with gas chromatography, based on the separation of fatty acid methyl esters (according to ISO 12966-4:2015 [30]), using a Shimadzu GC-17A gas chromatograph equipped with a Chrompack capillary column with a length of 25 m and a diameter of 0.25 mm. The stationary phase (a polyethylene glycol derivative) was deposited inside the column as a thin film of 0.2 \(\upmu\)m. A FID detector was used, and the mobile phase was helium of 99.9% purity. The operation parameters of the gas chromatograph were as follows: an injector and carrier temperature of 260 \({}^{\circ}\)C, a carrier gas flow rate of 2.0 mL/min, a 5 min plateau at the initial temperature of 70 \({}^{\circ}\)C, a temperature gradient of 4 \({}^{\circ}\)C/min, up to 235 \({}^{\circ}\)C, a split ratio of 1:28, and a total analysis time of 36.658 min. After the gas chromatograph reached the programmed parameters, 0.5 \(\upmu\)L of hexane solution of fatty acid methyl esters was injected using a syringe. The retention times for short- and long-chain fatty acids had been recorded previously. To measure the vitamin B1 content in the samples, each one was heat-treated with diluted sulfuric acid and subjected to enzymatic hydrolysis. The quantification of vitamin B1 in extracts is traditionally based on spectrofluorimetric detection (Cary-50 UV-VIS Spectrophotometer, Agilent, Santa Clara, USA) after an oxidation step to convert vitamin B1 to thiochrome.