## 2 Materials and Methods  
For the initial analysis of dietary fiber content, starchy products from different food groups, widely available and consumed in Poland, were selected, as shown in Figure 1. Standard carbohydrate products were implied, but a group of legumes was also chosen to compare the fiber content. Such products as brown rice, bulgur goats, millet groats, green lentils, red lentils, peas, beans, and chickpeas were selected. An analysis of the fiber content was carried out, and based on this, three products with the highest fiber content were selected for further analysis. Legume seeds, including white beans, chickpeas, and green lentils, were utilized for this study. All dry-form seeds were purchased at a grocery store in Warsaw and came from Melvit S.A. (Warsaw, Poland). The Resistant Starch Assay Kit for the measurement and analysis of resistant starch in plant materials and starch samples was bought from Megazyme International Ireland (Bray Business Park, Bray, Co. Wicklow, Ireland). The following official analysis methods were used: AOAC Method 2002.02, AACC Method 32-40.01, CODEX Type II Method. All chemicals, standards, and reagents were of analytical grade, and reputable suppliers provided other materials. The seeds were ground in an analytical electric grinder (Rommelsbacher EKM 100, Rommelsbacher ElektroHausgerate GmbH, Dinkelsbuhl, Germany), sifted through a 1 mm sieve (Labindex S.C., Warszawa, Poland), dried, and then packed in airtight glass containers with a closure. The Gravimetric (dryer-weight) method determined the dry matter content at 105 \({}^{\circ}\)C [33]. Dietary fiber content was measured using the AOAC 991.43 method. The samples underwent sequential treatment with the following enzymes: alpha-amylase, protease, and amyloglucosidase. Subsequently, ethanol precipitated the soluble fiber, separating the protein and glucose from the samples. The residue was filtered, successively washed with ethanol and acetone, and then dried and weighed. One duplicate was analyzed for indigestible protein and the other for ash. Dietary fiber represents the residue after analysis adjusted for indigestible protein and ash content. Starch-water solutions (20%, \(w/w\)) were prepared at room temperature and hermetically sealed in high-density polyethylene containers. The packaged samples were placed into a cylindrical loading chamber and subjected to high hydrostatic pressures at 200, 400, and 600 MPa for 3, 5, 6, and 9 min at room temperature (25 \({}^{\circ}\)C) in an HPP chamber (EXDIN Solutions Ltd., Krakow, Poland), with water as the pressure transfer medium. The time to reach the determined pressure was less than 90 s, and the decompression time was less than 15 s. Following the process, a portion of the samples was directly analyzed for RS content. In contrast, the remaining portion was stored under refrigeration (4 \({}^{\circ}\)C) for 24 h before undergoing the same analysis. Each analysis was carried out in triplicate. RS analyses were performed using the AOAC 2002.02 method. Samples underwent incubation and shaking with pancreatic \(\alpha\)-amylase and amyloglucosidase (AMG) in a water bath at 37 \({}^{\circ}\)C for 16 h. The non-resistant starch was dissolved and hydrolyzed to D-glucose through the combined action of the two enzymes. The reaction was halted by adding an equal volume of ethanol or methylated industrial spirit (IMS, denatured ethanol), and the RS was recovered in pellet form during centrifugation. Subsequent steps included two washes by suspension in aqueous IMS or ethanol (50% \(v/v\)), followed by centrifugation. The free liquid was removed through decanting. The granular RS was then dissolved in 2 M KOH and stirred vigorously in an ice water bath with a magnetic stirrer. The solution was neutralized with acetate buffer, and the starch was quantitatively hydrolyzed to glucose using AMG. D-glucose was measured with glucose oxidase/peroxidase (GOPOD), and RS content was measured in the sample.