# Enhancing the Integration of Protein-Rich Oat Waste Material into Meat Formulations
## 4 Discussion  
According to [PERSON] et al. [24], the protein content in oat grain depends on its variety, and it ranges from 9.7 to 17.3%, with the highest levels noted in the naked oat variety. This is important information for producers whose aim is to obtain protein hydrolyses. As mentioned in the Section 1, the material left over from \(\beta\)-glucan extraction typically contains 23.7-25.1% of protein. The material used in our study showed an increased protein content (42%). The hydrolysis allowed us to obtain a higher protein content in the final product (52%). However, it was not as high as that obtained by other researchers [25], mainly because in our case, we did not isolate the protein before the hydrolysis. Higher protein content results from the fact that after hydrolysis, we used only soluble fractions, discarding the pellet consisting of fat and carbohydrates, as well as mineral substances. The proportions of the basic constituents changed. Oat protein has garnered interest in recent years due to its distinct composition and pleasant sensory attributes compared to those of legumes and oil seeds [26]. The protein contains globulins, albumins, glutelins, and prolamins. Additionally, oats are gluten free and rich in sulphur-containing amino acids [27]. From a practical standpoint, the higher protein content enables more efficient production of the hydrolysate. Hydrolysis changed the proportions of the basic component contents (Table 1). The oat raw material contained more fat and mineral substances, which decreased after the hydrolysis. According to [PERSON] et al. [10], hydrolysis can induce significant changes in protein structure, affecting the amino acid pattern, protein conformation, and molecular weight profile. Literature data on the subject show that modification by enzymatic hydrolysis is highly dependent on the nature of the protein and the degree of hydrolysis, which must be controlled to avoid excessive proteolysis leading to undesirable effects impairing functionality [28; 29]. The degree of OPH hydrolysis was quite low. After 3 h of hydrolysis, the DH was only 12.06 \(\pm\) 1.01%. The oat protein hydrolyses exhibited faint bands around 37 and 22 kDa (Figure 1), which likely represent the acid and basic polypeptide oat globulin, respectively [30]. Furthermore, there were noticeable wide bands in the hydrolyses within the weight range between 10-20 kDa. This suggests that the basic polypeptide of oat globulin, approximately 22 kDa in size, was partly broken down into smaller pieces. Overall, the electrophoretic profiles of oat protein hydrolyses indicated significant shifts towards lower molecular weight peptides, suggesting their potential nutritive value and biological significance [10]. Plant-derived peptides could be thought to exhibit antioxidant activity [31], with certain amino acids acting as metal chelators and hydrogen/electron donors through their interaction with free radicals, thereby stopping radical chain reactions or preventing their formation [32]. The hydrolysis process can also be well-reflected by measuring the amount of produced free amino acids [33]. The results are consistent with previous literature data in which it has been stated that glutamic acid and leucine are the most abundant amino acids in oat protein [10]. Generally, free amino acids are not effective antioxidants. However, other researchers [34; 35] found that hydrophobic amino acids could express significant performance in regards to the functional properties of food proteins. These amino acids present in protein hydrolyses can exhibit excellent antioxidant properties and may be incorporated into other foods as supplements. Typically, the antioxidant activity of protein hydrolyses is not determined by individual amino acids alone, but by their combination with peptides [36]. The OPH obtained in this study exhibited a considerable content of free hydrophobic amino acids, especially isoleucine (58.36 mg/100 g) and leucine (49.43 mg/100 g).