## 3 In Silico Studies on the Biological Activities of Meat Peptides--Theoretical Approach
It can be divided into the following universal steps: (I) Identification of potentially bioactive peptides on the basis of the structure-function patterns; (II) Identification of proteases effective in releasing new biopeptides; (III) Experimental verification using hydrolyses or synthetic peptides; and (IV) Identification of new peptides/sources [38; 39]. The research on food will contribute to gaining better knowledge on the influence of enzymatic hydrolysis with digestive enzymes and of simulated in vitro absorption on the biological activity of peptides derived from meat proteins. As shown above (Figure 2), one of the areas of activity of scientists studying the mechanisms of the digestion of food products is the creation and analysis of in silico hydrolysis models. By using bioinformatics tools, it is also possible to estimate the antinutritional/toxic properties of food. The tools offered by the databases were used for this purpose. One of them is BIOPEP-UWM, which offers, among others, the possibility of searching for the sequence of allergenic proteins (including epitopes), while another tool is the ToxinPred website for the prediction of peptide toxicity [23; 43; 44; 45]. [PERSON] et al. [30] and [PERSON] [14] also used in silico tools to assess the antinutritional (toxic) properties of bovine/porcine proteins from a variety of meat muscle and byproducts. The in silico approach can also enable the evaluation of the allergenic properties of the peptides from food. The best-known animal-based food allergens are found in milk, but meat could also be a potential source. Therefore, it was assessed whether the use of acid whey (a byproduct of the dairy industry) in the preparation of mature beef would affect the allergenic properties of the product through in silico analysis (based on information available in \"Allergic proteins and their epitopes\" in the BIOPEP-UWM database) [35]. Within the sequence of the analyzed peptides, the epitopes (i.e., the part of the macromolecule recognized by the immune system, which forms 2% of all analyzed peptides), with a common LEKFDK  
Figure 3: Tools used to identify and validate bioactive peptides from food (based on [38]). sequence, responsible for potential allergic reactions in consumers, were located. The authors of the study identified them as a linear epitope of the Bos d 5 allergen, which is a characteristic of the allergenic bovine protein (_Bos taurus_) beta-lactoglobulin, gene A. The presence of this epitope was confirmed only in bovine myoglobin. Moreover, the authors of the study indicate that the use of whey did not adversely affect the allergenic properties of the fermented beef product [35]. Among all, the results of their study indicate that this type of food product is a potentially good source of bioactive compounds and is important for reducing the effects of noninfectious diseases, mainly because of the high content of DPP-IV and ACE-I inhibitors, as well as antioxidants. The in silico characterization of the allergenicity of proteins from foods, including meat sources, was also carried out by [PERSON] et al. [46]. The authors indicate that _Bos taurus_ meat is mostly responsible for triggering allergenicity. The meat of _Gallus gallus_ (poutlry) was, however, found to be free from allergenic factors [46]. In addition to bioactivity, [PERSON] et al. [47] also assessed the allergenicity and toxicity of papain hydrolyses (previously identified as the best enzymes for the production of biologically active peptides in an in silico analysis [30]) from bovine blood globulins. It was shown that the hydrolysates were not toxic but, rather, contained potential allergenic peptides.