## 3 Results  
### In Silico Analysis  
Many data concerning molecules can be found in databases [5]. The BIOPEP-UWM database of sensory peptides and amino acids [20] was used to analyze the in silico fragments released from soybean proteins. These peptides were searched for the presence of shorter bitter-tasting fragments, including indicators. The results are shown in Tables 1 and 1 (in the Appendix A). They include only released fragments that (a) contained bitter-tasting motifs and (b) consisted of four amino acid residues at a minimum. Shorter fragments were not discussed. They were di- and tri-peptides that could already match the sequences with a known taste sensation (i.e., bitterness). \begin{table}
\begin{tabular}{c c c} \hline \hline \multicolumn{3}{c}{**Parent Peptides Released from Profilin Due to the Simulated Action of:**} \\ \hline
**B 1** & **F** & **P** & **PK** \\ \hline Number of parent peptides/number of parent peptides containing bitter-tasting indicators & & \\ \hline
9/7 & 5/2 & 7/5 & 4/1 \\ \hline Total number of parent peptides/total number of parent peptides containing bitter-tasting indicators & = 25/15 \\ \hline \multicolumn{3}{c}{**Parent peptides released from globulin 7S due to the simulated action of:**} \\ \hline
**B** & **F** & **P** & **PK** \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Number of parent peptides including these containing bitter-tasting indicators found in soybean protein sequences. Regardless of the substrate and enzyme applied, all released fragments were the potential sources of motifs matching the sequences collected in the BIOPEP-UWM database and known in the literature as bitter-tasting. Thus, it was the premise to define them as parent peptides. Taking into consideration all enzymes applied in the study, the highest number of parent peptides was potentially released from \(\beta\)-congplycinin (\(\alpha\)-chain), while profilin was the protein revealing the smallest number of peptides produced. Generally, the best in silico enzymatic potential aiming to produce parent peptides from all soybean protein sequences was represented by bromelain and papain. Other enzymes, i.e., ficin and proteinase K, produced less parent peptides than the above enzymes. However, in most of the cases, proteinase K was predicted to be slightly better than ficin considering the number of peptides potentially released from soybean proteins. The most abundant potential sources of parent peptides containing one bitter-tasting indicator at minimum were: profilin (7 sequences, enzyme used: bromelain), 7S globulin (16 sequences each, enzymes used: bromelain and papain), glycinin (17 sequences, enzyme used: bromelain), \(\beta\)-congplycinin (\(\beta\)-chain) (18 and 17, enzymes used: bromelain and papain, respectively), and \(\beta\)-congplycinin (\(\alpha\)-chain) (23 sequences, enzyme used: bromelain). The highest total number of parent peptides with encrypted bitter-tasting indicators, regardless of the enzyme used, was determined in the \(\beta\)- and \(\alpha\)-chain of \(\beta\)-congplycinin (43 and 53 out of 78 and 93 generally released, respectively). Considering the enzymes that produced such parent peptides (i.e., with encrypted indicators), their ranking was as follows: bromelain > papain > ficin > proteinase K. The criterion in this ranking was the total number of parent peptides (i.e., the higher the number, the better place in the rank) containing one indicator of bitter taste at a minimum. Dipeptides rather than tripeptides with or without the status of a bitter-tasting indicator were the great majority of motifs found in the parent peptides. Both two and three amino acid fragments were observed in the following peptides: ERPG-RP, RPG (source: profilin hydrolyzed with ficin); RQLEENLVVFOLA-VF, LE, LV, DL, EEN (source: 7S globulin hydrolyzed with proteinase K); SRPG-RP, RPG (source: 7S globulin hydrolyzed both with bromelain and ficin); EENL-EEN (source: 7S