# The Influence of Proteolytic Salt Modification on the Aging Potential of Final Wort
## 4 Conclusions  
The study investigated the influence of a varied precursor concentration (amino acids and dicarbonyls) by different proteolytic malt modification levels on the formation of the aging potential during wort boiling. Summarily, it could be shown that a higher proteolytic malt modification level (calculated by soluble nitrogen content within malt specifications for brewing purposes) increased amino acid content, dicarbonyl concentration, Strecker aldehyde concentration, and the concentration of 4-VP-releasable Strecker aldehydes within malt specifications for brewing purposes. An enhancement of these substance classes lead to an increased aging potential for the final product beer out of final wort. Finally, the model-boiling studies confirmed the hypothesis that a higher amino acid content at the beginning of boiling, by an increased malt modification level, maximized the aging potential originating from the final wort toward the follow-up beer product. Some precursors or substances presented in Table 5 showed a good correlation (R\({}^{2}\) > 0.8) to the soluble nitrogen content of the used malt. Table 5 shows their calculated limits in final wort according to the soluble nitrogen specifications for brewing purposes (isothermal 65 \({}^{\circ}\)C mashing procedure) [39; 40] in this study. Other components observed in this study showed no linear dependency to soluble nitrogen content and could not be used as indicators of the aging potential due to malt modification levels. Although the calculated range was suitable for the brewing industry, the upper limit generally indicated a higher aging potential than the lower malt modification level. These values of single substances could be used as an alignment to evaluate the aging potential originating from wort for the final beer in comparable brewing setups. Further promising analytes to align the aging potential could be Amadori products, such as \(\varepsilon\)-fructosyllysine (FL), because they act as direct 3-DG precursors. They should be regarded in future studies. Thus, it could be shown that an increased proteolytic malt modification level influences the aging potential formed during wort boiling for pale lager beers.  
**Supplementary Materials:** The following are available online at [[https://www.mdpi.com/article/10.3390/foods10102320/s1](https://www.mdpi.com/article/10.3390/foods10102320/s1)]([https://www.mdpi.com/article/10.3390/foods10102320/s1](https://www.mdpi.com/article/10.3390/foods10102320/s1)), Supplementary Excel document shows the concentrations of amino acids, free aldehydes, and 4-VP-releasable aldehydes at all sampling points during word boiling.  
**Author Contributions:** A.N.: conceptualization, visualization, investigation, and writing-original draft. F.L.: conceptualization, visualization, investigation, and writing-original draft. M.G. ([PERSON]): formal analysis and investigation. M.G. ([PERSON]): conceptualization, writing-review and editing, supervision, and funding acquisition. T.B.: writing-review and editing and supervision. All authors have read and agreed to the published version of the manuscript.  
**Funding:** The IGF Projects (AiF 20624 N and AiF 20151 N) were supported via AiF within the program for promoting the Industrial Collective Research (IGF) of the German Ministry of Economic Affairs and Energy (BMWi), based on a resolution of the German Parliament.  
**Data Availability Statement:** The data presented in this study are available within the article.  
**Acknowledgments:** The authors are deeply thankful to [PERSON] and [PERSON] for performing the analytics of the cysteinylated aldehydes.  
**Conflicts of Interest:** The authors declare there are no conflict of interest.