Production of Special Fruit Beer With Addition of Cupuassu (Theobroma grandiflorum) Pulp and Prolyl Endopeptidase to Improve Volatile Compounds and Physicochemical Parameters.

This study assessed the feasibility of incorporating cupuassu pulp and the commercial protease Aspergillus niger prolyl endopeptidase (AN-PEP) in the production of fruit beer. To preliminarily evaluate the impact of the protease on the beer protein profile, one-dimensional SDS-PAGE was employed. The volatile compounds were analyzed using headspace solid-phase microextraction (HS-SPME)-GC-MS, whereas physicochemical parameters were evaluated following the American Society of Brewing Chemists (ASBC) methods. The band profiles from electrophoresis indicated the degradation of high-molecular-weight proteins, such as gluten, in the formulations treated with protease (A1 and A2). In two out of the three formulations, elevated levels of 3-methyl-1-butanol, linalool, and 2-phenylethanol were detected, suggesting that the protease may have played a role in the release of volatile flavor compounds. The beers produced exhibited low alcohol content, ranging from 2.80% to 3.44% (v/v). On the basis of these findings, we conclude that the combination of AN-PEP and cupuassu pulp is a viable approach to producing fruit beer with a predominantly floral, sweet, and whiskey-like aroma profile, showing preliminary evidence of degradation of high-molecular-weight proteins (including potential gluten fractions) by the action of the protease. PRACTICAL APPLICATIONS: The results obtained in this study serve as a foundation for the development of new approaches in the artisanal and sustainable production of fruit beer, providing information for the creation of innovative beers with added value, as well as promoting and valorizing local ingredients for the craft beer sector.