(208f) Optimization of Aroma Profiles through Selective Removal of Off-Flavors: An Exemplary Study in Alcohol-Free Beers

A delicate balance of aroma molecules characterizes the distinctive flavor profile of foodstuffs and beverages. If off-flavors are present, this profile is distorted. In alcohol-free beers, such a lack of balance is often induced by the enhanced perception of wort flavors. In general it is recognized that wort flavor is caused by so-called Strecker aldehydes that are typically produced by a heat-induced reaction between a reducing sugar and an amino acid. Nonetheless, formation may occur via multiple routes, therefore their occurrence is difficult to prevent. The aim of this work is hence to develop a technology that can engineer the desired flavor profile and fine-tune the aroma concentration to the respective product. Considering the sensitive nature of foodstuffs and beverages, a high selectivity at mild operation conditions is required, desirably with low capital investment and operational costs.

In the first part of this study, a technical solution to this challenging task was developed by identifying potential bottlenecks and proposing process concepts circumventing these. Consequently, the feasibility of the technology was evaluated to demonstrate the proof of concept. In the final step, the impact of the beverage constituents on the process efficiency was tested to gain insight into the involved mechanisms and to determine process robustness. Based on these findings, it is possible to design a new processing operation that facilitates a controlled off-flavor capture from alcohol-free beers.