Novel Desaturation Cell to Quantify Gushing Intensity: A Preliminary Study on Model Solutions

Abstract

Beer gushing is an unwanted phenomenon that occurs when the beer foam spontaneously gushes out when a bottle or can is opened. Despite long-term research, gushing still has not been fully explained. To our knowledge, there is no simple, quick, and inexpensive method for reliably measuring gushing intensity. In this article, a desaturation cell enabling saturation, step-wise pressure drop, and image analysis of foam formation is presented. The gushing intensity was evaluated through foam formation rate and relative final foam volume. To study the physicochemical mechanism of gushing, the measurements were carried out in a simple gushing matrix made of water and bovine serum albumin (BSA), the aggregates or micelles of which serve as nucleation sites for bubble formation. The effect of hop bitter compounds (iso-α-acids and tetrahydro-iso-α-acids) and essential oils (linalool) in the BSA matrix was also tested. The hop bitter compounds increased the foam formation rate significantly while affecting the foam volume less. Linalool at low concentration caused an extremely high foam formation rate whereas, at higher concentration, did not affect the foaming of the BSA matrix.