Abstract

Beer foam is one of the most important parameters for consumers, affecting their purchase decision and satisfaction. Studies indicate that foam stability is positively influenced by its viscosity, and based on this fact the brewing industry uses propylene glycol alginate (PGA) as a stabilizer. However, PGA has its use restricted by Brazilian legislation to 0.07 g/L of beer. The objective of this research was to present alternatives to PGA, improving beer foam stability by adding other hydrocolloids, which does not have a maximum amount established by Brazilian legislation, and determining those with the greatest influence on the foam stability without significantly changing the colloidal stability and pH of the beverage. Colloidal stability, viscosity and foam shaking tests showed that the higher the hydrocolloid concentration in the beer, the greater the foam stability. PGA exhibited the best performance among the hydrocolloids tested, followed by Genu® Pectin type 106 HV and Genu® GUM type RL 200-Z, which had a significantly better foaming capacity than the control. Differently from the initial hypothesis, the foam stability was found to be more influenced by the chemical structure of the hydrocolloids, mainly their degree of esterification, than by foam viscosity.

Key words: Beverages, technology, viscosity.