Content of trans- and cis-iso-alpha-bitter acids as indicator of sensorial beer stability.

Abstract

Content of cis- a trans- isomers of iso-α-bitter acids has been studied during beer storage at 8 °C, 20 °C and 30 °C. Stereoisomers of iso-α-bitter acids have been determined in beers by optimised method based on Harms and Nitzsche method. High-performance liquid chromatography (HPLC) method utilizing photodiode array detection (PDA) detection is able to resolve six stereoisomers of iso-α-bitter acids. Content of trans- isomers decrease during beer storage, while content of cis- isomers remains almost constant. Lag time and T150 values have been measured in fresh beer and beer after storage.Content of cis- a trans- isomers of iso-α-bitter acids has been studied during beer storage at 8 °C, 20 °C and 30 °C. Stereoisomers of iso-α-bitter acids have been determined in beers by optimised method based on Harms and Nitzsche method. High-performance liquid chromatography (HPLC) method utilizing photodiode array detection (PDA) detection is able to resolve six stereoisomers of iso-α-bitter acids. Content of trans- isomers decrease during beer storage, while content of cis- isomers remains almost constant. Lag time and T150 values have been measured in fresh beer and beer after storage.

Keywords

• beer
• storage
• sensorial stability
• bitter acids
• HPLC