Peptides modulate Cu(II) reactivity toward hop-derived polyfunctional thiols in beer

Area of Science:

• Food Chemistry
• Brewing Science
• Sensory Analysis

Background:

• Polyfunctional thiols are crucial for desirable beer aroma but are unstable.
• Copper in brewing environments can degrade these aroma thiols.
• Maintaining thiol stability is a challenge in beer production.

Purpose of the Study:

• To investigate the stabilizing effect of a barley-derived dipeptide, glycyl histidine (Gly-His), on polyfunctional thiols in beer.
• To understand the mechanism by which Gly-His interacts with copper (Cu(II)) in beer.
• To assess the potential of Gly-His in preserving hop-derived aroma compounds.

Main Methods:

• Utilized glycyl histidine (Gly-His) as a model dipeptide.
• Studied the interaction between Gly-His and copper (Cu(II)) in beer.
• Assessed the impact of Gly-His on the stability of polyfunctional thiols under brewing conditions.

Main Results:

• Glycyl histidine (Gly-His) forms stable complexes with copper (Cu(II)) in beer.
• This binding interaction is proposed to shield polyfunctional thiols from copper-induced degradation.
• The study demonstrates a potential method to enhance the stability of aroma thiols.

Conclusions:

• Barley-derived dipeptides like Gly-His can act as protectors for labile polyfunctional thiols in beer.
• Complexation of copper by Gly-His offers a promising strategy to maintain beer's aromatic quality.
• This finding has implications for improving the shelf-life and sensory profile of hop-forward beers.