Monoclonal antibody probe for assessing beer foam stabilizing proteins

Area of Science:

• Food Science
• Biochemistry
• Analytical Chemistry

Background:

• Beer foam stability is crucial for consumer acceptance and is influenced by specific hydrophobic polypeptides.
• Understanding the role and conformation of these polypeptides is key to controlling foam quality.
• Existing methods for assessing foam potential are empirical and lack molecular specificity.

Purpose of the Study:

• To develop a specific assay for quantifying foam-stabilizing polypeptides in beer.
• To investigate the relationship between these polypeptides and beer foaming properties.
• To track changes in foam-positive polypeptide levels during the brewing process.

Main Methods:

• Production of a monoclonal antibody (Mab; IFRN 1625) targeting foam-stabilizing hydrophobic polypeptides.
• Development of an enzyme-linked immunosorbent assay (ELISA) using IFRN 1625 for quantifying foam-positive polypeptides.
• Correlation of ELISA results with empirical foam retention measurements (Rudin head retention values).

Main Results:

• The Mab's binding characteristics suggest polypeptide conformation is critical for foam stabilization.
• A strong correlation was observed between ELISA-determined foam-positive polypeptide levels and Rudin head retention values across various beers.
• Foam-positive polypeptide levels increased during barley germination and slightly post-fermentation, but decreased during later processing steps like filtering.

Conclusions:

• The quantity of foam-positive polypeptides directly relates to beer foaming potential.
• Brewing and processing significantly alter the levels of these key foam-stabilizing polypeptides.
• The developed ELISA assay offers a valuable tool for quality control in the brewing industry.