Quality Control System for Beer Developed with Monoclonal Antibodies Specific to Barley Lipid Transfer Protein

Non-specific lipid transfer protein (LTP) in barley grain reacted with the IgE in sera drawn from food allergy patients. A sandwich-type of enzyme-linked immunosorbent assay (ELISA) was developed with mouse monoclonal antibodies raised against LTP purified with barley flour. This ELISA showed a practical working range of 0.3–3 ng/mL and no cross-reactivity with wheat, adlay and rye. Using this ELISA, LTP was determined in several types of barley-foods, including fermented foods such as malt vinegar, barley-malt miso and beer. LTP content in beer of the same kind was approximately constant, even if manufacturing factory and production days were different. Not only as a factor of foam formation and stability but also as an allergen, controlling and monitoring of LTP in beer should be considered. Taken together, our LTP-detecting ELISA can be proposed as an appropriate system for the quality control of beer.