Title

Antimicrobial Effects of Hops

Presenter Information

Wendy Lopez
Eric Foss

Document Type

Oral Presentation

Location

SURC Ballroom C/D

Start Date

16-5-2013

End Date

16-5-2013

Abstract

Hops are a main ingredient used in brewing to create and enhance different styles of beer and are the source of hop bitterness acids which include alpha and beta acids. It has been hypothesized that hops reduce microbial growth in beer and contribute to stability of the product. There have been few studies investigating variation of antimicrobial activity in different hop varieties and their effectiveness at reducing growth of different bacterial contaminants. Therefore, we investigated antimicrobial activity of six varieties of hops, with different alpha acid ratings, on growth inhibition of three bacterial species. Discs were soaked in prepared hop extracts and placed on a lawn of bacterial growth in a petri dish. The diameter of growth inhibition was measured after 24 hours. The results indicated significant differences in inhibition among the varieties (ANOVA p < 0.0001) and in among bacterial species (ANOVA p< 0.0001). There was a trend for higher alpha acid hops decreasing microbial growth.

Poster Number

29

Faculty Mentor(s)

Steve Wagner

Additional Mentoring Department

Biological Sciences

This document is currently not available here.

Share

COinS
 
May 16th, 8:20 AM May 16th, 10:50 AM

Antimicrobial Effects of Hops

SURC Ballroom C/D

Hops are a main ingredient used in brewing to create and enhance different styles of beer and are the source of hop bitterness acids which include alpha and beta acids. It has been hypothesized that hops reduce microbial growth in beer and contribute to stability of the product. There have been few studies investigating variation of antimicrobial activity in different hop varieties and their effectiveness at reducing growth of different bacterial contaminants. Therefore, we investigated antimicrobial activity of six varieties of hops, with different alpha acid ratings, on growth inhibition of three bacterial species. Discs were soaked in prepared hop extracts and placed on a lawn of bacterial growth in a petri dish. The diameter of growth inhibition was measured after 24 hours. The results indicated significant differences in inhibition among the varieties (ANOVA p < 0.0001) and in among bacterial species (ANOVA p< 0.0001). There was a trend for higher alpha acid hops decreasing microbial growth.