6. Sensory and instrumental analyses of compounds affecting the KIRE (crispness) of beer

Seiko Miyashita (1), Minoru Kobayashi (1), Kaori Kikuchi (1), Naoki Kato (1), Susumu Masuda (1), Masayuki Aizawa (1); (1) Asahi Breweries, Ltd., Moriya, Ibaraki, Japan

Technical Session 2: Sensory I
Sunday, August 14  •  9:45–11:30 a.m.
Tower Building, Second Level, Grand Ballroom

In the development of beer products, it is extremely important to understand the relationship between the flavor characteristics of beer and compounds that affect sensory evaluations. Consumers use a variety of terms to describe beer flavors. In particular, the terms body and smoothness are important when evaluating beer flavors in the Japanese market. Although an internationally standardized definition of body has been established, no consensus has been reached on a definition for smoothness. At present in Japan, smoothness is generally defined as the difference in flavor between the first and last mouthfeel, and desirable smoothness leaves no residue or unpleasant flavors after drinking. To identify compounds that affect beer smoothness, 14 kinds of lager-type beer and low-malt beer produced by major breweries in Japan were analyzed. Gas chromatography-flame ionization detection was used for the measurement of flavor compounds, and high-performance liquid chromatography and spectrophotometry were used for the measurement of taste compounds. Quantitative descriptive analysis (QDA) data regarding the body and smoothness of each sample was also collected using a trained panel. For the selection of the candidate compounds affecting body and smoothness, chemical and sensory data were subjected to projection to latent structure (PLS) regression analysis to calculate PLS models that can predict each sensory attribute. The results of the analysis revealed a highly predictive PLS model for body using the data for taste compounds. Smoothness was strongly correlated with QDA data and the predictive PLS models for both flavor and taste compounds; however, smoothness showed a weak correlation when only the data for taste compounds were included. Additionally, using sensory evaluations, we assessed the effect of such compounds as medium-chain fatty acids, hop aroma, and esters, which significantly affect smoothness. The results confirmed that these compounds were negatively correlated with smoothness.

Seiko Miyashita is an analyst at the Department of Brewing and Flavor Technology Research Laboratories for Alcohol Beverages at Asahi Breweries Ltd. She graduated from the Department of Material and Life Science in the Graduate School of Engineering at Osaka University before joining Asahi Breweries Ltd. in 2009. She has been engaged in the research and development of analytical technology since 2011, with a particular focus in the area of brewing science.