Presentation Information
[P02-173]Identification of Key Compounds Responsible for the Fruity Aroma of the Hop Variety Murakami Seven
○Emiko Tanaka1, Taeko Tsukahara1, Kanako Sasaki1, Tetsu Sugimura1 (1. Kirin Holdings Company, Limited (Japan))
Keywords:
beer,aroma,hop,GC-MS
Hops (Humulus lupulus) are an essential raw material that imparts bitterness and characteristic aroma to beer. Aroma characteristics vary widely depending on hop variety, and beers with diverse hop-derived aroma profiles have attracted increasing attention. Murakami Seven, a Japanese hop variety recently developed by Kirin, produces beers with a distinctive fruity aroma often described as reminiscent of mandarin orange or fig. However, the compounds responsible for this characteristic aroma have not yet been identified.In this study, we aimed to identify the compounds contributing to the characteristic fruity aroma of Murakami Seven. Beers were brewed at a 200 L scale using single hop varieties (Murakami Seven, Hersbrucker, Cascade, and Kirin No. 2). Gas chromatography–olfactometry (GC-O) combined with GC-MS differential analysis was used to screen candidate compounds contributing to the characteristic aroma. Quantitative analysis of the selected compounds in beer samples was performed using GC-MS.
To evaluate the sensory contribution of the candidate compounds, an omission test was conducted using the automated omission system (GC-MS Aroma Designer, Shimadzu Corporation). Volatile compounds in beer brewed with Murakami Seven were collected using a dynamic headspace method and introduced into the omission GC-MS system. Aroma bags containing all volatile compounds and bags in which the candidate compounds were selectively omitted were prepared and evaluated by sensory analysis.
Four compounds—2-decanone, 2-nonanol, 2-undecanone, and methyl geranate—were identified as candidate contributors to the characteristic fruity aroma of Murakami Seven. Quantitative analysis revealed that these compounds were present at higher concentrations in beer brewed with Murakami Seven than in beers brewed with other hop varieties. Sensory evaluation indicated that the omission of these four compounds tended to decrease the perceived fruity aroma, whereas other attributes such as herbal or woody notes were not significantly affected.Furthermore, hop cones harvested at different maturation stages were evaluated using small-scale fermentation tests. The concentrations of all four compounds tended to increase as the hop cones matured.These results suggest that these four compounds contribute to the characteristic fruity aroma of Murakami Seven. The findings provide useful insights for hop breeding, optimization of harvest timing, and the development of beers with diverse aroma profiles.
To evaluate the sensory contribution of the candidate compounds, an omission test was conducted using the automated omission system (GC-MS Aroma Designer, Shimadzu Corporation). Volatile compounds in beer brewed with Murakami Seven were collected using a dynamic headspace method and introduced into the omission GC-MS system. Aroma bags containing all volatile compounds and bags in which the candidate compounds were selectively omitted were prepared and evaluated by sensory analysis.
Four compounds—2-decanone, 2-nonanol, 2-undecanone, and methyl geranate—were identified as candidate contributors to the characteristic fruity aroma of Murakami Seven. Quantitative analysis revealed that these compounds were present at higher concentrations in beer brewed with Murakami Seven than in beers brewed with other hop varieties. Sensory evaluation indicated that the omission of these four compounds tended to decrease the perceived fruity aroma, whereas other attributes such as herbal or woody notes were not significantly affected.Furthermore, hop cones harvested at different maturation stages were evaluated using small-scale fermentation tests. The concentrations of all four compounds tended to increase as the hop cones matured.These results suggest that these four compounds contribute to the characteristic fruity aroma of Murakami Seven. The findings provide useful insights for hop breeding, optimization of harvest timing, and the development of beers with diverse aroma profiles.
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