Relationship between Rice Variety and Sake Metabolome
In recent year, distinctive varieties of sake-rice have been developed, in addition to the so-called“King of Sake Rice,” Yamada Nishiki. Each variety of sake rice has its own influence on the qualityof the rice-koji and the subsequent brewing processes and finished products. The relationshipbetween the rice varieties and the compositions of finishes sake has long been a never-ending
subject to research, but the effects of brewing conditions are so dominant that the research in thisfield has been stalled. In the latest study, we applied the same small-batch brewing process to threevarieties of sake rice at polishing ratios of 70% and 50%: Omachi, the oldest variety used to makesake; Yamada Nishiki, which is derived from the Omachi lineage; and Hattan Nishiki No. 1, which
was bred from a completely different lineage. The results showed that the overall sake metabolome
was greatly affected by the rice polishing ratio and in addition, a clear relationship was observed
between sake metabolome and rice variety. We formulate the discriminant for rice varieties frommetabolome data based on small-batch production, and the discrimination accuracy was 100%
when we analyzed commercial sakes made from three rice varieties. Qualities of commercial sakesvary depending on many factors, including koji mold, yeast, fermentation and storage conditions,but the effect of the rice varieties was observed in the metabolite composition of sake. The aim offurther research is analyzing other sake rice varieties, especially focusing on varieties that arebeing newly developed.
* Sake metabolome is a phrase that refers to the overall composition of finished sake.

It was possible to distinguish between varieties of sake rice byanalyzing the overall composition of finished sake (sakemetabolome)

Relationship between Rice Variety and Sake Metabolome
Three Varieties of Rice

Sake Metabolite Analysis

Omachi： This variety of rice was isolated more than 150 years ago. It is one ofthe oldest varieties of sake rice. Approximately 2/3rd of the existing sake rice isconsidered to have been derived from this lineage.
Yamada Nishiki： “King of Sake Rice.” It was obtained in 1923 by cross breedingof “Yamadaho” and “Tankan Wataribune” (selectively bred varieties derived
from the lineage Omachi). Its production yield is the highest in Japan.
Hattan Nishiki No. 1： The representative sake rice from Hiroshima. It was bredat the Hiroshima Prefectural Agricultural Exp. Station in 1983. It is derived froma lineage different from Omachi and has originated from food rice.

Koji rice
Kake rice

Small Batches（3 Datasets）

Cluster Analysis of Sake Metabolome
Tree graph

Discriminant Creation and Commercial Sake Analysis

Yamada Nishiki Hattan Nishiki

CreatingDiscriminants from70% Small-Batch
SamplesOmachi

Discrimination Analysis of Commercial Sake Using
Discriminants Based on a Small Batch of Sake
(Rice Polishing Ratio, 23%-70%)
Omachi
HattanNishiki

Yamada Hattan
Nishiki Nishiki

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50%

Commercial Sake:
Yamada Nishiki 8,
Omachi 3, andHattan Nishiki 3
Samples

YamadaNishiki○Omachi

100% ability to distinguish even with different samples

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Creating discriminants from metabolome data based on a small batch of sake○○

Rice polishing ratio has a high effect, and rice variety
also has an effectDistinguish between rice varieties is possible for a small batch
Distinguish between rice varieties is also possible for commercial sake