2021 Research results

1.Analysis of the sake exhibited at the Toji Seminar in Heisei 20～31(2008-2019)

Author

Naoto Okazaki, Masaaki Inahashi, Katsumi Nakahara, Hirokazu Hasuda, Takafumi Mutoh, Hitoshi Shimoii, Yasuzo Kizaki, Dai Hirata and Masaki Okuda

Abstract

As one feature of the sake production year based on the sake rice analyses, the digestibility Brix shows a high positive correlation with the glucose and a negative correlation with the items/factors related to the fermentation process, alcohol, sake meter values etc. As a result, it was indicated that the glucose content showed a positive correlation (p=10%) with the overall evaluation. In a factor analysis, factor 1 -- solubility of the raw material rice, with respect to the fermentation, high digestibile Brix and glucose, contribute to the evaluation were good ; factor 2 - i-AmOH, al-added amount, low acidity, were interpreted as density and cleanliness. This result could lend credence to the report by Sato et al. who proposed the basic structure of the taste of sake. In the sake group with minimal fragrance defects, we analyzed the effect of the sake components on the overall evaluation for each exhibition year. Et-Cap, glucose, sake degree, amino acid degree, and i-AmOAc were selected as the items/factors with a great contribution. However, it was suggested that the changes in the panel's examination criteria affected the contribution rate of Et-Cap and glucose to the overall evaluation.

Source

J. Brew. Soc. Japan, 116(4), 290-299 (2021)

2.Classification and threshold measurement of aroma compounds aimed for establishing the reference standards of sensory analysis of Honkaku shochu and Awamori

Author

Yukio Osafune, Kenji Toshida, Jinshun Han, Atsuko Isogai and Nobuhiko Mukai

Abstract

The relationship between aroma compounds and flavor terminology is an important step in establishing a sensory evaluation system. The detection and recognition thresholds of 16 compounds were determined to identify the compounds contributing to the aroma characteristics of Honkaku shochu and Awamori, both traditional Japanese spirits. The odor activity values calculated using detection thresholds suggested that 13 compounds affect the quality of Honkaku shochu and Awamori. Further, the sensory attribute terms of these compounds are summarized. Thirty-two compounds were selected as candidates for reference standards from among 55 compounds (threshold determined) based on their contribution to the quality and characteristics in Honkaku shochu and Awamori. The result of classifications of the candidates of the reference standard suggested that these compounds were divided into 8 groups according to their aroma characteristics. These findings help to establish reference standards, terminology, and a flavor wheel for the evaluation of Honkaku shochu and Awamori.

Source

J. Brew. Soc. Japan, 116(4), 279-289 (2021)

3.Investigation of Methanol Content in Potato Shochu

Author

Nobuhiko MUKAI, Akinori MUTO, Toshihiro YOSHIMURA, Kaori ONODERA, Kenji TOSHIDA, Jinshun HAN and Yukio OSAFUNE

Abstract

The authors investigated the methanol content in potato shochu (137 samples of sweet potato shochu, 6 samples of potato shochu, and 3 samples of Japanese yam shochu. There were no samples which exceeded the regulation level of methanol of the Japanese Food Sanitation Act. In sweet potato shochu made from Koganesengan, the methanol content using sweet potato koji was significantly higher than that using rice koji. The methanol content of sweet potato shochu made from purple lineages was significantly higher than that made from Koganesengan.

Source

J. Brew. Soc. Japan, 116(5), 347-351 (2021)

4.A Correlation Analysis between Quantitative Scale Evaluation Values and Analytical Values of Shochu

Author

Nobuhiko MUKAI, Jinshun HAN and Yukio OSAFUNE

Abstract

The authors investigated the quantitative scale evaluation of barley shochu and sweet potato shochu. Five kinds of evaluation items (body, sweetness, bitterness, aftertaste and overall evaluation) were used for the scale evaluation. The evaluation of sweetness had a significant correlation with that of the overall evaluation in both barley shochu and sweet potato shochu. As a result of a multiple regression analysis, it was found that sweetness and aftertaste were important to the overall evaluation. Futhermore, the correlation analysis between scale evaluation values, general components, and flavor components was investigated.

Source

J. Brew. Soc. Japan, 116(5), 352-361 (2021)

5.Comparative analysis of sake rice varieties utilizing earlier-period-rice analysis data collected from 2002-2019 crop years

Author

Kei Takahashi, Masaki Okuda, Midori Joyo, Mineyo Numata, Bao Hong-Bin, Hiromi Kohno

Abstract

Sequential earlier-period-rice analysis data gathered from the 2002-2019 crop years, comprised of 707 samples in total, were examined focusing on a comparison within sake rice varieties. We discovered varied rice properties in Japanese sake brewing among different rice varieties. The weight of 1,000 rice grains was heavier across Hanafubuki, Okuhomare, and Hyogokitanishiki, followed by Yukimegami, Homarefuji, Akitasakekomachi, Yamadahishiki, Kitashizuku, Senbon-nishiki, and Hattan-nishiki. Water absorption during 20 minute periods was higher in Kyonohana and Dewanosato, followed by Homarefuji, Gin-noyume, Hyogokitanishiki, Hattan-nishiki, Yamadahishiki, Ipponjime, and Hanafubuki. Brix was particularly high in Dewanosato, followed by Kyonohana, Homarefuji, Akitasakekomachi. The ratio of Brix/folmol nitrogen was higher in Dewanosato, followed by Yukimegami, Yamadanishiki, Gin-noyume, Nakateshinsenbon, and Homarefuji. Crude protein was higher in Okuhomare, Ginpu, Kitashizuku, Fukuhikari, and Hyogokitanishiki, but lower in Yukimegami, Dewanosato, Yamadanishiki, Nakateshinsenbon, Akitasakekomachi, Gin-noyume, and Sanukiyoimai. Brewing properties across all rice varieties analyzed did not considerably vary from the properties of rice harvested within the same production area, indicating that sake rice variety strongly affects rice properties upon sake brewing.

Source

J. Brew. Soc. Japan, 116(6), 428-441 (2021)

6.Time course study for elucidating annual variation of the brewing properties of sake rice utilizing earlier-period-rice analysis data collected from 2002-2019 crop years

Author

Kei Takahashi, Masaki Okuda, Midori Joyo, Mineyo Numata, Bao Hong-Bin, Hiromi Kohno

Abstract

In the present study, we investigated the annual variation in the brewing properties of sake rice utilizing earlier-period-rice analysis data gathered from 2002-2019 across all rice varieties analyzed. The annual variation for water absorption during a 20 minute period of table rice was higher than sake rice. Water absorption during both 20 minute and 120 minute periods of a large amount of rice varieties was higher among rice harvested during the year 2010, when the highest mean August temperature was recorded in Japan. The starch digestibility (Brix) of a large amount of rice varieties was lower in the years 2007, 2010, 2012, and 2019, during which higher temperatures from July to September contrasted with other crop years. Brix values of Gohyakumangoku varied widely within a year depending upon the production district, indicating that the variety is likely to be strongly affected by meteorological conditions in regards to its digestibility. The annual variation of crude protein and potassium concentrations within white rice varied depending on rice variety and the production district. Brix values of Yamadanishiki and Gohyakumangoku from 2008 to 2018 were strongly and negatively correlated with the mean data of sake cake ratios for junmai ginjo and ginjo of the corresponding year, suggesting that the Brix value would be available for the estimation and improvement of premium sake brewing practices. Taken altogether, by analyzing the annual variation, we discovered that the brewing properties of sake rice can be considerably altered by meteorological conditions, and that the effects of meteorological conditions upon brewing properties vary depending on the type of rice variety in question.

Source

J. Brew. Soc. Japan, 116 (6), 442-454 (2021)

7.Principal Component Analysis of Hop-Derived Odorants Identified by Stir Bar Sorptive Extraction Method

Author

Toru Kishimoto, Satoko Teramoto, Akiko Fujita, Osamu Yamada

Abstract

Beers hopped with 79 varieties were brewed in small-scale fermenters, and 127 hop-derived compounds were picked up by comparing with the chromatogram of unhopped beer, after the analysis of the Stir Bar Sorptive Extraction gas chromatography-mass spectrometry method. “Hop creep effect” could be seen, that is, larger amounts of hop pellets in the wort resulted in lower concentrations of the apparent extracts of the beers. The 127 hop-related flavor compounds were used to examine the interrelationship with the hop varieties by principal component analysis (PCA). Different varieties and amounts of hop pellets based on equal amounts of alpha-acids were added to the cooled wort. Addition of higher amounts of hops resulted in lower concentrations of apparent extracts of beer, suggesting the presence of dextrin-hydrolyzing enzymes in the hops. PCA largely established five directions. Direction I including Cascade, Amarillo, Citra, Simcoe, Mosaic, Wai-iti, and Hallertau Blanc varieties was linked to geraniol and citronellol, both known to contribute to citrus characteristics. Direction II including Bobek, Styrian Gold, and Moutueka varieties was associated with linalool and 6-methyl-5-hepten-2-one. Direction III including Hersbrucker and Saphir was linked to sesquiterpene alcohols. Direction IV was associated with hydrophobic monoterpenes, and direction V was linked to hydrophobic sesquiterpenes. Further study of these hop varieties and constituents can help advance our knowledge in using different hop varieties to achieve defined aroma and taste of beer.

Source

Journal of the American Society of Brewing Chemists, 79, 272-280 (2021)

8.Genome editing to generate sake yeast strains with octuple mutations that confer excellent brewing characteristics

Author

Tomoya Chadani, Shunsuke Ohnuki, Atsuko Isogai, Tetsuya Goshima, Mao Kashima, Farzan Ghanegolmohammadi, Tomoyuki Nishi, Dai Hirata, Daisuke Watanabe, Katsuhiko Kitamoto, Takeshi Akao, Yoshikazu Ohya

Abstract

Sake yeast is mostly diploid, so the introduction of recessive mutations to improve brewing characteristics requires considerable effort. To construct sake yeast with multiple excellent brewing characteristics, we used an evidence-based approach that exploits genome editing technology. Our breeding targeted the AWA1, CAR1, MDE1, and FAS2 genes. We introduced eight mutations into standard sake yeast to construct a non-foam-forming strain that makes sake without producing carcinogens or an unpleasant odor, while producing a sweet ginjo aroma. Small-scale fermentation tests showed that the desired sake could be brewed with our genome-edited strains. The existence of a few unexpected genetic perturbations introduced during breeding proved that genome editing technology is extremely effective for the serial breeding of sake yeast.

Source

Cells, 10 (6), 1299 (2021)

9.Draft Genome Sequence of Saccharomyces cerevisiae Strain Awamori Number 101, Commonly Used to Make Awamori, a Traditional Spirit, in Okinawa, Japan

Author

Masatoshi Tsukahara, Kotaro Ise, Maiko Nezuo, Haruna Azuma, Takeshi Akao, Hirohide Toyama

Abstract

We report here the draft genome sequence for Saccharomyces cerevisiae strain Awamori number 101, an industrial strain used for producing awamori, a distilled alcohol beverage. It was constructed by assembling the short reads obtained by next-generation sequencing. The 315 contigs constitute an 11.5-Mbp genome sequence coding 6,185 predicted proteins.

Source

Microbiology Resource Announcements, 10 (25) , e01414-20 (2021)

10.VvMYBAs induce expression of a series of anthocyanin biosynthetic pathway genes in red grapes (Vitis vinifera L.)

Author

Puspa Raj Poudel, Akifumi Azuma, Shozo Kobayashi, Kazuya Koyama and Nami Goto-Yamamoto

Abstract

The role of MYBA transcription factors in anthocyanin biosynthesis has been established in many plants including grapevine (Vitis vinifera L.); however, not all of the target genes of MYBAs in grapevine have been elucidated. The aim of this study was therefore to identify targets of VvMYBAs by using berry skin from a red grape (Pinot Noir) and its white mutant (Pinot Blanc), and from white grapes (Italia and Muscat of Alexandria) and their red mutants (Benitaka and Flame Muscat). First, microarray and reverse-transcription real-time PCR data revealed that, in addition to the anthocyanin specific biosynthetic genes, i.e. UDP-glucose flavonoid:3-O-glucosyltransferase (UFGT) and O-methyltransferase (OMT), a gene involved in anthocyanin transfer into vacuoles, i.e. glutathione S-transferase (GST), as well as flavonoid-3’,5’-hydroxylase (F3’,5’H) were highly upregulated in red grapes. From collective findings, it is likely that these genes are probably induced only by VvMYBAs. By contrast, genes involved in upstream flavonoid biosynthesis, such as phenylalanine ammonia-lyase (PAL), chalcone synthase 3 (CHS3), flavanone-3-hydroxylase (F3H), dihydroflavonol 4-reductase (DFR), and leucoanthocyanidin dioxygenase (LDOX), were expressed in white grapes and moderately upregulated in red grapes. These genes seem to be induced by both VvMYBAs and other transcription factors. The electrophoretic mobility shift assays results revealed that VvMYBA1 and/or VvMYBA2 proteins interact with the promoter region of UFGT, CHS3, and LDOX. Collectively, our findings suggest that VvMYBAs regulate the expression of all genes involved in anthocyanin biosynthesis, and that VvMYBA protein directly interacts with not only UFGT, but also CHS3 and LDOX.

Source

Scientia Horticulturae, 283, 110121 (2021)

11.1H-NMR metabolomics-based classification of Japanese sake and comparative metabolome analysis by gas chromatography–mass spectrometry

Author

Yuji Hayashi, Takanori Komatsu, Kazuhiro Iwashita, Eiichiro Fukusaki

Abstract

Six categories of Japanese sake have been established by the National Tax Agency of Japan. In this system, the rice polishing ratio and the addition of alcohol are the main criteria for classification. The most common nuclear magnetic resonance (NMR) spectrometry method is 1H-NMR, and has higher throughput than gas chromatography–mass spectrometry (GC–MS) or liquid chromatography–mass spectrometry (LC–MS) analysis due to its short measurement time, easy sample preparation, and high reproducibility. However, owing to the production of dominant ethanol signals, metabolome analyses have not been used for classifying Japanese sake using 1H-NMR. In this study, a technique to selectively suppress ethanol signals was used to classify Japanese sake by 1H-NMR, and a model was constructed to predict the rice polishing ratio. The results were compared to those obtained by GC–MS. The suppression of ethanol signals enabled the detection of trace components by 1H-NMR. In a principal component analysis (PCA) score plot of 1H-NMR spectra with ethanol signal suppression, PC1 was associated with both the addition of alcohol and the rice polishing ratio. Additionally, the separation of samples observed was similar when PCA score plots of 1H-NMR and GC–MS data were compared. Similarly, to predict the rice polishing ratio using partial least squares regression analysis, a model was constructed using 1H-NMR data, and showed nearly similar values for precision and predictive performance with the model constructed using GC–MS data. These results suggest that metabolomic analyses of Japanese sake based on 1H-NMR spectral patterns may be useful for classification.

Source

Journal of Bioscience and Bioengineering, 131(5), 557-564(2021)

12.Construction of transcription factor gene deletion library of Aspergillus luchuensis

Author

Osamu Yamada, Naoko Nishibori, Risa Hayashi, Toshihide Arima, and Osamu Mizutani

Abstract

We selected 96 genes of Aspergillus luchuensis for the construction of a transcription factor gene deletion library. Of these, we successfully deleted 93 genes using Agrobacterium-mediated transformation (AMT) of A. luchuensis RIB 2604 ΔligD strains. We obtained only heterokaryonic strains after deletions of adaB, anBH1, hacA, hapB, hsf1, metR, and sonC gene, and additionally, could not obtain deletion strains for genes abaA and mcmA. The deletion strains will be available through our website (https://www.nrib.go.jp).

Source

The Journal of General and Applied Microbiology, 67, 118-123 (2021)

13.Cutinase-like biodegradable plastic-degrading enzymes from phylloplane yeasts have cutinase activity

Author

Hirokazu Ueda, Jun Tabata, Yasuyo Seshime, Kazuo Masaki, Yuka Sameshima-Yamashita, and Hiroko Kitamoto

Abstract

Phylloplane yeast genera Pseudozyma and Cryptococcus secrete biodegradable plastic (BP)-degrading enzymes, termed cutinase-like enzymes (CLEs). Although CLEs contain highly conserved catalytic sites, the whole protein exhibits ≤ 30% amino acid sequence homology with cutinase. In this study, we analyzed whether CLEs exhibit cutinase activity. Seventeen Cryptococcus magnus strains, which degrade BP at 15 C, were isolated from leaves and identified the DNA sequence of the CLE in one of the strains. Cutin was prepared from tomato leaves and treated with CLEs from 3 Cryptococcus species (C. magnus, Cryptococcus flavus, and Cryptococcus laurentii) and Pseudozyma antarctia (PaE). A typical cutin monomer, 10,16-dihydroxyhexadecanoic acid, was detected in extracts of the reaction solution via gas chromatography–mass spectrometry, showing that cutin was indeed degraded by CLEs. In addition to the aforementioned monomer, separation analysis via thin-layer chromatography detected high-molecular-weight products resulting from the breakdown of cutin by PaE, indicating that PaE acts as an endo-type enzyme.

Source

Bioscience, Biotechnology, and Biochemistry, 85, 1890-1898 (2021)

14.Changes in sake making properties of sake rice during storage

Author

Masaki Okuda, Kei Takahashi, Bao Hong-Bin, Hiromi Kohno, Midori Joyo, Nobuhiko Mukai, Yasuhiro Tsuchida, Eizo Yoshinaka, Akihiko Takami, Yuji Kiriyama, and Yoshihiko Murai

Abstract

The changes in sake making properties of sake rice were investigated during storage of brown rice grains under 4～30℃ for 24 months in two kinds of moisture contents. Significant changes in sake making properties of sake rice- -except for a small increase of potassium concentrations- -have not been observed when the brown rice grains have been stored under 10℃ at the rice warehouse in Hyogo Prefecture and under 4℃ and 10℃ at NRIB for 24 months. On the other hand, the broken rice ratio of a milling test, potassium concentrations of polished rice, and viscosity at RVA have increased during storage of brown rice under 30℃ at NRIB for 6 months. Although the hexanal concentrations in brown rice have increased during storage even under 4～10℃, those in polished rice have not been detected during storage under 4～10℃ for 24 months. The present study suggested that the sake making properties of sake rice would not deteriorate either by both storing rice grains under 10℃ or maintaining the moisture content of rice grains without changes in moisture.

Source

J. Brew. Soc. Japan, 116(7), 521-534 (2021)

15.Influence of moisture contents of steamed rice grains on starch retrogradation and enzyme digestibility during storage

Author

Takeki Tanaka, Masaki Okuda, Kei Takahashi, and Nobuhiko Mukai

Abstract

In the production of sake, the enzyme digestibility of the steamed rice grains is a critical factor to realize a good quality of sake and to utilize rice grains efficiently. The retrogradation of rice starch in the steamed rice grains proceeds during sake making, and the enzyme digestibility of the steamed rice grains decreases significantly. However, the influencing factors of the retrogradation of starch in the steamed rice grains have not been elucidated clearly. In the present study, the relationships between the moisture content in steamed rice grains, the retrogradation of rice starch, and the enzyme digestibility were examined to clarify the influencing factors of the retrogradation of the starch. Steamed rice grains with a high moisture content showed a faster retrogradation of starch and lower enzyme digestibility than those with a low moisture content after storage in a plastic bag. Moreover, when the moisture content in the steamed rice grains decreased during storing under lower humidity conditions, the rate of the retrogradation and the decrease of the enzyme digestibility were slight. The present results indicated that the moisture contents of the steamed rice grains have a significant influence on rice starch retrogradation and enzyme digestibility after storing in conditions such as the cooling process of steamed rice grains in Daiginjyo sake production.

Source

J. Brew. Soc. Japan, 116(8), 593-605 (2021)

16.Effects of fermentation nutrients for wine on sake brewing (Part1)
-Effect of addition on sake quality-

Author

Sachiko Iizuka, Ryoko Kanda, Satoko Teramoto, Akiko Fujita, and Osamu Yamada

Abstract

Fermentation nutrients are widely used in winemaking for the manufacturing soundness, and their use is permitted as an article which is not treated as raw materials of alcoholic beverages by the Liquor Tax Law and Liquor Administrative Law or regulation interpretation notifications in Japan. However, there are few data in the literature for their use in sake brewing. In this study, we have investigated the effects of the use of fermentation nutrients for wine (Stimula Sauvignon Blanc and Optimum White) on sake brewing and considered the possibility of the development of products with new characteristics. It was shown that the addition of Stimula Sauvignon Blanc promoted fermentation and improved the utility efficiency of raw materials in a one-step preparation for fermentation mash. The contents of isoamyl acetate and ethyl caproate of the samples with the addition of Stimula Sauvignon Blanc were higher than that of the control (no addition). In the results of the sensory evaluation of brewed sake from the one-step and three-step preparation for fermentation mash, the scores of the brewed sake with the addition of the fermentation nutrients were the same level as the control (no addition). The characteristic comments such as “lychee”, ‘fruity”, “muscat” and “citrus” in those samples show a possibility in which the use of the fermentation nutrients on sake brewing provides a potent tool for the development of products with new characteristics.

Source

J. Brew. Soc. Japan, 116(9), 641-653 (2021)

17.Phenolic compounds and phenolic flavor in sake

Author

Nobuhiko Mukai, Jinshun Han, and Nahoko Nishibori

Abstract

The authors　conducted a sensory evaluation and measured the phenolic compounds of 35 samples of sake. The maximum contents of phenolic compounds were as follows: p-coumaric acid: 0.4 mg/l; ferulic acid: 5.4 mg/l; 4-vinylphenol: 204.1 μg/l; 4-vinylguaiacol: 282.7 μg/l and guaiacol: 58.0 μg/l.　The contents of 4-ethylphenol and 4-ethylguaiacol were very low. As a result of a multiple regression analysis, the intensity of phenolic flavor was almost able to be explained by 4-vinyilguaiacol and guaiacol. Using activated carbons, most of the p-coumaric acid, ferulic acid, 4-vinylphenol, and 4-vinylguaiacol in sake was removed, but guaiacol could only be removed up to 35%.

Source

J. Brew. Soc. Japan, 116(9), 662-669 (2021)

18.Analysis of sake components presented to the Japan sake awards 2020

Author

Toru Kishimoto, Akiko Fujita, Sachiko Iizuka, Ryoko Kanda, Satoko Teramoto, Osamu Yamada, and Nami Goto-Yamamoto

Source

Report of the Research Institute of Brewing, 193, 1-16 (2021)

19.Review of the 43rd Honkaku Shochu and Awamori Contest in 2020

Author

Nobuhiko Mukai, Atsuko Isogai, Masaki Okuda, Kazuo Masaki, Kei Takahashi, Yukio Osafune, Takayuki Emura, Hisashi Yazawa, and Nami Goto-Yamamoto

Source

Report of the Research Institute of Brewing, 193, 17-32 (2021)

20.Analysis of beer components presented to craft beer contest of Japan brewers association in 2021

Author

Shinichi Ito, Hisashi Yazawa, Kaori Isobe, Satoko Teramoto and Takayuki Emura

Source

Report of the Research Institute of Brewing, 193, 33-39 (2021)

21.Evaluation of Aspergillus oryzae specie for the production of candidate mycotoxins listed by the Ministry of Agriculture, Forestry and Fisheries, Japan

Author

Sharon Marie Bahena-Garrido, Yuko Komatsu, Ryota Saito and Kazuhiro Iwashita

Abstract

In this report, we investigated the production of 6 candidate mycotoxins in A. oryzae species based on the MAFF list of risk assessment. We evaluated the possible production of these mycotoxins using a tandem approach as reported in the previous paper. Based on the DI-HRMS data and further validation by LC-Q/TOF-MS, our results indicate no significant traces of these candidate mycotoxins. Thus, we conclude that these 6 mycotoxins were not detected in A. oryzae species grown in all 11 culture conditions.

Source

Report of the Research Institute of Brewing, 193, 40-47 (2021)

22.Evaluation of components contributing to the International Bitterness Unit of wort and beer

Author

Toru Kishimoto, Satoko Teramoto,　Akiko Fujita, and Osamu Yamada

Abstract

This study evaluated the components that contribute to the International Bitterness Unit (IBU) of wort and beer. A range of samples were analyzed in this study, including beer with 47.5 IBU containing 39.9 ppm iso-α-acid, and one with 49.9 IBU containing only 2.2 ppm iso-alpha acid. The IBU value of wort and beer is mainly contributed by iso-α-acid, non-isomerized α-acid, oxidative polar compounds, and malt-derived polar components. The isomerization of α-acid to iso-α-acid is initiated between 60 °C and 70 °C and the isomerization ratios accelerate rapidly at higher temperature. In the wort boiled below 60 °C, over 50% of the IBU value was contributed by non-isomerized α-acid. Most of the non-isomerized α-acid disappeared during fermentation, whereas the concentration of iso-α-acid was stable. The disappearance of α-acid resulted in a large decrease in the IBU value during fermentation, and the isomerization ratio influenced the degree of the decrease. Over 80% of the IBU value was contributed by the oxidative polar compounds in the beer hopped with the pellet stored at 40 °C for 90 days. Bitterness intensity was less in the beers with deteriorated hops than in those with non-deteriorated hops, despite both having the same IBU values.

Source

Journal of the American Society of Brewing Chemists, 80, 53-61(2022)

23.Relationship between flavor compounds in sake exhibited at the Annual Japan Sake Awards and meteorological conditions during grain filling and the properties of rice starch

Author

Masaki Okuda, Midori Joyo, Bao Hong-Bin, Kei Takahashi, Atsuko Isogai, Nobuhiko Mukai,Toru Kishimoto, Ryoko Kanda, Sachiko Iizuka, Hanae Izu, Akiko Fujita, and Osamu Yamada

Abstract

In the present study, the relationship between the flavor compounds in sake exhibited at the Annual Japan Sake Awards and the meteorological conditions during grain filling and the properties of rice starch during the 2009-2018 brewing years were investigated. The mean concentration of ethyl caproate in sake exhibited at the Annual Japan Sake Awards showed significant correlations with the maximum Baume, the ratio of sake cake, the gelatinization temperature, the enzyme digestibility of steamed rice grains, and the temperature during one month at grain filling of the Yamadanishiki rice cultivar harvested at Hyogo, but that of isoamlylacetate, isoamylalcohol, and ethylacetate did not. Therefore, when the temperature during grain filling of Yamadanishiki was lower and the enzyme digestibility of steamed rice grain was higher, the mean concentration of ethyl caproate in sake exhibited at the Annual Japan Sake Awards was higher. The present study indicated the possibilities that the meteorological conditions during rice grain filling cause the change in digestibility of sake rice and have considerable influence on the ethyl caproate concentrations in daiginjyo-sake.

Source

J. Brew. Soc. Japan, 116(12), 839-852(2021)

24.Quantitative stability of the folates highly accumulated in a non-Kyokai sake yeast

Author

Yusuke Shibata, Toshinari Takahashi, Tomoko Morimoto, Muneyoshi Kanai, Tsutomu Fujii, Takeshi Akao, Tetsuya Goshima, and Tasuku Yamada

Abstract

Pressed sake cake, a by-product of sake brewing, is a rich dietary source of folates, which are important vitamins for humans. However, considerable losses of folates occur during storage and cooking. We have previously reported that Km67, the house sake yeast strain of Kiku-masamune sake brewery, can accumulate high folate levels. In this study, we found that the folate content of pressed sake cakes produced with Km67 remained at approximately their maximum level after the fermentation activity stopped. To elucidate the mechanisms of high folate accumulation in Km67, we analyzed the expression of 23 folate-metabolizing genes. The expression of ABZ1 and FOL3 was almost always higher in Km67 than in Kyokai no. 701 yeast (K701), which suggested that enhanced expression of the genes involved in folate biosynthesis was a mechanism of high folate accumulation in Km67. We found that the folates of Km67 pressed sake cakes were quantitatively stable at 4°C under refrigerated storage conditions. In addition, the homocysteine content of Km67 pressed sake cakes was almost always higher than that of K701 pressed sake cakes. This result suggests that a reason for high folate accumulation in Km67 yeast is the need to reduce the intracellular concentration of homocysteine. Our results provide biologically meaningful information on folate metabolism in yeast.

Source

Journal of General and Applied Microbiology, 67 (5), 214-219 (2021)

25.Influence of moisture contents of steamed rice grains on starch retrogradation and enzyme digestibility during storage

Author

Shun Mitsui, Koji Yamamoto, Akitoshi Ito Akane Ieda, Tetsuya Kondo, Nobuyuki Sugiyama, Takeshi Akao, Akihiro Yoshimura, Yasuaki Sakakibara, Hideya Funai, Naoyuki Haramoto, Motoyuki Shimizu, and Masashi Kato

Abstract

Synchrotron light with a wide wavelength range has features such as high brightness and high directivity. We examined the possibility of using synchrotron light in a mutation method. Specifically, by synchrotron light irradiation, we attempted to breed non-urea producing sake yeast which makes it possible to reduce ethyl carbamate (ECA) in sake. After synchrotron light irradiation using FIA2 (Aichi sake yeast) as a parent strain, we selected candidate strains of arginase-deficient mutants using the CAO medium (containing canavanine, arginine (Arg) and ornithine (Orn)), the Arg medium, and the Orn medium. We performed a similar selection process for ethyl methane sulfonate (EMS) treatment. We selected non-urea producing sake yeast from these selected strains through a 100 g scale fermentation test. Among the selected non-urea producing sake yeasts, FIA2Arg was selected as a practical yeast because of having the same alcohol and acid producing ability as the parent strain FIA2. FIA2Arg was acquired by synchrotron light irradiation, results showing that synchrotron light was available in the mutation method. We sequenced the CAR1 locus (encoding the arginase) to about 16 (11 acquired mutant strains by synchrotron light irradiation. and 5 acquired mutant strains by EMS treatment) of 21 acquired non- urea producing sake yeasts. Base substitution from G/C to A/T occurred in 5 of 9 acquired mutant strains with base substitution by synchrotron light irradiation. It was found that mutations by synchrotron light irradiation were less biased in base substitution from G/C to A/T as compared with EMS treatment. Deletion also occurred to some extent (in 4 of 11 acquired mutant strains by synchrotron light irradiation). As a result of a pilot scale (100 kg) sake brewing test, it was confirmed that FIA2Arg did not pro- duce urea and had brewing characteristics equivalent to FIA2.

Source

J. Brew. Soc. Japan, 116 (10)，703-712 (2021)

26.Relationships between enzyme digestibility of brewer’s rice and air temperature during ripening period in brewer’s rice cultivars in Hyogo prefecture

Author

Masaru Ikegami, Yukihiro Isono, Hiroyuki Fujimoto, Masanobu Kato, Takuma Sugimoto,　Kei Takahashi, and Masaki Okuda

Source

日本作物学会紀事, 90(4), 451―456（2021）

27.Growth characteristics of Aspergillus oryzae in the presence of 2,4,6-trichlorophenol

Author

Michiko Endo, Chika Matsui, Naomi Maeta, Yurina Uehara, Ryoya Matsuda, Yuzo Fujii, Akiko Fujita, Tsutomu Fujii, and Osamu Yamada

Abstract

During the making of rice-koji for sake production, 2,4,6-trichlorophenol (TCP) is O-methylated to 2,4,6-trichloroanisole (TCA) by the koji-mold, Aspergillus oryzae, resulting in a musty/moldy off-odor, which significantly reduces the quality of sake. Thus, we aim to develop A. oryzae strains with a less-efficient ability to produce TCA. TCP is a fungicide that suppresses the growth of fungi, whereas TCA does not. The exact effects of TCP on the growth of A. oryzae are unknown. However, it is assumed that a strain with low TCP conversion ability will be sensitive to TCP concentration. In this study, we investigated the effects of the different concentrations of TCP on the growth suppression of A. oryzae. As the TCP concentration in the media increased, the growth rate, and conidia formation of A. oryzae slowed down. No growth was observed in liquid culture (for 1 day at 30℃) containing more than 30 µg/mL of TCP and in agar culture (for 7 days at 30℃) containing more than 50 µg/mL of TCP. However, A. oryzae was able to grow on alpha rice containing higher concentrations of TCP. The results in agar culture are consistent with the effects of TCP on other Aspergillus species.

Source

Journal of General and Applied Microbiology, 67, 256-259(2021)

28.Expression profiles of amylolytic genes in AmyR and CreA transcription factor deletion mutants of the black koji mold Aspergillus luchuensis

Author

Wataru Hashimoto, Hiraku Arai, Osamu Mizutani, Osamu Yamada, Takahiro Shintani, and Katsuya Gomi

Abstract

The black koji mold, Aspergillus luchuensis, which belongs to Aspergillus section Nigri, is used for the production of traditional Japanese spirits (shochu) mainly in the southern districts of Japan. This mold is known to produce amylolytic enzymes essential for shochu production; however, mechanisms regulating amylolytic gene expression in A. luchuensis have not been studied in as much detail as those in the yellow koji mold, Aspergillus oryzae. Here, we examined the gene expression profiles of deletion mutants of transcription factors orthologous to A. oryzae AmyR and CreA in A. luchuensis. A. luchuensis produces acid-unstable (AmyA) and acid-stable (AsaA) α-amylases. AmyA production and amyA gene expression were not influenced by amyR or creA deletion, indicating that amyA was constitutively expressed. In contrast, asaA gene expression was significantly down- and upregulated upon deletion of amyR and creA, respectively. Furthermore, the glaA and agdA genes (encoding glucoamylase and α-glucosidase, respectively) showed expression profiles similar to those of asaA. Thus, genes that play pivotal roles in starch saccharification, asaA, glaA, and agdA, were found to be regulated by AmyR and CreA. Moreover, despite previous reports on AsaA being only produced in solid-state culture, deletion of the ortholog of A. oryzae flbC, which is involved in the expression of the solid-state culture-specific genes, did not affect AsaA α-amylase activity, suggesting that FlbC was not associated with asaA expression.

Source

Journal of Bioscience and Bioengineering, 132(4), 321-326(2021)

29.Prediction method for determining the carbon stable isotopic composition of berry sugars in the original must of Chardonnay wines

Author

Fumikazu Akamatsu, Hideaki Shimizu, Yukari Igi, Aya Kamada, Kazuya Koyama, Osamu Yamada, and Nami Goto-Yamamoto

Abstract

The carbon stable isotopic composition, as indicated by the δ¹³C value, of wine ethanol is inherited from berry sugars, but little is known about the variation in sugar δ¹³C values of Japanese grapes relative to overseas grapes. This study found a large variation in sugar δ¹³C values of Chardonnay grapes grown in Japan (−27.2 ± 0.9‰, mean ± standard deviation, n = 33), with sugar δ¹³C values depending on the δ¹³C values and content of monosaccharides. After complete fermentation, the carbon isotope discrimination between berry sugars and wine ethanol was 1.5 ± 0.1‰. Ethanol δ¹³C values and carbon isotope discrimination enabled prediction of sugar δ¹³C values in the original must. Imported wines had higher sugar δ¹³C values than those of wines made from Japanese grapes, suggesting drier overseas viticulture conditions. The determination of sugar δ¹³C values in grape berries provides valuable information for viticulture and wine authentication.

Source

Food Chemistry, 369, 130854(2022)

30.Chemometric approaches for determining the geographical origin of Japanese Chardonnay wines using oxygen stable isotope and multi-element analyses

Author

Fumikazu Akamatsu, Hideaki Shimizu, Sakura Hayashi, Aya Kamada, Yukari Igi, Kazuya Koyama, Osamu Yamada, and Nami Goto-Yamamoto

Abstract

Determining the geographical origin of wines is a major challenge in wine authentication, but little information is available regarding non-parametric statistical approaches for wines. In this study, we collected 33 domestic Chardonnay wines vinified on a small scale from grapes cultivated in Japan, and 42 Chardonnay wines imported from 8 countries, for oxygen stable isotope and multi-element analyses. Non-metric multidimensional scaling (NMDS), kernel principal component analysis (KPCA) and principal component analysis (PCA) were applied to the oxygen stable isotopic compositions (δ¹⁸O) and the concentrations of 18 elements in the wines to compare the extractions by parametric and non-parametric methods. The non-parametric methods, NMDS and KPCA, separated domestic from imported Chardonnay wines better than the parametric method, PCA. Of 19 variables, 18 were important for geographical discrimination, with the δ¹⁸O value being the most significant in all statistic methods. Non-parametric multivariate analyses will help discriminate domestic from imported Chardonnay wines.

Source

Food Chemistry, 371, 131113(2022)

31.Distillation behavior of aroma compounds during spirits distillation and product properties of a triple distillation of Awamori

Author

Yukio Osafune, Kenji Toshida, Jinshun Han, Atsuko Isogai, Munehiro Miyamoto, Johji Aizawa, and Nobuhiko Mukai

Abstract

Triple distillated Awamori "sho" was developed by a new production method for Japanese hard liquor which has a sweet flavor, cleanliness, and smoothness. It was commercialized by 12 Awamori manufacturers in Okinawa. To determine the unique characteristic of the spirits, multi distillations using small pot stills were performed and the distillation behavior of various aroma compounds were analyzed. As a result, the distillation behavior was mainly classified to five groups. Moreover, the concentrations of the aroma compounds increased and decreased respectively through both the second and the third distillations. In addition, the commercially available three times distillated Awamori was analyzed and compared with normal Awamori (Ippanshu). There was a significant difference in some volatile compounds, and they showed the same tendency as with the small pot still study. It is suggested that these compounds, which were changed through the multi distillation, contribute to the characteristics of the triple distillated Awamori.

Source

J. Brew. Soc. Japan, 117(2), 111-130(2022)

32.Analyses of sake stored for 10 years in the “100 Year Sake Storage Project”

Author

Atsuko Isogai, Hanae Izu, Ryoko Kanda, Yuriko Ikeda, Yukari Igi, and Tsutomu Fujii

Abstract

We carried out analyses of sake stored for 10 years presented for the “100 Year Sake Storage Project”. Comparing the sake before and after storage, absorbance at 280nm and 430nm, b* of CIE color value, and the concentration of 3-deoxyglucosone significantly increased. Acidity and the concentrations of most amino acids tended to decrease, although increases in amino acids were observed in some samples. As for flavor components, major aroma components such as ethyl acetate, isoamyl acetate, and ethyl caproate decreased, while carbonyl compounds, ethyl esters of branched chain fatty acids and organic acids, polysulfides and harman tended to increase, although some aldehydes decreased in some samples. Ethyl lactate and ethyl phenylacetate were shown to exist at concentrations exceeding their sensory threshold, in addition to sotolon, isovaleraldehyde, methional, benzaldehyde, dimethyl trisulfide, dimethyl disulfide and harman, which were previously reported to contribute to the aged sake flavor. Principal component analysis indicated that the more amino acids and organic acids the sake contains, the larger the changes were in the components mentioned above. A high correlation between the increment of ethyl carbamate (EC) during storage and urea concentration before storage suggested that urea is the dominant factor of EC formation in sake.

Source

J. Brew. Soc. Japan, 117(3), 181-194(2022)

33.Effect of high temperature and short maceration on red wine making

Author

Hideaki Shimizu，Minori Kono, Kazuya Koyama, Kazuhiro Iwashita, and Nami Goto-Yamamoto

Abstract

The effects of high temperature and short maceration (HT&S) of vinification processes were examined in eight wineries and the National Research Institute of Brewing by analyzing the chemical and/or sensory characteristics of produced wines. In the 2017 laboratory-scale vinification of Muscat Bailey A (MBA), HT&S wines had higher color intensity than control wines. In 2018, the effect of HT&S varied according to grape variety: HT&S increased the color intensity of MBA and Merlot wines, but not wines made from three other varieties. As regards pilot- and plant-scale vinification, HT&S tended to increase wine color intensity when the maceration temperature was controlled appropriately, and some HT&S wines received favorable evaluation with regard to astringency or body in the sensory analysis compared with control wines. However, the HT&S technique requires further improvement of the following two items prior to practical application in wineries. The first item is the pressing time, which is dependent on the degree of extraction of the anthocyanin and proanthocyanidin from skin and seed, the grape variety, and the temperature changes during maceration. The second item is temperature control between 28 and 30 ℃ in the early stage of fermentation, which is difficult to achieve when the fermentation scale is large.

Source

Journal of ASEV Japan, 32, 111-125(2021)

34.Chromosome-level genome sequence data and analysis of the white koji fungus, Aspergillus luchuensis mut. kawachii IFO 4308

Author

Kazuki Mori, Chihiro Kadooka, Ken Oda, Kayu Okutsu, Yumiko Yoshizaki, Kazunori Takamine, Kosuke Tashiro, Masatoshi Goto, Hisanori Tamaki, and Taiki Futagami

Abstract

Aspergillus luchuensis mut. kawachii is used primarily in the production of shochu, a traditional Japanese distilled alcoholic beverage. Here, we report the chromosome-level genome sequence of A. luchuensis mut. kawachii IFO 4308 (NBRC 4308) and a comparison of the sequence with that of A. luchuensis RIB2601. The genome of strain IFO 4308 was assembled into nine contigs consisting of eight chromosomes and one mitochondrial DNA segment. The nearly complete genome of strain IFO 4308 comprises 37,287,730 bp with a GC content of 48.85% and 12,664 predicted coding sequences and 267 tRNAs. Comparison of the IFO 4308 and RIB2601 genomes revealed a highly conserved structure; however, the IFO 4308 genome is larger than that of RIB2601, which is primarily attributed to chromosome 5. The genome sequence of IFO 4308 was deposited in DDBJ/ENA/GenBank under accession numbers AP024425–AP024433.

Source

Data in Brief, 41, 107888(2022)

35.Effects of exogenous peptidase addition on the concentration of pyroglutamyl peptides in sake and its taste characteristics

Author

Katsumi Hashizume, Junya Ohno, Toshihiko Ito, and Masaki Okuda

Abstract

Effects of exogenous peptidase addition on the concentration of pyroglutamyl (pGlu) peptides in sake and also on the taste characteristics of sake were investigated. The addition of peptidase agents involving high acid carboxypeptidase (ACP) activity to sake decreased bitter-tasting peptides and increased (pGlu)L-ethyl. The addition of a peptidase agent with high (pGlu)peptide ethyl ester forming activity but low ACP activity increased (pGlu)LF-ethyl and (pGlu)LFNP-ethyl in sake ; however, it did not increase (pGlu)L-ethyl. These effects were also observed in test of adding purified (pGlu) peptide ethyl ester forming enzyme. It was suggested that the increase of (pGlu) oligo peptide ethyl esters except (pGlu)L-ethyl yielded positive effects on the taste of sake. The addition of a peptidase agent with high (pGlu)peptide ethyl ester forming activity but low ACP activity increased (pGlu) oligo peptide ethyl esters in the digestion solution of the rice protein body (PB) by rice koji enzymes, but it did not increase (pGlu)L-ethyl. Addition of the peptidase to the sake mash caused similar effects as the addition to the PB digestion solution, but the effects were quite weak.

Source

J. Brew. Soc. Japan, 117(1), 45-54(2022)

36.Pyroglutamyl peptide ethyl ester forming activity in rice koji for sake brewing made by commercial koji starters.

Author

Katsumi Hashizume, Junya Ohno, Toshihiko Ito, and Masaki Okuda

Abstract

Two pyroglutamyl (pGlu) peptide ethyl ester forming activities in rice koji samples made by twelve commercial koji starters and Aspergillus oryzae RIB128 were analyzed. The (pGlu)LFGP-ethyl forming activity, type(A) activity, was found only in the rice koji made by so-called “high glucoamylase starter” and RIB128, while the (pGlu)LFGPNVNPW-ethyl forming activity, type(B) activity, was found in all koji samples. The type(A) activity in koji samples showed high relationship (R2 = 0.90) between glucose forming activity, while the type(B) activity did not show the high relationship.

Source

J. Brew. Soc. Japan, 117(1), 55-58(2022)

37.Analysis of sake making procedures accelerating dimethyl trisulfide formation during sake storage

Author

Kei Sasaki, Nahoko Nishibori, Satoko Yoshida, Muneyoshi Kanai, Atsuko Isogai, Osamu Yamada, Nami Goto-Yamamoto, and Tsutomu Fujii

Abstract

Dimethyl trisulfide (DMTS) is responsible for hineka, an off-flavor in sake that develops during storage. We analyzed sake samples which were donated by sake companies, and extracted and demonstrated 4 sake making factors which could possibly affect DMTS concentration in sake after 7 days of storage at 70℃ (DMTS-pp): differences in yeast strains, differences in shubo (yeast seed mash called kimoto or sokujomoto) making methods with or without of the addition of alcohol to moromi, and differences in moromi pressing methods. Small scale fermentation tests and comparisons of sake commercially made with similar conditions except for shubo revealed that the differences in yeast strains and the differences in shubo making scarcely affect DMTS-pp. On the other hand, we found that the addition of alcohol to moromi decreased DMTS-pp, probably due to a dilution effect, and that DMTS-pp decreased more than the dilution ratio. Also, the pressing process of sake mash was found to affect DMTS-pp. Seme (later fraction of sake obtained under high pressure) has a higher DMTS-pp compared with arabashiri (free run fraction) and nakadare (middle fraction). In seme, absorbance at 260 nm was higher than that of arabashiri and nakadare. These results suggest that yeast cell leakage may affect DMTS-pp in seme.

Source

J. Brew. Soc. Japan, 117(2), 101-110(2022)

38.Isolation and sake-brewing characteristics of mating mutants of strain GY115-a3 with high fermentation and ginjo-ka production abilities

Author

Mai Okumura, Kazuo Masaki, Akihiro Yoshimura, Yoshinori Sawai, Kentaro Hisamatsu, Yuto Harada, Satoshi Iwamoto, Masaya Shimada, Takashi Hayakawa, and Tomoyuki Nakagawa

Abstract

In this study, we aimed to breed strain GY115-a3 by mating with strain Ce41, which is high ethyl caproate-producing mutant strain derived from Gifu prefecture yeast, strain G. Among the obtained mating mutant strains between strain GY115-a3 and strain Ce41, the tetraploid strains showed the production characteristics for the unique organic acid composition like strain GY115-a3, and also had high fermentation and ginjo-ka production abilities, similar to those of strain Ce41. From these results, it was concluded that the expected mating mutant strains, such as a3×Ce41_1 and a3×Ce41_5, which inherited characteristic properties from the both parent strains, could be bred.

Source

Japan Association of Food Preservation Science, 48(2), 67-72(2022)