2022 Research results

1.Effects of variety and vintage on the minerals of grape juice from a single vineyard

Author

SHIMIZU Hideaki, AKAMATSU Fumikazu, KAMADA Aya, KOYAMA Kazuya, IWASHITA Kazuhiro, and GOTO-YAMAMOTO Nami

Abstract

The mineral composition of wine depends on the soil where the grapes are grown, and therefore has been used to distinguish the geographical origin of different wines. However, several factors, including grape variety and vintage, also alter the mineral content of wine. Here, we measured the concentration of 18 elements in 9–10 grape varieties grown in a single vineyard under the same conditions (soil, weather, pruning, and fertilizer) for three years to explore the variation in mineral composition within a vineyard. In principal component analysis, grape varieties were differentiated by the first principal component (PC1), which was mainly contributed by four elements (Ca, Sr, Ga, and Ba; loading score >0.7), while vintages were differentiated by PC2 and PC3, which were mainly contributed by three (Mg, P, and S) and one (Mn) elements, respectively (loading scores >0.7). Both grape variety and vintage affected grape mineral concentration; however, the extent of variation among grapes from our single vineyard was relatively small in comparison to variations previously reported among grapes from different vineyards.

Source

Journal of Food Composition and Analysis, 107, 104377 (2022)

2.Different carbon stable isotopic compositions of CO₂ in sparkling sake using natural and exogenous carbonation methods

Author

AKAMATSU Fumikazu, FUJII Tsutomu, IGI Yukari, FUJITA Akiko, YAMADA Osamu, and ISOGAI Atsuko

Abstract

Sparkling sake has recently become a popular alcoholic beverage and is manufactured using one of two types of carbonation method. In this study, we determined the carbon stable isotopic composition (expressed as δ¹³C) of CO₂ bubbles derived from rice (natural carbonation) or petroleum (exogenous carbonation) in sparkling sake to address authenticity. Our results showed that the CO₂ δ¹³C values (−25.8 ± 0.5‰) in sparkling sake manufactured using natural carbonation increased by 0.4 ± 1.2‰ relative to glucose δ¹³C values (−26.2 ± 1.0‰), while the ethanol δ¹³C values (−28.2 ± 0.3‰) decreased by 2.0 ± 1.0‰ relative to glucose δ¹³C values. The CO₂ δ¹³C values of sparkling sake manufactured using natural carbonation were significantly higher than those manufactured using exogenous carbonation (−31.3 ± 3.4‰). However, there were no significant differences in the δ¹³C values of glucose and ethanol in sparkling sake manufactured using either natural or exogenous carbonation methods. Carbon stable isotope analysis of CO₂ bubbles in sparkling sake will help determine the carbon source of CO₂ and contribute to the authenticity of sparkling sake.

Source

Journal of Food Composition and Analysis, 109, 104474 (2022)

3.Identification of 2-furanmethanethiol contributing to roast aroma in honkaku shochu and awamori

Author

OSAFUNE Yukio, TOSHIDA Kenji, HAN Jinshun, KISHIMOTO Toru, IIZUKA-FURUKAWA Sachiko, ISOGAI Atsuko, and MUKAI Nobuhiko

Abstract

Honkaku shochu and awamori are traditional Japanese spirits. 2-Furanmethanethiol (2FM), a volatile thiol, was identified as a roast aroma compound in honkaku shochu and awamori. The detection threshold of 2FM in 25% (v/v) ethanol water solutions was determined as 1.6 ng/L. The odor activity values, calculated using the detection threshold suggested that 2FM affects the quality of honkaku shochu and awamori. The odor activity values of 2FM were higher in barley shochu distilled at atmospheric pressure than in sweet potato shochu, rice shochu and awamori; therefore, 2FM is considered to contribute to the characteristics of barley shochu.

Source

Journal of Bioscience and Bioengineering, 133(6), 555-559 (2022)

4.Isolation of Aspergillus oryzae mutants producing low levels of 2,4,6-trichloroanisole

Author

ENDO Michiko, ITO Ren, ISE Ayaka, UETA Shinya, YAMAMURA Mei, UEHARA Yurina, FUJII Yuzo, KANDA Ryoko, FUJITA Akiko, ISOGAI Atsuko, FUJII Tsutomu, and YAMADA Osamu

Abstract

Musty or moldy off-odor in sake severely reduces its quality. Such off-odor is caused by 2,4,6-trichloroanisole (TCA), a compound that is produced by Aspergillus oryzae during sake production by O-methylating the precursor 2,4,6-trichlorophenol (TCP). TCP suppresses the growth of fungi, including A. oryzae, although TCA does not. Therefore, strains that are unable to convert TCP to TCA should be sensitive to TCP in the medium. Nevertheless, A. oryzae with a disrupted O-methyltransferase gene (ΔomtT) grew in a medium containing TCP. In agar medium, we observed no growth difference between the ΔomtT strain and a non-disrupted transformant; however, a significant growth delay was observed with the ΔomtT strain grown in liquid medium containing 0.5 µg/mL of TCP. This strain was more sensitive to low concentrations of TCP, suggesting that omtT contributes to the conversion (detoxification) of TCP in liquid culture. We generated A. oryzae RIB 40 mutants by ultraviolet irradiation and then cultured them in liquid medium containing TCP to obtain strains that did not produce moldy odor. The slow-growing strains were cultured in agar plates and then used to make koji with added TCP. We obtained three strains with lower TCA-producing ability and with sufficient hydrolase activities for sake brewing.

Source

Journal of General and Applied Microbiology, 68, 24-29 (2022)

5.Phylogenetic analysis of Aspergillus luchuensis strains based on whole genome analysis

Author

TSUKAHARA Masatoshi, AZUMA Haruna, MIZUTANI Osamu, YAMADA Osamu, and TOYAMA Hirohide

Abstract

Artificial selection of microorganisms in the fermentation industry may promote differentiation into domestication. Black‑koji mold utilized for awamori brewing appears to be optimized for alcohol fermentation and safe manufacturing with a high enzymic activity，citric acid production，and null toxin productivity. Recently，the diverse strains of black‑koji mold were proved to be identical in several genetic codings and were defined as a novel species, Aspergillus luchuensis. In this study，to determine the genetic basis for the diversity of A. luchuensis, a genome comparison of 41 strains including A. luchuensis and related species was conducted. Whole genome sequencing was performed by the next‑generation sequencer. Each obtained short reads data was mapped to the A. luchuensis RIB2604 (NBRC4314) genome as reference. The detected single nucleotide variants were retained for subsequent phylogenic analysis. The results indicated the differentiations accounting for diverse traits occurred in A. luchuensis， and that A. luchuensisis divided into two groups.

Source

J. Brew. Soc. Japan，117(6)，413-421 (2022)

6.S-adenosyl-L-homocysteine extends lifespan through methionine restriction effects

Author

OGAWA Takafumi, MASUMURA Koji, KOHARA Yuki, KANAI Muneyoshi, SOGA Tomoyoshi, OHYA Yoshikazu, T Keith Blackwell, and MIZUNUMA Masaki

Abstract

Methionine restriction (MetR) can extend lifespan and delay the onset of aging-associated pathologies in most model organisms. Previously, we showed that supplementation with the metabolite S-adenosyl-L-homocysteine (SAH) extends lifespan and activates the energy sensor AMP-activated protein kinase (AMPK) in the budding yeast Saccharomyces cerevisiae. However, the mechanism involved and whether SAH can extend metazoan lifespan have remained unknown. Here, we show that SAH supplementation reduces Met levels and recapitulates many physiological and molecular effects of MetR. In yeast, SAH supplementation leads to inhibition of the target of rapamycin complex 1 (TORC1) and activation of autophagy. Furthermore, in Caenorhabditis elegans SAH treatment extends lifespan by activating AMPK and providing benefits of MetR. Therefore, we propose that SAH can be used as an intervention to lower intracellular Met and confer benefits of MetR.

Source

Aging Cell, 21(5), e13604 (2022)

7.Genetic architecture of berry aroma compounds in a QTL (quantitative trait loci) mapping population of interspecific hybrid grapes (Vitis labruscana×Vitis vinifera)

Author

KOYAMA Kazuya, KONO Atsushi, BAN Yusuke, Sharon Marie Bahena-Garrido, OHAMA Tomoko, IWASHITA Kazuhiro, FUKUDA Hisashi, and GOTO-YAMAMOTO Nami

Abstract

BACKGROUND: Although grapes accumulate diverse groups of volatile compounds, their genetic regulation in different cultivars remains unelucidated. Therefore, this study investigated the volatile composition in the berries of an interspecific hybrid population from a Vitis labruscana ‘Campbell Early’ (CE) × Vitis vinifera ‘Muscat of Alexandria’ (MA) cross to understand the relationship among volatile compounds and their genetic regulation. Then, a quantitative trait locus (QTL) analysis of its volatile compounds was conducted.
RESULTS: While MA contained higher concentrations of monoterpenes and norisoprenoids, CE contained higher concentrations of C6 compounds, lactones and shikimic acid derivatives, including volatiles characteristic to American hybrids, i.e., methyl anthranilate, o-aminoacetophenone and mesifurane. Furthermore, a cluster analysis of volatile profiles in the hybrid population discovered ten coordinately modulated free and bound volatile clusters. QTL analysis identified a major QTL on linkage group (LG) 5 in the MA map for 14 monoterpene concentrations, consistent with a previously reported locus. Additionally, several QTLs detected in the CE map affected the concentrations of specific monoterpenes, such as linalool, citronellol and 1,8-cineol, modifying the monoterpene composition in the berries. As for the concentrations of five norisoprenoids, a major common QTL on LG2 was discovered first in this study. Several QTLs with minor effects were also discovered in various volatile groups, such as lactones, alcohols and shikimic acid derivatives.
CONCLUSION: An overview of the profiles of aroma compounds and their underlying QTLs in a population of interspecific hybrid grapes in which muscat flavor compounds and many other aroma compounds were mixed variously were elucidated. Coordinate modulation of the volatile clusters in the hybrid population suggested an independent mechanism for controlling the volatiles of each group. Accordingly, specific QTLs with significant effects were observed for terpenoids, norisoprenoids and some volatiles highly contained in CE berries.

Source

BMC Plant biology, 22, 458 (2022)

8.Modeling the sake brewing characteristics of rice from brown rice metabolites

Author

KOBAYASHI Takuji, KUMAZAKI Tsutomu, MORIKAWA Kana, KOMATSU-HATA Yuko, OKUDA Masaki, TAKAHASHI Masayuki, SAITO Ryota, ODA Ken, YAZAWA Hisashi, and IWASHITA Kazuhiro

Abstract

Sake, soy sauce, miso (Japanese bean paste), and beer are made from grains. The characteristics of the grain significantly affect the quality of the final product. Many studies have been performed to evaluate the sake-brewing characteristics of rice. However, current rice analysis methods are time and labor intensive and require large samples. We developed a novel method for predicting the brewing characteristics of sake rice using ＜1 g of sample. Brown rice extracts were analyzed by ultrahigh-performance liquid chromatography quadrupole time-of-flight mass spectrometry, and mass chromatogram data were used as explanatory variables. The objective variables were the physical and chemical properties of the rice, the enzymatic activity of the rice-koji, the fermentation properties of the sake mash, the standard analytical values of the sake, and the flavor component concentrations in the sake. Prediction models were developed using the orthogonal projections to latent structures method. The prediction performances of the models were verified, and 32 out of the 54 objective variables were used in well-performing models. In conclusion, we developed a method for predicting the rice properties and brewing characteristics from results acquired by analyzing ＜1 g of brown rice. The method is a powerful tool for breeding new sake rice cultivars for good brewing characteristics in early generations and will improve our understanding of fluctuations in the brewing characteristics of sake rice before each sake brewing season starts.

Source

Journal of Bioscience and Bioengineering, 134(2), 116-124 (2022)

9.Effects of temperature conditions after rice heading on enzyme digestibility (Brix) of steamed rice for the 2002–2019 crop years.

Author

TAKAHASHI Kei, OKUDA Masaki, JOYO Midori, and NUMATA Mineyo

Abstract

The Brix value obtained by enzymatic digestion of steamed rice based on national brewer rice unified analysis methods is assumed to be important for Japanese sake brewers to estimate the digestibility of newly cropped rice and re-establish sake brewing procedures based on this value. Here, we explored the relationship between Brix and temperature during the rice developmental period using sequential earlier-period rice analysis data gathered from the 2002–2019 crop years for 24 rice varieties as well as data from the Automated Meteorological Data Acquisition System (AMeDAS). The Brix of Gohyakumangoku significantly differed depending on the production district. The Brix of Ginpu, Suisei, and Kitashizuku cropped in Hokkaido were positively correlated with the mean and maximum temperatures during the 15 days after heading (DAH) of rice. In all 17 rice cultivars for sake brewing, except for that cropped in Hokkaido, the Brix value was clearly and negatively correlated with maximum temperature during the middle and later stages over a month of rice development, rather than the average temperature during 30 DAH, depending on the rice cultivar. In some table rice cultivars, we did not observe a correlation between the Brix and temperature during the rice developmental period. Thus, by utilizing the optimized temperature conditions and the term after heading of rice, the Brix of the rice cultivars for sake brewing could be estimated more precisely.

Source

J. Brew. Soc. Japan, 117(7), 503-518 (2022)

10.Influence of the properties of brewing water on sake brewing

Author

OKUDA Masaki, JOYO Midori, TERAMOTO Satoko, MUKAI Nobuhiko, TAKAHASHI Mutsuki, SUZUKI Sarasa, TSUCHIDA Hiroshi, HIRAIDE Toshie, YABUSAKI Shiho, KARADA Yukihiko, and HISADA Kenichiro

Abstract

We investigated the influence of the water properties on the sake brewing process and sake compounds, using eleven kinds of water from sake breweries, a kind of pure water, and a kind of ultra-hard water from overseas. In the present study, we focused on the element concentrations which were relatively high in the brewing water as compared with those in the raw rice, the hardness, and the anions in the brewing water. The sakes were produced in three ways using rice with three different polishing ratios. The profiles of the produced sake using ultra-hard water differed significantly from those using the other water for sake brewing. The differences in sake meter, amino acidity, several flavor compounds and organic acids in the produced sake among 13 kinds of water tended to be similar in the three kinds of polishing ratios. In the taste sensor analysis of the produced sake, the sensor responses of Sour, Bitter and miscellaneous taste, Umami richness, Astringent stimulation and Astringency, in the sake using hard water differed significantly from those with soft water. The concentrations of compounds such as sake meter, amino acidity, several flavor compounds in the produced sake have shown a significant correlation with the concentrations of inorganic compounds such as Mg, Ca, Cl^-, SO₄^2- and hardness. The digestion test of steamed rice by koji in each brewing water have shown that high concentration of SO₄^2- and Ca in brewing water resulted in high residual α-amylase activity and digestibility and low amino acid concentration in the digested solution. The above profiles of digested solutions have shown high correlations with the profiles of sake such as amino acidity, flavor compounds, and fermentation speed. The results of the digestion test in the inorganic ion solutions suggested that the SO₄^2- effectively caused the high residual α-amylase activity, high digestibility and low amino acid concentration in the digested solution. The present study shows that the inorganic compounds such as SO₄^2- in brewing water can significantly influence the digestibility of steamed rice, fermentation speed, and the concentration of sake compounds.

Source

J. Brew. Soc. Japan, 117(8), 580-608 (2022)

11.Analysis of the compounds responsible for “sweet/caramel” and “burnt” characters in sake presented to Sake Contests and the factors affecting their formation

Author

ISOGAI Atsuko, YOKONO Mizuki, KUBOTA Kento, UETA Takeshi, KOMAGOE Marumi, FUJII Tsutomu, OCHIAI Nobuo, and SASAMOTO Kikuo

Abstract

“Sweet/caramel” and “burnt” characters are perceived in about 10% of sake submitted to Sake Contests. We investigated the compounds responsible for the characters. Comprehensive volatile component analysis indicated that sake with a “sweet/caramel” or “burnt” character contained higher levels of aldehydes, acetals, and sulfur compounds compared with controls, or gold prize sake without the characters. In addition, several aroma compounds reminiscent of a “sweet” odor including homofuraneol were found by GC-olfactometry. Addition of the compounds detected by the comprehensive analysis and GC-olfactometry to control sake tended to increase the intensity of “sweet/caramel” and “burnt” odors in sensory analysis, which suggested their contribution to the characters. To investigate the brewing conditions causing the characters, small-scale sake brewing was carried out. Adding an enzyme agent to the moromi mash or lengthening the fermentation period increased the concentrations of aldehydes, acetals, sulfur compounds, and homofuraneol as the increment of the original extract and ratio of dead yeast. In addition, storage of sake before pasteurization greatly increased aldehydes and acetals. These results indicate that rice dissolution, yeast cell death, and storage affect the formation of compounds responsible for “sweet/caramel” and “burnt” characters.

Source

J. Brew. Soc. Japan, 117(9), 657-667 (2022)

12.Study on the decreasing property of enzyme digestibility of sake rice in ethanol containing buffer

Author

HIRASAWA Ryotaro, HONMA Ichiro, NISHIDA Ikuhisa, KANEOKE Mitsuoki, OKUDA Masaki, and HIRATA Dai

Abstract

To estimate the decreasing property of enzyme digestibility (ED) in sake mash of the steamed rice of Gohyakumangoku (GOM) and Koshitanrei (KOS) harvested in Niigata prefecture, we examined the ED of GOM and KOS in ethanol-containing buffer using Yamadanishiki (YAM) as a control rice. As a result, as in previous reports of other rice varieties, the ED of GOM and KOS decreased the longer they remained in the liquid. In addition, the ED decreased in the presence of ethanol, and it decreased more with increased ethanol concentration. Previous reports showed that the ED of the rice of a 50% polishing ratio was higher than that of a 70% polishing ratio. However, in this study, regarding the relative enzyme digestibility (rED) with the ED of the start (day 0) as 100%, the decrease in rED in the rice of a 50% polishing ratio was larger than that in the rice of a 70% polishing ratio regardless of the rice variety. This result suggested that highly polished rice is more likely to undergo aging in liquid than low-polished rice.Further, the rED that decreased after 20 days in liquid was set to 100%, and the decreasing ratio of rED in the early stage (0-10 days) and the late stage (10-20 days) of being left in liquid was investigated. As a result, the decreasing ratio of rED tended to differ depending on the variety. Finally, the sum of ED (early total Σ1 + late total Σ2 = Σ3) was estimated and compared by dividing the period in liquid into the early stage (1-11 days) and the late stage(11-21 days). As a result, Σ1 and Σ3 of KOS and YAM were larger than those of GOM, and this result showed the same tendency as the previous report. However, in the rice of a 50% polishing ratio, Σ2 of GOM was the largest among these rices. These results suggested that the ED of rice differs depending on the variety and rice polishing ratio.
From the above, it was suggested that the ED of rice was affected by the variety,rice polishing ratio, and ethanol concentration in the early and late stages of being left in the liquid. Further analysis will be required to estimate the ED of steamed rice in sake mash.

Source

J. Brew. Soc. Japan, 117(9), 647-656 (2022)

13.Sake brewing by mixed culture using Gifu university yeast strain GY115-a3 and Gifu prefecture yeast strain NFG

Author

OKUMURA Mai, YOSHIMURA Akihiro, SAWAI Yoshinori, HISAMATSU Kentaro, MASAKI Kazuo, SHIMADA Masaya, HAYAKAWA Takashi, and NAKAGAWA Tomoyuki

Abstract

In this study, we aimed to show the possibility of sake brewing by mixed culture using Gifu University yeast strain GY115-a3 and Gifu Prefecture yeast strain NFG. A large-scale sake fermentation by mixed culture using strains GY115-a3 and NFG produced a unique type of sake that possessed a light and dry taste (values for alcohol, sake meter, and acidity of 16.7%, -3.7, and 1.82, respectively), and a similar malic acid/succinic acid (MA/SA) value (0.46) and content of ginjo-ka as a case of single culture using strain GY115-a3 and strain NFG, respectively. These results indicate that sake brewing by mixed culture of sake yeast strains together with strain GY115-a3 is useful for making a unique type of sake with flavor and taste produced by strain GY115-a3.

Source

JOURNAL of the JAPANESE SOCIETY of TASTE TECHNOLOGY, 21(1), 27-31 (2022)

14.Analysis of sake components presented to the Japan sake awards 2021

Author

KISHIMOTO Toru, FUJITA Akiko, IIZUKA Sachiko, KANDA Ryoko, TERAMOTO Satoko, YAMADA Osamu, and FUKUDA Hisashi

Source

Report of the Research Institute of Brewing, 194, 1-17 (2021)

15.Review of the 44th Honkaku Shochu and Awamori Contest in 2021

Author

MUKAI Nobuhiko, ISOGAI Atsuko, OKUDA Masaki, MASAKI Kazuo, TAKAHASHI Kei, OSAFUNE Yukio, BOERZHIJIN Surina, and FUKUDA Hisashi

Source

Report of the Research Institute of Brewing, 194, 18-34 (2021)

16.Analysis of beer components presented to craft beer contest of Japan Brewers Association in 2022

Author

KUSAKA Kazutaka, TERAMOTO Satoko, and EMURA Takayuki

Source

Report of the Research Institute of Brewing, 194, 35-41 (2021)

17.Short-length Homologous Region exhaustive Search algorithm (SHRS): A primer design algorithm for differentiating bacteria at the species, subspecies, or strain level based on a whole genome sequence

Author

TAKAHASHI Masayuki, MORIKAWA Kana, and AKAO Takeshi

Abstract

In fields such as the food industry, it is very important to identify target bacteria at the species level or lower for optimal product quality control. Bacteria identification at the subspecies or lower level requires time-consuming and high-cost analyses such as multi-locus sequence typing and amplified fragment length polymorphism analyses. Herein, we developed a primer design algorithm for precisely identifying bacteria based on a whole genome DNA sequence that is easy to apply. The algorithm designs primer sets that produce fragments from all input sequences and maximizes the differences in the amplicon size or amplicon sequence among input sequences. We demonstrate that the primer sets designed by the algorithm clearly classified six subspecies of Lactobacillus delbrueckii, and we observed that the resolution of the method is equal to that of a multi-locus sequence analysis. The algorithm allows the easy but precise identification of bacteria within a short time. (SHRS is available freely from PyPI under the MIT license.)

Source

Journal of Microbiological Methods, 203, 106605 (2022)

18.Presence of disulfide-bonded thiols in malt and hops as the precursors of thiols in beer

Author

KISHIMOTO Toru, HISATSUNE Yuri, FUJITA Akiko, and YAMADA Osamu

Abstract

Disulfide-bonded thiols in malt and hops were first identified as possible precursors of thiols in beer. The presence of disulfide-bonded 3-mercaptohexan-1-ol (3MH) was confirmed in malt and hops by observing an 8.9-9.9 times increase in the 3MH concentration in hopped water and unhopped wort after the reduction using tris(2-carboxyethyl)phosphine (TCEP), a reducing agent specific for disulfide bonds. The presence of disulfide-bonded 4-mercapto-4-methylpentan-2-one (4MMP) was confirmed in hops by observing 2.1 and 5.1 times increase in the 4MMP concentration after reduction in hopped water. Proteins, peptides, and amino acids having sulfhydryl groups or other thiol substances were assumed to form disulfide bonds with polyfunctional thiols in malt and hops. The release of thiols by the reduction of disulfide-bonded thiols during fermentation was first identified. A 65-82% of disulfide-bonded 3MH were reduced during fermentation, and as a result, concentrations of 3MH in hopped water and unhopped wort increased by 9.5-14.2 times during fermentation.

Source

Journal of Agricultural and Food Chemistry, 70(41), 13413-13418(2022)

19.Light modulates transcriptomic accumulation of anthocyanin biosynthetic pathway genes in red and white grapes

Author

POUDEL Puspa Raj, KOYAMA Kazuya, and GOTO-YAMAMOTO Nami

Abstract

Anthocyanin is an important component in grape berry skin and strongly affects its quality. Transcription factors, VvMYBA1 and VvMYBA2 (VvMYBA1/2), are known to control anthocyanin biosynthesis. In addition, cultivation and environmental factors, such as light, influence anthocyanin accumulation. The present study aimed to clarify the effect of shading (reduced light condition) on transcriptomic regulation of anthocyanin biosynthesis using a red-wine grape cultivar, Vitis vinifera ‘Pinot Noir’, and its white mutant caused by the deletion of the red allele of VvMYBA1/2, ‘Pinot Blanc’. A decisive influence of VvMYBA1/2 on the expression of an anthocyanin-specific gene, UDP-glucose: flavonoid 3-O-glucosyltransferase, was observed as expected. On the other hand, upstream genes of the pathway which are shared by other flavonoids were also expressed in ‘Pinot Blanc’, and the mRNA levels of some of these genes were decreased by shading in both cultivars. Thus, the involvement of light-sensitive transcription factor(s) other than VvMYBA1/2 was suggested for the expression control of the upstream genes of anthocyanin biosynthetic pathway. Also, it was suggested the effects of these factors are different among isogenes.

Source

Journal of Plant Biotechnology, 49, 292-299 (2022)

20.Influence of meteorological conditions during grain filling and the properties of rice starch on flavor compounds in ginjyo sake

Author

OKUDA Masaki, JOYO Midori, BAO Hong-Bin, TAKAHASHI Kei, and MUKAI Nobuhiko

Abstract

In the present study, daiginjyo-sake making tests on a small scale were conducted using 40% polishing ratio rice to reveal the relationship between the flavor compounds in daiginjyo-sake and the meteorological conditions during grain filling and the enzyme digestibility of steamed rice. The concentration of ethyl caproate, alcohol concentration, sake meter, glucose concentration in the produced sake and fermentation rate showed significant correlations with the gelatinization temperature of the material raw rice, the enzyme digestibility of steamed rice grains, and the temperature during the grain filling of rice. When the temperature during grain filling of Yamadanishiki was lower and the enzyme digestibility of steamed rice grain was higher, the concentration of ethyl caproate in sake was higher. This result tends to be similar with the previous statistical analysis of Annual Japan Sake awards. The concentration of ethyl caproate in sake produced using rice cultivars with high enzyme digestibility of rice and slow fermentation rate was higher than those with low enzyme digestibility of rice and fast fermentation rate. The present study indicated that the meteorological conditions during rice grain filling cause the change in digestibility of sake rice and fermentation rate, and have considerable influence on the ethyl caproate concentrations in daiginjyo-sake.

Source

J. Brew. Soc. Japan, 118(1), 37-57(2023)

21.Comprehensive electrophoretic karyotyping for strains belonging to major lineages of Kyokai sake yeast

Author

MORIOKI Marie, ZHOU Yan, GOSHIMA Tetsuya, OKAZAKI Naoto, and AKAO Takeshi

Abstract

Pulse-field gel electrophoresis was performed on 139 Kyokai sake yeast strains belonging to the K6, K7, K9, and K10 lineages (including crossbreds). The result indicated the presence of polymorphism in electrophoretic karyotype within each lineage. Meanwhile, a conserved karyotype was found in all the lineages, except the K10, implying that the original strains of the K6, K7, and K9 lineages might have inherited it from a respective common ancestor for them. This makes lineage differentiation by electrophoretic karyotypes difficult. Electrophoretic karyotypes of the K10 lineage strains shared characteristic bands and band losses that were not observed in the other lineages, hence indistinguishing it from others, as suggested in a previous study. The polymorphisms present in the electrophoretic karyotype within each lineage indicate that karyotypic changes may occur during the maintenance of stock strains at culture collections. Thus, the karyotypic polymorphism can be used as an index for quality control of the strains in conservation or improvement processes.

Source

J. Brew. Soc. Japan, 118(3), 171–174 (2023)

22.Comprehensive genetic and brewing charecterisation of Mie sake yeast strains

Author

MARUYAMA Hironori, OZAWA Atsuki, YAMAZAKI Eiji, and AKAO Takeshi

Abstract

In Mie Prefecture, five sake yeast strains (MK1, MK3, MK5, MK7, and MLA12) have been developed and are widely used by local breweries. We comprehensively investigated the genetic and brewing characteristics of these Mie sake yeast strains to reveal their properties in detail. Ploidy estimation revealed that MK1, MK3, MK5, and MLA12 were diploid, but MK7 was tetraploid. Genotyping of RIM155067ins indicated that all Mie sake yeast strains belong to the K7 group. The results of electrophoretic karyotype and whole-genome analysis indicated that MK1 and MK3 are in the K10 lineage, while MK5 and MK7 are in the K9 lineage. Chromosomal aneuploidy estimation revealed that MK3 had trisomy of Chr.3 and Chr.10, while MLA12 had trisomy of Chr.3. The determination of the genotype of FAS2^G3748A and LEU4^C1652T revealed that MK3 had the FAS2 variant homozygously, MK7 and MLA12 had it heterozygously, and MLA12 had the LEU4 variant heterozygously. Compared brewing characteristics of small-scale sake brewing test roughly reflected their genomic background, and principal component analysis revealed the difference in brewing characteristics of each yeast strain. Moreover, products fermented by MK7 and MLA12 showed a unique character.

Source

J. Brew. Soc. Japan, 118(2), 115–127 (2023)