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Relationship between oxidation of wine phenols and wine quality: effects of phenol oxidation on pigment decolorization and haze formation in red wines, and on their functionality

Research Project

Project/Area Number 10660119
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field 食品科学・栄養科学
Research InstitutionUniversity of Yamanashi

Principal Investigator

YOKOTSUKA Koki  Yamanashi University Fac. Eng. Professor, 工学部, 教授 (60020450)

Co-Investigator(Kenkyū-buntansha) OKUDA Tohru  Yamanashi University Fac. Eng. Research Associate, 工学部, 助手 (10252008)
TAKAYANAGI Tsutomu  Yamanashi University Fac. Eng. Assistant Professor, 工学部, 助教授 (00252007)
Project Period (FY) 1998 – 1999
Project Status Completed (Fiscal Year 1999)
Budget Amount *help
¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1999: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1998: ¥1,800,000 (Direct Cost: ¥1,800,000)
KeywordsGrape / Wine / Protein / Haze / Polyphenol / Electrophoresis / HPLC / Polyphenoloxidase / フェノール / アミノ酸
Research Abstract

1. Effect of grape proteins on haze formation in wine
The contents of free amino acids, peptides, and proteins in the juices, seeds, and skins from two red and four white grape varieties (Koshu, Semillon, Chardonnay, Riesling, Cabernet Sauvignon, and Muscat Bailey A) were investigated. In the juices, total free amino acids varied with the variety, ranging from 400 to 2230 mg/L at 19oBrix during berry ripening. The soluble protein content ranged from 100 to 500 mg/L, with Semillon grape juice containing the highest amount among six varieties. Less than 1 mg/g of free amino acids was extracted from seeds, and proteins were obtained in the range between 20 and 40 mg/g. The free amino acid content in skins was small, and the amounts of proteins extracted ranged from 1 to 5 mg/g.
Since the protein concentrations are low in Cabernet Sauvignon and Muscat Bailey A, which are red wine varieties, it was difficult to obtain proteins from their juice or wine and fractionation by electrophoresis was … More not sufficient. On the other hand, Semillon grape have a high protein content, so in the following experiments, protein were prepared from Semillon grape juice and wines fermented in the same ways as those used to make free-run and red wines.
Proteins were fractionated from juice and two wines using salting-out precipitation with ammonium sulfate and HPLC on Superdex 75HR. The proportions of proteins in the protein fractions (lyophilisates) were about 90% in the cases of the juice and free-run wine and about 45% for the wine fermented on skins (the remaining compounds were mostly sugars). The protein fractions were fractionated by gel electrophoresis. The electrophoretic patterns of the juice and free-run wine protein fractions were very similar to each other but very different from that of the fraction from wine fermented on skins.
Haze formation was investigated using the protein fractions mentioned above. Proteins and seed phenols were mixed in wine-like model solutions and the mixtures were allowed to stand for 12 hours. They were the centrifuged and the supernatants obtained were analyzed by HPLC. Haze formation differed with the protein judging from HPLC patters (protein peaks) obtained:
2. Fractionation and purification of grape polyphenol oxidases
Polyphenoloxidases, by which phenolic compounds were readily bound to proteins to form haze, were fractionated and purified by various column chromatographies and their enzymatic and chemical properties were investigated. The molecular weight of a polyphenoloxidase was about 40 kDa, and its optimum pH was 6.3. Less

Report

(3 results)
  • 1999 Annual Research Report   Final Research Report Summary
  • 1998 Annual Research Report
  • Research Products

    (3 results)

All Other

All Publications (3 results)

  • [Publications] Tohru Okuda: "Purification and characterization of polyphenol oxidase from Muscat Bailey A grape juice"American Journal of Enology and Viticulture. 50. 137-143 (1999)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] Tohru OKUDA: "Purification and characterization of polyphenol oxidase from Muscat Bailey A grape juice."Am. J. Enol. Vitic.. 50(2). 137-143 (1999)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] Tohru OKUDA: "Purification and characterization of polyphenol oxidase from Muscat Bailey A Grape Juice."American Journal of Enology and Viticulture. 50巻・2号. 137-143 (1999)

    • Related Report
      1999 Annual Research Report

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Published: 1998-04-01   Modified: 2016-04-21  

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