The biological focus is on the years and bacteria found in association with wine, as part of an attempt to examine the biological characteristics of the world’s greatest wines.
The role of yeast in winemaking is well-established. Yeast is needed to distinguish wine from grape juice. Yeast converts the sugars of wine grapes into alcohol and carbon dioxide through fermentation. The process can be varied, such as varying the sugar content which leads to more alcohol and varying the fermentation time, which affects the degree of dryness.
The role of bacteria is less well established, although studies have indicated that bacteria contribute to the overall aroma. Certain bacteria assist with the extract of compounds from the solids in grape must. This is by modifying grape-derived molecules and by producing flavour-active metabolites.
To advance scientific understanding of the role of microorganisms in wine production, University of British Columbia Okanagan campus researchers Dan Durall and Mansak Tantikachornkiat developed a technique that allows the DNA profile in yeast and bacteria samples to be fully characterized.
In a statement, Dr. Durall explains: “Since only live micro-organisms are relevant in the various stages of fermentation as they relate to the senses, this study provides some of the important tools that will be necessary to determine why different types of wine taste and smell as they do.”
To identify the best strains, the researchers worked through dozens of different yeast and bacteria samples. For this they used a method based on a light-sensitive dye called propidium monoazide. The new method allowed for a more rapid analysis.
It is hoped the research will not only allow the best yeasts and bacteria to be identified for use with future wine making, the process should also allow for the identification and subsequent elimination of microorganisms that are responsible for wine spoilage.
The new research into wine has been published in the International Journal of Food Microbiology. The research paper is headed “The use of propidium monoazide in conjunction with qPCR and Illumina sequencing to identify and quantify live yeasts and bacteria.”
