The production of reduced-alcohol wines using Gluzyme Mono® 10.000 BG-treated grape juice
AbstractHigh alcohol wines have become a major challenge in the international wine trade. Several physical processes are
used to produce wines with reduced-alcohol content, all of which involve the selective extraction of ethanol based
on volatility or diffusion. In this study, the possibility of Gluzyme Mono® 10.000 BG (Gluzyme) (Novozymes, South
Africa) to reduce the glucose content of synthetic grape juice before fermentation was investigated in order to produce
wine with reduced-alcohol content. Gluzyme is a glucose oxidase preparation from Aspergillus oryzae, currently used
in the baking industry. Glucose oxidase catalyses the oxidation of glucose to gluconic acid and hydrogen peroxide
(H2O2) in the presence of molecular oxygen. Gluzyme was initially used in synthetic grape juice, where different
enzyme concentrations and factors influencing its efficiency were investigated under winemaking conditions. The
results showed up to 0.5% v/v less alcohol at an enzyme concentration of 20 kU compared to the control samples.
This reduction in alcohol was increased to 1 and 1.3% v/v alcohol at pH 3.5 and pH 5.5 respectively in aerated (8
mg/L O2) synthetic grape juice using 30 kU enzyme. Secondly, Gluzyme was used to treat Pinotage grape must
before fermentation. Gluzyme-treated wines at 30 kU enzyme concentration after fermentation contained 0.68%
v/v less alcohol than the control wines. A decrease in acetic acid concentration of the treated compared to control
wines was also observed.
A copyright form will be e-mailed to the corresponding author when the manuscript has been accepted for publication.
In principle, the Author agrees to the following when he/she signes the copyright agreement:
I hereby assign to the SOUTH AFRICAN SOCIETY FOR ENOLOGY AND VITICULTURE (SASEV) the copyright of the text, tables, figures, supplementary material, illustrations and other information (the Material) submitted with the manuscript to be published in SOUTH AFRICAN JOURNAL OF ENOLOGY AND VITICULTURE (SAJEV) (the "Article"). The copyright becomes effective from the date the Article has been accepted for publication in SAJEV.
This is an open access journal, and the authors and journal should be properly acknowledged, when works are cited.
Author's may use the publishers version for teaching purposes, in books, theses, dissertations, conferences and conference papers.
A copy of the authors' publishers version may also be hosted on the following websites:
- Non-commercial personal webpage or blog.
- Institutional webpage.
- Authors Institutional Repository.
The following notice should accompany such a posting on the website: This is an electronic version of an article published in SAJEV, Volume XXX, number XXX, pages XXX - XXX, DOI. Authors should also supply a hyperlink to the original paper or indicate where the original paper (www.journals.ac.za/index.php/sajev/) may be found.
Authors publishers version, affiliated with the Stellenbosch University will be automatically deposited in the University's Institutional Repository SUNScholar.
Articles as a whole, may not be re-published with another journal.
The following license applies:
Attribution CC BY-NC-ND 4.0