The production of reduced-alcohol wines using Gluzyme Mono® 10.000 BG-treated grape juice

Abstract

High 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 (H 2 O 2 ) 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 O 2 ) 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.

An efficient continuous flow process for the synthesis of a non-conventional mixture of fructooligosaccharides

“…In the exiting flow stream, glucose represents 26% (w/w) of the mixture and its presence complicates the purification of the FOS mixture, in particular, the isolation of blastose. Therefore, we exploited a method reported in the literature for glucose removal based on its enzymatic oxidation to gluconic acid catalyzed by a commercially available glucose oxidase (Gluzyme Ò mono 10000 BG, from Novozymes); the formed gluconate can be precipitated as calcium salt and easily removed (Biyela, Du Toit, Divol, Malherhe, & Van Renshurg, 2009;Sheu et al, 2001). A final semi-preparative HPLC step was necessary to obtain either the pure FOS mixture or blastose (97% purity).…”

Strategies for reducing alcohol concentration in wine

“…Commercial preparations of the enzyme added to grape juice were found to decrease ethanol concentration in the resulting wine by 0.7% v/v compared with that of untreated wines (Biyela et al . ). As GOX works more efficiently when oxygen is supplied, this outcome could potentially be improved upon by must aeration.…”

Synthesis of fructo-oligosaccharides using grape must and sucrose as raw materials

“…It is worth mentioning that at industrial scale one of the most important factors that affect production costs is the enzyme price (Martins Meyer, Melim Miguel, Rodríguez Fernández, & Dellamora Ortiz, 2015). In this sense, Biyela et al (2009), who also studied enzymatic reduction of glucose content of grape juice to obtain reduced alcohol wine, reinforce the idea that higher amounts of enzyme improve glucose reduction yield. Therefore, a compromise between enzymatic costs and products yield must be considered when defining the conditions for glucose oxidation.…”