The Production of Reduced-Alcohol Wine Using Glucose Oxidase-Treated Juice. Part II. Stability and SO₂-Binding

¹ Viticulture and Oenology Group, Faculty of Science and Technology, Eastern Institute of Technology, Private Bag 1201, Taradale, New Zealand
² Wine Science Group, Lincoln University, Canterbury, New Zealand.

gpickering{at}eit.ac.nz

The physical and chemical stability of reduced-alcohol white wine produced from glucose oxidase (GOX)-treated juice was investigated. GOX wines show increased SO₂-binding power compared to control wines, above that which can be explained by the juice aeration process required for enzymatic activity. A higher concentration of carbonyl compounds may account for this increased SO₂ demand, and more sulfate is formed in GOX wines. GOX wines also had a more golden color, possibly due to increased quinone production and regeneration of oxidizable phenolic substrate. They were stable against browning after six months of bottle age, whereas control wines continued to brown throughout the two-year period of monitored aging. GOX wine appeared to be stable with respect to 'pinking' reactions and other parameters examined. Although heat/cold tests suggest they are at more risk of developing a protein haze, no haze was observed.

Key words: reduced-alcohol wine, low-alcohol wine, glucose oxidase, catalase, reduced sugar grape juice, juice oxidation, stability, aging, sulfur dioxide

Submitted on January 3, 1998
Revised on April 27, 1999