Membrane technology for the processing of fruit juices and beverages has been applied mainly for clarification using ultrafiltration and microfiltration, and for concentration using reverse osmosis. The effects of product preparation, membrane selection, and operating parameters are important factors influencing filtration rate and product quality. Technological advances related to the development of new membranes, improvement in process engineering, and better understanding of fruit beverage constituents have expanded the range of membrane separation processes. Developments in novel membrane processes, including electrodialysis and pervaporation, increased the array of applications in combination with other technologies for alternate uses in fruit juices and beverages.

Membrane processing of fruit juices and beverages: a review.

This paper reviews the technologies available for the production of dealcoholised, low- and reduced-alcohol wines. While the sensory quality in the early years was in many instances unsatisfactory, significant improvements in production methods have occurred, with technologies based on membranes and spinning cones now the most commonly used. Lower processing temperatures, improved aroma retention and recovery and a better understanding of the role of adjuncts in addressing flavour imbalances have led to a general improvement in overall quality. The continuing consumer resistance towards these wines in many market sectors is also discussed. It is concluded that this may be largely attributable to ongoing limitations in sensory quality and to promotional issues, including limited advertising budgets and a low level of awareness of recent improvements in quality.

Low- and Reduced-alcohol Wine: A Review

The production and sale of alcohol-reduced wines, and the lowering of ethanol concentration in wines with alcohol levels greater than acceptable for a specific wine style, poses a number of technical and marketing challenges. Several engineering solutions and wine production strategies that focus upon pre- or postfermentation technologies have been described and patented for production of wines with lower ethanol concentrations than would naturally arise through normal fermentation and wine production techniques. However, consumer perception and acceptance of the sensory quality of wines manufactured by techniques that utilize thermal distillation for alcohol removal is generally unfavorable. This negative perception from consumers has focused attention on nonthermal production processes and the development or selection of specific yeast strains with downregulated or modified gene expression for alcohol production. The information presented in this review will allow winemakers to assess the relative technical merits of each of the technologies described and make decisions regarding implementation of novel winemaking techniques for reducing ethanol concentration in wine.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1750-3841.2011.02448.x

Production Technologies for Reduced Alcoholic Wines

There is a growing consumer demand for wines containing lower levels of alcohol and chemical preservatives. The objectives of this study were to express the Aspergillus niger gene encoding a glucose oxidase (GOX; β-d-glucose:oxygen oxidoreductase, EC 1.1.3.4) in Saccharomyces cerevisiae and to evaluate the transformants for lower alcohol production and inhibition of wine spoilage organisms, such as acetic acid bacteria and lactic acid bacteria, during fermentation. The A. niger structural glucose oxidase (gox) gene was cloned into an integration vector (YIp5) containing the yeast mating pheromone α-factor secretion signal (MFα1S) and the phosphoglycerate-kinase-1 gene promoter (PGK1P) and terminator (PGK1T). The PGK1P-MFα1S-gox-PGK1T cassette (designated GOX1) was introduced into a laboratory strain (Σ1278) of S. cerevisiae. Yeast transformants were analysed for the production of biologically active glucose oxidase on selective agar plates and in liquid assays. The results indicated that the recombinant glucose oxidase was active and was produced beginning early in the exponential growth phase, leading to a stable level in the stationary phase. The yeast transformants also displayed antimicrobial activity in a plate assay against lactic acid bacteria and acetic acid bacteria. This might be explained by the fact that a final product of the GOX enzymatic reaction is hydrogen peroxide, a known antimicrobial agent. Microvinification with the laboratory yeast transformants resulted in wines containing 1.8–2.0% less alcohol. This was probably due to the production of d-glucono-δ-lactone and gluconic acid from glucose by GOX. These results pave the way for the development of wine yeast starter culture strains for the production of wine with reduced levels of chemical preservatives and alcohol.

Expression of the Aspergillus niger glucose oxidase gene in Saccharomyces cerevisiae

Expression of the Aspergillus niger glucose oxidase gene in Saccharomyces cerevisiae and its potential applications in wine production

The possibilities of using the reverse osmosis process for the production of low alcohol content wine without having to add water are described. Two reverse osmosis systems were employed. The first was equipped with ethanol-permeable membranes and the second with selective ethanol-retention membranes. The permeate-exchange unit ensures the water and ethanol balance of the system. The product intended for manufacture by the proposed technique remains `wine9 by its composition and organoleptic quality.

G. Moulin

Papers

A Reverse Osmosis for the Production of Low Ethanol Content Wine