The market for zero-alcohol wine is creating fresh opportunities for wine producers, but processing these products creates new contamination challenges. A key challenge for producers of zero-alcohol wine is preserving the product’s delicate flavour profile, and several different dealcoholisation methods are employed to achieve this. These include vacuum distillation, reverse osmosis, and the spinning cone column. The dealcoholised wine is then put through a filtration process to ensure microbial stability and product quality. However, alcohol is a natural inhibitor of microbial organisms, and removing it results in a greater contamination risk.
There are further risks. The pH of zero-alcohol wines can differ to that of wines containing alcohol, and this can allow other bacteria to grow. These would not normally be a concern due to the acidic nature of standard alcoholic wines, but non-alcoholic wines are more sensitive to oxygen, which can lead to oxidation and the growth of aerobic microorganisms that can spoil the flavour and reduce shelf life. Microorganisms can also adhere to the surfaces of packaging materials and equipment. If this is not controlled, biofilms can form and contaminate the wine during packaging.
Optimising filtration for zero-alcohol wine
In order to effectively remove microorganisms which can be present in zero-alcohol wines, filtration systems require tighter membranes than those used for traditional wines. If a winery is introducing a zero-alcohol wine to its range, the filtration processes should be optimised for the new product.
Technical support from an established filtration specialist, such as Parker, can help wineries in overcoming the challenges posed by the increased risk of contamination. For example, in a recent case, a European producer of non-alcoholic wine had identified that Zygosaccharomyces was present in its product post-filtration. This can thrive in harsh, high-sugar environments, and if it remains at the bottling stage, it can re-ferment, causing sediment, an undesirable appearance and potential damage to the bottle. The company was using 0,45 micron membranes in the filtration process. However, following guidance from Parker, these were replaced by 0,2 micron membrane filters. Following this, no contamination was reported, indicating that the tighter membrane was successful in eliminating the presence of Zygosaccharomyces.
The importance of filter integrity testing
In preventing contamination of a zero-alcohol wine and its process equipment, it is also vital that wineries and bottling plants identify incidences of filter failure by implementing regular filter integrity testing. This should be integrated into a HACCP system.
To support wine producers, Parker has developed BEVCHECK portable semi-automated integrity testing units and BEVCHECK PLUS fully automated integrity testing units. These solutions use compressed gas to accurately measure the diffusional flow or pressure decay of liquid membrane filters and provide operators with simple ‘pass or fail’ results. The BEVCHECK and BEVCHECK PLUS units have IP53 splash-proof protection and a robust construction, and have been specially designed for use in wineries.
To protect the quality of their products, brand reputation and operational efficiency, wineries introducing zero-alcohol wines to their ranges should put their processes under a microscope as it is essential that costly contamination incidents are prevented and production is maintained. This is brought into even sharper focus by the substantial cost of dealcoholisation equipment and its associated infrastructure. Wasted product batches will not help wineries receive a return on investment.
Drawing on a wealth of expertise, Parker’s technical support group can assist businesses in optimising their filtration processes and preventing contamination, including advising on filter selection, system design and cleaning processes, and providing onsite technical analysis.
Parker has also developed a range of membrane filters for use in the wine industry, including the BEVPOR PS, BEVPOR PW, and BEVPOR PH filters which have been validated against typical wine spoilage organisms. It also recently launched BEVPOR Caustic Stable, developed for use by beverage manufacturers who need to employ higher concentrations, typically more than 2%, of sodium hydroxide in their CIP regimes.
Parker offers several other filtration and separation technologies that bring significant benefits to products and processes. Nitrogen is extensively used in winemaking to prevent oxidation, maintain flavour, and extend shelf life by displacing oxygen from tanks, barrels and bottles. NITROSource nitrogen gas generators can cost-effectively produce food-grade nitrogen on demand using a source of compressed air for use in all processes. Why buy nitrogen when you can make it? Parker also offers a full range of compressed air treatment filters and dryers that carry third party certification for use within the food and beverage industry.
For more information contact Lisa De Beer, Parker Hannifin SA, lisa.debeer@parker.com, www.parker.com/za
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