Most soft drinks, beer, bottled water and other common beverages, are comprised of more than 90% water. The quality of water is therefore crucial for a good tasting beverage. Beverage manufacturers adhere to strict water quality standards to meet health regulations and to produce safe, standardized water that maintains consistency in flavor, color and body. Impurities, such as suspended particles, certain dissolved solids (or ions), metals, organic matter and bacteria may result in taste and color defects. Membrane filtration technologies including ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) are commonly used to remove such impurities and produce the desired water quality ideal for beverages.
TurboClean® Bev 8040-UF elements may be used to remove larger particles present in the beverage make-up water and deliver high quality water for soft drinks, energy drinks and bottled water. The TurboClean® Bev 8040-UF element features a 10 kDa membrane suitable to remove suspended particles, proteins and viruses.
TurboClean® Beverage Cellulose Acetate RO and NF elements are the best performing cellulose acetate (CA) membrane elements for producing high quality water for beverage production. These elements have been certified to NSF/ANSI Standard 61 for use in drinking water systems. The combination of the patented TurboClean hard shell technology with the chlorine tolerance of CA membranes makes these elements optimal for ensuring a safe and sanitary system environment.
TurboClean® Beverage Thin-Film Composite RO elements deliver high purity, low TDS (dissolved solids) water for beverages. TurboClean Beverage RO elements are available in several membrane chemistries: standard high rejection RO - ACM2, low-fouling RO - X-20™, and low-energy RO - LE.
The patented TurboClean hard shell offers a safe and sanitary operating system with none of the stagnant areas created by the brine seals of fiberglassed membrane elements where bacterial growth is often found.
Data Sheets & Links
Fruit juices are popular beverages due to their nutritional and antioxidant properties. Apple juice in particular, is a healthy choice because it contains vitamin C and healthy polyphenol antioxidants that are essential for overall health.
Apple juice is processed and sold in many forms. Fresh apple juice or sweet cider is made from ripe fruit that has been pressed and bottled or packaged without preservatives directly into a bottle, called “direct juice”. This fresh apple juice or sweet cider is typically opaque or cloudy because it has not undergone a filtration process to remove coarse particles such as pulp. Clarified apple juice is juice that has been filtered to remove solids and appears more transparent.
As summarized in Figure 1, after the apples have been harvested, inspected and cleaned, they are sent to a hammer or grating mill for grinding. The juice is then extracted from the mashed apples using a press. Apple juice collected from a press or extractor typically contains suspended solids and other viscous soluble materials (pectin) that have the potential to form after-bottling hazes. The juice may then be directly pasteurized, killing any bacteria present in the fruit puree and denaturing residual enzymes, resulting in a natural-looking apple juice product. For a clear juice product, the raw apple juice is typically enzyme-treated (using pectinase) to hydrolyze the pectin molecules so that they can no longer hold juice. This process is known as depectinization and is an important step to reduce viscosity and help flocculate suspended matter. After the enzyme treatment, the suspended matter is removed from the juice using filtration processes.
Centrifugation is sometimes used to remove high molecular weight solids. For further clarification, tubular or capillary microfiltration membrane modules may be used. Capillary modules such as MICRODYN™ MD 200 CV or MICRODYN™ MD 150 CP offer capillaries with an inner diameter of 1.8 mm (0.071 inches).
MICRODYN MF membrane is made of polypropylene, offering great chemical resistance. It is also very resistant to abrasion and other mechanical damage due to its homogeneous construction. MICRODYN MF membrane modules may also be periodically back washed to remove deposited solids from the membrane surface.
After clarification, the clear juice is pasteurized and bottled.
Data Sheets & Links
Winemakers and brewers are careful not to produce wine or beer with too much alcohol as this may pose a variety of challenges. With too much alcohol, the wine or beer may taste “hot” and may not sell at full value or result in additional taxes. Also, if the alcohol by volume (ABV) in the bottle differs from that stated on the label, compliance issues may result.
Additionally, the demand for nonalcoholic beverages is increasing due to newer consumption practices that are reducing alcohol intake for a variety of reasons: healthier lifestyle, drinking and driving regulations, religious reasons, pregnancy or abstinence. As such, more and more nonalcoholic beer and wine beverages are being produced with a maximum ABV of 0.5%.
There are several ways to produce nonalcoholic or alcohol-reduced beer and wine (Figure 1). Two ways to remove alcohol (ethanol) from beverages is to interrupt fermentation, which restricts the formation of ethanol, or by steaming off the ethanol by boiling. However, both these methods may negatively affect the flavor of the beverage. In order to better control the alcohol content and maintain the beverage’s flavor, winemakers and brewers may use membrane processes, including reverse osmosis, nanofiltration or dialysis, for targeted alcohol reduction or dealcoholization.
Reverse Osmosis & nanofiltration for Dealcoholization
In order to better control the alcohol content, winemakers and brewers may use reverse osmosis (RO) or nanofiltration (NF) for targeted alcohol reduction or dealcoholization without changing the flavors, tannins and other elements in the wine or beer.
As wine or beer is fed into the RO or NF system, the small, uncharged molecules such as water and ethanol pass through the membrane as permeate while most elements including color, tannins and flavor do not (retentate).
Dealcoholization systems using spiral-wound RO and NF membrane elements are typically operated with diafiltration to help dilute the wine or beer with water to increase the alcohol extraction capacity (Figure 2A). As the permeate (mainly water and ethanol) is withdrawn from the feed, deaerated water is added to the retentate at the same flow rate to keep the volume in the system constant. The retentate from the first loop may be sent to a second loop to remove any additional ethanol.
Alternatively, the RO or NF permeate (the colorless and tasteless water and alcohol mixture) may be distilled to separate the alcohol from the water (Figure 2B). The distilled alcohol may be used in the production of other beverages while the water can then be recombined with the RO or NF retentate (the color, flavor and tannins), resulting in a tasteful wine or beer with reduced alcohol.
Dialysis for Dealcoholization
Dialysis is another method that uses membranes for ethanol removal. Dialysis is based on the use of capillary membrane modules such as DIADYN CD 4 PS 513 modules. Beer or wine flows counter-currently to the dialysate (e.g. water), as shown in Figure 3. Low molecular weight solutes, such as ethanol, pass through the membrane as a result of the concentration gradient between the two solutions. Ethanol permeates from the beer or wine to the dialysate, trying to reach equilibrium (similar ethanol concentration on either side of the membrane).
The alcohol-rich dialysate is then sent to a stripper column where ethanol is removed by evaporation. The remaining alcohol-free dialysate is reused in the dialysis unit to remove additional ethanol while minimizing the permeation of flavor compounds.
Dialysis, like RO and NF dealcoholization systems, has minimal impact on the flavor of the beer or wine.
For more information or questions on wine or beer dealcoholization, please contact MICRODYN-NADIR.