Sterilizing water and other liquid content in food and beverage processing often involves high heat. But the energy needed to produce that heat is costly, and high temperatures can diminish product quality.
Ultraviolet (UV) technology has been around for several decades and is a safe, energy-efficient, and inexpensive alternative to heat treatment. Food and beverage manufacturers can use it on its own or incorporate it into filtration, reverse osmosis, or pasteurization processes. It treats liquids used in drinks like bottled water, sodas, beer, and juice, as well as sanitizes water for vegetable washes and meat and poultry processing. UV disinfection is also an approved substitute for thermal pasteurization, as long as it meets Pasteurized Milk Ordinance requirements.
To learn more about the advantages of treating liquids with UV technology, we spoke with Ismail Gobulukoglu, Chief Scientist, and Sarah Brown, Marketing Campaign Specialist, at Aquafine Corporation.
Founded in 1949, Aquafine became part of Trojan Technologies in 2005. Using UV light, the company developed solutions for fluid treatment in industrial settings such as aquaculture, microelectronics, and food and beverage. Although disinfection is its primary use, UV is also successful in ozone destruction, elimination of chlorine and chloramines, and reduction of total organic carbon (TOC).
A cost-cutting alternative to heat and chemical treatments
Raising the temperature is an effective way to kill off pathogens. In dairies, for example, thermal pasteurization uses sufficient heat to destroy pathogens without impacting the milk’s natural qualities. However, generating that heat is expensive. Even if the equipment is affordable, it takes a lot of energy, which drives up overall costs.
“UV has significantly lower operating costs,” Gobulukoglu says. That’s because UV disinfection is like powering a fluorescent tube light, requiring only a small fraction of the energy heat pasteurization consumes. A heat pasteurizer might use 400 kW to heat 480 gallons per minute of water from 41°F to 161.6°F, while Aquafine’s UV system needs just 5kW to disinfect the same volume. UV technology also boasts high performance, simple operation, and low maintenance costs.
UV sterilization also has advantages over chemical treatments. It works by penetrating the cell membranes of microorganisms, damaging the nucleic acid, and preventing them from carrying out normal cell functions like replication. As a result, at least 99.9% of the cells either die off or are rendered incapable of infecting a host. Unlike chemical treatments, the process doesn’t add any toxins, residues, etc. that could change the pH, flavor, color, smell, or overall quality of the liquid. UV also doesn’t produce any harmful byproducts.
A solution for treating sweetened drinks
In the beverage sector, UV is effective for disinfecting liquid sweetener or syrup. Here are several applications where UV is becoming more widely used:
- Bottler’s grade white sugar is the most commonly used sweetener in the beverage industry, and it must meet certain requirements for factors like color, pH, and microbe count. With this type of sugar, downstream UV disinfection can reduce bacterial spores.
- Brown sugar has a darker color and isn’t acceptable as a bottler’s grade sugar unless it goes through a decolorization process. That process typically involves heating the sugar to 185 F°. “But there are new projects coming up that use ion-exchange resins and activated carbon for discoloration combined with UV,” says Sven Leifer, Aquafine’s Sales Manager.
- High fructose corn syrup and isoglucose are produced in such a way that the disinfection requirements of other sugar types don’t apply. In some cases, where UV treatment can be used as a storage treatment for these syrups.
- Cool sugar dissolving processes (122-140 F°, depending on Brix) paired with UV treatment have replaced hot dissolving processes.
- While in storage, sugar content settles at the bottom of the tank, which creates a diluted layer at the top where organisms can grow. The longer the product stays in storage and the warmer the temperature, the greater the possibility of bacterial growth. Humid environments can also increase this risk by causing condensation. To minimize spore populations, UV treatment can treat product as it enters the storage tank, during recirculation, or from the headspace of the tank.
- Though carbonated and acidic drinks have a greater defense against bacterial growth, sensitive beverages like energy drinks, tea, and juice don’t have the advantage of carbonation and low pH levels. Sensitive drinks also require gentle processing, which means pasteurization is common for these applications. However, UV treatment can protect the flavor and nutrient content that’s often lost in pasteurization processes. It’s also not clear how successful pasteurization is at controlling thermophilic spores, so UV disinfection may be the more efficient option.
Compared to other UV technologies, Aquafine’s solution is unique because it uses low-pressure lamps that have many advantages over medium-pressure systems. Low-pressure technology is less expensive to operate, more energy-efficient, and easier to maintain, requiring lamp changes annually rather than multiple times a year. The lamps are also more environmentally-friendly, as they contain 10 times less mercury than medium-pressure lamps. Aquafine’s technology is also capable of treating intermittent flow systems without switching off lamps, so it isn’t limited to continuous flows.
Aquafine will be returning as a PROCESS EXPO exhibitor this fall through Trojan Technologies. “It was a great show for us last time,” Brown says. “We got a lot of great leads. We’re looking forward to showcasing our technology and our product.”
To learn more about UV disinfection and see full-scale units, visit Trojan Technologies at Booth #560 at PROCESS EXPO.