UV Disinfection: Its Role in the Bottled Water and Beverage Industries

Within a market that is progressively regulated and prioritizes safety, the bottled water and beverage sectors are obligated to adhere to increasingly stringent quality criteria. The emergence of microbial growth stemming from impure water sources or sugary solutions and flavor enhancers can lead to undesirable discoloration, off-putting tastes, reduced shelf life, and heighten the potential for consumer infections. Moreover, as manufacturers strive to meet consumer desires for diminished chemical additives, the susceptibility to contamination is amplified. Hence, comprehensive microbial disinfection across the entire production process becomes a critical necessity.

An alternative disinfection approach that is gaining widespread approval is UV disinfection. UV effectively eradicates a comprehensive range of spoilage microorganisms, encompassing bacteria, viruses, yeasts, molds, and even their spores. This environmentally-conscious, low-maintenance technology obviates the necessity for chemical treatment, yet guarantees elevated levels of disinfection.

UV Disinfection: How It Works

UV lies within the electromagnetic spectrum, positioned between visible light and X-rays. A distinct segment of the UV spectrum, spanning from 185 to 400nm (referred to as UV-C), exhibits potent germicidal properties, reaching its zenith efficacy at 265nm. Within these wavelengths, UV infiltrates microorganisms’ cell membranes and disrupts their DNA, rendering them incapable of replication and ultimately resulting in their demise.

A customary UV disinfection setup comprises a UV lamp encased within a safeguarding quartz casing, situated within a cylindrical stainless steel enclosure. The liquid intended for treatment enters from one end and traverses the entire chamber’s length prior to emerging from the opposing end. UV demonstrates efficacy across a wide spectrum of liquids, encompassing pure spring water, municipal water, processed and filtered water, dense sugar syrups, various beverages, and effluents.

Two primary classifications of UV technology stem from the variety of UV lamps employed: low-pressure (LP) and medium-pressure (MP). LP lamps generate monochromatic UV emissions, confined to a single wavelength at 254nm. In contrast, MP lamps yield polychromatic UV emissions, spanning an output range of 185-400nm.

Advantages of Medium Pressure UV

Multiple factors advocate the suitability of MP lamp-centered UV systems for application within the bottled water and beverage sectors. To begin with, when treating fluids containing elevated levels of suspended solids, like certain mineral waters, there’s a propensity for deposits to accumulate on the quartz sleeves encasing the UV lamps, diminishing their effectiveness. To counter this, MP systems incorporate a mechanical wiper mechanism that moves along the quartz sleeve’s length, ensuring its cleanliness. In comparison, achieving this functionality with LP systems is more intricate, given that they typically feature multiple UV lamps, rendering automated wiping not always feasible.

Furthermore, recent studies investigating the reactivation of E. coli DNA subsequent to UV exposure from LP and MP lamps demonstrated a significant repair process occurring with DNA subjected to UV emitted by LP UV lamps. In contrast, DNA exposed to UV from MP lamps exhibited minimal repair, as observed across multiple studies1,2,3.

The research team deduced that the beneficial impact was attributed to the extensive UV emissions of MP lamps, spanning from 185 to 400nm. This wide-ranging UV spectrum appears to induce harm to various intracellular components, including enzymes, alongside DNA. This induced damage seems to irreversibly incapacitate the DNA repair mechanisms of the cells. In contrast, low-pressure UV lamps generate a sole UV peak at 254nm, solely affecting DNA and permitting repair enzymes to mend the DNA structure.

Advantages of UV Disinfection

UV disinfection holds numerous benefits over alternative approaches. Unlike chemical biocides, UV treatment doesn’t introduce toxins or residues into water and avoids any modification to the chemical makeup, taste, aroma, or pH of the treated liquid. This aspect holds particular significance within the bottled water and beverage sectors, where chemical dosing of incoming process water can result in undesirable flavors and changes to the final product’s chemical attributes.

UV treatment serves multiple roles, acting as a primary method for water disinfection or as a supplementary measure alongside other purification techniques like carbon filtration, reverse osmosis (RO), or pasteurization. Since UV treatment doesn’t leave behind any residuals, the optimal setup for a treatment system is just before the point of use (POU). This arrangement guarantees the elimination of microbiological contaminants from incoming water and minimizes the potential for contamination after treatment.

UV Applications in Beverage Industry

Spring Water and Municipal Supplies

While incoming spring water and municipal sources typically lack harmful or pathogenic microorganisms, this assumption should not be taken for granted. UV disinfection effectively treats such water without the use of chemicals or pasteurization. Moreover, UV enables the recycling of process water, leading to cost savings and heightened productivity, all while maintaining product quality.

Sugar Syrups

Sugar syrups utilized for flavoring purposes can serve as fertile breeding grounds for microorganisms. While syrups boasting exceptionally high sugar concentrations typically discourage microbial proliferation, any latent spores may become viable once the syrup is diluted. By subjecting both the syrup and dilution water to UV treatment before deployment, any dormant microorganisms can be effectively neutralized.

CIP

Maintaining the microbiological safety of the CIP (Clean-In-Place) final rinse water, which is employed to expel foreign substances and disinfecting agents, is paramount. Seamless integration of fully automated UV disinfection systems into CIP rinse cycles guarantees that the concluding rinse water remains devoid of microbiological impurities. Thanks to their robust construction, MP lamps are immune to abrupt shifts in CIP water temperature, including scenarios where scalding (80°C/176°F) liquid is immediately followed by cold (10°C/50°F) liquid.

Disinfection of Filter

Stored filtrate from reverse osmosis (RO) and granular activated carbon (GAC) filtration is frequently employed for processing water, yet it can inadvertently foster bacterial growth. UV treatment presents an efficient solution for disinfecting both stored RO and GAC filtered water, a method that has been utilized in various process industries for an extensive period.

Dechlorination

Granular activated carbon (GAC) filters frequently serve to dechlorinate process water, eliminating the undesirable taste often linked to chlorine disinfection. This ensures the final product maintains its natural flavor, devoid of any undesirable tastes or aromas. Integrating UV systems prior to GAC filters employed for dechlorination enhances filter efficacy, extending the lifespan of carbon runs and subsequently reducing operational expenses.

Disinfection of Packaging & Surface

Surface disinfection systems find application in diminishing microbial populations on diverse packaging materials such as glass and plastic bottles, cans, lids, and foils. Through subjecting these surfaces to UV radiation prior to the filling process, the presence of food spoilage microorganisms is eradicated. This elongates the product’s shelf life and curtails the potential for contamination.

Disinfection of Tank Head Space

UV systems have the capability to disinfect displacement air intended for pressurizing tanks or pipelines containing perishable liquids. Storage tanks, in particular, are vulnerable to bacterial colonization and the infiltration of air-borne spores leading to contamination. As a preventive measure, immersible UV treatment systems have been developed to seamlessly integrate into the headspace of the tank, effectively disinfecting the enclosed air.

Wastewater

Wastewater generated by manufacturing facilities can undergo treatment without resorting to ecologically harmful chemicals. This guarantees that all effluents align with local environmental mandates. As previously discussed, the UV treatment of process water not only enables its reclamation but also substantially curtails the volume of wastewater generated.

Conclusion

Conforming to the progressively stringent hygiene criteria essential for bottling water and producing beverages presents a substantial challenge. Any enhancements made to the facilities and machinery must yield swift returns on investment while delivering quantifiable enhancements in product quality.

For manufacturers aiming to enhance the final product’s quality, opting for UV disinfection system presents a viable and cost-effective solution. This method of disinfection has already gained widespread acceptance for treating drinking water on a global scale. It is extensively employed in applications demanding high purity, such as pharmaceutical and semiconductor manufacturing, where the utmost water quality is imperative.

The installation of UV disinfection systems is straightforward and causes minimal disruption to the facility. These systems entail minimal maintenance, requiring only the replacement of UV lamps approximately once a year, contingent on usage. This uncomplicated task takes just a few minutes and can be performed by general maintenance personnel.