Water Conditioning & Purification Magazine

The Risk of Pure Water Microbial Contamination in Beverage and Service Appliances

By James Peterson

While centralized or equipment-inlet purification systems address source-water quality and contamination concerns for commercial beverage and service equipment, they are not addressing the full scope of risk in products, particularly as these appliances become more complex. Recent trends indicate that consumers are looking for added features, such as flavoring and carbonation in their water appliances. For instance, nearly 574 million gallons of sparkling water were sold in the US in 2016 alone (worth $6.1 billion), compared to 263 million gallons in 2011 (worth $2.6 billion).(1) As new features are incorporated into product design, however, the most important feature, purification/sterilization, becomes increasingly challenging to ensure a hygienic environment within the appliance.

When water is brought into or enters an appliance, it flows through an initial filtration unit to remove chlorine, making the water vulnerable to rapid microbial contamination. Improper water quality management in appliances can not only pose a significant health risk, it can also result in expensive ongoing maintenance and unexpected repairs. Implementing water purification in beverage and service appliances is essential when designing safe products that also align with consumer trends.

Growing complexity of water-based appliances
Consumer preferences for beverage consumption have become increasingly complex over recent years to go beyond just selecting tap versus bottled water or regular versus decaf coffee. For instance, trace minerals are now considered a crucial factor to the way water tastes, and can affect the taste of beverages like coffee, espresso and tea. From a wellness perspective, balancing the mineral content, pH or additions of functional extracts or nutrients has brought the market into the high-value region of consumer wellness. Sparkling water has also gained popularity, with some brands becoming trendier among consumers. In the same vein, consumers are increasingly looking beyond regular drip coffee to cold brew, espresso and lattes.

As a result of shifting trends in water and coffee consumption, there is a growing market opportunity to design appliances that offer more features to meet these consumer demands. Manufacturers are eager to capitalize on this opportunity and are looking to offer as many of these functions in one appliance as possible. For instance, one system includes flavoring, carbonation and sweetener options all in one machine. Coffee appliance makers are creating all-in-one solutions to offer a wide variety of coffee and tea beverages. Regardless of whether an appliance offers one or 20 water-based drinks, there is one feature that must always be a top priority: purity.

Increased risk of water contamination
Whether a product is dispensing coffee, flavored or sparkling water, appliance manufacturers are responsible for ensuring that the appropriate purification methods are in place. As the focus moves from safety to luxury in the design process, there are new risks for bacteria growth from these feature and component additions. The first line of defense is traditionally chlorine, which is used to minimize the growth of microorganisms as water flows from the treatment source to the tap or appliance at the other end. Once water travels from the source and reaches the appliance, it will often pass through a carbon filtration device to remove the chlorine, not only to make it safe for consumption but also to improve the taste and odor of the water.
When dechlorinated water moves into a storage tank, heater or chiller (depending on the appliance), it’s now unprotected against opportunistic waterborne pathogens and vulnerable to contamination. For example, water sitting static in a storage tank, especially in heating appliances, warms to the ambient temperature, creating an environment where biofilm may form, which can host a range of bacteria, algae and other microorganisms. The most common points of vulnerability or risk within an appliance include:

  • Inlet water. Both benign and potentially pathogenic bacteria can enter a system from aging infrastructure.
  • Inlet filter. Once organisms (benign or pathogenic) get into the filter, they can continue to multiply, generating concentrations of microorganisms higher than what may be just harmless levels from the tap.
  • Hot/cold storage tanks. When filled or even just damp, these tanks continue to provide an environment for bacterial growth.
  • Spigot or tap. Exposure to air can quickly support and accelerate the growth of microorganisms on the surface of the tap, potentially spreading the bacteria back into the appliance lines.

How to incorporate water purification into modern water systems
Minimizing bacteria once present is time consuming and expensive. It is therefore critical to have the right tools and processes in place to mitigate the risks before they become a problem. Every system, whether serving a single-family home, a large corporate office or more sensitive populations such as schools or healthcare facilities, should have some form of end-of-line disinfection to provide treatment to the problem itself rather than relying on intermittent sanitization shut-downs or constantly reacting to contamination issues after they occur. There are several methods for mitigating contamination risks within a complex water system. For instance, high-performance microbial filtration cartridges use extremely fine membranes to filter out microorganisms and reduce bacteria. While effective, these advanced membranes generally require expensive annual replacements and have the potential to clog if particulate levels in the water exceed membrane ratings. Another approach is to implement a regular (and frequent) schedule for sanitizing equipment, which is commonly recommended by the appliance manufacturer.

Mercury lamp UV systems are also highly effective at reducing microorganisms, but they are less efficient and must be replaced at least annually at each dispense location. With UVC LED systems, the disinfection technology is similar to that of mercury lamps but with a smaller footprint and extended lifetime. Similar to LED light bulbs, this LED chip technology requires less frequent maintenance and offers more consistent performance from on/off cycling for most dispenser systems. Also due to their small size, UVC LEDs can be integrated into appliance locations where UV lamps have been historically challenging to use. As a result, appliances are now beginning to emerge with LEDs integrated directly into tanks or spigots to help protect those areas that can support bacterial growth between cleaning cycles.

The future of consumer water appliances
As beverage appliances become more complex in features and with the growth of bottle fillers—both for the hotel, restaurant and café industries as well as consumer use—more beverages are going through some kind of purification process. While there is so much opportunity for innovation and growth in the water market as a result of evolving consumer trends, there are new risks and concerns for consumer safety that need to be addressed head-on during the design and installation processes. It is critical to equip appliances such as coffee makers, water coolers and beverage dispensers with the proper tools and technology to ensure that they are dispensing safe, clean water.

References

  1. USA Today. “Fizz quiz: What’s the hottest new thing in soft drinks?” https://www.usatoday.com/story/money/food/2018/02/01/flavored-sparkling-water-sales-bubbling-up/1059761001/

About the author
James Peterson is responsible for the strategic direction of Crystal IS products focused on water markets. He develops business models for UVC emitters and ensures these product lines meet specific customer needs in water markets. Prior to Crystal IS, Peterson co-founded Vital Vio, a company that designs, engineers and manufactures LED lighting systems that reduce bacteria and other organisms from at-risk environmental surfaces.

About the company
Crystal IS, an Asahi Kasei company, is a manufacturer of high-performance UVC LEDs. The company’s products are suitable for monitoring, disinfection and sterilization in a variety of applications, including commercial and consumer POU water purification, as well as infection control in air and on surfaces in healthcare industries. For more information, visit cisuvc.com.

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