Carbonated soft drinks (CSD) are popular around the globe with billions sold each year. Carbonated beverages are available in bottles, cans or through fountain dispense — often used in quick-serve restaurants (QSR). A soft drink dispenser, a.k.a. a soda fountain combines flavored syrup and carbon dioxide (CO2) with chilled, purified water. Post mix syrup is supplied and pumped from bag-in-box (BIB) containers. Virtually all of the popular brands of soft drinks are now available in this format.
Adding carbon dioxide to a beverage carries the risk of product contamination with potentially expensive consequences — including off-flavors and odors, spoilage, product recalls and damaged reputation.
Consumers expect high quality and consistent taste. Foul taste, odors, and off-appearance can change the way they view the product and may alter their decision to buy more of it — directly impacting the food and beverage manufacturer’s bottom line. Left unchecked, this can have a dramatic impact on their reputation and success in the market.
It is the responsibility of soft drink manufacturers to adhere to national regulations based on codes and standards ensuring that their BIB post-mix syrup meets regional legislation. In the United States, soft drinks are regulated by the Food and Drug Administration (FDA). Soft drink ingredients must comply with all applicable FDA safety requirements which are globally recognized.
The ISBT changed its Fountain Carbon Dioxide Quality & Food Safety Guideline in 2016 on the use of an in-line CO2 protection device from optional to recommended, such are the concerns in the industry about contaminants being introduced through the CO2.
Approximately 90% of a conventional CSD serving is composed of water, with the remaining 10% consisting of the post-mix syrup and CO2. The CO2 content is low, usually between 0.3% - 0.6%. The recommended quality steps are undertaken to ensure a quality soft drink by the soft drink post-mix syrup suppliers include sterilization checks, temperature checks, the inclusion of a line water filter system, and the checking of fresh syrup use-by dates.
To protect the consumer and guarantee taste, the use of a CO2 filter is now recommended and is used in the same way as the water filter.
A quality incident is defined as gas delivered to the point-of-use with contamination levels exceeding the specification in the table below:

Concerns are mounting in the beverage industry over poor quality carbon dioxide used in carbonation of beverages — resulting in a greater focus placed on the purity of CO2 used in fountain dispense.
In CSD dispense food-grade, CO2 is recommended for CSD dispense. This grade of gas has a purity of 99.9%. Failure to comply with these standards could result in a quality incident.
ISBT (International Society of Beverage Technologists) & EIGA (European Industrial Gas Association) both have International recommended standards. In these standards, potential contaminants are named with a critical PPM limit of acceptance, referenced in table 1. CO2 used in CSD fountain dispense is generally supplied by gas supply companies using cylinders or by replenishing on-site mini-bulk tanks. The quality of CO2 is controlled and monitored at the production plant and will be accompanied by a certificate of analysis from the gas supplier.
Using ISBT food-grade gas still comes with the risk of post-shipment contamination, such as:
CO2 quality incident protection systems, such as Parker's PC02-400 system, offer a comprehensive solution to preserve and guarantee the quality of gaseous carbon dioxide used in the CSD bottling industry. The PCO2 is installed to protect against poor quality contaminated gas which may pass through the supply chain and into the beverage during the bottling process. As with the CSD bottling process, the CO2 gas used in fountain dispense must be free of particles, micro-organisms and unwanted chemical compounds. The existence of these contaminants may result in a quality incident.
The Parker PCO2-400 system has been designed to operate within the CO2 flow rate requirements of a typical quick-serve restaurant or beverage dispense facility that uses a mini-bulk supply of CO2. Located post cylinder, the single-column system will act as a protective barrier against any potential impurities that may be present in the gas stream guaranteeing CO2 quality and consumer protection.
Parker's three-layered adsorbent bed adsorbs contamination as it flows through. The three materials preferentially adsorb differing contaminants providing effective protection against a wide spectrum of potential contaminants known to create beverage flavor defects.
Below is a typical installation of the Parker PCO2 system:

Quality standards in the food and beverage industry are stringent and are under constant review. CO2 usage is subject to active guidelines to ensure the quality of gas remains within safe limits for contaminants and impurities. Parker’s multi-bed technology is well established in bottling plants throughout the world, helping producers to reduce the risk of quality incidents, ensure the beverage maintains its high-quality taste, and maintain brand reputation. Parker CO2 Quality Incident device provides the same protection for quick-serve restaurants — meaning the same multi-bed technology can successfully be used as a quality incident protector for point of use fountain dispense.
Now, watch this video to learn more about the PCO2 system.
This blog was contributed by Danny Silk, product manager, specialist filtration, Parker Gas Separation and Filtration Division, EMEA.
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