|
Monitoring Beverage Grade CO2 for Impurities
|
|
Judy Williams
April 01 , 2015
|
|
|
Carbon Dioxide (CO2) is a colourless, odourless and flavourless gas liquefied and used for the carbonation of soft drinks and other carbonated beverages. Not only does CO2 provide the bubbles in carbonated beverages, it also acts as a preservative. Seems simple; colourless, odourless, flavourless, what can the problem be?
Carbon dioxide has many sources worldwide and is often produced as a side product of a variety of different processes throughout different industries. Some of these processes include fermentation, combustion, ammonia and hydrogen production, as well as the creation of bioethanol. There are also natural wells of carbon dioxide throughout the world. With the diverse production processes and the complicated supply chain, there are ample opportunities for contaminants to be present in CO2.
CO2 contamination
Although all food and beverage grade CO2 undergoes a purification process, sometimes trace impurities make their way into the supply. There have been incidents in the past where CO2 contamination has made it to the finished product. The tangible and non-tangible costs associated with rebuilding reputations and restoring consumer confidence could have been eliminated had trace impurities in the CO2 been detected prior to the bottling or canning process.
The International Society of Beverage Technologists (ISBT) was created to act as a committee to set and govern standards for CO2 quality. These standards are voluntary and have been adopted and widely accepted in the US and other countries as well. The ISBT Guidelines are used by both CO2 suppliers and beverage manufacturers.
Analytical methods
In addition to Quality Guidelines, there is a section that addresses Analytical Methods. The quality section outlines the impurities, their impact on the finished product and the acceptable levels to maintain quality and safety standards. The analytical methods section provides guidelines on proven analytic methods and instruments that can be used to identify these impurities. Using the proper analytical instrumentation both CO2 suppliers and bottlers can ensure that the product supplied and used in the carbonation process is at an acceptable safety level.
Ensuring quality
To ensure only high-quality CO2 is used in the final beverage product, the CO2 should be analysed at all transfer points. Before it leaves the suppliers, when it arrives at the beverage plant and then prior to being used in the final product. Analysing at these points throughout the process ensures that there are no contaminants added from the transport or storage processes.
Baseline a Mocon company, provides analytical solutions for monitoring trace impurities in CO2at both the supplier and bottlers facilities. Baseline’s analysers exceed the ISBT performance criteria and adhere to recommended methodologies for the specified impurities. This is not the case for all beverage CO2 monitoring systems. For further information regarding ISBT and their standards, go to their website www.bevtech.org.
Some of the critical trace impurities Baseline instrumentation monitors for include total hydrocarbons, aromatic hydrocarbons (BTEX), acetaldehyde, methanol and sulfur.
See the table for the impact the impurity has on the finished product and the recommended analysis method.
Impurities Analysis
AMB – Acetaldehyde, Methanol & Benzene
AMB impurities in CO2 can impart off odours or flavours into a finished product. Benzene is considered a carcinogen and is a regulated contaminant. Baseline’s BevAlert Series 8900 Gas Chromatograph is used to analyse for these components. Utilising a photoionisation detector (PID), the AMB in the gas sample is separated in the column and then sent to the detector for the analysis of each of these gases. The analysis can be completed less than 360 seconds with lower detection limits of < 50 ppb acetaldehyde, < 2 ppm methanol and < 2 ppb benzene.
ABTEX – Acetaldehyde, Benzene, Toluene, Ethylbenzene and Xylenes
The ABTEX analysis is also completed using the BevAlert Series 8900 Gas Chromatograph (GC). Acetaldehyde imparts sensory effects on the CO2 while the aromatic hydrocarbon component (BTEX) is a regulated contaminant. Once again the Series 8900 BevAlert GC is equipped with a PID. This analysis can be completed in < 720 seconds with lower detection limits of < 50 ppb acetaldehyde, < 2 ppb benzene, < 5 ppb toluene, < 5 ppb ethylbenzene and < 5 ppb xylene.
Total Sulfur
Sulfurous compounds in CO2 can impart off odours and flavours into the finished beverage. The analysis performed by the BevAlert Series 8900 is a total sulfur analysis. This is performed by converting all sulfurs to hydrogen sulfide. The conversion is done to comply with the ISBT requirements of a total sulfur reading. Equipped with a photoionisation detector (PID) the analysis is completed in about 300 seconds with lower detection limits of < 20 ppb hydrogen sulfide.
Depending on the source of the CO2, other impurities may be present. Baseline’s analysers can also measure vinyl chloride, hydrogen sulfide, ethanol, n-Pentane, ethylene oxide, dimethyl ether as well as others.
For hydrocarbon counts, the Baseline Series 9000 Total Hydrocarbon Analyzer (THA) is used. The Series 9000 THA operates in a continuous mode with a response time of < 5 seconds and identifies the presence of hydrocarbon concentrations. Utilising a FID (flame ionisation detector) due to its sensitivity and specificity for hydrocarbons, the Series 9000 has a lower detection range down to < 10 ppb.
These instruments can be used for individual analyses or as a complete system. The BevAlert Analytical System was designed specifically for on-site use in the bottling facility, although many CO2 suppliers find it useful to have all the instrumentation contained in one cabinet as well.
The BevAlert Analytical System (automated version) incorporates all the instrumentation into a NEMA 3R wash down rated cabinet with multipoint sampling options. The system is fully automated with integrated software and a LCD touchscreen display panel. Since sampling is done at multiple points, this allows the system to monitor and a step through a complete analysis of a common sample at the same time.
The analysis results refer to the same sample point at the same time making it easier to track data and quality results by the source. All analysis results can be combined for easy generation of a Certificate of Analysis. Remote control capabilities allow for the sample to be initiated from different locations, this is especially useful for incoming trailer sampling.
Baseline’s instruments and systems are well known in the industry for their CO2 monitoring capabilities and are approved by CO2 suppliers and soft drink bottling companies.
The overall quality of any carbonated beverage is derived from the quality of its ingredients. Because of the diversity of CO2 sources worldwide it is important to analyse for impurities. For quality assurance, brand confidence and reliability take a proactive approach and detect any trace impurities prior to the bottling process.
(The author is sales and marketing coordinator, Baseline,
Inc. Lyons [www.baselineindustries.com.])
|
|
|
|
|
|
|
|
TOPICS
|
That foods might provide therapeutic benefits is clearly not a new concept. ...
|
|
|
|
|