UV Disinfection of Liquids in Food & Beverage Production
Major food and beverage producers around the world use UV disinfection to provide micro-biologically pure water and ingredients, which help protect the flavour and shelf life of their products. Food and beverage producers build their reputation around the purity of the product, emphasising the fact that it is natural. UV disinfection is favoured by food and beverage producers worldwide because it doesn't adulterate the flavour of the end product.
Outbreaks of water-borne pathogens can place food and beverage producers at high risk of damaging product recalls and product liability exposure. In addition, UV disinfection effectively extends the shelf life of the end product, providing huge cost savings for producers.
Advantages of Using UV Disinfection in Food & Beverage Production
Ultraviolet disinfection is the most cost effective method of water disinfection and process water treatment, it is superior to alternatives, it's safe and has no detrimental effects.
UV water treatment and process water treatment is effectively monitored in Hanovia UV systems
Permanent, accurate ultraviolet disinfection records are produced, so all batches can be traced, which is ideal for ISO9000 etc
Ultraviolet disinfection is the most cost effective method of water disinfection
Superior to Alternatives
Chlorine is often unacceptable because of flavour effects
Sterile filtration does not remove all the spores from the water
Ultraviolet disinfection is the most environmentally friendly way to reduce the number of viable organisms, without causing further pollution.
No Detrimental Effects
UV disinfection has no effect on pH, colour, flavour or aroma
UV disinfection has no detrimental effect on product stability
UV disinfection leaves no residue
WIth UV disinfection overdosing is not possible
Safety
With UV disinfection no hazardous chemicals are required
With UV disinfection no toxic by-products are produced
Watch the Video About Performance Qualified UV Disinfection Systems (see below)
How Does Ultraviolet Disinfection Work?
Ultraviolet energy causes permanent inactivation of micro-organisms by disrupting its DNA so that they are no longer able to maintain metabolism or reproduce. All bacteria, spores, viruses and protozoa (including Cryptosporidium and Giardia oocysts are permanently inactivated by UV). The maximum effectiveness occurs at between 240nm and 280nm. The Hanovia UV systems produce these wavelengths in abundance.
The Mechanism of Ultraviolet Disinfection
Strong sunlight disinfects water by permanently de-activating bacteria, spores, moulds and viruses. Over a century ago, scientists identified the part of the electromagnetic spectrum responsible for this well-known effect; wavelengths between 200nm and 300nm, often called UV-C. The most effective single wavelength is typically UV at 265nm, however recent research in the USA has shown that 271nm light and 263nm light are the most effective UV wavelengths for the deactivation of particular target organisms.
The mechanism of kill is well documented and unlike chemical disinfectants the organism is unable to develop any immune mechanisms. The mechanism of kill involves the absorption of photons of UV energy by the DNA, which fuses the DNA and prevents replication. DNA (Deoxyribonucleic acid) consists of a linear chain of nitrogen bases known as purines (adenine and guanine) and pyrimidines (thymine and cytosine). These compounds are linked along the chain by sugar-phosphate components. The DNA of most forms of life is double stranded and complimentary; the adenine in one strand is always opposite thymine in the other, and linked by a hydrogen bond, and guanine is always paired with cytosine by a hydrogen bond. The purine and pyrimidine combinations are called base pairs. When ultraviolet light of a germicidal wavelength is absorbed by the pyrimidine bases (usually thymine) the hydrogen bond is ruptured. The dimer that is formed links the two bases together, and this disruption in the DNA chain means that when the cell undergoes mitosis (cell division) the DNA is not able to replicate. The most effective wavelengths to achieve this effect are found between 263nm to 275nm, and the peak wavelength distribution is dependent on the target organism.
The optimal operating temperature is 15oC, and the lamp output will fall off rapidly as the lamp temperature migrates from this condition. These lamps should not be used if the water is hot or cold, or if the water flow is intermittent as the temperature build up will cause the lamp output to decrease. Frequent switching of these lamps will have a detrimental effect on lamp life, and the most probable failure mode will be failure of the filaments, which become brittle. The article "The dying of the light" describes the variable output of these mass produced lamps and offers some suggestions as to how the performance might be optimised. Typically these lamps have an efficiency of 25-30%, which is temperature dependent. The lamp life is typically 8000 hours, and the lamps have the advantage of being mass produced and easily second sourced.
Amalgam lamps have been developed recently to overcome the problems associated with traditional low-pressure technology. This type of lamp contains a mercury amalgam, and typically up to 120mg of mercury is contained in each lamp. The Amalgam lamp is typically very long, and not unusually can be more than 1.5 m (5 feet) in length. Once switched on, the Amalgam lamp output is not effected by water temperature fluctuations, however the large size of the lamp does mean that they can take up to 800 seconds to get to full power, and the warm up time is temperature dependant, as the successive strikes below illustrate.
Ultraviolet Disinfection Applications
Research is now being undertaken to verify the effect that shorter wavelength ultraviolet light has on the other cell membrane of the organism. This shorter wavelength is more energetic and is absorbed by the organisms outer membrane. A lethal insult is effected, which means that the cell is unable to effectively regulate osmotic pressure. This effect coupled with the fusing of the DNA means that UV is a simple, elegant disinfectant and one that will increasingly replace the more traditional chemical techniques.
The Production of Ultraviolet Light
Ultraviolet light is most typically generated from a low pressure or a medium pressure lamp. These lamp types are different in character and performance, and are described below:
Low Pressure ultraviolet lamps are the most common lamp type and are the oldest source of ultraviolet light. The consist of a quartz envelope that separates two tungsten filaments. The lamp is evacuated to <10torr and approximately 60mg of mercury is introduced into the quartz envelope. The spectral output of this lamp type is monochromatic, a single line output at 253.7nm. A fluorescent lamp is a low-pressure lamp that has the inner surface of the lamp coated with phosphors to absorb all of the 253.7nm light, and only emit the longer wave visible light. This lamp type is typically 1 meter (3 feet) in length. This lamp has an output that is temperature dependent and can take up to 400 seconds to get to full output in cool or hot water.
The medium pressure ultraviolet lamp that is built by Hanovia is designed to have a spectral output that is specifically enhanced in the germicidal region. These lamp types are often called polychromatic, as they have a continuous output from 200nm up to the long wave visible light. Medium pressure lamps have a deeper vacuum produced within the quartz envelope (typically 1000 torr) and a 3.5Kw lamp will contain approximately 300mg of mercury. The Hanovia lamps have an efficiency of between 15% to 20%, depending on lamp type, and typically 15 low pressure lamps or 6 amalgam lamps will have a comparable output. The medium pressure lamp is hot running and typically the lamp surface will reach 800oC, however the protective sleeve that separates the lamp from the fluid being treated will not usually rise above 60oC. An over temperature detector will power down the lamp should the water flow stop for an extended period. Medium pressure lamps are typically from 20cm to 1.5M in length and a variety of quartz types are selected depending on the required spectral output; pure fused silica is used for disinfection, dopants are introduced to enhance particular spectral regions, or to inhibit ultraviolet wavelengths which at extremely high ultraviolet doses could have detrimental effects.
The Hanovia ultraviolet lamps are built at the Slough factory in a clean room environment. Every lamp is individually tested before despatch, and each batch is 100% documented to ensure that in the unlikely event of a lamp failure, every lamp made in the suspect batch can be traced. Hanovia manufactures in excess of 12,000 lamps per annum. Each lamp is individually numbered and any lamp failure is investigated and a failure mode analysis report generated.
Ultraviolet Technology in Use
Ultraviolet technology is now applied by a broad range of operators from municipal effluent to ultrapure rinse water, and from viscous high brix sugar syrups to air. The technique has been successfully extended to disinfect packaging materials prior to filling, and new developments have included the use of UV to deodorise nuisance smells from industrial or municipal dischargers. Ultraviolet is also applied to drinking water to assist in the destruction of pesticides or other contaminants that have entered the aquifer, such as NDMA or MTBE. In each case, the ability of a monitoring system to measure the fluence being emitted by the lamp allows the operators to have confidence in the integrity of the system. Hanovia systems are designed to be fail safe and the control protocols that are used will not allow untreated water of effluent to be sent forward. The dedicated ultraviolet monitor measures the output from each lamp. The monitors are sealed and do not allow any operator adjustment. The Hanovia ultraviolet monitor measures intensity in absolute units of mw/cm2. An online transmittance monitor measures the transmittance of the fluid being treated, and not unusually surface water can have a very high fluctuation in transmittance. Use is made of data logging facilities to demonstrate the adequacy of treatment, and to provide a permanent record of disinfection. This transparency is often required by a regulator or by those further up the supply chain to demonstrate that the water used to make product or water used as a part of the manufacturing process in wholesome.
Applications of UV Water Treatment in Food & Beverage Production
Pre-treatment disinfection
Direct contact fluids and ingredients
CIP, Bottle Rinse or Wash Waters
Liquid Sweeteners
Tank headspace and Venting
And many others
Pre-treatment Disinfection
Placement of the UV treatment system ahead of the carbon filters for dechloramination provides higher carbon filter efficiency resulting in longer carbon runs, thus decreasing your operating costs. In addition to extending the life of carbon beds, dechlorinating process water will remove the off-flavours associated with chlorine disinfection. The flavour of the final product will remain unadulterated and free from undesirable flavours and odours.
Post Carbon
The carbon filter forms an ideal environment for micro-organisms to grow rapidly, thus producing biological contamination. UV disinfection of carbon filtered water has been an accepted application for many years. Ozone has the same detrimental effects on beverage flavours as chlorine compounds, thus ozone must be removed from product waters. UV systems also provide a safe, simple means of deozonation.
Material Storage Tanks and Venting
Material storage tanks require protection as well, eliminating intrusion during drain and fill operations.
CIP, Bottle Rinse or Wash Water
Even water used to clean surfaces or used in CIP operations can be a source of contamination. UV is an approved method of reducing bacteria without the use of chemicals
Liquid Sweeteners
Sucrose based sweeteners can be prime breeding ground for micro-organisms. UV can directly treat the syrups.
Wastewater
Process plant effluents can be treated without the use of environmentally hazardous chemicals.
Aquaculture
Fluidquip Australia have supplied Hanovia UV Disinfection systems to some of Australia's largest Aquaculture facilities for several decades. To view more on Aquaculture click here.
Direct Contact Water or Ingredient Water
UV can disinfect direct contact or ingredient water preventing contamination without chemicals or pasteurisation.
Tank Headspace
Material storage tanks require direct headspace protection as well as eliminating intrusion during drain and fill operations.
Find Out Where UV Disinfection Fits Into Your Existing Bottled Water Production Processes
Hanovia Pureline UV disinfection systems have been designed specifically for the chemical free treatment of water used in the production of beverages. A Pureline UV disinfection system can easily fit into existing pipework and existing processes.
In an increasingly regulated and safety-conscious market food & beverage industries have to meet ever more stringent standards on water quality and bio-security. UV is ideal for these applications as it is both effective and chemical-free. Bio-security is very important to understand from both the supplier and customer perspective. It is a fine balancing act between providing an appropriately-sized treatment system on the one hand while ensuring viable cost of ownership on the other.
UV Treatment of Water in the Food and Beverage Industries
In an increasingly regulated and safety-conscious market, the food and beverage industries have to meet ever more stringent standards of quality. Microbial growth due to contaminated water or ingredients can cause discolouration, off flavours and shortened shelf-life. The threat of contamination is further increased as manufacturers respond to demands for less chemical additives and preservatives. Effective microbial disinfection of the whole process is therefore essential. UV treatment of water is ideal for the food & beverage industries.
A non-chemical disinfection method which is gaining increasing acceptance is UV treatment of water. UV treatment of water kills all known spoilage microorganisms, including bacteria, viruses, yeasts and moulds (and their spores). It is a low maintenance, environmentally friendly technology which eliminates the need for chemical treatment while ensuring high levels of disinfection.
Benefits of UV Treatment of Water
UV treatment of water has many advantages over alternative methods. Unlike chemical treatment, UV treatment of water does not introduce toxins or residues into process water and does not alter the chemical composition, taste, odour or pH of the fluid being disinfected.
UV treatment of water can be used for primary water disinfection or as a back-up for other water purification methods such as carbon filtration, reverse osmosis or pasteurisation. As UV treatment of water has no residual effect, the best position for a treatment system is immediately prior to the point of use. This ensures incoming microbiological contaminants are destroyed and there is a minimal chance of post-treatment contamination.
Direct contact water
Although municipal water supplies are normally free from harmful or pathogenic microorganisms, this should not be assumed. In addition, water from private sources such as natural springs or boreholes could also be contaminated. Any water used as an ingredient in food or beverage products, or coming in direct contact with the product, can therefore be a source of contamination. UV treatment of water disinfects this water without chemicals or pasteurisation. It also allows the re-use of process water, saving money and improving productivity without risking the quality of the product.
CIP (Clean-in-Place) rinse water
It is essential that the CIP final rinse water used to flush out foreign matter and disinfecting solutions is microbiologically safe. Fully automated UV treatment of water can be integrated with CIP rinse cycles to ensure final rinse water does not reintroduce microbiological contaminants. Because of their mechanical strength, MP lamps are not affected by any sudden changes in the temperature of the CIP water.
Filter disinfection
Stored reverse osmosis (RO) and granular activated carbon (GAC) filtrate is often used to filter process water, but can be a breeding ground for bacteria. UV treatment of water is an effective way of disinfecting both stored RO and GAC filtered water and has been used in the process industries for many years.
Dechlorination
GAC filters are also often used to dechlorinate process water, removing the ‘off’ flavours often associated with chlorine disinfection, meaning the flavour of the final product remains untainted and free from unwanted flavours or odours. UV treatment of water ahead of GAC filters used for dechlorination improves the performance of the filters and results in longer carbon runs, so decreasing operating costs.
Sugar syrups
Sugar syrups can be a prime breeding ground for microorganisms. Although syrups with a very high sugar content do not support microbial growth, any dormant spores may become active after the syrup has been diluted. UV treatment of water , both syrup and dilution water prior to use will ensure any dormant microorganisms are deactivated.
UV treatment of wastewater
Effluent from beverage manufacturing facilities can be treated without the use of environmentally hazardous chemicals. This ensures all discharges meet with local environmental regulations. As already mentioned, because process water can be treated and re-used with the UV treatment of water this also leads to a significant reduction in the amount of waste water produced.
UV Disinfection of Liquids in Food & Beverage Production
