The Role of UV in the Food, Beverage and Brewing Industries

12/11/2015 - 03:42

Perry Henderson


Anderson Dahlen Inc. becomes an authorized distributor of Aquionics Ultraviolet (UV) disinfection, deozonation, and dechlorination products. Aquionics is a North American supplier of food, beverage, pharmaceutical, and industrial UV disinfection equipment.


Introduction

The food, beverage and brewing industries operate under exacting safety and quality standards. Any microbial contamination in the process can cause discoloration, affect flavor and shorten shelf-life, not to mention potential health risks to consumers. Effective microbial disinfection of the whole process is therefore essential.

An increasingly popular non-chemical disinfection method is ultraviolet (UV) disinfection. UV eliminates all known spoilage microorganisms, including bacteria, viruses, yeasts and molds (and their spores). It is a low maintenance, environmentally friendly technology which eliminates the need for chemical treatment while ensuring high levels of disinfection.

How UV disinfection works

UV is the part of the electromagnetic spectrum 185-400nm (known as UV-C). These wavelengths of light have a very strong ‘germicidal’ effect, destroying microorganisms by inactivating their DNA and other intracellular molecules. It is especially effective against microorganisms such as Listeria, Legionella and Cryptosporidium (and their spores, which are resistant to chlorine).

A typical UV disinfection system for processing applications consists of a UV lamp housed in a protective quartz sleeve and mounted within a cylindrical stainless steel chamber. The liquid enters at one end and passes along the entire length of the chamber before exiting at the other end. Virtually any liquid can be effectively treated with UV, including raw municipal water, filtered process water, viscous sugar syrups, beverages and industrial effluent.

Benefits of UV Disinfection

UV disinfection has many advantages over alternative methods. Unlike chemical treatment, UV does not introduce toxins or residues into process water and does not alter the chemical composition, taste, odor or pH of the fluid being disinfected.

UV treatment can be used for primary water disinfection or as a back-up for other water purification methods such as carbon filtration, reverse osmosis or pasteurization. As UV 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.

UV applications in the food, beverage and brewing industries

Direct contact water
Although municipal water should be free from harmful or pathogenic microorganisms, it should still be treated before entering the process. Water from private sources such as natural springs or boreholes – often used in mineral water – could be contaminated and absolutely has to be treated. In effect, any water used as an ingredient in food or beverage products, or coming in direct contact with the product, can be a source of contamination. UV disinfects this water without chemicals or pasteurization. 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 disinfection systems can be integrated with CIP rinse cycles to ensure final rinse water does not reintroduce microbiological contaminants.

Filter disinfection
Reverse osmosis (RO) and granular activated carbon (GAC) are often used to filter process water, but can be a breeding ground for bacteria. UV 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' flavors often associated with chlorine disinfection, meaning the flavor of the final product remains untainted and free from unwanted flavors or odors. Placing UV systems ahead of GAC filters used for dechlorination improves the performance of the filters and results in longer carbon runs, so decreasing operating costs.

Cooling media and chiller disinfection
Some meat and dairy products are subject to contamination after heat treatment or cooking. UV provides an excellent way to protect foods from contamination by contact-cooling fluids.

Sugar syrups
Sugar syrups can be a prime breeding ground for microorganisms. Although syrups with very high sugar content do not support microbial growth, any dormant spores may become active after the syrup has been diluted. Treating the syrup and dilution water with UV prior to use will ensure any dormant microorganisms are deactivated.

Liquid sweeteners
Sucrose-based sweeteners can be a prime breeding ground for microorganisms. UV systems are available specifically for treating these syrups.

Dairy
UV Systems can provide a time- and cost-effective alternative to standard pasteurisation – and UV Systems are recognized in the US Food and Drug Administration’s 2011 Pasteurized Milk Ordinance guidelines.

Brine
Brines can also be a breeding ground for harmful pathogens, so effective UV treatment is essential. UV dramatically slows the growth of microorganisms, allowing the brine to be used for longer and saving costs for the producer. Another benefit of UV is that it will not affect the taste or appearance of the product being used in the brine.

De-aerated liquor
De-aerated liquor is added as part of a high gravity brewing process, often in the packaging operation. This liquor is added directly to the beer so needs to be kept free from contamination by gram negative bacteria, which can cause off-flavors and acidity.

Yeast preparation
The problems associated with yeast preparation in breweries are well recognized and include hazes, altered fermentation and surface membranes on packaged beer. A single cell of Sacchoromyces (var. Turbidans) in 16 million cells of pitching yeast will cause detectable hazes. UV destroys all known yeasts and their spores.

Waste water
Effluent from food, beverage and brewing 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 UV, this also leads to a significant reduction in the amount of waste water produced.

Bromates and bottled water – UV as an alternative to ozonation

Aquionics’ UK sister company Hanovia has recently been working with Nongfu Spring Co. Ltd., one of China's leading producers of bottled water and beverages, to supply UV systems for their production plants across China. This is a major milestone in the bottled water industry – particularly in China – because presently in that country virtually all bottled water is disinfected using ozone. And around the world ozone is still the disinfection method of choice for many producers. The decision by Nongfu Spring to opt for UV was driven by a number of reasons, not least of which was concerns about ozonation by-products such as bromate. In fact, Hanovia has noticed that more and more bottled water and soft drinks producers are now looking for ozone alternatives, and enquiries about UV are on the increase. Bromide ions occur naturally in many spring waters and on their own pose no problem. However, the presence of ozone can cause conversion of bromide into bromate, with the consequent potential for consumer health problems. The World Health Organization (WHO) lists bromate as a carcinogenic substance and recommends its maximum limit in mineral water be set at 0.01mg/l (10ppb). In July 2008 the Chinese General Administration of Quality Supervision, Inspection and Quarantine (AQSIQ), recommended in a revised draft national standard for drinking water and mineral water that a maximum limit for bromate in bottled water be in line the WHO guidelines. This limit has now been in force since October 2009.

Conclusion

Meeting the rigorous hygiene standards required in the production of food and beverage products is a real challenge. If improvements need to be made to plant and equipment, they need to bring quick returns on the investment and measurable improvements in product quality. For manufacturers seeking to improve the quality of the end product, UV is an economic, realistic option. It is an established method of disinfecting drinking water throughout the world, and is also widely used for high purity applications such as pharmaceutical processing and microchip manufacturing, where water of the highest quality is essential.