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Trichloromethane (TCM) is a residue caused by the interaction of chlorine (from cleaning detergents and water) with milk. TCM in milk must be at levels less than 0.002mg/kg to meet production guidelines to exporting countries. Maintaining low milk TCM levels on the farm is achieved in most instances by practising correct milking equipment cleaning procedures.
For example, for processors selling butter into German supermarkets, a legal limit exists for TCM of 0.1 mg/kg of product. While TCM levels in Irish products are now well within this limit, competition between the different exporting countries means that Ireland’s product needs to be as good if not better than others.
Two students from west Cork believe many dairy farmers are not aware of TCM in milk. Therefore, they set about researching and studying the topic in a project for the Young Scientist Exhibition. As part of the project, they sent out a survey to industry members and dairy farmers in west Cork. Subsequently, the students developed an indicator method for farmers to test for the presence of chlorine in the milk line.
Mark Shorten explains: “This product safely allows farmers know when all chlorine (detergent) has been rinsed out of the milk line. This will help farmers avoid the contamination of milk with chlorine. We developed an indicator strip which we called the TCM strip and also an indicator powder which was named the TCM kit which reacts with chlorine in the rinsing water of the milk plant.”
Conor Lehane said: “Our indicator method would aid farmers to detect chlorine in their milk line. At the end of rinsing their parlours, the farmers would test their rinse water and the indicator would change colour to pink if chlorine was present. If chlorine was not present, there would be no colour change and farmers would then know to stop rinsing the milk line. The indicator should allow farmers who use too much water cut down on water usage, and farmers who use too little water to increase the volume of water they use.”
Conor and Mark carried out multiple experiments on a number of different farm samples to test for chlorine in the rinse washings and TCM in the milk. At the end of the project they designed a suitable washing method for farmers to avoid TCM.
New products developed
As part of the project for the Young Scientist competition, Mark and Conor developed two new products to test for the presence of chlorine. One product is an indicator DPD strip which is white. It is packaged in a sealed bottle where it cannot be affected by moisture. When this product comes in contact with chlorine in the rinsing water of the milk plant, it changes colour to pink. The shade of pink will tell you how many parts per million (ppm) are in the water. They called this product the TCM Strip. The second product developed is an indicator as a powder. It is packaged in an airtight sachet. The sachet comes in a sealed plastic bag with a bottle. You insert the powder into the bottle and pour in a sample of water. The powder goes pink when it comes into contact with the chlorine. Again, the shade of pink tells how much chlorine in parts per million (ppm) are in the water.
Washing procedure
In terms of washing procedure, what can farmers do to reduce TCM levels? The students recommend:
1. Once finished milking, wash the external surface of clusters.
2. Rinse the milk line with 14 litres of cold water per unit.
3. Add the detergent to hot water (70°C to 80°C) – 9 litres of water per unit.
4. Allow the detergent mixture to circulate for 10 minutes. (You can retain some of this for evening milking wash, but dump the first 5 litres after circulating as this may be contaminated with residue)
5. Rinse immediately after main wash with 14 litres per unit of cold water.
6. Ensure system is drained completely before milking.
Survey results
Questionnaires about TCM were given out all across west Cork and 185 returned survey results were analysed.
39% of those surveyed didn’t know what TCM was.
59% were not aware of what TCM does to milk.
60% of people would use a new product to test for TCM if it was developed.
82% of people would like if the TCM result was sent out with other composition and quality results.
Irish company makes breakthrough in thermoduric bacteria testing
A company based in Ballina, North Tipperary, claims to have made the biggest breakthrough globally for microbiology testing in the dairy industry in over 100 years.
The dairy technology company is a spin-off from the Technopath Group and recently it unveiled a new system for detecting thermoduric bacteria in dairy products which Oculer claims will save the dairy industry in Ireland up to €200m annually through reduced farmer penalties, superior product shelf-life and enhanced protein concentration.
Officially launched by Tipperary-based Minister for the Environment Alan Kelly, the company will create at least 20 jobs in sales, R&D and engineering over the next two years. The revolutionary high-throughput, rapid microbiological method for testing incoming raw milk, in-process milk and dairy produce will target a global thermoduric bacteria testing market valued at €150m per annum.
Milk Test New Zealand, the independent laboratory that carries out thermoduric bacteria testing for over 97% of the NZ fairy industry, is due to receive a system in Hamilton early this year.
Thermoduric bacteria are naturally occurring bacteria that survive the pasteurisation process and are responsible for downstream issues such as spoilage of finished products, reduced shelf life and reduced protein concentrations – all of which have huge economic impact on the world’s dairy manufacturers.
A spokesperson for Oculer said rapid detection of the bacteria will significantly reduce spoiling of product and help eradicate shelf-life issues. It will also eliminate some bacteria entirely in other milk-related products, such as milk powder destined for the infant formula industry.
Launching the product, Minister Kelly said: “Oculer’s achievement in this international breakthrough for microbiology diagnostics is a huge validation of Ireland’s place as a global leader in dairying.
“With sales of dairy products forecast to reach $494bn in 2015, this breakthrough has the potential to reach into every single market in the world. It also again proves Ireland is a leading international player for research and development, spinning out some of the smartest technology companies on the planet. At a local level, I am immensely proud that one such company is here on our own doorstep and have been delighted to work with the team here over the past two years as they build towards this monumental day that will bring positive change for the industry across the world.”
Brian Byrne, CEO of Oculer, added: “Not only will test results be available to milk suppliers in 24 hours, Oculer will enable co-ops and dairy processors to react faster to positive results than they currently can by using the traditional agar method – but it also informs milk farmers where the source of the problem originated. Thermoduric bacteria can only be effectively eliminated when the source of the problem is accurately and reliably identified.”
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