Nav: Home

Concentrating milk at the farm does not harm milk quality

February 15, 2017

At dairies, the reverse osmosis filtration technique is extensively used to remove water from milk to be used for further processing such as e.g. cheese or milk powder. However, many resources would be saved if it was possible to move this process to the farms, since you would reduce the amount of water transported.

In cooperation with the Danish dairy company, Arla, PhD student Ida Sørensen and Associate Professor Lars Wiking from Department of Food Science at Aarhus University have examined how milk quality is affected when concentrating the milk is carried out on-farm.

Ida Sørensen explains:
  • Even though the reverse osmosis technique is widely used, we only have limited documentation of how it affects milk quality. Milk is a rather delicate raw material so it is important to identify how key quality parameters such as protein breakdown and level of free fatty acids (FFA) and total bacterial count are affected. These parameters are important to the taste, smell and look of the final product.

    She continues:

  • It is important that on-farm concentration does not deteriorate the quality. Normally, it is not a problem that the fat globules in the milk are damaged in the process at the dairy, as the milk is subsequently pasteurized. However, when carrying out milk concentration at the farm, the milk is left unpasteurized and all the enzymes and micro-organisms are still there and therefore the milk is more delicate, Ida Sørensen explains.

No quality deterioration

The researchers at Aarhus University have analyzed experiments with both the so-called ultrafiltration, which is supposed be more gentle to the milk, and with the reverse osmosis technique, which requires a higher pressure on the milk but also retains the lactose which may be an advantage in for example milk powder. Neither the total bacterial count, or the FFA-levels nor the protein breakdown were negatively affected by reverse osmosis; the concentrated milk could very well be used for both cheese and milk powder.

Analyses also demonstrate that the quality and durability of milk powder made from concentrated milk is the same as for powder made from ordinary milk; in cheese, however, there is a minor difference as to how the enzymes react; and in the experiments, concentrated milk coagulated approximately ten minutes later than regular milk.
  • My theory is that it is more difficult for the enzymes to 'get through', Ida Sørensen says and explains that concentrated milk is thicker -- more like coffee cream -- and this might explain why coagulation takes a little longer.

Significant interest -- but is it worthwhile?

Concentration of milk on the farm, or during transport from farm to dairy, is carried out in many other countries in the world, e.g. in Texas, USA, where both herds and distances are huge. Different models exist as to how on-farm milk concentration may become a reality. The farmer may buy the filtration equipment himself and achieve an additional price for the milk. Or perhaps the dairy could buy, maintain and service the filtration installation or it could be acquired through some kind of leasing agreement.

Herd size and distance to the dairy in particular, are of major importance when considering resources and profitability, as small installations typically use more power than one large installation, says Ida Sørensen; she has just presented the results of the studies at a major conference in Dublin.
  • While farmers have shown significant interest in the idea, the dairies seem more skeptical; especially in relation to finances as well as the handling of this new type of milk. Arla is currently making calculations in relation to the profitability of this project, as energy consumption and investments should be balanced in proportion to cost savings.
Facts about the project

"New sustainable milk concentration technology for dairy herds" is a five year project which ends this year. Project participants include Arla Foods amba/Arla Foods Ingredi­ents PS (Arla), Danmarks Kvægforskningscenter (the Danish Cattle Research Center - DKC) and Aarhus University (AU). In addition, GEA Process Engineering (GEA) is affiliated as an external consultant.

The project is financially supported by Mælkeafgiftsfonden (Milk Taxation Foundation - MAF) and the Green Development and Demonstration Programme (GUDP).

Aarhus University

Related Enzymes Articles:

Fungal enzymes team up to more efficiently break down cellulose
Cost-effectively breaking down bioenergy crops into sugars that can then be converted into fuel is a barrier to commercially producing sustainable biofuels.
How enzymes communicate
Freiburg scientists explain the cell mechanism that transforms electrical signals into chemical ones.
Pac-Man-like CRISPR enzymes have potential for disease diagnostics
UC Berkeley researchers have found 10 new variants of the Cas13a enzyme, the Pac-Man of the CRISPR world, that hold promise for disease diagnostics.
Hydrogen production: This is how green algae assemble their enzymes
Researchers at Ruhr-Universit├Ąt Bochum have analyzed how green algae manufacture complex components of a hydrogen-producing enzyme.
New studies unravel mysteries of how PARP enzymes work
A component of an enzyme family linked to DNA repair, stress responses, and cancer also plays a role in enhancing or inhibiting major cellular activities under physiological conditions, new research shows.
Understanding enzymes
A new tool can help researchers more accurately identify enzymes present in microbiomes and quantify their relative abundances.
Light powers new chemistry for old enzymes
Princeton researchers have developed a method that irradiates biological enzymes with light to expand their highly efficient and selective capacity for catalysis to new chemistry.
Research finds enzymes essential for DNA repair
Scientists at The Australian National University and Heidelberg University in Germany have found an essential component in the DNA repair process which could open the door to the development of new cancer drugs.
New step towards clean energy production from enzymes
Oxygen inhibits hydrogenases, a group of enzymes that are able to produce and split hydrogen.
Genetic diversity of enzymes alters metabolic individuality
Scientists from Tohoku University's Tohoku Medical Megabank Organization have published research about genetic diversity and metabolome in Scientific Reports.

Related Enzymes Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Climate Crisis
There's no greater threat to humanity than climate change. What can we do to stop the worst consequences? This hour, TED speakers explore how we can save our planet and whether we can do it in time. Guests include climate activist Greta Thunberg, chemical engineer Jennifer Wilcox, research scientist Sean Davis, food innovator Bruce Friedrich, and psychologist Per Espen Stoknes.
Now Playing: Science for the People

#527 Honey I CRISPR'd the Kids
This week we're coming to you from Awesome Con in Washington, D.C. There, host Bethany Brookshire led a panel of three amazing guests to talk about the promise and perils of CRISPR, and what happens now that CRISPR babies have (maybe?) been born. Featuring science writer Tina Saey, molecular biologist Anne Simon, and bioethicist Alan Regenberg. A Nobel Prize winner argues banning CRISPR babies won’t work Geneticists push for a 5-year global ban on gene-edited babies A CRISPR spin-off causes unintended typos in DNA News of the first gene-edited babies ignited a firestorm The researcher who created CRISPR twins defends...