Milk is not just milk

The composition of milk is seasonally variable and this variation is a challenge for the dairies in, for example, the cheese-making process. Scientists from Aarhus University have headed a research project that has traced the importance of this variation in relation to the qualityof cheese.

2012.09.13 | Søren Tobberup Hansen

Scientists from Aarhus University have headed a research project that has traced the importance of this variation in relation to the qualityof cheese. Photo: AU

It is common knowledge in the dairy sector that the quality of dairy products – particularly that of yellow cheese and cream cheese – is influenced by seasonal fluctuations.

 

The objective of the research project was therefore to better understand the link between the seasonal variations in the milk composition and the quality of the cheeses produced.

 

- We wanted to analyse seasonal changes in the composition of milk and determine the effects on the quality of cheese. An understanding of this relationship can help dairies to achieve a higher and more homogeneous quality of their cheeses, says post-doc and project manager Kell Kleiner Andersen from Aarhus University.

 

The scientists collected a total of 266 milk samples from one organic and two conventional dairies and analysed the individual milk constituents.

 

- We analysed the composition of the milk at protein, fat, mineral and metabolite level, and for all the parameters we documented a seasonal variation. The parameter with the greatest influence on the cheese-making properties of the milk was most surprisingly its pH value, says Kell Kleiner Andersen.

                                                                                               

Although the number of samples was relatively small when set against comparable studies in other countries where the data material typically is based on 1000 samples, the scientists have been able to develop methods to characterise the complexity of milk at a level of detail not previously seen.

 

This knowledge will benefit the dairies as it has resulted in new methods of measuring and recording quality at the dairies.

 

- A lot of the variation that is important for the quality of the dairy products has been quantified. In addition we have developed new tools that can be directly implemented in the quality control systems at the Danish dairies, says Kell Kleiner Andersen.

 

One of the tools is a model to determine milk pH, which is of crucial importance for the milk’s ability to coagulate and be turned into cheese. The model can be integrated into the MilkoScan milk-testing equipment that is used in most dairies.


The dairies can use the results of the project to optimise their cheese production, both in terms of cheese quality and production economy. In this way the project has contributed indirectly to strengthening the competitiveness of the dairies.

 

The project is funded by the Danish Innovation Law and the Danish Dairy Research Foundation and is a collaboration between the University of Copenhagen, Foss, Arla Foods, Thise Dairy and Aarhus University.

 

Further information: Post-doc Kell Kleiner Andersen, Department of Food Science, telephone: +45 8715 7842, e-mail: kell.andersen@agrsci.dk

 

 

 

Research, Food