Organic milk of high quality

The objective of the project is to create a background for the production of organic high quality milk and highly processed organic dairy products with a well-described history and a composition that differs from conventionally produced milk, just as there will be focus on the fact that the organic milk is gently treated during the whole process from milking to the subsequent processing.

The research effort will be holistic and based on 1) use of large quantities of grazing/grass-field products in the feeding of the milking cow, 2) use of a gentle handling and pumping of the milk in connection with milking, and 3) introduction of novel gentle pasteurisation technologies which can retain the original properties of the milk.

High quality milk based on the use of grazing and a high ratio of legumes in the feeding ration
Development of new milk types takes place on the basis of special producers of milk with use of large quantities of legumes and herbs in the feeding ration to examine the transfer of precursors for aroma components or direct transfer of flavour components. Moreover, farm studies will be carried out on the use of a balanced ratios of legumes and minimum quantities of maize-based products in the feeding ration for hereby to develop a feeding concept to enable the organic milk producer to produce milk with a composition, nutritional properties and flavour that differ from conventionally produced milk. Development of this product will take place considering the productivity, animal welfare and economy in the production just, as it will be examined whether the cows have preferences as regards the choice of different legumes and herbs.

An increased use of legumes and grazing will result in a change of the milk fatty acid composition to such an extent that it is of significance for the oxidative stability of the milk, while an important effort will treat the possibility to prevent oxidation in the milk by securing that the cow has an optimum rumen function and hydrogenation ability and a sufficient transfer of significant antioxidants. The produced types of milk are characterised in relation to composition, content of selected flavour components, oxidative stability and sensory attributes, as well as connections between sensory attributes and the chemical composition of the milk will be examined. Moreover studies concerning the consumers’ willingness to pay an additional price for these newly developed milk types will be carried through, and it will be examined whether specific consumer segments have a preference for these milk types.

Gentle handling, pumping and pasteurization of the milk in connection to milking
A main causes to quality deterioration of organic milk is the pumping which takes place on the farm in connection to milking which causes a destruction of the milk fat globules. This results in an increased level of free fatty acids in the milk, and in organic un-homogenised milk products deterioration of the milk fat globules will give an increased risk for formation of creaming in the products during storage. Examination of the formation of creaming will take place in relation to denaturation of the agglutinins of the milk, which may prevent aggregation of fat in the milk carton. The introduction of AMS (automatic milking systems) has caused huge quality deteriorations in relation to increased lipolysis and destruction of the milk fat globules and if you only use milk from AMS-systems it is expected that one would be able to taste that this milk is rancid. At the same time mobile AMS systems are one of the future milking technologies that can secure grazing in large herds. It is expected that the de novo synthesis of milk fat will be reduced, which could influence the stability of the milk fat globule at mechanical stress. This will be examined in connection with development of new milk types based on grazing.

Gentle pasteurisation methods that can retain the original attributes of the milk
One of the treatments that influence the milk attributes is the pasteurisation. New methods for pasteurisation of milk have been developed. These are based on a quick heating of the milk to very high temperatures but for a very short time (infusion pasteurisation). Studies have shown that this method is more gentle to the milk than traditional low pasteurising, as only a moderate denaturation of the milk proteins takes place, but that the method at the same time has a high killing effect on bacteria and spores. Most important is that studies have shown that this type of pasteurisation may secure a milk production with a freshness that is superior to conventional low-pasteurised milk. The effort aims at establishment of a gentle pasteurisation of organic milk in consideration of flavour and shelf life, but also to examine how these new methods influence the functional properties in relation to processing.


Project title
Organic Milk of High Quality - Development of Production Concepts Based on grazing of the Dairy Cows and Gentle Treatment of the Milk during Handling and Processing (ORMILKQUAL)

Project leader
Jacob Holm Nielsen, Faculty of Agricultural Sciences, University of Aarhus. P.O. Box 50, DK-8830 Tjele
Tel: +45 8999 1163. Fax: +45 8999 1564. E-mail: jacobh.nielsen@agrsci.dk

Project participants
Troels Kristensen, Karen Søegaard and Lars Wiking (Faculty of Agricultural Sciences, University of Aarhus), Richard Ipsen, Ylva Ardö og Wender L.P. Bredie (Faculty of Life Sciences, University of Copenhagen)

Project website

Publications