What milk makes

Visitors to the 81st Virginia Show were treated to a visual display by Teagasc researchers that unveiled the numerous products ensuing from the processing of raw milk.

Presented by researchers Jonathan Magan, Conor Fitzpatrick and Liam Kelly of the Teagasc Food Chemistry and Technology Department, Moorepark, their presentation centred on the Milk Tree (available to view below) – and tracked the milk production cycle from consumption of grass and concentrates to the end product, or in this case end products.

Research Officer in Teagasc Moorepark, Dr Jonathan Magan explained: “Through our display, we wanted to give farmers and those attending an understanding of the sheer utility of milk, and its capacity to be transformed into a variety of streams and side streams.”

To achieve this, fresh grass and concentrates – amassing to approximately 20kg of dry matter – were showcased to represent an average cow’s approximate feed intake. The approximate raw milk yield of an average cow, along with the gross composition that milk, was also displayed.

From this raw milk yield, with a composition of 3.5% protein, 4.2% fat, 4.6% lactose, and 0.7% minerals (total 13% solids), the Teagasc researchers provided a visual representation of the variety of products and their yields that can be produced when 20L of raw milk is processed. The products listed below, along with their weights, represent how much of that one product can be produced from 20L of raw milk; it should not be interpreted that all of these products can be produced from the same 20L of milk.

The following product yields were on display: 2.81kg of whole milk powder; 2kg of cheese; 1.77kg of skim milk powder; 2.22kg of cream; 1.11kg of butter; 0.58kg of casein powder; 1kg of lactose; 0.93kg of milk protein concentrate powder; 1.14kg of milk permeate powder; 0.165kg of whey protein isolate; and 0.05kg of buttermilk.

Figure 1: The products generated from raw milk (Image source: International Dairy Federation)

Learn more about the International Dairy Federation (IDF) here

More than just milk

Given the growing interest in alternative isolated protein sources, Dr Magan pointed to the importance of understand raw milk’s capacity to generate numerous products and by-products, and why when comparing both in terms of waste, carbon and water efficiency, the resulting products and co-products from milk need to be examined and compared to those from alternative protein sources.

Dr Magan explained: “Milk is a nutrient dense product but we need to accurately represent the distribution of carbon and water costs of milk production across the wide number of products and co-products which can be derived from it. Our display shed light on some of these products."

Pictured from left to right at the Teagasc display at the Virginia Show are Conor Fitzpatrick, Jonathan Magan and Liam Kelly.

He continued: “Milk is often misrepresented as a single product and compared against other alternative isolated protein sources, which often provide no useable side streams. Our presentation gave examples of points at which streams diverge, but also showed where they can go on to be isolated as particular commodities or recombined as ingredients in other formulations.

“Examples include: the separation of milk fat and skim milk; the use of fat for cream and butter or for standardisation of cheese or skim milk or whole milk powder manufacture; and the successive stages of membrane filtration used to concentrate milk protein products, with the resultant milk permeate and lactose side streams available for use in skim milk powder standardisation, infant milk formula manufacture (with whey protein concentrates and skim milk powder); and the use of lactose for pharmaceutical applications.”

The Teagasc researchers also presented information on the grass-fed milk story, discussing the nutritional benefits for milk composition from pasture-based feeding systems in terms of milk fatty acid composition, vitamin composition and butter and cheese product quality.

Also read: Irish grass-fed cows produce more nutritious milk

Learn more about the Teagasc Food Chemistry and Technology Department here.