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Paving the whey towards a circular bioeconomy

TResearch Autumn

Teagasc researchers are collaborating with Munster Technological University (MTU), Ireland, and Lund University, Sweden, to transform dairy waste into value-added and environmentally sustainable products.

Whey, the main by-product of the dairy processing sector, is rich in lactose, proteins and micronutrients. Due to this nutrient-rich profile, whey and residues derived from whey have a very high biological oxygen demand (BOD) and chemical oxygen demand (COD).

Unfortunately, high BOD and COD levels are extremely hazardous to the environment if disposed of directly into waterways or on land. As such, dairy waste streams derived from whey need to be treated before they can be discharged – which can prove expensive.

Believing there is a better solution for this dairy waste problem, Teagasc researchers have partnered up with researchers from Ireland’s Munster Technological University (MTU) and Sweden’s Lund University, and established the EBSTAR project. Through this project, the researchers are investigating the use of microbial bioprocessing technology to transform dairy residues – particularly the underutilised acid whey and salted whey – into renewable and valuable products.

Understanding the different types of whey-based waste streams

The project team aims to generate high-value bio-based products such as food additives, bioplastics and biogas from low-cost whey waste residues, using a unique multi-bioreactor biorefinery process.

Depending on the technology utilised, various types of whey are generated from the separation of casein from milk to make cheese. The two most common types of whey are sweet whey and acid whey.

Sweet whey is generated from the production of most cheeses or casein products. The protein component of sweet whey is very valuable and is used to produce protein powders for infant nutrition, sport performance-enhancing formulas and food additives. After the protein is extracted from the sweet whey, however, the remaining lactose-rich component is underutilised.

Acid whey is generated from the production of Greek yoghurt, cottage cheese and acid casein, and it has a sour-like taste. It is complex to process in contrast to sweet whey because it has a low pH which affects protein stability. It is also difficult to remove water from acid whey.

There is a third significant dairy by-product that also needs mentioning – salted whey. Salted whey is generated during the production of semi-hard and hard cheeses such as Cheddar. It contains between 4% and 10% salt depending on cheese type, which affects its potential to be further processed into value-added products.

To improve the yield of bio-based products from these waste streams, the project team are carrying out their work with the aid of innovative bioprocessing techniques, the use of novel microbial groups and an adaptive laboratory evolution approach.

Taking a circular bioeconomy approach

It has been recognised that the food sector needs to move away from an unsustainable linear model of production – or a ‘take, make and waste’ approach – to a more sustainable circular model. The goal is to reduce waste, the carbon footprint and the reliance on fossil fuels, all while helping to feed the rising world population.

Following a circular bioeconomy model – continuously producing value-added products and focusing on zero waste and pollution generation – is a major challenge for the dairy industry. But by harnessing the use of microbial fermentation technology to sustainably and efficiently biotransform low-cost materials such as whey-based waste streams into high-value bio-based products, the EBSTAR project is offering a potential solution for the dairy sector.

A life cycle sustainability assessment will be conducted on this bioprocess system as part of the project, to assess its environmental impact and establish hotspots for cost and emission reductions. The hope is that this work will demonstrate the potential broad applicability of a multi-bioreactor waste valorisation system for dairy manufacturers and other industries, helping them to develop an economical and sustainable solution to making dairy waste residues commercially viable and renewable.

TResearch Autumn

Figure 1. The EBSTAR biorefinery concept for acid whey and salted whey

80 to 190 million tonnes of salted whey and acid whey are generated annually.

9L of whey is generated per 1kg of cheese.



The EBSTAR project is funded by the Science Foundation Ireland Frontiers for the Future programme (ref. 19/FFP/6560). Brenda Barry is supported by the Teagasc Walsh Scholarship scheme (ref. 2019235).


The contributors wish to thank EBSTAR project partners Ed van Niel (Lund University) and Micheal Callanan (Munster Technological University).


Brenda Barry

MSc Walsh Scholar

Biosciences Department

Teagasc Food Research Centre,
Moorepark, Co. Cork.


Eoin Byrne

Post-doctoral Researcher

Biosciences Department

Teagasc Food Research Centre,
Moorepark, Co. Cork.


Olivia McAuliffe

Principal Research Officer

Biosciences Department

Teagasc Food Research Centre,
Moorepark, Co. Cork.