Reducing the Environmental Footprint of Greek Yogurts

Project entitled:

Improving EcoEfficiency in Milk Processing by Optimizing the Usage of Milk Components: the Case of Greek Yogurt

Highlights

• Concentrated “Greek-type” yogurt has seen an exponential increase in consumption but has consequently generated acidic whey that is managed as residual matter.
• This environmental problem, the costs of development related to Greek yogurt production and its value to consumers raises questions about eco- efficiency (EE) in milk processing.
• This project allows for a more specific comparison between the environmental impact (using a life cycle assessment (LCA) approach) of ultrafiltration before filtration (UF-MILK) and post fermentation (UF-YOG).
• The ultimate goal of the research is to develop decision-making tools for industrial dairy processors, based on life cycle assessment data and the notion of industrial ecology, in order to optimize the use of milk’s natural components.

Objectives

• Describe the impact of technological choices on process efficiency and on the use of milk components for a model Greek yogurt production sequence;
• Develop an analysis framework to assess the EE of the processing of Greek yogurt;
• Identify and assess the external channels for the valorization of co-products and industrial synergies;
• Develop and validate a modelling tool for environmental and economic impact assessments and an optimization tool based on the EE indicator for milk processing.

Results and potential benefits

Preliminary observations:

• The experimental data generated on a pilot scale show that choosing the milk concentration process before fermentation (UF-MILK) allows for a better usage of milk components than if ultrafiltration is completed after the fermentation stage (UF-YOG). The absence of lactic acid in the UF-MILK co-product facilitates valorization of the milk solids present in the permeate.
•  However, the energy required for the heat treatment of UF-YOG is greater than for UF-MILK yogurt.
• A comparative Life Cycle Assessment (LCA) of the two processes concluded that the environmental balance for the entire life cycle presents disadvantages for the UF-MILK process in comparison to the traditional ultrafiltration (YOG) process due to the larger initial quantity of milk required. Milk production is responsible for approximately 80% of the impacts on the life cycle of Greek yogurt.
• The volumic concentration used to concentrate the milk has a direct effect on the environmental impact of Greek yogurt.

These conclusions must nevertheless be expanded upon in regards to the valorization potential for sweet whey permeate resulting from the UF-MILK process in comparison to acidic permeate. (The impacts of the process may in part be allocated to the co-products of the UF permeate, reducing those of yogurt).

Perspectives:

• The classical analysis of mass balance and environmental impacts (LCA) will allow for the development of an analysis chart that industrial dairy producers will be able to use in order to optimize their processes while improving their energy efficiency.

Professionals trained

• Adriana Paredes-Valencia (MSc): Holding a graduate diploma in sustainable development (France), Adriana has acquired practical experience in dairy research where she has utilized life cycle assessment (LCA) fundamentals in order to interpret her own data.
• Catherine Houssard (PhD): With a background in agri-food engineering, Catherine has worked in the industrial sector for over 15 years. Catherine has begun PhD research on the concept of energy efficiency in order to better adapt energy usage to the dairy industry.

Financial contribution

Partnership for innovation in dairy production and dairy processing (EPI 2011-2017):

• Fonds de recherche du Québec – Nature et technologies
• Ministère de l’Agriculture, des Pêcheries et de l’Alimentation du Québec
• Novalait