Don’t cry over spoiled milk, encourage supply chain for longer shelf life | Source
Too much milk is thrown, which was a problem long before this time of a pandemic of global food insecurity. It is estimated that one in three gallons of milk is wasted in America, according to US Department of Agriculture data from the previous decade. A group of scientists, including one currently at Washington University in St. Louis, used mathematical models to integrate knowledge from several disciplines – milk production and processing, microbiology, and the supply chain – thus striving to tackling a centuries-old problem: spoiled milk.
Their research, in particular, found two main strategies that could be used early in the milk supply chain – on the farm and in the processing plant – to prevent psychrotolerant (cold growing) bacteria forming spores. contaminate and deteriorate prematurely. milk:
- Premium payments such as premiums (or penalties) based on a lower (or higher) number of harmful bacteria in raw milk;
- Invest in processing level spore reduction technologies.
Their study, finding that adopting both strategies could improve the shelf life of milk from half a day to 13 days, was published on July 8 in one of the Frontiers journals, Borders in sustainable food systems.
“In general, I would say this is not a one-size-fits-all prescription problem,” said Fouough Enayaty Ahangar, a new supply chain optimization teacher at Olin Business School. “The results of our optimization models demonstrate that the optimal combination of interventions strongly depends on the characteristics of each individual dairy processor. These characteristics include the volume of milk processed and the quality of the raw milk supplied. Therefore, our optimization models provide new decision tools from which individual processors can benefit and determine the best strategy for their installation.
At the intersection of food science, demographic and veterinary medicine, and the supply chain lie bottles of milk, creating a global problem the longer they stay. So Enayaty Ahangar teamed up with researchers from his old institution – Sarah Murphy, Nicole Martin, Martin Wiedmann and lead author Renata Ivanek at Cornell University – to test the strategies through modeling.
This study targeted the problem of premature spoilage of milk caused by bacteria – Bacillus sp. and Paenibacillus sp. – which enter raw milk on farms and whose resistant spores can survive pasteurization. (There is another pasteurization, but it costs more and consumers complain about the taste of milk after going through the higher temperatures used.)
Comparing their results with data from the Department of Agriculture from 24 states and based on a cow producing 64 pounds or 15 half-gallons of milk per day, the team conducted 24 case studies – or generated instances, as they called them – looking at the size of the processor, the number of milk producers in the supply chain and the planning horizon, which is five and ten years from now.
Premium payments or interventions at production level: Farmers should be encouraged to implement fixes and improve processes from the start – starting with cow’s udder milk – if they are rewarded for consistent high quality milk in terms of bacterial contamination. sporulating and penalized for poor quality milk. .
Contracts similar to this bonus / penalty directive already exist for American farmed products such as eggs and chicken, the authors noted. In this article, the researchers propose a new flexible bonus / penalty system based only on the initial number of raw milk spores at production.
Spore reduction investment or processing interventions: Milk processors know that technologies such as microfiltration and bactofugation are expensive to acquire, install and operate. But this research illustrated how using both of these approaches, including a third double-bactofugation method, was the most effective long-term way to remove sporulating bacteria from milk.
Their models predicted, using such interventions and investments at the processing level, that the shelf life of milk would increase at all levels. This improved shelf life – defined as the first day that 5% of milk packages have a specific bacterial count – ranged from 20 to 26 days (for small processing plants) to 28 to 31 days (average) at an average of 34 days (large).
“The dairy industry is paying more and more attention to the importance of using raw milk that is low in spores to produce high quality dairy products, but there is no plan for decision makers to industry on how to achieve it ” Murphy mentionned. “It’s important to note that our study contributes to the conversation about how the industry can invest in dairy farmers and technologies and provides tools that can help industry decision makers.
“Our focus was mainly on how the process can better allocate its budget to extend the shelf life of its processed milk,” said Enayaty Ahangar.
In short, research has shown that medium and large processors can implement interventions and improve the shelf life of their milk for up to 13 and 12 days, respectively.
“Working with Cornell’s veterinary school, one of the best in the United States, has been an incredible experience for me,” said Enayaty Ahangar, an industrial engineer by training and optimization specialist. “I was able to work with epidemiologists, microbiologists, food scientists, people from business schools…. And because our new optimization models integrate methods and knowledge from several disciplines, I think our article has the potential to be a good starting point for many other research projects in the food industries.
“The ultimate goal of our research is to support the development of a sustainable dairy production supply chain, where milk waste is reduced in a cost-effective manner for all actors in the production and consumption continuum. food, and is socially and environmentally sound, ”said Ivanek. “Decision support tools such as mathematical models of milk spoilage developed through the multidisciplinary research effort of this study are an integral part of this journey.”
Wiedmann added: “This project continues the development of digital tools for dairy and food supply chains, which will play an important role as decision support tools for industries as they continue to grow. improve the productivity and sustainability of nutritious foods. “
This work was supported by the Food and Agriculture Research Foundation, grant number CA18-SS-0000000206.