Arla Foods Ingredients has been investigating ways to upcycle delactosed permeate (DLP) in a more sustainable way. DLP is a residual dairy stream generated in large volumes during lactose production; most of it is currently used as material for biogas production. But in a partnership with Enorm, the region’s largest insect farm, the ingredients business has found a way to upcycle the material into an animal feed ingredient.
Arla Foods Ingredients has been supplying Enorm with DLP as part of a trial for several years. Enorm uses DLP as feed for the larvae of the black soldier fly (BSF). According to research, BSF larvae have potential to be used as a feed ingredient for ruminants, for example to substitute soybean meal and fish meal. BSF is rich in protein, fat and other beneficial nutrients.
Since early December 2023, Enorm has expanded its capacity to process DLP through the opening of a new facility in Flemming, Denmark – and Arla Foods Ingredients will ramp up deliveries of DLP in the coming months.
Because its destination will be feed rather than biogas, the partnership will allow upcycled DLP to move up in the ‘waste hierarchy’ - Arla Foods Ingredients estimates that the partnership will enable its Danmark Protein facility to achieve a 16% reduction in food waste that way.
Sønke Møller, senior sales developer at Arla Foods Ingredients, told DairyReporter: “Our Danmark Protein facility uses filtration technology to produce whey protein concentrates and lactose. Delactosed permeate (DLP) is a residual dairy stream generated in large volumes during lactose production. Because it is difficult to use in feed, most DLP is currently used as material for biogas production.”
Møller said that DLP has potential to be used as food-grade material, but this is challenging. “Using it as feed material for larvae requires additional processing steps in order to fulfil animal by-product regulations. For example, the pH of the DLP has to be reduced to <6 for at least an hour, and – when delivering products for feed purposes – the nutritional content has to be more stable than products for biogas.”
Roughly 25% of the total volume of DLP generated by Arla Foods Ingredients will be utilized under the new partnership, DairyReporter understands. The ingredients subsidiary of the dairy co-operative says it will increase DLP deliveries to Enorm to 15 truckloads, which in Denmark amounts to more than 30mt, as Møller explained. “The volume will increase by 30 times compared to the volume used in the trial facility today, and will account for roughly 25% of the total DLP volume,” he said.
So, how does the process occur naturally – what is the larvae’s role in transforming DLP and does the insect consume all components of the dairy co-product, we asked. “The fantastic thing about the larvae is that they continue eating and consume everything,” Møller explained. “When there is a surplus of nutrients, these will be excreted. Nutrients not utilized by the larvae and the larvae shell (frass) will be send to a biogas plant. The remaining protein, carbohydrates and fat will then be converted into methane.”
Arla Foods Ingredients has estimated that this partnership will enable a 16% food waste reduction at its Danmark Protein facility, but how significant is this in the context of the company's wider sustainability goals? Møller again: “The food waste at our Danmark Protein facility is calculated on the basis of the volume of by-products sold to biogas customers. Additionally, there is a loss of protein, fat and lactose when cleaning the processing equipment, which goes to the effluent plant. A significant amount of organic matter (lactose, fat and protein) is now going to Enorm instead of being used for biogas production, reducing the amount of food waste by an estimated 16%.”
“Arla has an ambition, set out in its Future26 strategy, to reduce food waste,” he added. “So where it’s possible to use dairy by-streams for food or feed, this is prioritized. We’re not yet at the stage where all food waste can be avoided, but our processes and production side-streams are the subject of ongoing research and review. In 2021, we established a new platform for monitoring food waste and capturing the necessary data to track our performance. The Arla group goal is to reduce food waste at processing level by 50% between 2015 and 2030.”
“In broad terms, the food industry overall is making efforts to reduce waste, so I would expect to see more companies directing more by-products for feeding purposes.”
The next big challenge would be to plan and arrange the deliveries necessary for Arla Foods Ingredients to meet the demand from Enorm, we were told. “In the future we’ll be looking for other dairy by-streams that can be used for feed - where they’re not already being used for that purpose,” Møller said.
The protein meal produced from the larvae does not have the potential to be used as a protein source for milking cows, however. Møller explained: “Cows are very good at utilising protein from cheaper vegetable protein sources, like clover, grass and rapeseed. It therefore makes more sense to use larvae protein meal for fish, piglets and petfood where it can substitute fishmeal or other expensive protein sources.”
Black soldier fly as feed ingredient for ruminants
Dewi Apri Astuti and Komang Gede Wiryawan
Published: 1 February 2022, Anim Biosci. 2022 Feb; 35(2): 356–363.