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Recycling side streams

"We need to rethink value creation"

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From 19 to 22 March 2024, Anuga FoodTec in Cologne will show why the transformation of industrial side streams into innovative recyclables is an integral part of modern food production. At the Albstadt-Sigmaringen University of Applied Sciences, Prof. Dr Andrea Maier-Nöth is heading a research project on this, the aim of which is to recycle side streams in innovative products. She and her team combine this question with the trend that domestic plant-based protein sources are increasingly in demand.

A growing number of start-ups have made food upcycling the heart of their brands. There are several examples of how leftover food is processed further. Nevertheless, around eleven million tonnes of food end up in the rubbish every year ...

Recycling Symbol

©DLG Petra Sarow

Prof. Andrea Maier-Nöth: Now you might think that most food is thrown away in private households. In fact, however, the food industry contributes significantly to waste. When food is marketed or processed, only a certain proportion of the raw materials used is utilised, the rest ends up in the waste ...

... and is therefore waste without added value?

Which doesn't have to be the case, because these products can contain valuable sustainable proteins or other nutrients as well as fibre. These products are called side streams because they occur "alongside" the intended production of a food. In many cases, side streams are edible or can be useful for the production of other foods. Here we need to rethink the word creation.

To what extent does the concept of recycling side streams, which you are also pursuing as part of your research at Albstadt-Sigmaringen University, go beyond pure food upcycling?

Food upcycling saves food from ending up in the bin as supposed waste. Within the framework of our "side streams" project, we are going well beyond this, because we want to bring together the providers of side streams and potential users here in Baden-Württemberg in order to find the highest-quality use possible for the recyclables that are produced. Together with farms, we want to implement a farm-to-fork concept that combines local conditions such as soil characteristics and regional marketing potential in product development in order to prevent unused side streams from occurring in the first place. In addition, a value creation network for bioeconomic knowledge and - previously unused - biogenic raw materials is to be established. Exchange and cooperation with different companies and organisations in the sense of cross-industry innovation is also important for achieving this.

Which nodes in the value chain are addressed in the project?

The goal of the project is to close regional material cycles, to reduce the generation of food waste or to use side streams, and to optimise the domestic and especially the sustainable and plant-based protein supply through innovative approaches. In addition, biodiversity is to be increased through sustainable cultivation methods and consumer acceptance of sustainable nutrition is to be strengthened through innovative nutrition concepts and food. The question is combined with the trend that domestic vegetable protein sources are increasingly in demand.

That means recycling side streams not only reduces food waste. It can also contribute to a healthy diet?

Absolutely, because side streams still contain many high-quality nutrients, e.g. vegetable proteins. Specifically, we are therefore studying products in which side streams from protein-rich field beans, lupins and hemp have been processed. Together with the project partners, we were able to cultivate these soil-improving crops at suitable locations in order to develop new products from them. In the project, our team therefore also deals with the question of how consumers evaluate concepts for sustainable products and their side streams, and which criteria are decisive for them when making a purchase.

Isn't there often a lack of knowledge about how much "value" is actually left in the leftovers?

Unfortunately, side streams that are generated directly in companies are often still declared as "waste". This means they are lost for utilisation as food. Moreover, methods and the necessary transparency for the utilisation of these nutrient-rich residual materials are still largely lacking, so that they are fed as animal feed or used in biogas plants. The consequence of this insufficient utilisation is that enormous turnover potentials are not exploited. And sometimes costs are even incurred for the disposal of the residual materials and the possibilities of supplying the population with high-quality, alternative proteins and nutrients remain unused. In addition, insufficient knowledge for processing side streams encourages ecologically unbalanced cultivation of other commodities such as soy and wheat, which in turn negatively impacts soil health.

From this perspective, particularly small and medium-sized enterprises are likely to encounter limits when it comes to closing their material cycles and making better use of residual materials ...

Yes, because the side streams of small producers often do not reach the scale at which recycling by a large processor is worthwhile. Ultimately, margins in the food industry are often insufficient for justifying higher production costs without price adjustments. Furthermore, as many side streams from agriculture and food production only have a short shelf life and decompose quickly, collection systems with long transport distances are hardly feasible. Therefore, many are only recycled at a low utilisation level.

And that means?

Our consumer study has shown that there is great potential for side streams in the region. However, there must be communication between the place of origin and the place of marketing. Online platforms don't seem to be effective here, as several projects have failed to implement them. Personal contact via direct approach, on the other hand, is a central guarantee for success, based on active information gathering and trust building. In addition, it is essential that the recovery of a side stream needs a suitable new product that covers the production costs. It is possible that such side stream-based products will become more attractive in the future through tax incentives or reduced CO2 costs. In the end, however, consumer acceptance is the most important aspect.

Side streams must be processed or preserved immediately. Are new technologies and processes required here?

Above all, the economically and energetically feasible conservation of perishable side streams directly at the producer is one of the hurdles. The small regional producer has neither the knowledge nor the financial resources to be able to use established technology for preservation such as heat, high pressure or filtration in an economically sensible way. This requires innovative ideas and solutions that need to be tested and evaluated in research projects. In addition, the appropriate end products must be generated as quickly as possible from the preserved raw materials of the side streams.

What has been the problem up to now?

Currently, there is a lack of intelligent ideas for the economically feasible preservation or reprocessing of side streams where they occur. Ecologically sound collection systems could be established on this basis. The great variety of unused side streams requires a great variety of innovative, product-oriented and individual solutions.

What is the best way to overcome the challenges on the way to market launch?

In our project we have seen that targeted development works when all partners contribute their expertise from the beginning. Starting with microbiology, which primarily deals with the stabilisation of side streams, analytics to evaluate the nutrient content, food technology to name suitable processing methods and finally consumer research to develop the products in a consumer-oriented way. The limited human and financial resources can then be bundled for the promising research and development approaches and applied with maximum efficiency.

Successful examples have been around for some time. With pectin as a by-product of apple juice production, a gelling agent is available that has become an indispensable part of everyday life in the food industry ...

Thanks to upcycling of side streams, the range of natural food additives is becoming more comprehensive. Alternatives to animal products are also becoming established through by-products, for example aquafaba, the cooking broth from cooked chickpeas, which can be used as a protein substitute. We've found that the brew of other legumes also has optimal foam-forming properties and the potential for other protein alternatives is high.

What needs to be done to establish additional promising by-products?

Basically, the focus must be on stabilisation and the highest possible quality recyclability of the side streams. These often have different physicochemical properties and perishability risks. These can be liquid protein solutions such as milk, dry, free-flowing products such as bran or pasty-solid oil press cake and semi-dried fruit and potato residues. All of these side streams require a wide variety of technologies and processes for preservation, using both tried-and-tested processes that have been in use for years and the latest ones.

No easy task ...

.... but it's worth it, as our project shows! We've developed a germination and drying cabinet that can be used for small companies. It has the potential to produce even small batches in compliance with food legislation and to process small quantities of by-products into stable products. Nevertheless, material recycling outside the food chain, for example for biopolymers, textiles or cleaning agents, should always be considered if the effort to stabilise a side stream is too high. By saving fossil resources, this can result in an important substitute product for the ecological circular economy.

How can the side streams that are already available on the market be made "visible" for all participants in the value chain?

There are already initiatives that record side streams in databases. This enables interested users to assess whether a product development for a side stream is worthwhile. However, the reproducibility of the quality of a side stream and the continuity of the accumulating quantities still have to be determined individually for each product. The costs for analyses, microbiological evaluation and the amount of work involved should not be underestimated. We had looked at side streams from the production of vegetable oils, fruit juices, potato products and tofu in project applications. But there are certainly still many side streams with great potential that we have not yet focused on.

How would you assess the legal situation? Does the development of products of this kind encounter obstacles due to legal regulations?

One challenge in projects with many different regional partners is, of course, ensuring food quality and safety. Small suppliers in particular need a lot of support because they are concerned that they may misunderstand or not be able to implement the requirements of food law. In future projects, one focus should therefore be on supporting small businesses in product development at an early stage so that food law requirements are taken into account from the outset. Otherwise the innovative products will ultimately fail due to the costs and effort required for subsequent adaptation to food law-compliant production.

Another challenge is to bring consumers on board and familiarise them with side streams so that the products experience increased acceptance later on when they are launched ...

In this context, it's important to already carry out external communication work with the public during product development and to make the consumer aware of the added value of side-stream products and explicitly also of plant-based protein sources. A wide variety of media and campaigns can be used for this. But comprehensive nutrition counselling can also include education so that physicians and nutritionists can bring the knowledge to the future consumer.

Keyword certification: Do we need uniform labels and criteria for raw materials and recycling concepts in order to increase the marketing potential?

We don't have a final opinion on that yet. Certifications are a double-edged sword. On the one hand, they facilitate the exchange of side streams and ensure their quality. On the other hand, this also creates costs that make the products more expensive in the end. Many certificates that are on the market may confuse consumers more than they help them.

Prof. Dr. Andrea Maier-Nöth

Prof. Dr Andrea Mair-Nöth from the Albstadt-Sigmaringen University of Applied Sciences intends to enable companies to make the best possible use of the side streams that arise - entirely in the spirit of the regional circular economy.

Side streams are in many cases edible or can be useful for the production of other foods.

Prof. Dr. Andrea Mair-Nöth
Hochschule Albstadt-Sigmaringen

Many companies are producing side streams but have not been using them to create added value.

Prof. Dr. Andrea Mair-Nöth
Hochschule Albstadt-Sigmaringen

Thanks to upcycling of side streams, the range of natural food additives is becoming more comprehensive.

Prof. Dr. Andrea Mair-Nöth
Hochschule Albstadt-Sigmaringen