Side streams constitute the resulting biomass generated during production processes, much of which is still treated as waste. GEA is engaged with key partners in the EU to develop new ways to valorize fruit and vegetable residues by turning them into much sought-after functional proteins and other bioactive ingredients for use across diverse applications.
The demand for protein is growing, driven by a combination of population growth, rising incomes and urbanization. However, the growing environmental load of animal rearing and its associated production costs, as well as changing consumer tastes, has resulted in the increased extraction of functional proteins and other useful compounds from plants. Traditionally, imported soybean meal has been the preferred source of plant-derived, high quality protein. Today, however, there is greater focus on identifying less expensive and less resource-intensive alternatives, including non-GMO options, which yield proteins without the use of extensive heat, solvents and harmful chemicals.
An important source for these valuable compounds can be found in the excess biomass generated as a result of fruit and vegetable processing. In specific cases, like the juice industry, some side streams are utilized. Likewise, raw material processers may use their extra biomass as feed or as fertilizer on fields. However, a lot of biomass continues to be burned or disposed of in ways that are harmful to the environment even though it still contains valuable ingredients. This includes not only proteins, but also phenols, for example, which have antioxidant or antimicrobial properties, as well as dietary fibers and pigments. Extracting and refining these ingredients requires processes that are sufficiently gentle, energy efficient and cost-effective for diverse stakeholders across a value chain to benefit from them; and of course the process and end products must meet tough industry-specific regulations. And to be viable, a network – beginning with farmers, producers and processors, all the way to the end-user or sector-specific customer – is required to ensure a steady supply and demand scenario.
Pro-Enrich: Tackling global challenges together
In 2018, GEA joined the Pro-Enrich consortium, partnering with 15 additional stakeholders from industry and research institutes from seven EU member states to demonstrate a new business model: a closed bioeconomic cycle for extracting high-value components from specific agricultural side streams. A three-year project headed by the Danish Technological Institute (DTI), Pro-Enrich is funded by the Bio Based Industries Joint Undertaking under the EU Horizon 2020 research and innovation program. The aims of the consortium are also aligned with the U.N. Sustainable Development Goals – both of which are committed to increasing food production while reducing food waste and agriculture’s overall environmental footprint.
In Europe alone, millions of tons of biomass are produced each year. Rapeseed and olive oil production, as well as the processing of citrus fruits and vegetables, such as tomatoes, for example, are major contributors to biomass waste. And although containing valuable compounds, they have been considered of low-value because extraction was either too difficult, too costly or both.
Using new methods and processes, Pro-Enrich is taking biomass from these four side streams to test the technical and commercial feasibility of extracting ingredients from them in both small and large-scale bio-processing environments. The resulting functional proteins, polyphenols, dietary fibers and pigments will then be tested and used in food, feed, cosmetics and adhesive applications.
Although we’re exploring specific side streams, our goal is develop a flexible biorefinery model that operates 12 months of the year, and that will allow others to follow suit, extracting valuable ingredients from the same or completely different crop residues.“– Dr. Anne Christine Hastrup, Pro-Enrich Project Coordinator, Danish Technological Institute
Setting the standard for sustainable functional ingredients production
The Pro-Enrich biorefinery process, aspects of which are split between facilities at the DTI and Bangor University (BU) in the UK, begins with biomass residues undergoing a coupled mechanical pre- and wet processing step which uses enzymes to release specific compounds. From there, a combination of GEA Disc-Stack Separators and GEA Decanters, among other methodologies, are employed to gently extract and separate the relevant compounds, while ensuring purity, functionality and quality. Each step must be cost-effective, energy-efficient and maximize raw material usage while delivering high-quality products.
The last step, drying, ensures material stability and shelf-life. From there, the proteins and bioactives are tested in real-life applications by the end-customers in the consortium – with feedback about performance going back to the processing experts for any necessary refining. “Even though Pro-Enrich is only responsible for delivering at the pilot level,” explains Dr. Anne Christine Hastrup, Pro-Enrich Project Coordinator, Danish Technological Institute, “it’s tremendously useful to have all of our partners onboard, particularly the end-use customers who can test as well as influence our fractionations to ensure they’re getting something useful at a viable market value.”
Rapeseed (canola) meal/press-cake
Rapeseed, or canola, is a major crop worldwide and in the EU, grown primarily as a source of oil. The by-product of rapeseed oil extraction is protein-rich, rapeseed meal, which is often used in feed for ruminants, pigs and chickens. However, it has tended to be produced by exposing the by-product to high temperatures and sometimes chemicals during extraction, rendering it unusable in food-grade and other feed applications.
An increase in cold-pressed rapeseed oil has resulted in more rapeseed meal availability for further processing. Although still being developed and improved upon, by using cold methods, proteins and protein-derived ingredients can be extracted more gently and retain more of their original nutrients and functionality, making them a better option for use in foods and pet food and a good alternative to soy. Pro-Enrich will also focus on methods and processes to remove problematic, but also potentially valuable low-level glucosinolate and phytate components.
Olive pomace & olive mill wastewater
The EU is the world's leading olive oil producer – most of which is used for human consumption. After the oil has been recovered in the mill, what is left over is olive pomace, which consists of pulp, skin, pits and olive mill wastewater (OMWW), which is what is decanted from the resulting olive oil that has been purified and centrifuged. Olive oil extracts can be a major environmental issue given their high organic loads and low pH level. And at present, stronger legislation is needed to better regulate olive mill discharges throughout the EU.
The resulting pomace contains large quantities of phenolic compounds, some proteins and dietary fiber which can be extracted and isolated for reuse in therapeutic and other health and wellness-related products and adhesives. OMWW contains phenolic compounds, sugars and organic acids which can be used in the cosmetic and adhesives industries, in food ingredients and in dietary supplements. Removing phenols from OMWW also improves its purity level before discharge or further use in process water.
Citrus fruit residues
Oranges, lemons, grapefruits and mandarins dominate global fruit cultivation, much of which is processed for making juice, jam or marmalade. Citrus waste, which consists of peel, fruit mass, seeds and pulp is already used to some extent; for example, apple, grape and lemon peels left over from juice making are used to make pectin. Likewise, citrus peel is used in the production of essential oils, Hesperidin, a bioflavonoid, and pulp fractions.
Additional applications however, remain largely unexplored, which includes isolating polyphenolics, antioxidants, carbohydrates, proteins and dietary fibers and other valuable compounds for reuse in high-value food ingredients, cosmetics, pet food and dietary supplements.
If classified as a vegetable (versus a fruit) as defined by the EU, then the tomato is the world's most consumed vegetable. In Europe, tomatoes are primarily grown in greenhouses to allow for near year-round production.
Tons of waste in the form of skin and seeds is generated when tomatoes are processed – most of it going unused. However, through extraction, polyphenolics, proteins, pigment, carbohydrates, dietary fibers and other valuable compounds can be isolated for reuse in high-value food ingredients, cosmetics, pet food and dietary supplements.
Technology obviously plays an integral role in this project. That said, engaging and networking with the project partners and other companies is critical, because it connects the very stakeholders required if we are to further the aims of the bioeconomy.“– Dominik Krienke, Specialist Process Technology Renewable Resources, GEA
The measure of success
For Pro-Enrich, technical processes are only one aspect of the project; in addition to demonstrating that these compounds can be more efficiently and sustainably produced, the team facilitates supply chain building across different sectors to ensure these side streams, and the high-value ingredients extracted from then, can be utilized across the EU or globally. The team’s unique constellation includes the necessary stakeholders along the entire value chain to facilitate this new business model: from farming and biomass supply (Emmelev, Anecoop, MARZI FRANKA, Olivar de Segura), processing and technology experts (GEA, Tailorzyme), hosting and expertise for pilots, processing and analytics (InnoRenew, DTI, BU), manufacturers (Mars, Tate and Lyle, Chimar, Natac) and specialists to drive further engagement, promote and disseminate information about Pro-Enrich’s work (Agro Business Park, Innovarum).
Although GEA was brought onboard specifically for their technical processing expertise, they’ve made important contributions at all stages of the project given their tremendous knowledge, experience and flexibility.“– Dr. Anne Christine Hastrup, Pro-Enrich Project Coordinator, Danish Technological Institute