Pro-Enrich focused on the following feedstocks:
1) Citrus/tomato – these large waste streams constitute a severe environmental burden. Inherent compounds hold potential as dietary supplements.
2) Olive pomace and olive wastewater – large volumes produced as a by-product of olive oil production, which have high levels of pollutants, and are difficult to dispose of. Contains high levels of phenolic compounds with potential as dietary supplements and adhesives.
3) Rapeseed press cake – high levels of protein that can replace conventionally used soy protein products in food/feed.
The supply chain and quality assessment of the raw materials was performed by collecting information on the specific needs of end-users, in relation to product purity and functionality requirements. The most promising products have been identified from each raw material. These are proteins from rapeseed cake and tomato residues and polyphenols from olive side-streams, tomato pulp and orange peel. Enzymatic processing of residues has been performed after initial trials to identify and assess the effect of selected enzymes on the recovery of targeted products.
Lab and pilot trials have been completed, integrating enzymatic and mechanical processing, recovery and purification of proteins from hot and cold pressed rapeseed cake, respectively. These process steps include unit operations such as wet milling and membrane filtration. Various types of rapeseed cake have been considered and have been individually analysed to investigate compositional differences. Valorisation of hot-pressed rapeseed cake and cold pressed rapeseed cake has been selected due to availability. Kg-scale protein concentrate (50-70%) and isolate (92%) were obtained. Protein extracts derived from rapeseed cake have been tested by industrial partners, which showed that while the products could be used in wood adhesive formulations, they did not currently meet criteria for pet food applications.
Three different olive by-products have been analysed: wet pomace, dry pomace and olive mill wastewater (OMWW). These residues haves been assessed for the recovery of polyphenols with OMWW as the most promising source. A novel method for polyphenol extraction from OMWW has been developed using magnetic particles for polyphenol extraction. These materials function in solution, bonding to solubilized phenols, and are then physically pulled from solution using magnets. The bond between the magnetic particles and phenols is then cleaved and the particles can be re-used indefinitely. The methodology for total polyphenol content has been prepared and validated to assess efficacy of extraction.
A method for separating the seeds from the pulp and juice has been developed for tomato side streams and bioactive compounds were targeted. Carotenoid extraction and fractionation processes were developed with carotenoids content of 20-25% and lycopene 5-15% obtained.
Citrus peel and pulp have been separated and analysed, with bioactive ingredients naringin and hesperidin being identified as commercially important. Purities up to 90 % have been achieved for extraction and purification of citrus flavonoids, mainly hesperidin. In vitro functionally testing in cosmetics has been undertaken to better support application uses.
A preliminary market analysis of the biomasses in the project has been performed. Parameters such as the total available volume worldwide and within the project, current value chains and current uses have been analysed. The market potential of target products (proteins, carbohydrates etc.) has been assessed as well as the economic feasibility and the environmental impact.
A review of the European legislation relating to the food and feed sectors and the application of Pro-enrich derived products has been conducted. The legislation was related to feedstock selection, the proposed biorefinery approach and evaluation of materials in end-products.
All of the results support the Bioeconomy policy, to strengthen and scale-up the bio-based sectors, unlock investments and markets. They affect all levels of the value chain from the raw material suppliers by opening up new markets for technology developers, business and sustainability analysts and presents alternative sources of proteins/bioactives for producers.
