Extraction of bioactive compounds and/or macromolecules from food by-products and wastes

Fruits and vegetables produce at least 25–30% of by-products (e.g., peel, seeds, pomace). In addition, each year more than 20 million tons of fishery and aquaculture wastes (e.g., fins, heads, skin, and viscera) are discarded at sea. Both agri-food and marine wastes contain valuable compounds (e.g., polyphenols, flavonoids, tannins, organic acids, terpenes, vitamins, collagen, gelatin, peptides, polyunsaturated lipids, chitin). Once extracted, these components can be used as such or bio-transformed in several industries. Conventional extraction techniques require large amounts of organic solvents and long time, are costly, and show low yields. Such shortcomings could be overcome by using novel extraction methods. Although various green extraction techniques have been explored, sustainable processes satisfying the need for lowering costs have not yet been sufficiently standardized and upscaled.

Biomass by-products and waste from several matrices and/or industries (fruit and vegetables, cereals, legumes, spent coffee, breweries, dairies, milling olives, cooking oils, forestry, beekeeping, seaweed, fishery) will represent the starting materials for recovering bioactive molecules, either purified (e.g., peptides, mono/polysaccharides, lipids, organic acids, phenolics, lignin, carotenoids, terpenes, vitamins, glucosinolates/isothiocianates, chitin) or in mixture (e.g., essential oils). Waste biomasses processed by fermentation and/or enzymatic catalysis as in Task 2.1.2, will be also considered to obtain compounds of industrial interest. The following sustainable extraction techniques will be applied:

• CO2-Supercritic Fluid Extraction (POLIMI, CNR, ENEA)

• Green solvents, such as Deep Eutectic Solvents (DES) and Natural DES (NADES) (POLIMI, UNICATT, CNR, UNINA, UNIMI)

• PEF-assisted extraction/Microwave/ultrasound-assisted extraction (POLIMI, UNIBO, UNIMI)
  Cavitation-based extraction (CNR)

• Autohydrolysis (UNICATT)

• Membrane filtration system (e.g., microfiltration, ultrafiltration, nano-filtration, reverse osmosis) (POLIMI, CNR)

• Ultracentrifugation coupled to filtration (CNR)

For each technique, the parameters applied during the extraction process will be optimized. In addition, when green solvents will be used, optimization of the solvent recovery and reuse will be investigated to achieve a cost-effective process. Finally, combinations of different extraction techniques will be scouted.

At least one sustainable and cost-effective extraction process for by-products and wastes from each agrifood and marine chain will be optimized.