Apples are the second most widely grown fruit in the world and in Europe. A large proportion of the crop is consumed fresh, while the rest is processed into juice, concentrates, compotes and cider. At regional level, the cider industry, which produces ciders and apple juice, generates large volumes of organic residues, called by-products if valorized and waste otherwise. Of these residues, pomace alone accounts for 25-30% of the raw material. Today, some fresh pomace is used to produce biogas and compost, and some is dried to produce pectin. However, these residues contain high levels of bioactive molecules such as polyphenols, which are valuable ingredients for food and non-food applications. These compounds are also highly concentrated in apple tree pruning, another bioresource not yet exploited by the cider apple sector.
The design and demonstration of a bio-refining process for the recovery of cider-making residues is important in order to involve the stakeholders in the cider-making sector in a more efficient use of these co-products from an environmental (closing cycles) and economic (product diversification) point of view. In particular, the demonstration includes technological solutions for the stabilisation of these co-products and for the cascade extraction of molecules of interest (polyphenols, pectins, cutins) upstream and for the production of biogas and agricultural fertilisers downstream.
