Based on the concepts of a circular economy and sustainability, this research aims to enrich foods by incorporating extracts from food by-products into them.

As the south of Galicia and the north of Portugal are major producers of Castanea sativa Miller chestnuts, it is imperative to devise sustainable uses for the by-products generated during their processing.

Chestnuts' consumption is widely promoted for its nutritional value and health benefits. It is a starchy fruit that is rich in vitamin C and minerals and gluten-free, making it great for people with coeliac disease, as well as being low in fat. There are several studies that describe the shells and hedgehogs of chestnuts as promising sources of bioactive compounds and fibre. Taking the nutritional advantages associated with both chestnut flour and chestnut by-products by various authors as a starting point, the aim is to extract tannins from the shells and hedgehogs for future incorporation into the flour. The shells will be heat-treated, dried, roasted, and boiled in thermal water. The hedgehogs will only be freeze-dried before being extracted. It is also hoped that we will ascertain the feasibility of incorporating the extracts of these by-products into chestnut flour, which is also made using different thermal processes, including drying, roasting, and boiling in thermal water, and is rich in minerals. The main aim of this study is to optimise a food product, chestnut flour, with added value by incorporating extracts from chestnut shells and hedgehogs. The aim is to produce a nutritionally enriched product with greater antioxidant capacity, thereby increasing the shelf life of chestnut flour.