Application of an hazelnut by-product for innovative functional food production: preliminary results

In the European Union, each year, food industries produced nearly 300 million of tons of organic by-products that represented an additional cost for their disposal. It becomes necessary on one hand an optimization of the process/product finalized to reduce the by-products production and on the other hand a valorisation of the residue obtained. In last years many researchers focused their works on the valorisation of the by-products as functional ingredients for novel foods production due to the bioactive compounds contained like fibre and polyphenols. Hazelnut skin represents 2.5% by weight of the raw material and it is discarded upon roasting. Until now it has been used as animal bedding but a lot of research underlined its potentiality as a source of natural antioxidant and dietary fibre. The aim of this research was to evaluate the feasibility of use the Tonda Gentile Trilobata hazelnut skin as ingredient into a ripened cheese. Hazelnut skin was added at a rate of 3% (w/w) of fibre so that the resulting product could be labeled as “fiber source” as required by the European Community Regulation. The samples were evaluated in term of gross composition (ash, moisture, protein, fat, carbohydrates, dietary fibre), total phenolic content with Folin-Ciocalteu method, radical scavenging activity with DPPH• method, fatty acids, proteolysis with Urea PAGE, sensory characteristics. The results underlined that the hazelnut skin addition increases dietary fibre and antioxidant content of cheeses without change the macro-compositional characteristics of obtained products and consumer’s appreciation. It will be necessary new research to evaluate the effects of different cultivars or the process by which the by-product is obtained on the compositional and nutritional characteristics on the dairy products where it will be added.