###### Abstract  
Several agri-food byproducts represent valuable sources of compounds to be reutilized for nutritional, nutraceuticaltial, and cosmetic purposes. Examples especially comprise byproducts from the processing of fruits such as pomace, because of their richness in nutrients (e.g., fibers) and bioactive compounds (e.g., polyphenols) that can be destined for animal and human use. However, in agreement with the principles of circular economy that are being promoted during the most recent years, other understudied agri-food byproducts of both plant and animal origin are being evaluated to assess their possible reutilization and valorization. In this review, we aim at summarizing the most recent research dealing with the extraction of nutrients and bioactive compounds from agri-food byproducts using innovative and sustainable approaches. Specifically, the review is focused on byproducts generated in large amounts (tons/year) by the food industry of Northeast Italy, namely, honey, red fruits (grapes and berries), and chicory, which are especially of interest for their content in phenolic acids, flavonoids, anthocyanins, and dietary fiber. The potential applications of these byproducts and extracts in cosmetic, nutraceuticaltial, and nutritional fields are also discussed, referring to the published literature, as well as their potential utilization as sources of novel bioactive compounds with pharmacological applications. agri-food byproducts; honey; chicory; grape; berries; sustainable extraction +
Footnote †: journal: applied sciences  
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progressively and proportionally with the increasing development of the food industry [8]. A large part of these products derives directly from the processing of crops such as oranges, grapes, apples, and tomato, which generates tons of pomace (i.e., peels and seeds mainly) per year [9; 10; 11]. However, wastes are also produced due to technical and management limits in the post-harvest, processing, and distribution steps and the high productivity and quality standards required by the market that frequently lead to food discharge by retailers [12; 13]. The disposal of nonedible food waste and agri-food byproducts represents an economic, environmental, and social issue due mainly to the high amounts produced, their physicochemical characteristics, and their perishability. These products are frequently disposed of by incineration or landfilling, but this can cause soil, air, and water pollution. Efforts have been made to find alternative solutions in order to reduce the environmental impact of the agri-food chain and to increase its profitability. Many of these involve the reuse of agri-food byproducts and wastes as substrates for the production of biofuels [14] or the development of novel materials with potential utilization in medicine [15] and food technology [16], instead of their disposal. Residues obtained from fruits, cereal, and vegetables processing also represent valuable sources of bioactive compounds and nutrients (e.g., sugars, fats, dietary fibers, vitamins, and polyphenols) to be used in animal and human nutrition or as ingredients of nutraceuticals [17]. In this regard, one of the main issues that scientists and developers have to deal with is finding proper extraction methods for these compounds due to the chemical diversity and complexity of these materials. Extraction protocols should be selective for the compounds of interest in order to yield safe final products suitable for human use, but also environmentally sustainable and economically viable [18]. Also, they should not affect unstable compounds such as several plant secondary metabolites, which can be susceptible to thermal or oxidative degradation, for example.