Not only what is food is good - polyphenols from edible and nonedible vegetable wastes

The primary challenge for all kinds of industries in terms of green processes is the transition from a fossil resource-based economy to one based on renewable raw materials processing. The food and beverage industry is undoubtedly the largest manufacturing sector in the European Union (EU); byproduct management in the food industry is hence a great concern in the areas of environmental protection and sustainability. Because agrifood industry waste is almost entirely of biological origin, the two general ways to reuse it have been either as animal feed (not always adequate due to difficulties in properly balancing the nutritional requirements) or as combustion feedstock or fertilizers, sometimes causing major environmental issues. Furthermore, among all known sustainable resources (solar, wind, geothermal), only biomass coming from food and feed crops, dedicated energy crops, trees, agriculture residues, et similia currently represents an accessible source for chemicals and products with high added value. For example, these materials usually contain high levels of cellulose, hemicellulose, lignin, and proteins, which can be used as renewable natural resources either for inexpensive, ecofriendly materials (such as low-cost adsorbents) or destined to supplement food products and ready meals .As a matter of fact, the number of food products enriched with dietary fibers coming from agronomic byproducts introduced to the market has increased due to several beneficial effects mainly on the digestive system. In a recent paper, Naziri and coworkers critically discussed the possibility of waste recycling in three of the primary traditional productions in Macedonia, that is, olive oil, wine, and rice. They reported high-value nutrient recovery animal feed, thermal energy production, alcohol production, and composting as the currently available ways for waste utilization in Greece. These processes, once optimized, can be practical examples of the so-called "circular economy," whose concept was introduced by Pearce and Turner, which is defined as "a regenerative system in which resource input and waste, emission, and energy leakage are minimized by slowing, closing, and narrowing material and energy loops. This can be achieved through long-lasting design, maintenance, repair, reuse, remanufacturing, refurbishing, and recycling". In other words, circular economy promotes resource minimization and the adoption of cleaner technologies . A painless transition from the conventional, open-ended economy to the circular economy has been, and still is, one of the primary strategies of the European Commission. Apart from the previously mentioned dietary fibers, food and agroindustrial residues are known to constitute a good natural source of bioactive molecules such as vitamins, minerals, pigments, and antioxidants to be used as food additives and/or nutraceuticals; in fact, other than contributing to the overall process sustainability, natural ingredients used in daily life products have greater acceptability for most people over their synthetic counterparts .