Orange peel waste in the Circular Economy: an integrated assessment approach

To save natural resources, a shift to a circular economy is required. Putting Circular Economy concepts into practice helps reduce waste and upholds the EU's fundamental recycling, reuse, and prevention directives. Given the amount generated annually in Europe (more than 58 million tons), special attention must be paid to food and food industry waste. Specifically considering the production of orange juice, about 55 million tons per year of orange waste are created worldwide, Italy is the second-largest producer of oranges in the EU 27 after Spain. Every year, enterprises that manufacture orange juice in Italy generate hundreds of tonnes of orange peel waste (OPW), which is a mixture of pulp, seeds, and peel that accounts for up to 60% of the fresh citrus weight. The novelty of this study lies in its analysis of a broader range of technological alternatives, using a multi-criteria evaluation methodology to assess sustainability from a comprehensive, global perspective. Concerning the production of biomaterials, this study proposes a comprehensive evaluation of a technology applied by an Italian company, focusing on the manufacturing of objects through the utilization of raw materials such as orange waste. The production process of the biopolymer entails a series of steps including a drying phase, followed by milling to achieve a fine powder which is subsequently blended with a biopolymer matrix. This mixture is then extruded into filament form, which is further utilized for the creation of various design objects. To assess its potential as a circular waste management solution, the technology will be compared with alternative valorization routes for OPW, a versatile feedstock with potential applications including energy recovery via incineration, conversion into animal feed—thanks to its palatability and ease of pelletization—and use in anaerobic digestion, provided that inhibitors like D-limonene are removed or mitigated through pre-treatment or co-digestion. The comparison will be conducted through a three-step assessment framework consisting of: (i) Holistic Diagnosis, (ii) Life Cycle Assessment of OPW processing alternatives, and (iii) Multi-Criteria Decision Analysis combined with a Circular Economy performance evaluation. This methodology assesses technologies, context, and stakeholder involvement, and can be applied to various types of waste beyond the food sector to support the circular economy. Integrating waste reuse into production through innovative technologies is a key step toward more sustainable, circular, and resilient industrial systems; fully evaluating these processes—economic, social, and environmental—is equally crucial to ensure their overall sustainability and applicability. Acknowledgements This study was carried out within the Agritech National Research Center and received funding from the European Union Next-GenerationEU (PIANO NAZIONALE DI RIPRESA E RESILIENZA (PNRR) – MISSIONE 4 COMPONENTE 2, INVESTIMENTO 1.4 – D.D. 1032 17/06/2022, CN00000022).