Food loss and waste represent a global challenge threatening food security and exacerbating climate change. Upcycling food waste into value-added products is increasingly recognized as an effective pathway toward a circular economy. This study introduces a novel integrated multi-criteria decision-making (MCDM) framework based on Circular Intuitionistic Fuzzy Sets (CIFS) combined with MEREC objective weighting and CIFS-MARCOS ranking, an approach not previously applied to food waste upcycling. Ten prominent upcycling strategies were identified from recent literature and evaluated against twelve sustainability criteria by ten food industry experts. Results revealed “market potential”, “public awareness of upcycled products,” and “food quality and safety” as the most influential criteria. Among strategies, producing sustainable textiles from food waste ranked first, followed by sustainable packaging, novel food ingredients, and bioenergy production. The proposed framework effectively handles uncertainty and dynamic interdependencies among criteria, offering a robust and original tool for prioritizing upcycling pathways.
Introduction
The circular economy and zero-waste economy are emerging as central components of the discourse on sustainable living, offering significant benefits for both humanity and ecosystems. An innovative approach to achieving this goal involves transforming food waste into value-added products. Food waste, discarded at various stages of the supply chain from production to consumption, poses a global challenge with profound environmental, economic, and social implications. These wastes encompass fresh horticultural products, dairy, meat, seafood, grains, expired materials, and consumption leftovers, all of which hold potential for utilization in other industries, while restaurants and the catering sector also generate substantial waste through surplus materials and unsold food. Global solid waste production is projected to increase from 2.01 billion tons in 2016 to 3.4 billion tons by 2050, with approximately one-third of food produced for human consumption (1.3 billion tons annually) being wasted, incurring an economic cost of $1 trillion, which rises to $2.6 trillion when accounting for social and environmental impacts.
Methodology
The methodology of this research is grounded in the integration of empirical and theoretical knowledge. Empirical data were collected through surveys conducted with experts. Using purposive sampling, ten experts with 10 to 25 years of experience in the food industry were selected. The selection criteria included their distinguished academic and practical backgrounds, which enabled a comprehensive and in-depth understanding of food waste valorization concepts and their practical strategies. Additionally, the theoretical foundation of the study was established through a thorough review of the literature, from which key criteria and indicators related to food waste valorization were extracted. To integrate these two knowledge domains and model the inherent uncertainty in expert judgments, Circular Intuitionistic Fuzzy Sets (CIFS) were employed. The developed multi-criteria decision-making framework in this study performs criteria weighting using the CIFS-MEREC method and strategy ranking using the CIFS-MARCOS method (see Figure 1). This approach enhances the accuracy and reliability of the analysis under complex decision-making conditions.
Findings
The results indicate that, in the ranking of strategies, the production of sustainable textiles from food waste secured the top position, as it simultaneously achieves economic value addition and reduces environmental impacts. Following this, sustainable packaging, the production of new food products from waste, and bioenergy production were ranked sequentially. This ranking suggests that the most successful strategies are those that close the resource cycle while generating economic value, thereby exhibiting the greatest potential for advancing sustainable development goals.
Results and Discussion
This research provides a comprehensive framework for prioritizing food waste valorization strategies, addressing the lack of integrated multi-criteria ranking despite extensive technical and environmental studies. By integrating Circular Intuitionistic Fuzzy Sets (C-IFS), MEREC, and MARCOS, twelve sub-criteria across environmental, economic, social, and technical dimensions were evaluated, yielding ten key strategies. Market potential, public awareness, and food quality and safety emerged as top priorities, offering strategic insights for stakeholders. Transforming food waste, such as fruit peels or coffee grounds, into high-value fibers, natural dyes, or vegan leather requires investment in research and development and collaboration with eco-conscious fashion brands. Converting waste like corn starch or shrimp shells into biodegradable films and containers addresses plastic pollution by developing competitive, durable, and cost-effective alternatives. Repurposing agricultural residues into protein, flour, or enriched foods demands stringent safety and quality standards to gain consumer trust. Producing biogas and biofuels through anaerobic digestion offers a scalable solution, reliant on robust infrastructure and a consistent waste supply.
Conclusion
The findings highlight a shift from traditional approaches, such as bioenergy, to innovative, high-value solutions like sustainable textiles. Strategy selection should align with waste type, technological capacity, and market needs, with hybrid approaches optimizing sustainability and profitability. The proposed C-IFS, MEREC, and MARCOS framework ensures robust decision-making for stakeholders, despite limitations including a limited expert sample and reliance on qualitative data. Future research should expand expert input and investigate long-term impacts, such as food security, employment, and emissions reduction. Integrating MEREC and MARCOS with MABAC and C-IFS could further enhance decision-making precision. This multi-criteria framework provides a solid foundation for policy-making, investment, and future research in the circular economy.