Circular bioeconomy approach for the recovery of polyphenols and dietary fibres from orange pomace waste

Abstract

The orange juice processing industry generates substantial peel and pomace waste, which, if not managed responsibly, poses significant environmental challenges. However, these byproducts are rich in bioactive compounds with notable health benefits. Conventional extraction methods often rely on toxic, non-biodegradable solvents, making them environmentally unsustainable. The present work addresses this using a circular bioeconomy approach, for developing green and scalable methods for valorising orange pomace waste (OPW) using non-toxic, recyclable deep eutectic solvents (DESs). Four DESs and a benchmark solvent (Ethanol: Water 50 % v/v) were used for the extraction of bioactive compounds from OPW under optimized conditions. LP: MA (1:1) DES emerged as the most effective, achieving high total phenolic content (TPC) as confirmed through FTIR spectroscopy, SEM, CHN analyses, and computational modeling. The DES extracts exhibited strong antibacterial and antioxidant properties, validated by DPPH, FRAP, ABTS, and TFC assays, highlighting their potential for sustainable healthcare applications (SDG 3). The solid residue, containing 41–47.98 % dietary fiber, supports a zero-waste approach (SDG 2 & 12), while the recyclability of DESs for four cycles minimizes resource consumption and environmental impact (SDG 13). By integrating green chemistry, waste valorization, and circular bioeconomy principles, this study advances sustainable industrial practices, promoting better resource utilization and environmental pollution mitigation, in alignment with global sustainability goals.