Upcycling of Mixed Fruit Juice By-Products for Flour Production and Application in Plant-Based Burgers.

Agro-industrial by-product valorization has emerged as an important strategy for developing sustainable functional ingredients aligned with circular economy principles. This study aimed to produce flour from mixed juice processing residues composed of strawberry, pineapple, and ginger and to evaluate its application in plant-based burger formulations. The mixed fruit juice residue flour exhibited high total dietary fiber content (35.76 g/100 g), predominantly insoluble fiber, along with significant levels of phenolic compounds, resulting in elevated antioxidant capacity (ORAC: 377.21 µmol TE g- 1) and antifungal activity, suggesting multifunctional and natural preservative properties. Plant-based burgers were formulated with 10% and 15% mixed fruit juice residue flour incorporation and evaluated for physicochemical, technological, and sensory properties. Flour addition increased ash (1.70-2.95 and 3.36 g/100 g) and total fiber contents (7.19-8.28 and 8.99 g/100 g) while maintaining moisture levels comparable to similar plant-based products. Technological analyses demonstrated suitable structural integrity, texture profile, and cooking performance, indicating that product quality was not impaired by flour incorporation. Sensory evaluation with 97 untrained panelists revealed high consumer acceptance, with five of seven attributes showing acceptance indices above 80% on a nine-point hedonic scale. Overall acceptance scores were 7.56 and 7.40 for burgers containing 10% and 15% mixed fruit juice residue flour, respectively, demonstrating that incorporation did not compromise sensory perception despite fruit-derived compounds. Overall, these results demonstrate that mixed fruit juice residues can be successfully converted into value-added functional ingredients and incorporated into plant-based meat analogs, contributing to food waste reduction, enhanced nutritional quality, and development of sustainable foods aligned with current consumer demands.