Upcycled Orange Peel Ingredients: A Scoping Review on Phytochemical Composition, Extraction Techniques, and Biorefinery Strategies

Orange peels, the juice industry's massive leftover, are hiding a treasure trove of health-boosting compounds—and scientists are finally learning how to unlock them.

Every glass of orange juice leaves behind a mountain of peels. But these scraps are far from useless. Packed with phenolic compounds, pectin, carotenoids, and essential oils, orange peels are a goldmine for nutrition and sustainability.

A new scoping review, covering studies from 2003 to 2023, maps the rise of orange peel upcycling. The numbers tell a clear story: research has exploded over the past decade. Using Scopus data and VOSviewer, scientists identified hotspots and gaps in the field, comparing conventional and green extraction methods.

Currently, polyphenol- and pectin-rich extracts dominate research and applications, thanks to their high nutritional and economic value. Innovative multi-extraction and zero-waste biorefinery models are emerging, but most are still in early development. Carotenoids and other bioactives remain underexplored, and standardization and scalability are ongoing hurdles.

The future of orange peel valorization lies in integrated green extraction and biorefinery frameworks that support clean-label products and circular economy goals. To get there, researchers must prioritize standardized protocols, scalable technologies, underutilized compounds like carotenoids, and clear regulatory pathways.

Key Points

• Orange peel research has surged exponentially since 2003.
• Polyphenols and pectin are the main focus for nutrition.
• Carotenoids and scalability remain underexplored challenges.