Non-starch Polysaccharides from Fruit and Vegetable Waste: Potential and Sustainable Recycling Approaches

Fruit and vegetable wastes represent a rich source of unconventional carbohydrates with applications in pharmaceuticals, packaging, tissue engineering, and other industrial sectors, offering sustainability, cost-effectiveness, health benefits, and support for a circular economy. While common starch serves as the main source of dietary energy, non-starch polysaccharides (NSPs), such as cellulose, hemicellulose, and pectin, have diverse glycosidic bonds and complex architectures that render them indigestible by humans. These NSPs, which constitute the plant cell wall, are valued for their functional properties, including modulation of the gut microbiota and antioxidant activity. This review provides a detailed comparison between NSPs extracted from fruit and vegetable waste and those obtained from conventional sources. We demonstrated that NSPs obtained from food waste have significant advantages in terms of extraction efficiency, cost-effectiveness, and environmental impact, while maintaining essential functional and structural characteristics. Their versatility is reinforced by innovative applications as excipients in drug delivery systems, wound-healing scaffolds, biodegradable packaging, bioadhesives, flocculants, and adsorbents. Additionally, using agro-industrial residues as raw materials reduces dependence on primary resources, minimizes waste generation, and promotes sustainable development. We describe both established and emerging green extraction techniques and correlate the molecular characteristics of NSPs with their performance in pharmaceuticals, tissue engineering, and controlled-release agents. Taken together, these insights reinforce the key role of NSPs derived from fruits and vegetables in advancing a truly circular economy.Graphical Abstract