Extraction and encapsulation of purple corn cob anthocyanins into starch- and zein-based delivery systems

Anthocyanins (ACNs), a class of flavonoid pigments found in many red-purple fruits, vegetables and cereals, have gained significant attention due to their diverse biological properties. Thanks to their antioxidant and anti- inflammatory activity, the consumption of a diet enriched in these compounds has been found to provide health-beneficial effects against numerous pathologies including cardiovascular and neurodegenerative diseases. However, ACNs low bioavailability, limiting their distribution in the human body after oral administration and, consequently, their therapeutic use, is a significant issue. To answer this challenge, encapsulation within poly- meric systems has been proposed. Under the wider view of a circular economy approach, this study explores the encapsulation of ACNs extracted from purple corn cob wastes using two biomacromolecules, zein and starch, to formulate micro and nanostructures. The resulting delivery systems were characterized in terms of encapsulation efficiency, size and morphology through Ultra Performance Liquid Chromatography coupled to a time-of-flight mass spectrometer, Dynamic Light Scattering and Scanning Electron Microscopy, respectively. Both zein-based nanoparticles and starch-based microstructures showed promising colloidal stability and encapsulation effi- ciencies. Nevertheless, only zein-based nanoparticles exhibited no cytotoxicity in human intestinal cells and can represent a starting point to investigate a potential enhancement in ACNs bioavailability.