Bioaccessibility and Antioxidant Capacity of Alkaloids from Microencapsulated Extract of Eggplant (Solanum melongena L.) Biomass

Eggplant is a vegetable grown worldwide, and due to quality standards, large amounts of biomass are generated after harvest. Biomass is considered a source of bioactive compounds with antioxidant properties. Therefore, this research aimed to evaluate the bioaccessibility (BA) and antioxidant capacity of microencapsulated alkaloids from eggplant fruit biomass. Eggplant biomass was collected, and the total alkaloid content, antioxidant capacity (TEAC, FRAP, and ORAC), and alkaloid profile (UPLC/MS) were determined before and after the in vitro digestion of encapsulated and non-encapsulated alkaloids. In vitro digestion significantly reduced the total alkaloid content and antioxidant capacity of alkaloid-rich extracts. Microencapsulation increased the bioaccessibility of alkaloid-rich extracts threefold, and the antioxidant capacity increased by up to 50%. The antioxidant capacity of digested microcapsules increased, and their bioaccessibility was higher than that of non-encapsulated alkaloids. Solamargine and solasonine decreased by 17 and 15% BA, respectively, during in vitro digestion; however, microencapsulation protected these alkaloids during in vitro digestion and enhanced their content. This study demonstrates that microencapsulation is a feasible option to protect alkaloids and preserve their antioxidant capacity during gastrointestinal digestion, as well as to give added value to eggplant plant biomass.