Nanoencapsulation of Anthocyanin Extract from Fermented Black Garlic (FBG) Based on Biocompatible Polymeric Materials

Abstract

Garlic contains various polyphenolic compounds such as anthocyanin, a bioactive, water-soluble compound generally known for its remarkable health-enhancing properties. However, it is chemically unstable and easily degrades due to various environmental conditions (temperature, pH, presence of oxygen and light, etc.) in addition to its low bioavailability due to fast metabolization and low absorption in the body. Therefore, a nanoencapsulation strategy is essential to address these limitations. In this work, anthocyanin extraction from FBG (Ilocos variety) with 85% acidified ethanol and its encapsulation using the chitosan-alginate nanoparticle system via pre-gelation and polyelectrolyte complex formation were demonstrated. Anthocyanin-loaded chitosan-alginate nanocapsules were characterized in terms of structural features, particle size, morphology, encapsulation efficiency, total phenolic content (TPC), and radical scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH). The obtained anthocyanin-loaded nanocapsules have small particle sizes ranging from 50.7 nm to 92.0 nm with high encapsulation efficiency (T3: 78.82%, T2: 68.18%, T1: 65.77%). Results showed that a higher initial concentration of anthocyanin extract promotes higher encapsulation efficiency. Antioxidant activity of the nanocapsules showed low phenolic content (0.11 mg GAE/g) but high DPPH scavenging activity (14.02 mg AAE/g). The chitosan-alginate complex has successfully encapsulated the anthocyanin from fermented black garlic.