Sustainable valorization of organic solid wastes: macromolecular humic acid-stabilized cinnamon essential oil emulsions with enhanced antibacterial properties
摘要
Traditional Chinese medicine residues, tangerine meat, and soy sauce residues are significant organic solid wastes in China and cause various environmental issues. To promote the valorization of these wastes, macromolecular humic acid (HA) is extracted from composted tangerine meat, Chinese medicine residues, and soy sauce residues and subsequently utilized to stabilize cinnamon essential oil (CEO) emulsions. Compared with commercial humic acid (CHA), compost-derived HA contains more aliphatic groups, is more polar, and is highly dispersed in water under neutral and alkaline conditions. HA-stabilized CEO emulsions were formulated, and the effects of the pH, HA concentration, and oil content on the emulsion characteristics were assessed. The emulsion formed with 2.00% (w/w) HA and 50% (v/v) CEO at a pH of 7 yielded the smallest droplet diameter (8.12 ± 0.28 μm) and exhibited superior storage stability over a 20-day period. Furthermore, HA-stabilized CEO emulsions demonstrated potent antibacterial effects on gram-negative and gram-positive bacteria. This research presents a novel method for encapsulating essential oils using extracts derived from organic solid waste.