N2 Nanobubbles Synergized With Limonene and Ultrasound for Enhanced Extraction of Terpenes From Camellia Oleifera Shells

Camellia oleifera shells, waste material obtained after oil extraction, contain a significant number of terpenes. This study introduces a novel, eco-friendly, and sustainable method to combine N 2 -NBs with limonene and ultrasound to enhance terpene extraction from food waste. N 2 -NBs suspension stabilized by Tween 80, resulting in 255 nm size with reduced surface tension. Raman spectroscopy indicates strong hydrogen bonding at 1646 cm⁻¹, suggesting that the enhanced release of compounds and micelle formation improved the solubility of terpenes. Meanwhile, SEM demonstrated that the collapse of N 2 -NBs effectively disrupted cell walls. Together, these mechanisms significantly enhanced terpene compounds' release, solubility, and overall yield. Combining Tween 80 and N 2 -NBs with ultrasound achieved a terpene yield of 42.88 ± 1.87 mg/g DW, significantly higher than the 10.96 ± 2.87 mg/g DW from ethanol extraction. These findings highlight the novel eco-friendly approach to effectively extract terpenes, which can be useful for industrial applications. Practical applications The novel, eco-friendly extraction method can be used to reuse food waste. High-yielding extraction method can be used to extract pharmaceutical compounds. Extracted terpenes can be used for various food industry applications.