Integrated Extraction of Tea Tree Oil and Polysaccharides From Melaleuca alternifolia Using Three-Phase Partitioning: Process Optimization, Techno-Economic Analysis, and Sustainability Evaluation.

Conventional tea tree oil extraction approaches such as steam distillation are limited by excessive water and energy input, alongside the production of polysaccharide-rich waste residues. This study systematically explored the application of three-phase partition (TPP) method in Melaleuca alternifolia for integrated extraction of tea tree oil (TTO) and polysaccharides, addressing challenges in conventional methods. Using ammonium sulfate ((NH4)2SO4) and tert-butanol (t-butanol), the TPP process operated under mild conditions (60°C). Through Box-Behnken Design optimization, TPP methods achieved 1.15% TTO and 5.57% polysaccharide yields rich in neutral pentoses. GC-MS analysis identified 32 volatile compounds in TPP-derived TTO, among which terpinen-4-ol (33.19%) served as the dominant bioactive constituent and satisfied the 30%-48% threshold specified in GB/T 26514-2011, while multiple minor terpene components fell outside the standard concentration ranges. A techno-economic evaluation revealed that the integrated process incurred a total direct material and electricity cost of 176.6 RMB for extracting 11.5 g of TTO and 55.7 g of polysaccharides, with t-butanol expenses constituting the majority (65.6%) of costs. Overall, this study is the first to establish a TPP process for simultaneous extraction of TTO and polysaccharides from M. alternifolia, offering a green, economically viable, and sustainable approach for industrial-scale bioactive compound recovery.