Function-transitioning supercritical fluid extraction: a novel approach to improve tea quality

The tea industry constitutes a substantial segment of the food sector, making the continuous advancement and innovation of its processing technologies essential. A systematic methodology was developed, employing a Function-Transitioning Supercritical Fluid Extraction (FT-SFE) to improve tea quality. This approach enabled the creation of a controlled sample library, which was used to establish proof-of-concept predictive models that quantitatively correlate flavor composition with sensory quality. FT-SFE reduced bitter and astringent compounds-particularly total esterified catechins (TETCs), a major astringent-resulting in improved infusion taste while maintaining the physical integrity of the dry tea leaves. The PLS-DA model identified total catechins, total polyphenols (TPPs), TETCs, and (-)-epigallocatechin gallate (EGCG) as the major chemical indicators of sensory quality. The by-products from the FT-SFE provided preliminary evidence of anti-inflammatory potential. This study developed a reproducible food processing approach whose application may affect resource utilization and provide potential economic benefits for tea production.