Formulation Optimization, Quality Characterization, and Flavor Profiling of Cookies Enriched with Ultrafine Dark Tea Powder.

Ultrafine dark tea powder (UDTP) was prepared by superfine grinding and sieving through a 200-mesh sieve, and incorporated into cookies to improve their textural properties, sensory acceptability and flavor characteristics. Through single-factor experiments and orthogonal testing, the optimal formulation was determined. The quality of cookies was evaluated by texture analysis, sensory evaluation, electronic nose (E-nose), and gas chromatography-mass spectrometry (GC-MS). Results showed that cookies supplemented with 4 g UDTP per 80 g butter exhibited significantly lower hardness and comparable fracturability, along with higher sensory scores in texture, odor and taste compared to basic butter cookies. E-nose and GC-MS analyses revealed that UDTP enrichment promoted the formation of desirable volatile compounds, particularly aldehydes, ketones, and heterocyclic compounds, which contributed to floral, fruity, roasted nutty, and caramel aromas. This study demonstrates that UDTP can effectively improve both the textural and flavor properties of cookies, providing a viable approach for developing tea-fortified baked products with enriched sensory profiles.