Temperature-driven differences in Amomum tsaoko quality and aroma formation

The drying temperature is a key factor affecting the quality of Amomum tsaoko (AT). This study explored the quality differences of AT at five drying temperatures: 40 °C (D4), 50 °C (D5), 60 °C (D6), 70 °C (D7), and 80 °C (D8). The results show that high temperature (D8) can reduce the loss of total flavonoids and total phenolic acids, D5 is more conducive to the retention of antioxidant capacity, and D6 has the highest contents of reducing sugars, amino acids, and volatile organic compounds (VOCs). In addition, we also identified 16 key aroma-active substances (AASs) in AT, mainly 2-Methoxy-3-isobutyl pyrazine. Among them, 14 are derived from carotenoid oxidation, glycoside hydrolysis, phenylpropanoid biosynthesis, lipid oxidation, and the Maillard reaction (MR). Correlation analysis further indicates that reducing sugars and amino acids not only have significant correlations with AASs in MR but also have significant correlations with AASs in the other four pathways. Finally, Fourier transform near-infrared spectroscopy and Fourier transform near-infrared spectroscopy were combined to establish a total of 117 models to predict the quality of AT at different drying temperatures. The residual predictive deviation values of each evaluation index ranged from 1.663 to 4.432, indicating the validity of the models.