To explore suitable drying methods for taro, and investigate the single and combined effects of ultrasound and far-infrared radiation, this study compared the quality effects of hot air drying (HAD), contact ultrasonic-enhanced hot air drying (CU-HAD), far- infrared radiation drying (FIRD), contact ultrasonic enhanced far-infrared radiation drying (CU-FIRD) and freeze-drying (FD). The quality indexes of taro were drying process, microstructure, physical characteristics (rehydration, hardness, and color), polysaccharides, flavonoids, polyphenols and antioxidant activity. The results showed that the surface of HAD products forms a hard shell, oxidation was serious, its hardness was the highest, the quality was the worst;FD's organizational structure was loose, the comprehensive quality was the best, but the drying time was the longest. The drying times of CU-HAD, FIRD and CU-FIRD were 26.32%, 47.37% and 63.16% lower than that of single HAD, respectively, and were 70.83%, 79.16% and 85.42% lower than that of FD, respectively. Compared with HAD and FIRD, CU-HAD and CU-FIRD with ultrasound application could make the tissue structure looser and the microporous channel larger, with lower hardness, improved rehydration and lower color difference. The drying rate of CU-FIRD was the fastest, and the corre- sponding contents of polysaccharides, flavonoids and polyphenols were 22.155, 0.286 and 0.974 mg/g, respectively, which were close to the quality index of FD and better than that of HAD, CU-HAD and FIRD. The evaluation order of drying rate was CU-FIRD>FIRD>CU- HAD>HAD>FD, and the evaluation order of product quality was FD>CU-FIRD>FIRD>CU-HAD>HAD. CU-FIRD could combine the advantages of CU-HAD and FIRD, and then speed up heat and mass transfers, greatly shortening the drying time of taro chips and pro- tecting product quality. CU-FIRD is suitable for the high-quality and rapid production of dried taro products.
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