Abstract:This study aimed to optimize vacuum freeze-drying （VFD） parameters for efficient debittering of tartary buckwheat，reducing bitterness，enhancing consumer acceptability，and maximizing nutrient retention.Hairy-kernel tartary buckwheat flour was subjected to aqueous extraction followed by vacuum freeze-drying（VFD） to produce debittered tartary buckwheat flour. The extraction temperature，extraction duration，and solidto-liquid ratio were selected as key factors. A Box-Behnken design （BBD） was employed to optimize the conditions with nutrient content and bitterness score as the indicators.Raw tartary buckwheat flour was mixed with water 1∶20 （g/mL），extracted at 20 ℃ for 20 min，and then dried via VFD or conventional hot-air drying（HAD）. The debittered flour samples were evaluated based on the content of total flavonoids，content of total sugars，content of crude protein，and bitterness score. The optimal conditions were determined as extraction at 13 ℃ and a solid-to-liquid ratio of 1∶17 （g/mL） for 19 min. The tartary buckwheat flour processed under these conditions had the content of the combined nutrient content reaching （76.17±0.23）%，with the lowest bitterness score. VFD outperformed HAD in nutrient retention，quality improvement，and bitterness reduction in debittering of tartary buckwheat. The optimized VFD process effectively reduces bitterness while retaining nutritional components.