Five different ultrafine milled flours (UMFs) were prepared from Tartary buckwheat via airflow ultrafine-grinding at different grinding pressures. The airflow ultrafine-grinding resulted in marked differences in particle size (from 100 to 10 μm). The UMFs were all brighter in appearance (higher L*) than Tartary buckwheat common flour (TBCF). Illustrated by the example of 70 °C, the UMFs were also found to have a greater water holding capacity (from 4.42 g/g to 5.24 g/g), water solubility (from 12.57% to 14.10%), and water solubility index (from 5.11% to 6.10%). Moreover, as the particle sizes reduced, the moisture content decreased (from 10.05 g/100 g DW to 7.66 g/100 g DW), as did the total starch content (from 68.88 g/100 g DW to 58.24 g/100 g DW) and the protein content (from 13.16% to 12.04%). However, the grinding process was also found to have negative effects on the mineral content of the Tartary buckwheat. Additionally, several substantial variations were found in their hydration properties along with grinding pressure changes in the differently ground UMFs. Consequently, fine Tartary buckwheat powders of a bright yellow color, with superior food processing properties, were prepared in this study by airflow ultrafine-grinding.

This experiment aimed to investigate the effects of four drying methods, namely, hot air drying (HAD), microwave drying (MD), vacuum drying (VD), and microwave vacuum drying (MVD), on the quality of lemon slices.The relevant indicators, including total phenolic content, ascorbic acid content, browning, color, reducing sugar content, volatile component measurements, and principal component analysis of 0 and 30 days storage, were compared after exposure to the four drying methods. The shortest time of 64 min was used to treat the lemon slices via MVD at 1 KW. These samples displayed the least damage after drying and the highest rehydration ratio of 4.12. The contents of VC, reducing sugars, and total phenols of MVD samples were significantly higher than those in the HAD, VD, and MD groups, retaining 105.94 mg/100 g, 21.35 g/100 g, and 77.81 mg GAE/g, respectively, while their color difference values were also the smallest, with a browning degree of 3.55, significantly lower than those in the other treatment groups (p < 0.05), and the degree of browning of the samples in the HAD treatment group was the most serious; in terms of volatile flavor substances, the lemon slice samples in the MVD and HAD treatment groups were more diverse and of better quality. The order of product sensory evaluation was: MVD > VD > HAD > MD. The final scores after comprehensive analysis revealed the order of the four drying methods as MVD, HAD, VD, and MD. Therefore, MVD had a better effect on the sensory perception and nutritional properties of the lemon slices, providing a useful alternative to the conventional drying method.

A starch‐rich portion is produced as a by‐product of black Tartary buckwheat processing. The effect of enzymatic combined with autoclaving–cooling cycles (one, two, or three times) on the physicochemical and structural properties of black Tartary buckwheat type 3 resistant starch (BRS) was evaluated. The autoclaving–cooling cycles enhanced solubility and reduced swelling, with the BRS content increasing from 14.12% to 25.18%. The high crystallinity of the BRS reflected a high molecular order. However, increasing the number of autoclaving–cooling cycles did not result in higher BRS content. The highest BRS yield in the autoclaved starch samples was 25.18% after double‐autoclaving–cooling cycles. Furthermore, the autoclaving–cooling cycles altered the crystalline structure of black Tartary buckwheat, and the subsequent crystallinity changed from 36.33% to 42.05% to 38.27%. Fourier‐transform infrared spectroscopy shows that the number of cycles results in more efficient double‐helical packing within the crystalline lamella. Principal component analysis showed that the autoclaving–cooling cycle treatment leads to significant changes in the molecular structure of resistant starch (RS). These results indicated that autoclaving–cooling cycles might be a feasible way for producing RS from black Tartary buckwheat starch with better structural stability to expand their application range.

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