Quinoa proteins (QP) have promise as a potential source of novel food ingredients, and it is of great interest to know how high-intensity ultrasound (HIUS) treatments affect the properties of QP. This work aimed to study the impact of on-off time-pulses of HIUS treatments on the structural and physicochemical properties of QP; samples were treated at 5, 10, 20, and 30 min with on-off pulses of 10 s/10 s, 5 s/1 s, and 1 s/5 s). Structural changes were evaluated using PAGE-SDS, circular dichroism, fluorescence spectroscopy, and differential scanning calorimetry. Meanwhile, physicochemical properties were also examined, including solubility, Z-average, polydispersity index PDI, and Z-potential. PAGE-SDS showed the appearance of polypeptides over 190 kDa in HIUS samples-treated. All samples presented 15.6% α-helices, 31.3% β-sheets, 21.8% β-rotations, and 31.4% random coils independent of the HIUS treatment. β-Turn structures and “random coils” were not affected by HIUS. When US 10 s/10 s and 1 s/5 s were applied, an increase in the % α-helix and a decrease in β-fold were observed, which could indicate a small conversion of β-folds to α-helices. Fluorescence spectra for all HIUS showed a significant increase (23%) of average fluorescence intensity and a decrease of λmax in relation to that of the control (346 dnm and 340 nm average HIUS treatment). DSC showed one endotherm in all cases (81.6–99.8 °C), and an increase in Td was observed due to the effect of the HIUS treatment. HIUS caused a 48% increase in solubility. The Z-average of the HIUS samples compared to that of the controls showed an increase from 37.8 to 47.3 nm. PDI and Z-potential values from the QP controls and the HIUS samples did not show significance differences and presented average values of 0.466 ± 0.021 (PDI) and −16.63 ± 0.89 (Z-potential). It is possible to conclude that HIUS treatments affect the secondary and tertiary structure of quinoa proteins, and these changes resulted in an increase of solubility and particle size. HIUS treatment as a new and promising technology that can improve the QP solubility properties and in that way allow its use as an ingredient with a good source of protein to develop different types of beverages/protein sauces.

藜麦蛋白（QP）有望成为新型食品成分的潜在来源，并且非常感兴趣的是了解高强度超声（HIUS）处理如何影响QP的特性。这项工作旨在研究HIUS治疗的开关时间脉冲对QP的结构和理化性质的影响；在5、10、20和30分钟对样品进行10 s / 10 s，5 s / 1 s和1 s / 5 s的开关脉冲处理。使用PAGE-SDS，圆二色性，荧光光谱和差示扫描量热法评估结构变化。同时，还检查了物理化学性质，包括溶解度，Z-平均值，多分散指数PDI和Z-电势。PAGE-SDS在HIUS样品处理后的190 kDa以上显示多肽的出现。所有样品均呈现15.6％的α螺旋，31.3％的β折叠，21.8％的β旋转，和31.4％的随机线圈不受HIUS处理的影响。β-Turn结构和“随机线圈”不受HIUS的影响。当使用US 10 s / 10 s和1 s / 5 s时，观察到％α-螺旋的增加和β-折叠的减少，这可能表明β-折叠向α-螺旋的转化很小。所有HIUS的荧光光谱均显示，与对照（346 dnm和340 nm的平均HIUS处理）相比，平均荧光强度显着提高（23％），而λmax降低。DSC在所有情况下（81.6–99.8°C）均显示出一个吸热峰，并且由于HIUS治疗的作用，Td升高。HIUS使溶解度增加了48％。与对照相比，HIUS样品的Z均值显示从37.8 nm增加到47.3 nm。QP对照和HIUS样品的PDI和Z电位值未显示显着性差异，平均值为0.466±0.021（PDI）和-16.63±0.89（Z电位）。可以得出结论，HIUS处理会影响藜麦蛋白的二级和三级结构，这些变化导致溶解度和粒径增加。HIUS处理技术是一种新的有前途的技术，可以改善QP的溶解性，从而可以将其用作具有良好蛋白质来源的成分，从而开发出不同类型的饮料/蛋白质酱。这些变化导致溶解度和粒径的增加。HIUS处理技术是一种新的有前途的技术，可以改善QP的溶解性，从而可以将其用作具有良好蛋白质来源的成分，从而开发出不同类型的饮料/蛋白质酱。这些变化导致溶解度和粒径的增加。HIUS处理技术是一种新的有前途的技术，可以改善QP的溶解性，从而可以将其用作具有良好蛋白质来源的成分，从而开发出不同类型的饮料/蛋白质酱。