Bioavailability is an important indicator for evaluating the nutritional value of protein. In this study, we investigated the effect of ultrasound on improving the bioavailability of daily-consumed dietary proteins (rice, oat, corn, and soy protein). The results indicated that there was a significant difference (P < 0.05) in in vitro simulation digestibility between the ultrasound pretreatment group and the control (without ultrasound pretreatment) group. After ultrasound pretreatment, the digestibility of four proteins increased 9.49% (rice), 9.97% (oat), 8.19% (corn), and 9.84% (soy), respectively. There was a significant difference (P < 0.01) in Caco-2 cell model absorption between the ultrasound pretreatment group and the control group. After ultrasound pretreatment, the Caco-2 cell model absorption increased 5.59% (rice), 4.16% (oat), 8.78% (corn), and 18.69% (soy), respectively. The results of CD (Circular Dichroism) and fluorescence spectroscopy indicated that ultrasound pretreatment changed the protein’s secondary structures and tertiary structure, and more hydrophobic residues were exposed. The results of molecular weight distribution indicated that ultrasound increased the content of 200–1000 Da peptides. The conclusion is that ultrasound pretreatment can effectively improve the bioavailability of these dietary proteins by changing protein structure and composition.

生物利用度是评估蛋白质营养价值的重要指标。在这项研究中，我们调查了超声对改善日常食用的蛋白质（大米，燕麦，玉米和大豆蛋白）生物利用度的影响。结果表明， 超声预处理组与对照组（无超声预处理）组的体外模拟消化率存在显着差异（P <0.05）。超声预处理后，四种蛋白质的消化率分别提高了9.49％（大米），9.97％（燕麦），8.19％（玉米）和9.84％（大豆）。有显着差异（P <0.01）在超声预处理组和对照组之间的Caco-2细胞模型吸收。超声预处理后，Caco-2细胞模型吸收分别增加了5.59％（大米），4.16％（燕麦），8.78％（玉米）和18.69％（大豆）。CD（圆二色谱）和荧光光谱的结果表明，超声预处理改变了蛋白质的二级结构和三级结构，并且暴露了更多的疏水残基。分子量分布的结果表明，超声增加了200–1000 Da肽的含量。结论是超声预处理可以通过改变蛋白质结构和组成来有效提高这些膳食蛋白质的生物利用度。