School of Food and Biological Engineering, Key Laboratory for Agricultural Products Processing of Anhui Province, Hefei University of Technology, Hefei, China.
J Food Sci. 2021 Jun;86(6):2410-2420. doi: 10.1111/1750-3841.15735. Epub 2021 Apr 27.
Tofu prepared by conventional methods often has a bitter taste and poor water-holding capacity (WHC). To improve the quality of the product, alternative processes must be developed. Herein, the effect of ultrasound pretreatment on the properties of soymilk and tofu gel derived thereof were investigated. Treatment of soymilk with ultrasound gave rise to a reduction in the particle size and an enhancement in the surface hydrophobicity, whereby optimum values were obtained after 15 min treatment. Subsequently, microbial transglutaminase (MTG) was added to ultrasound-treated soymilk to promote the soy protein crosslinking. The gel strength, WHC, and nonfreezable water content of MTG-catalyzed tofu gel obtained from treated soymilk increased with the extension of the ultrasound pretreatment time, whereas the free sulfhydryl content decreased because of the formation of disulfide bonds. Fourier transform infrared spectroscopy demonstrated variations in the secondary structure of MTG-catalyzed tofu gel. Furthermore, soymilk's exposure to high-intensity ultrasound pretreatment led to a tofu gel with a dense, homogenous, and stable network structure, as evidenced by scanning electron microscopy. Therefore, this study answers for the theoretical support of the industrial production of MTG-catalyzed tofu gel from ultrasound-treated soymilk. PRACTICAL APPLICATION: High-intensity ultrasound pretreatment improved the texture properties of MTG-catalyzed tofu gel. The resulting MTG-catalyzed tofu gel has potential application in industrial production.
传统方法制备的豆腐常常具有苦味和较差的持水力（WHC）。为了提高产品的质量，必须开发替代工艺。在此，研究了超声预处理对豆浆和由此衍生的豆腐凝胶性质的影响。豆浆经超声处理后，粒径减小，表面疏水性增强，15 分钟处理后达到最佳值。随后，向超声处理的豆浆中添加微生物转谷氨酰胺酶（MTG）以促进大豆蛋白交联。从处理后的豆浆中获得的 MTG 催化的豆腐凝胶的凝胶强度、WHC 和不可冻结水含量随着超声预处理时间的延长而增加，而游离巯基含量由于二硫键的形成而降低。傅立叶变换红外光谱表明 MTG 催化的豆腐凝胶的二级结构发生了变化。此外，豆浆暴露于高强度超声预处理会导致豆腐凝胶具有致密、均匀和稳定的网络结构，扫描电子显微镜也证明了这一点。因此，本研究为从超声处理的豆浆中生产 MTG 催化的豆腐凝胶的工业生产提供了理论支持。实际应用：高强度超声预处理改善了 MTG 催化豆腐凝胶的质构特性。所得的 MTG 催化豆腐凝胶在工业生产中具有潜在的应用。
