TG酶-MgCl2协同诱导对冷榨豆粉凝胶的影响

摘 要：以冷榨豆粉为原料，研究在转谷氨酰胺酶（transglutaminase，TG酶）与氯化镁（MgCl2）的协同诱导对其形成凝胶的影响。结果表明，以冷榨豆粉为原料制备的豆腐膳食纤维含量约是卤水豆腐3 倍，脂肪含量约为卤水豆腐的1/3；TG酶的加入会明显改善冷榨豆粉凝胶内部水分，使其更为均匀，且制成的豆腐凝胶具有更高的储能模量G’（10 498 Pa），表明形成更牢固的凝胶网络结构，从而导致MgCl2-TG酶豆腐的持水性最大（51.01%）、出品率最高（244%）；二级结构无规卷曲相对含量最高（21.45%）；维持凝胶网络的二硫键含量（5.46 μmol/g）接近卤水豆腐（7.02 μmol/g）；扫描电镜结果表明TG酶协同MgCl2使冷榨豆粉豆腐凝胶网状更为细致紧密，整体接近卤水豆腐。这表明，TG酶与MgCl2凝固剂协同作用可改善冷榨豆粉形成凝胶的品质，本研究为冷榨豆粉的多元开发提供了一定的理论基础。

Effect of Synergistic Induction of Transglutaminase and Magnesium Chloride on Gelling Properties of Cold-pressed Soy Flour

In this study, we evaluated the effect of synergetic induction of transglutaminase (TGase) and magnesium chloride (MgCl2) on the gel forming properties of cold-pressed soybean flour. The results showed that the dietary fiber content of tofu prepared from cold-pressed soybean flour using MgCl2 or in combination with TGase as a coagulant increased by three times, and the fat content was only one third compared to tofu prepared from tofu prepared from regular soybean flour using MgCl2 as a coagulant (control). Addition of TGase could obviously improve the internal water content of cold-pressed soybean flour gels, making the gel structure more uniform gel, and resulted in higher storage modulus G′ (10 498 Pa), indicating a stronger gel network structure, Consequently, the highest water-holding capacity (51.01%), product yield (244%) and random coil percentage (21.45%) were obtained. The disulfide bond content of tofu coagulated with TGase + MgCl2 (5.46 μmol/g) was close to that of the control sample (7.02 μmol/g). The scanning electron microscopic (SEM) results showed that the synergistic effect TGase and MgCl2 gave a more compact gel network structure, which was close to that in the control sample. Therefore, the synergetic effect of TGase and MgCl2 could improve the gelling properties of cold-pressed soybean meal proteins. The results of this study can provide a theoretical basis for diversified development of cold-pressed soybean powder.