超声-水热改性法提高小麦粉中抗性淀粉的含量及其面团特性分析

Improvement of Resistant Starch Content in Wheat Flour by Ultrasonic-hydrothermal Modification and Analysis of Dough Characteristics

摘要:

为开发高抗性淀粉含量的小麦粉并拓展其应用领域，以抗性淀粉含量为指标，通过筛选试验和优化试验，对超声-水热改性法（Ultrasonic hydrothermal，UHT）提高小麦粉中抗性淀粉含量的工艺进行了研究，分析了超声-水热改性小麦粉（UHT-WF）添加量对预混粉粉质、面团微观结构及流变学特性的影响。结果表明，UHT-WF的最优制备工艺参数为：小麦粉乳浓度50 wt.%、超声时间29 min、超声温度40 ℃、超声功率300 W、水热时间5 h、水热温度90 ℃、老化时间24 h，此工艺条件下，小麦粉中抗性淀粉含量由7.64 wt.%提高至23.93 wt.%；中长链及长链淀粉峰面积比增加，面筋含量下降；随UHT-WF添加量的增大，面团的粉质指数下降，面筋孔洞变大、孔隙面积比增加、结构变疏松，动态流变学特性呈现黏弹性下降。UHT处理有效提高了小麦粉中抗性淀粉含量，其面团特性发生了不同程度的变化。UHT-WF添加量超过40 wt.%后可作为主要原料应用于面筋弹性要求较低的面制品，也可直接作为高抗性淀粉主食、副食的原料，为开发低血糖生成指数的面制品提供理论依据与技术支撑。

Abstract:

In order to develop wheat flour with high resistant starch content and expand its application field, the technology of improving resistant starch content in wheat flour by ultrasonic-hydrothermal modification(Ultrasonic hydrothermal, UHT)was studied by screening test and optimization test, and the influence of the addition amount of UHT-WF on the powder quality, dough microstructure and rheological properties of premixed flour was analyzed. The results showed that the optimum preparation parameters of UHT-WF were as follows: wheat flour milk concentration 50 wt.%, ultrasonic time 29 min, ultrasonic power 300 W, ultrasonic temperature 40℃, hydrothermal time 5 h, hydrothermal temperature 90℃ and aging time 24 h. Under these conditions, The content of resistant starch in wheat flour increased from 7.64 wt.% to 23.93 wt.%. The peak area ratio of medium- and long-chain starches increases, while the gluten content decreases. With the increase of UHT-WF content, the farinograph index of dough decreased, the gluten holes became larger, the structure became loose, and the dynamic rheological properties showed a viscoelastic decline. UHT treatment effectively increased the content of resistant starch in wheat flour, and its dough characteristics changed in different degrees. When the UHT-WF addition exceeds 40 wt.%, it can be used as the main ingredient in flour products with lower gluten elasticity requirements, and can also be directly used as the raw material for staple food and non-staple food with high resistance starch, providing theoretical basis and technical support for developing flour products with low glycemic index.