高温流化改良红小豆蒸煮品质及其机理研究

为解决红小豆质地坚硬、蒸煮品质差、煮饭前需长时间浸泡的问题,采用高温流化技术对红小豆进行蒸煮品质改良,以满足其与白米煮饭时同煮同熟的需要。研究了补水量、流化温度、进料速度对红小豆吸水性能以及蒸煮硬度的影响,然后通过正交实验得到最佳工艺条件为:补水量10∶2、流化温度215℃、进料速度62 kg/h。经最佳工艺条件处理的红小豆吸水指数为194.03%、硬度为1 448.08 g,其蒸煮硬度与白米蒸煮硬度相近,达到了与白米煮饭同煮同熟的要求。通过SEM、XRD、DSC、RVA表征处理前后红小豆微观结构、热力学特性和糊化特性,发现高温流化的红小豆细胞间微孔直径增加、细胞壁破损、淀粉结晶度下降、淀粉热力学特性和糊化行为改变,这些变化可能是高温流化改良红小豆蒸煮品质的内在机理。

Cooking quality and mechanism of adzuki bean improved by high-temperature fluidization

Because of its hard texture and poor cooking quality, adzuki bean must be soaked for a long time before cooking. Here, the high-temperature fluidization technology was applied to improve the cooking quality of adzuki bean, so as to meet its needs for simultaneously cooking with rice. At first, the effects of water replenishment, fluidization temperature and feed rate on the water absorption performance and cooking hardness of adzuki bean were studied. Then the optimal processing conditions, i.e. water replenishment of 10:2, fluidization temperature of 215°C, and feed rate of 62 kg/h, were obtained by orthogonal test. The water absorption index and the cooking hardness of the adzuki bean treated by the optimal processing conditions were 194.03% and 1448.08 g, respectively. The cooking hardness of adzuki beans was to the nearly level of cooked rice thus satisfied the requirement of its simultaneous cooking with rice. In addition, the microstructure, thermodynamic properties and gelatinization properties of adzuki bean were characterized by SEM, XRD, DSC and RVA. After high-temperature fluidization, the diameter of intercellular micropore of adzuki beans increased. The damaging of cell walls, decreasing of starch crystallinity and changing of starch thermodynamic properties and gelatinization behavior were also caused by the treatment. These changes may explain the internal mechanism of how high temperature fluidization improves the cooking quality of adzuki bean.