挤压膨化和焙烤工艺对代餐粉特性的影响

以糙米、紫米、红米、大米、玉米等谷物为原料,辅加山楂、薏苡仁、山药、莲子、赤小豆、黑豆等药食同源物质,分别采用烘焙、挤压膨化等工艺制备代餐粉。分析了不同加工方式对谷物代餐粉微观形貌、晶体特性和糊化特性的影响。结果显示: 加工后淀粉圆形的颗粒结构减少或消失,形成较大的不规则颗粒结构,结构疏松。挤压膨化代餐粉晶体结构从A型转变成V型,其脂肪含量、糊化焓变、回生值、峰值时间、晶体结晶度比烘烤代餐粉低,吸水性指数、水溶性指数、衰减值均高于烘烤代餐粉。因而,挤压膨化代餐粉蛋白质损失较少,脂肪含量显著降低,不易老化,具有较好的产业化价值。

Effect of Extrusion and Baking on the Characteristics of Meal Replacement Powder

Using raw materials such as hawthorn, coix seed, yam, lotus seed, red bean, and black bean, as well as brown rice, purple rice, red rice, rice, corn and other cereals, different meal replacement powers were prepared through baking and extrusion processes. The effects of processing methods on the morphology, crystalline characteristics and gelatinization properties of cereal substitute meal powder were analyzed. The results show that after processing, the granular particle structural features of the starch could be weakened or eliminated, accompanied by the emergence of large irregular particles with loose matrices. The crystalline structure of extruded meal powder changed from A- to V-type, and its fat content, gelatinization enthalpy, retrogradation value, peak time and crystallinity were lower than baked meal replacement power. The water absorption index, water solubility index and attenuation value of extruded meal replacement power were higher than those for the baked meal replacement power Thus, the extruded product showed better industrial potentials, associated with the features involving low protein loss, reduced fat content, and weakened retrogradation tendency.