膨化技术与饲料生产过程控制.docVIP

Extrusion technology and process control in feed production 1 膨化加工的基本原理饲料生产中应用的膨化工艺???其主要设备为“螺杆式挤压膨化机”。物料送入膨化机中，螺杆螺旋推动物料形成轴向流动。同时，由于螺旋与物料、物料与机筒以及物料内部的机械摩擦，物料被强烈地挤压、搅拌、剪切，其结果物料被进一步细化、均化。随着压力的逐渐加大，温度相应升高在高温、高压、高剪切条件下，物料的物性发生变化，由粉状变成糊状，淀粉糊化，蛋白变性，纤维质部分降解、细化，致病菌被杀死，卫生指标提高，有毒成份失活。当糊状物料从模孔喷出的瞬间，在强大的压力差作用下，物料被膨化、失水、降温，膨化产品结构疏松、多孔、酥脆，且有较好的适口性和风味。The main equipment is the screw extruder. When we put materials into the extruder, the screw spiral promotes materials to axial flow. At the same time, the material is strongly extruded, mixed, cut from inner mechanical friction between the spiral and material, the material and cylinder as well as themselves, the result is that the materials are further refined and homogenized. With the pressure increased gradually, the corresponding temperature rise; under the function of high temperature、high pressure、high shear conditions, the physical properties of materials have been changed, as the powder into the paste, starch gelatinization, the protein denaturation, degradation and thinning of part fibrous, that pathogenic bacteria is killed, health indicators improved, toxic components inactivated. When the paste material erupted from the die hole, the material being extruded, dehydrated, cooled under the strong pressure difference, the extruded product has the characteristics of loose and porous structure, crispy taste, as well as good palatability and flavor. 2 膨化工艺及膨化产品的特点2．1由于机械摩擦所产生的热量，或由于送进膨化腔的直接蒸汽，或送进膨化腔夹套中的间接蒸汽的加热温度和压力逐渐升高。物料在高温高压环境下吸水膨胀，质构软化，在机械力的作用下溃散、细化、均化，细胞壁破裂，分子结构被打散，淀粉糊化，蛋白质变性。物性发生质的变化。所以，螺旋挤压式膨化机又有“连续式蒸煮器”之称he internal temperature of equipment and pressure is gradually increased due to the heat generated by mechanical friction, or the direct steam sent into extrusion chamber, or the heat by indirect steam sent into the jacket of extrusion chamber. Materials are water-swelling expanded, texture softened under the environment of high-temperature and high-pressure; scattered, thinned, homogenized under the action of mechanical