断奶仔猪大宗原料混合料膨胀加工参数试验研究

Study of expander processing parameters on common materials of piglet

文章旨在研究膨胀加工参数对大宗原料混合料（玉米、小麦、豆粕及膨化大豆比值为23：5：5：2）加工质量的影响。试验采用淀粉酶解法、胃蛋白酶一胰蛋白酶两步酶解法及容重器法分别测定物料淀粉糊化度、蛋白质体外消化率及容重，探讨膨胀加工参数中调质温度（75、80、85、90℃）、膨胀器环隙开度（2．6、2．3、1．9、1．5cm）、喂料速度（30、35、40、45、50Hz）对淀粉糊化度、蛋白质体外消化率及容重的影响规律、结果表明：随着调质温度的升高，调质料和膨胀料的糊化度随之升高，90℃时，调质料和膨胀料糊化度显著提高（P〈0．05）；调质料的蛋白质体外消化率先升高后降低，膨胀料蛋白质体外消化率变化不显著（P〉0．05）。同一喂料速度下，环隙开度降低，膨胀料糊化度升高，但膨胀料的蛋白质体外消化率变化不显著（P〉0．05）．当喂料速度为35、40Hz和50Hz时，糊化度逐渐升高，并且当喂料速度为50Hz，糊化度显著高于其他两组（P〈0．05）；喂料速度为50Hz时膨胀料蛋白质体外消化率显著低于其他喂料组（P〈0．05）。物料经过调质和膨胀后，容重显著降低（P〈0．05）、综合考虑物料的加工质量，初步认为混合料膨胀较优工艺参数的调质温度不宜过高，75～80℃为宜，环隙开度2．0～2．5cm，喂料速度35～45Hz．

This study was to investigate effects of expander processing parameters on quality of mixture material （corn： wheat： soybean meal： extruded soybean=23： 5： 5： 2）.Starch hydrolysis, pepsin-trypsin and the bulk density equipment were used to test starch gelatinization degree, in vitro protein digestibility and bulk density, aim to explore changes of expander processing parameters, such as conditioning temperature（75, 80, 85, 90 ℃）, the expander annular gap（2.6, 2.3, 1.9, 1.5 cm）, feed feeding rate （30, 35, 40, 45, 50 Hz）on the starch gelatinization degree, in vitro protein digestibility and bulk densi- ty.The results showed that： with the increasing of conditioning temperature, the starch gelatinization degree of conditioning material and expanded material improved at the same time and especially at 90 ℃, the starch gelatinization degree of conditioning material and expanded material significantly increased （P〈0.05）; The in vitro protein digestibility of conditioning material decreased first and then increased, the in vitro proteins digestibility of expanded material did not change significantly（P〉0.05）. Under the same tbeding rate, with the reduction of annulus gap, starch gelatinization degree of expanded material increased, but the in vitro protein digestibility was not significant（P〉0.05）. When the feeding rate of 35 Hz, 40 Hz, and 50 Hz, starch gelatinization degree was gradually increased, and at the rate of 50 Hz, starch gelatinization was significantly higher than other two groups（P〈 0.05）, but in vitro protein digestibility material was lowest（P〈0.05）. After of expandconditionexpanding, bulk density decreased by about 45 g/I. The better expander processing parameters： conditioning temperature 75-80℃,annulus gap 2.0-2.5 cm, feeding rate 35-45 Hz.