单颗粒花生挤压过程中的力学-出油特性Mechanics-oil output characteristics of peanut pellets during extrusion

Abstract

以单颗粒半粒花生为研究对象，利用原位观测结合质构仪测试的方式对花生进行挤压实验，研究花生在不同的压距、压速、保压时间及温度条件下的结构-力学-出油特性，并且建立相关的曲线拟合模型。结果表明：压距逐渐增大，花生所受峰值力也逐渐增大，花生表面被挤压开始变形，逐渐产生裂纹，压力较大时，花生变成饼状，裂纹布满整个表面；峰值力随着温度的升高先缓慢升高后急剧降低，再趋于稳定；压速及保压时间对峰值力无明显影响。递增的压距和保压时间皆能促进花生出油，而压速增加则会抑制花生出油；花生出油量随着温度的升高先缓慢增大后急剧减小，然后趋于稳定。花生颗粒挤压出油的最优条件为压距5 mm、压速0.5 mm/s、保压时间360 s和温度75 ℃。 Taking half of the single-grain peanuts as the research object, the in-situ observation combined texture analyzer was used to carry out the extrusion test to study the mechanics-oil output characteristics of the peanuts under conditions of different extrusion distance, extrusion speed, pressure holding time and temperature, and the relevant curve fitting model was established. The results showed that the peak force of peanuts increased with the increase of extrusion distance. The peanut surface was extruded and began to deform, gradually cracks occurred. When the pressure was higher, the peanut became a cake shape, and the cracks covered the whole surface. With the increase of temperature, the peak force first increased slowly, then decreased sharply, and then tended to be stable. The extrusion speed and pressure holding time had no obvious effect on the peak force. Increasing extrusion distance and pressure holding time could promote the oil output of peanuts, and the increasing extrusion speed could inhibit the oil output of peanuts. The oil output of peanuts increased slowly, then decreased sharply, and then tended to be stable with the increase of temperature. The optimal conditions for extruding oil from peanut pellets were obtained as follows: extrusion distance 5 mm, extrusion speed 0.5 mm/s, pressure holding time 360 s and temperature 75 ℃.

Keywords

• 花生；力学特性；出油量；曲线拟合
• peanut; mechanical characteristics; oil output; curve fitting