| 摘要 |
The extrusion die has a series of tubes (1) in parallel rows in two superimposed plates (2) held together by clamps (3). The plates have recesses 5 - 15 times the diameter of the tubes in their facing surfaces, while the distance between adjacent tubes is between 0.8 and 1.2 times their diameter. The cereal mixture, made from rice flour, maize flour, wheat flour, saccharose, palm oil, salt, spices and water, and having particles no bigger than half the diameter of the tubes, is forced through the die by a screw turning at 310 rpm. The mixture is cooked, extruded and expanded at a pressure of 40 - 180 bars and 105 - 180 degrees C, emerging from the die in strands with a porous texture, a coefficient of expansion of 1.5 to 2.5 and a residual water content of 5 - 12 %. The strands, which are stuck together, are cut into rectangles of 2.5 x 2 cm by a vertical blade which gives them a barrel or cushion shape. |
