| 摘要 |
A method and apparatus for incorporating one or more additives throughout an expanded food product. An expandable mixture of moistened farinaceous and/or proteinaceous materials is extruded at elevated temperatures and pressures through the die orifice of an expander-cooker into the cylindrical bore of a tubular extrusion die which is secured to the external face of the extruder die plate. The cylindrical bore of the tubular die has the same cross-sectional area and shaped as the die orifice of the extruder, so that as the mixture passes longitudinally through the tubular die it is still radially confined and is maintained at the same high pressure and temperature as when extruded through the die orifice. One or more liquid additives are injected under pressure into the body of the farinaceous and/or proteinaceous mixture as it is passed through the tubular die, through a nozzle mounted concentrically within the cylindrical bore of the tubular die. As the material is extruded from the tubular die into the atmosphere, it expands to form a porous structure. Simultaneously with the expansion of the mixture, the liquid additive diffuses throughout the porous structure, from the center to the exterior surfaces thereof, to thereby provide a porous expanded product in which the additive is incorporated throughout the product. |
