Co-extruded cereal processing line also starts out with an extruder machine, the same twin-screw extrusion machine that can be used for the direct expanded cereal. The machine creates the square-shaped pillows that are hollow in the middle. The special feature of co-extruded cereal is that inside square-shaped pillows, there is filling inserted in the center. To make this composition, the hollow pillows go through the filling process with cream feed and pillow crimper. These stuffed pillows then go into the dryer. At the end chocolate or cream-filled pillows, fruit-filled pillows, and stringy pillows.

For this extrusion process, it is quite common to see twin screw extrusion machines being used. A twin-screw extrusion machine is a device with co-rotating two screws intermeshing simultaneously, eliminating inactive zones in the length of the process. Twin screw extrusion machine is often selected over single screw extruder due its ability to handle sticky, oily or highly wet ingredients. It is also easy to clean as it has a self-wiping feature, and it can be used for a wide range of ingredients of particle sizes – fine powder to grain.

Keeping these in mind, you can explore all the natural coloring options. For instance, you can use coloring made out of turmeric to get bright yellow color, and you can use carrots (beta carotene) or a blend of vegetable juice for a bright orange shade. A reddish or dark purple can be attained from the anthocyanin fruit or vegetable extract. Beetroot juice is used for bluish or bright red, and paprika extract can make a reddish-orange hue.