Digestion a thin-walled expanded portion of the alimentary tract used for the storage of food prior to digestion. In some birds it is an expanded, muscular pouch near the gullet or throat. In adult doves and pigeons, the crop can produce crop milk to feed newly hatched birds. Certain insects may have a crop or enlarged esophagus. Herbivores have evolved cecums (or an abomasum in the case of ruminants). Ruminants have a fore-stomach with four chambers. These are the rumen, reticulum, omasum, and abomasum. In the first two chambers, the rumen and the reticulum, the food is mixed with saliva and
Retort pouch the pouch. The retort pouch construction varies from one application to another, as a liquid product needs different barrier properties than a dry product, and similarly an acidic product needs different chemical resistance than a basic product. Some different plastic layers used in retort pouches include: This multi-layer structure prevents the retort pouch from being recycled into other retort pouches or food packaging. However, the material can be recycled into an aluminized resin or up-cycled into textile materials. The weight of a pouch is less than regular cans or bottles, and the energy required to produce each pouch is less