Crop (anatomy) Crop (anatomy) A crop (sometimes also called a croup or a craw, or ingluvies) is a thin-walled expanded portion of the alimentary tract used for the storage of food prior to digestion. This anatomical structure is found in a wide variety of animals. It has been found in birds, and in invertebrate animals including gastropods (snails and slugs), earthworms, leeches, and insects. Cropping is used by bees to temporarily store nectar of flowers. When bees "suck" nectar, it is stored in their crops. In a bird's digestive system, the crop is an expanded, muscular pouch near the gullet or throat.
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