ABSTRACT
Cellular materials are generally characterized by connected fairly rigid cell walls, enclosing a fluid material. The fluid material may be liquid-like (wet cellular materials) or gas (dry cellular materials). Most vegetable and many fruit tissues belong to the first category, whereas most manufactured cellular materials belong to the second category. They contain gas-filled cells. Examples are bread and related products, expanded products formed by extrusion or by deep frying in oil, and biscuits.
