Physical Properties of Two Biological Cushioning Materials from Wheat and Corn Starches

Cereal Chem. 72(1):38-41 Physical properties of two biological cushioning materials made from dates were significantly higher than those of the wheat starch extrudates. wheat and corn starch extrudates were compared with those of commercial Both biological cushioning materials showed similar water absorption plastic foam cushioning material. Characteristics measured included isotherms at three temperatures when the equilibrium moisture contents dimensions, bulk and true densities, and water absorption isotherms at significantly increased as relative humidities increased. The S-shaped 15, 25, and 400C. Their properties under simple compression tests and plastic foam exhibited lower bulk and true densities. Simple compression stress relaxation tests were also examined. The C-shaped extrudate from tests and stress relaxation tests showed that the biological materials had corn starch showed more radial expansion than that of the wheat starch more unrecoverable plastic deformation than the plastic foams and also extrudate. But the bulk density and true density of the corn starch extru- indicated a difference between the two extruded cushioning materials. Loose-fill cushioning materials provide cost-effective protection for relatively lightweight products against shock or vibration dur- ing shipping and handling (Torok 1990). In addition to the impor- tant energy absorbing properties of cushioning materials, char- acteristics such as light weight, stability in ambient conditions, good resilience, and stress dissipation rate also should be con- sidered. As cushioned packages play an increasing role in world commerce, flexible, closed-cell, expandable polystyrene foam materials are being used more and more. Disposal of used plastic cushioning materials, which are derived from petroleum sources, has become a public concern (Larson 1989, 1990). Biological cushioning materials, such as extrudates from wheat and corn starches, are now available. The objective of this study was to compare the physical properties of two biological cushioning materials with those of plastic foam materials by measuring dimen- sions, bulk and true densities, water absorption isotherms, and compression properties.