MEETING ABSTRACT

O-20
Effects of eggshell powder as nucleating agent on the structure, morphology and functional properties of normal corn starch foams. Y. XU (1), M. A. Hanna (1). (1) Industrial Agricultural Products Center, University of Nebraska, Lincoln, NE, USA.

Corn starch and two types of eggshell powder (with particle size of 4–5 mm and 8–10 mm, respectively) composite foams were prepared by extrusion. Effects of eggshells on the structure, morphology, physical properties (unit density and expansion ratio), mechanical properties (spring index and compressibility) and thermal behavior (thermal transition and stability) of the foams were investigated. The foams’ cell size decreased and cell population increased with addition of eggshells into starch matrix. The foams’ unit density, expansion ratio, and compressibility decreased significantly (P < 0.05), while spring index increased significantly (P < 0.05) as the eggshells content increased from 0 to 6 wt%. Further increasing eggshells to 10 wt% increased unit density and compressibility and decreased expansion ratio and spring index. The thermal transition and stability increased with addition of eggshells. The optimum eggshells content was 6 wt% and the eggshell powder with small particle size had a favorable effect on the functional properties of the foams.