Self-supporting edible and biodegradable packaging films from polysaccharides
Abstract
Various self-supporting edible and biodegradable packaging films were made from cellulose, starch, and chitosan. Different strategies and technologies were used for different types of polysaccharides and different application targets. Sausage casing and ham wrap films were the primary targets. For ham wrap films, the target values were: tensile strength of 4.6 kg/mm 2 and elongation of 39%. Synergistic effects in mechanical properties were found for solution cast agar-konjac glucomannan-starch blend films. Blending ratio and preparation process were optimized. A recommended ratio was 1:1:2 for agar, konjac glucomannan, and starch. Fully cooking and mixing, casting on a warm surface, and drying from a gelled state were found desirable. Films with tensile strengths of 4.6–6.0 kg/mm2 and elongations of 33–60% were made from the ternary blends with different types of starch and 20% glycerol. These blend films were water sensitive. Heating films in an alkaline condition improved their wet strength to 0.5–0.7 kg/mm 2, which was close to the target value of 0.7 kg/mm 2 for sausage casing. To improve the chewability of regenerated cellulose films, cellulose was slightly methylated before regeneration. Wet strengths were between 0.39–0.96 kg/mm2 (the higher the D.S., the lower the wet strength).
Degree
Ph.D.
Advisors
BeMiller, Purdue University.
Subject Area
Food science|Polymers|Plastics|Packaging
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