Submitted to: Carbohydrate Polymers
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 21, 2004
Publication Date: July 10, 2004
Citation: Fishman, M.L., Coffin, D.R., Onwulata, C.I., Konstance, R.P. 2004. Extrusion of pectin and glycerol with various combinations of orange albedo and starch. Carbohydrate Polymers 57:p.401-413. Interpretive Summary: The need to add value to agricultural residues from fruit juice processing, use surplus corn and the co-products of biofuel production has prompted us to develop an edible, biodegradable film from the polysaccharides pectin and starch, a portion of the orange peel called albedo, and biofuel co-product glycerol. Albedo is a pectin-rich, inexpensive byproduct of orange juice production. In this work we show that pectin/albedo/starch/glycerol films fabricated by extrusion processing are comparable to extruded films of pectin/starch/glycerol in mechanical and microstructural properties and cost less to make since cheaper albedo can replace more expensive starch and pectin in the formulations. If these lower cost films can be commercialized, it will provide new uses for agricultural byproducts and more revenue for processors and manufacturers of agricultural materials.
Technical Abstract: Microstructural and mechanical properties of extruded pectin and glycerol films with various combinations of albedo and starch were determined by universal mechanical testing (UMT), dynamic mechanical analysis (DMA), optical microscopy (OM) and scanning electron microscopy (SEM). A glass transition and a second order transition attributed to the onset of translational motion of the pectin molecules was observed in all films. Observation by OM suggested that extrusion in the presence of dilute HCl was more effective in disintegrating albedo than either water or dilute citric acid. UMT, DMA and SEM analysis revealed that extruded pectin/albedo/starch/glycerol films provided better mechanical properties than pectin/albedo/glycerol films and were comparable in mechanical properties. to extruded pectin/starch/glycerol films.