Submitted to: American Association of Cereal Chemists Meetings
Publication Type: Abstract Only
Publication Acceptance Date: October 18, 2001
Publication Date: N/A
Technical Abstract: Solubilized starch forms a coating on co-jet-cooked lipid droplets, resulting in stable aqueous starch-lipid composites. To better understand this phenomenon, the role of native lipid material (normally present in cornstarch) on the amount and characteristics of the interfacial starch (IS) was examined. Paraffin was co-jet-cooked with native and solvent-defatted normal, waxy, and high amylose cornstarch. Composites were diluted and centrifuged, the paraffin particles collected, and the paraffin removed with cyclohexane. Starch films were also prepared by incubating polyethylene sheets in jet-cooked starch dispersions. IS in isolated wax varied from 3-8%, depending on starch type and native lipid present. Defatted normal cornstarch produced less IS than native normal cornstarch, but defatting had little effect on waxy starch. Morphology of IS observed by SEM was affected by lipid in the starting starch. Preferential adsorption of amylose and X-ray diffraction of IS suggested that lipid enhances the adsorption of amylose by forming helical inclusion complexes. Starch film formation on polyethylene showed similar lipid dependency. These results show that IS deposition on hydrophobic surfaces can be influenced by lipids and potentially could be modified to suit new applications of the starch-lipid composite technology.