COMPOSITION AND OIL-RETAINING CAPACITY OF JET-COOKED STARCH-OIL COMPOSITES

Jet-cooked starch-oil composites were evaluated to determine whether t he cooking procedure resulted in alteration of the chemical compositio n of either the starch or oil. Although these composites, both in dry form and in aqueous solution, were highly resistant to separation of s tarch and oil, there was no evidence of covalent bonding of the compon ents, and composition of the starch moiety was unchanged. Extraction o f oil from dried composites with a variety of organic solvents was not effective for complete recovery of oil; an amount of oil representing approximately 5% of the starting weight of the composite could be rec overed only after hydrolytic degradation of the starch. Extraction of oil from aqueous solutions of composites was also inefficient for comp lete oil recovery. The extent of extraction varied with concentration of both starch and oil. Typically, extraction repeated eight times wit h hexane recovered less than 80% of the oil from solutions with starch concentrations above 0.6%.