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ARS Home » Research » Publications at this Location » Publication #79126


item Knutson Jr, Clarence

Submitted to: American Association of Cereal Chemists Meetings
Publication Type: Abstract Only
Publication Acceptance Date: 10/12/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Fantesk starch-oil composites are prepared by jet cooking mixtures of oil and starch in water. When dry composites with oil:starch ratios below 0.5:1 are resuspended in water they remain stable at concentrations as low as 0.5%. However, when samples with oil:starch ratios of 1:1 were resuspended in water an opaque oily emulsion accumulated on the surface. This fraction did not disperse in hexane and resisted extraction. It was readily miscible in the aqueous layer but gradually rose to the surface. Addition of alpha-amylase disrupted emulsion with immediate release of oil. Oil content of the fraction was about 10% of the total oil in the composite, and starch content was 3-5% of the weight of the fraction. The fraction appeared to consist of microscopic oil droplets encased in firmly adhering starch, thus accounting for its water miscibility. Comparable fractions were obtained from composites with lower oil:starch ratios by extracting aqueous suspensions with 0.5 volume of hexane and separating th emulsion formed during agitation. Yields of these fractions, their oil:starch ratios, and their properties varied with proportion of oil in the original composite; fractions from low oil composites had higher density, enhanced miscibility in water, and greater suspension stability. These fractions appear to be important to the solution stability of starch-oil composites.