Abstract
The interaction between starch and sucrose ester of fatty acid was revealed, in a previous paper, to vary with the degree of substitution in the sucrose molecule. This paper is to explore relationship possibly existing in such interaction by describing the dependency on the structure of fatty acid moiety, i. e. its length of carbon chain and its degree of unsaturation.
Various sucrose esters were prepared using caprylic, lauric, stearic, oleic, linoleic and behenic acids as fatty acid moiety. Amylographic behavior, gel strength and swelling power of potato starch containing either one of these esters at 4% level were determined.
The gelatinization temperature of starch was found to vary by fatty acid constituent of the sucrose ester added to a constant mono-ester level, becoming higher in the presence of sucrose ester of longer chain and/or more saturated fatty acid. The fatty acid constituent of sucrose ester added to a constant mono-ester level was found to affect also both the rate of the increasing gel strength after gelatinization and the rate of diminishing swelling power of the gelatinized starch with the days elapsed, starch gel containing sucrose ester of longer chain fatty acid being harder to retrograde. These facts support the interpretation that the interaction being exercised between raw or gelatinized starch and the added sucrose ester is much directly dependent on the structure of the fatty acid moiety rather than on HLB of the ester.
