Relationships between thermal, rheological characteristics and swelling power for various starches

The swelling powers (SP) of 10 kinds of starches from cereals. roots, tubers, and peas have been determined at 55 degreesC to 95 degreesC. SP increased with temperature for all the starches tested. When the temperature was reaching the peak temperature (T-p) from differential scanning calorimetric thermogram, there existed an increase in SP. Potato, tapioca, and waxy corn starch yielded high SP and exhibited a maximum value near 80 degreesC. Low swelling starch, such as corn and rice starch, yielded greater peak storage modulus (G'(max)) in dynamic mechanical analysis. The corresponding loss tangent (tan delta (G'max)) correlated fairly (r(2) = 0.8) with SP measured at 75 degreesC. Granule size, amylose content, or heat of gelatinization alone did not significantly correlate with the SP for all the data obtained. An equation consisting of temperature effect and tan delta (G'max) was developed to explicate the relationships between thermal, rheological characteristics and SP. (C) 2001 Elsevier Science Ltd. All rights reserved.