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

The swelling powers (SP) of 10 kinds of starches from cereals. roots, tuber s, and peas have been determined at 55 degreesC to 95 degreesC. SP increase d with temperature for all the starches tested. When the temperature was re aching the peak temperature (T-p) from differential scanning calorimetric t hermogram, 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 t angent (tan delta (G'max)) correlated fairly (r(2) = 0.8) with SP measured at 75 degreesC. Granule size, amylose content, or heat of gelatinization al one did not significantly correlate with the SP for all the data obtained. An equation consisting of temperature effect and tan delta (G'max) was deve loped to explicate the relationships between thermal, rheological character istics and SP. (C) 2001 Elsevier Science Ltd. All rights reserved.