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°C to 95°C. SP increased with temperature for all the starches tested. When the temperature was reaching the peak temperature (Tp) 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°C. Low swelling starch, such as corn and rice starch, yielded greater peak storage modulus (G′max) in dynamic mechanical analysis. The corresponding loss tangent (tanδG′max) correlated fairly (r2=0.8) with SP measured at 75°C. 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 δG′max was developed to explicate the relationships between thermal, rheological characteristics and SP.