Journal of the Faculty of Fisheries and Animal Husbandry, Hiroshima University Volume 17 Issue 1
1978-08-10 発行

Determinations of Viscometric Constants in Empirical Flow Equations of Heated Starch Solutions

Kubota, Kiyoshi
Hosokawa, Yoshihiko
Suzuki, Kanichi
Hosaka, Hideaki
The flow equations of liquid foods are important bases to design various apparatuses and to control various plants. The viscometric behavior of heated starch solutions was measured at 30, 50 and 70°C. The capillary tube viscometer was used in these studies. Heated starch solutions of 3 and 5 wt% wheat, corn, potato and sweet potato starches were used as samples.

An empirical flow equation γ= (1/K) (gcτ-gcτy)n was assumed, and the viscometric constants n, τy and K were calculated using the non-linear least square method. The yield stress τy (gf/cm2) could be overlooked for the heated starch solutions studied, and a power-law flow equation was applied.

The values of flow behavior index n(-) in the power-law flow equation were about 1.2 to 1.4 for all samples studied. Values of K(gn/cmn•sec^2n-i) which fixed n=1.3 were obtained, and they were expressed by an equation of the Arrhenius from K=A exp(E/RgT). The values of E were 3 to 7 kcal/g-mol for studied samples.