Fr. Dintzis et Gf. Fanta, EFFECTS OF JET-COOKING CONDITIONS UPON INTRINSIC-VISCOSITY AND FLOW PROPERTIES OF STARCHES, Journal of applied polymer science, 62(5), 1996, pp. 749-753
This work examined the sensitivity of intrinsic viscosity values of je
t-cooked waxy maize starch to initial pH conditions and the effects of
jet-cooker steam pressure parameters upon the intrinsic viscosity and
flow viscosity values of four jet-cooked starches. Flow viscosities o
f the 10 wt % cooked starches and intrinsic viscosities in 90% DMSO-H2
O were the lowest when mixing and turbulence during steam jet-cooking
was increased (i.e., by adjusting steam line pressure vs. pressure wit
hin the cooking chamber to allow greater amounts of steam to flow thro
ugh the apparatus). The percent decreases of the intrinsic viscosity c
aused by the most severe cooking conditions compared to gentle cooking
conditions were 52, 45, 32, and 12, respectively, for waxy maize, wax
y rice, normal maize, and 70% high amylose maize starches. Initial pH
values, from 3 to 10.5, of waxy maize starch had minor effects upon th
e intrinsic viscosity of the jet-cooked material. (C) 1996 John Wiley
& Sons, Inc.dagger