Small amplitude oscillatory rheolog

Small amplitude oscillatory rheological measurements were
performed by a Carri-Med-CSL 100 rheometer (TA Instruments
Ltd., Surrey, England) equipped with a parallel plate system (20 mm, dia.). For these measurements, the gap size was set at 1.0 mm.
Strain and frequency were set at 0.5% and 1 Hz, respectively.
Effect of starch concentration. Starch suspensions of different
concentrations were loaded on the ram of a Carri-Med-CSL 100
rheometer and were covered with a thin layer of mineral oil. The
Theological properties were scanned from 45 to 950C at rate of
10
C/min (Lii et al 1995).
Effect of starch variety. Mixed starch suspensions (20%, w/w)
of KSS7 and TCW70 with different ratios (20:0, 15:5, 10:10,
5:15, and 0:20, by weight) were prepared for the investigation of
the effect of starch variety on the rheological property. The
Theological properties of the samples were scanned from 45 to
950C at rate of 1PC/min during heating, and from 95 to 5PC at
50
C/min during cooling, and at 5 min intervals up to 1 hr during
aging at 5
0C. All tests were performed in triplicate.
Effect of amylose content. Purified KSS7 amylose was added to
the samples for the measurement of the influence of the amylose on the rheological properties. An amylose solution (2%, w/w) was
prepared by dissolving amylose in 8% 1-butanol solution, fol-
lowed by removal of 1-butanol by heating in a boiling water bath
(Miles et al 1985a,b). For the preparations of different
concentrations of the amylose-starch suspensions, 2% amylose
solution was used as the solvent instead of deionized water. The
concentration and the condition used to measure the rheological
property of amylose-starch sample were identical to that for the
effect of starch variety.