THESIS

enzymes whereas most of the crystallites reformed during retrogradation are
embedded in the matrix (Granfeldt et al. 2000).
HI and GI (% )
90
80
70
60
50
40
30
20
10
0
0 4 8 16 24 48
Hydrolysis time (hr)
GI (121°C ) GI (95°C) GI (75°C)
HI (121°C) HI (95°C) HI (75°C)
Figure 20 Effect of pre-heated treatments and hydrolysis time on the calculated
hydrolysis index (HI) and glycemic index (GI) of RS III from 0 to 48-hr
debranched high amylose rice starch preheated at 75°C, 95°C and 121 o C
105
The estimated glycemic index (GI) based on HI of the developed RS
III sam ples ranged from 54.44 to 79.01 GI value (Table 1 6).
Degree of pullulanase
hydrolysis had an obvious
impact on starch retrogradation
and thus
on the predicted
glycemic resp onse. The high degree of
pullulanase hydrolysis and
degree of syneresis
led to a r eduction of HI and estimated GI for all preheated treatments.
The lowest GI
value was observed in the 4 to 48 hr debranching of 121 d .83
o C preheate treatment (60
to 54. 44 GI value) and followed by th e 4 to 48 hr debranching of 75 C preheated
(61.43 to 56.09 GI value). W hile, the 4 to 48-h debranching of 95 C preheated
treatment was highest this was 69.09 to 62.63 GI values.
o
o