Morphological, Physicochemical, and Pasting Properties of Modified White Sorghum (Sorghum bicolor) Starch

Figures & data

Figure 1 Scanning electron micrographs of native and modified starches under 1600× magnification: (a) nWSS, (b) aWSS, (c) oWSS, and (d) aoWSS.

Figure 2 Scanning electron micrographs of native and modified starches under 8000× magnification: (a) nWSS, (b) aWSS, (c) oWSS, and (d) aoWSS.

Table 1 Effect of chemical modifications on the swelling power and solubility of white sorghum starch.¹

	Temperature (°C)
	60	70	80	90
Swelling power (g/g)
nWSS	2.26^a	5.82^a	8.68^a	10.30^a
aWSS	2.34^a	2.33^b	2.39^b	2.73^b
oWSS*	2.13^a	4.29^c	5.96^c	6.67^c
aoWSS**	2.60^b	5.56^a	9.99^d	12.24^d
Solubility (g/100 g)
nWSS	1.26^a	1.89^a	4.80^a	7.12^a
aWSS	2.66^b	3.81^b	6.24^b	10.20^b
oWSS*	3.50^c	3.99^b	16.30^c	18.43^c
aoWSS**	4.94^d	17.16^c	20.85^d	30.49^d
^1All values are mean of triplicate determinations. Means within a column with different superscripts are significantly different at P ≤ 0.05.
*COOH = 0.19%; CHO = 0.07%.
**COOH = 0.19%; CHO = 0.07%; degree of acetylation = 0.06%.

Table 2 Effect of chemical modifications on the WRC of white sorghum starch.¹

	Temperature (°C)
	60	70	80	90
WRC (g/g)
nWSS	1.06^ab	1.66^a	6.22^a	7.86^a
aWSS	1.13^ab	2.63^b	7.70^c	8.68^b
oWSS*	0.98^a	1.86^a	5.35^b	5.79^c
aoWSS**	1.32^b	5.00^c	5.42^b	5.99^c
^1All values are mean of triplicate determinations. Means within a column with different superscripts are significantly different at P ≤ 0.05.
*COOH = 0.19%; CHO = 0.07%.
**COOH = 0.19%; CHO = 0.07%; degree of acetylation = 0.06%.

Table 3 Effect of chemical modifications on the pasting profile of white sorghum starch.¹

	Pasting properties
	PT	PV	TTP	HPV	CPV	BD	SB
nWSS	73.15^a	245.5^a	17.20^a	163.5^a	401.5^a	82^a	271^a
aWSS	71.70^b	164.5^b	14.90^b	48.5^b	137.0^b	115^b	84^b
oWSS*	72.05^b	54.5^c	12.43^c	12.0^c	18.0^c	42^c	6^c
aoWSS**	69.20^c	76.0^d	10.83^d	18.0^c	42.5^d	58^d	24^d
^1All values are mean of duplicate determinations. Means within a column with different superscripts are significantly different at P ≤ 0.05.
PT: Pasting temperature (°C); PV: peak viscosity (BU); HPV: hot paste viscosity (BU); CPV: cold paste viscosity (BU); BD: breakdown viscosity (BU); SB: setback viscosity (BU).
*COOH = 0.19%; CHO = 0.07%.
**COOH = 0.19%; CHO = 0.07%; degree of acetylation = 0.06%.

Table 4 Effect of chemical modifications on the paste clarity (%T) of white sorghum starch.¹

	Storage hours (h)
	0	24	48	72
nWSS	4.89^a	2.14^a	1.88^a	1.49^a
aWSS	17.66^b	4.88^b	4.28^b	3.56^b
oWSS*	39.01^c	8.99^c	7.63^c	6.92^c
aoWSS**	68.71^d	9.10^c	8.78^d	8.18^d
^1Values are mean of triplicate determinations. Means ± standard deviation within a column with different superscripts are significantly different at P ≤ 0.05.
*COOH = 0.19%; CHO = 0.07%.
** COOH = 0.19%; CHO = 0.07%; degree of acetylation = 0.06%.

Table 5 Effect of chemical modifications on the gel hardness (N) of white sorghum starch.¹

	Storage days
	1	3	7
nWSS	0.18^a	0.20^a	0.38^a
aWSS	0.12^b	0.17^b	0.27^b
oWSS*	ND	ND	ND
aoWSS**	ND	ND	ND
^1Values are mean of triplicate determinations. Means ± standard deviation within a column with different superscripts are significantly different at P ≤ 0.05.
*COOH = 0.19%; CHO = 0.07%.
**COOH = 0.19%; CHO = 0.07%; degree of acetylation = 0.06%.
ND: Not determined.