Physicochemical, rheological, morphological, and in vitro digestibility properties of cross-linked starch from pearl millet cultivars

Figures & data

Table 1. Degree of cross-linking (DC), amylose content (%), swelling power (g/g), and solubility (%) of cross-linked starches.

Cultivars	DC (%)	Amylose content (%)	Swelling power (g/g)	Solubility (%)
HC-10	40.8 ± 0.20^a	8.5 ± 0.32^d	7.50 ± 0.11^bc	9.0 ± 0.13^e
HHB-67	40.6 ± 0.31^a	7.9 ± 0.21^c	7.28 ± 0.11^b	6.4 ± 0.08^d
HHB-223	89.6 ± 0.19^d	6.5 ± 0.19^a	7.64 ± 0.29^c	3.6 ± 0.07^a
HHB-226	80.5 ± 0.17^b	6.3 ± 0.09^a	6.90 ± 0.12^a	5.6 ± 0.12^c
W-445	85.2 ± 0.28^c	7.2 ± 0.24^b	7.52 ± 0.25^bc	4.2 ± 0.09^b
GHB-732	89.7 ± 0.16^d	6.2 ± 0.11^a	6.72 ± 0.81^a	3.4 ± 0.10^a

Data are presented as mean± SD (n = 3). Values within the same column followed by

the same superscript are not significantly different (p < 0.05)

Table 2a. Pasting properties of cross-linked starches from different cultivars.

Cultivars	Peak viscosity (mPa.s)	Trough viscosity (mPa.s)	Breakdown viscosity (mPa.s)	Setback viscosity (mPa.s)	Final viscosity (mPa.s)	Pasting temperature (°C)
HC-10	1101 ± 4.1^e	803 ± 3.2^e	298 ± 1.9^d	103 ± 1.7^c	906 ± 3.6^e	89.6 ± 0.31^c
HHB-67	1164 ± 2.9^f	694 ± 5.1^d	470 ± 4.5^e	84 ± 0.8^b	778 ± 2.7^d	90.7 ± 0.27^d
HHB-223	299 ± 1.8^a	280 ± 3.7^a	19 ± 0.9^a	101 ± 1.4^c	381 ± 4.9^b	89.6 ± 0.19^c
HHB-226	553 ± 3.5^d	498 ± 2.8^c	55 ± 1.1^b	152 ± 2.4^d	650 ± 5.1^c	88.5 ± 0.20^b
W-445	425 ± 5.1^c	304 ± 5.8^b	121 ± 2.3^c	50 ± 1.9^a	354 ± 2.1^a	87.4 ± 0.07^a
GHB-732	315 ± 3.9^b	300 ± 1.8^b	15 ± 0.7^a	89 ± 2.7^b	389 ± 5.6^b	88.5 ± 0.11^b

Data are presented as mean± SD (n = 3). Values within the same column followed by the same superscript are not significantly different (p < 0.05)

Table 2b. Pasting properties of native starches from different cultivarsb.

Cultivars	Peak viscosity (mPa.s)	Trough viscosity (mPa.s)	Breakdown viscosity (mPa.s)	Setback viscosity (mPa.s)	Final viscosity (mPa.s)	Pasting temperature (°C)
HC-10	1860 ± 6.5^a	837 ± 4.2^a	993 ± 5.1^b	437 ± 2.4^a	1430 ± 3.3^a	71.0 ± 0.1^b
HHB-67	1960 ± 6.1^b	937 ± 4.4^b	1023 ± 5.6^c	579 ± 3.1^b	1602 ± 3.7^b	71.0 ± 0.0^b
HHB-223	2879 ± 5.5^d	1712 ± 5.7^d	1167 ± 4.3^d	1648 ± 3.3^e	2815 ± 4.1^d	70.4 ± 0.1^a
HHB-226	2845 ± 6.4^c	1636 ± 6.1^c	1209 ± 4.9^e	1484 ± 4.6^c	2693 ± 5.2^c	70.4 ± 0.2^a
W-445	2867 ± 4.2^d	1900 ± 7.2^f	967 ± 4.2^a	1994 ± 4.9^f	2961 ± 3.1^f	71.0 ± 0.0^b
GHB-732	3071 ± 6.1^e	1823 ± 9.1^e	1248 ± 5.1^f	1600 ± 4.2^d	2848 ± 4.2^e	70.4 ± 0.3^a

Data are presented as mean± SD (n = 3). Values within the same column followed by

the same superscript are not significantly different (p < 0.05)

Figure 1. Pasting properties of cross-linked starches from different pearl millet cultivars.

Cultivars are denoted by: A: HC-10; B: HHB-67; C: HHB-223; D: HHB-226; E: W-445; F: GHB-732.

Table 3. Rheological properties of cross-linked starches from different cultivars during heating.

Cultivars	Peak G′ (Pa)	Peak G′′ (Pa)	Peak tan δ	TG′ (°C)
HC-10	3300 ± 2.9^b	290 ± 1.7^b	0.08 ± 0.005^a	72.5 ± 0.18^a
HHB-67	4018 ± 3.4^c	286 ± 2.7^b	0.07 ± 0.003^a	77.5 ± 0.14^c
HHB-223	3344 ± 5.1^b	362 ± 3.1^d	0.10 ± 0.007^a	80.0 ± 0.28^d
HHB-226	2603 ± 6.7^a	258 ± 1.9^a	0.09 ± 0.001^a	80.1 ± 0.19^d
W-445	4970 ± 2.7^d	310 ± 2.3^c	0.06 ± 0.004^a	75.0 ± 0.21^b
GHB-732	4938 ± 5.4^d	537 ± 5.6^e	0.10 ± 0.002^a	75.0 ± 0.30^b

Data are presented as mean± SD (n = 3). Values within the same column followed by the same superscript are not significantly different (p < 0.05)

Table 4a. Rheological properties of native starches from different cultivars during frequency sweep.

Cultivars	G′ (Pa)	G′′ (Pa)	tan δ
HC-10	4749 ± 4.4^a	163 ± 2.1^a	0.03 ± 0.001^b
HHB-67	5574 ± 5.9^d	164 ± 2.5^a	0.02 ± 0.003^a
HHB-223	5525 ± 5.3^c	228 ± 3.1^c	0.04 ± 0.001^b
HHB-226	6564 ± 7.1^f	206 ± 1.8^b	0.03 ± 0.002^b
W-445	4870 ± 4.1^b	167 ± 2.9^a	0.03 ± 0.003^b
GHB-732	6194 ± 7.4^e	218 ± 3.5^bc	0.03 ± 0.001^b

Data are presented as mean± SD (n = 3). Values within the same column followed by the same superscript are not significantly different (p < 0.05)

Table 4b. Rheological properties of cross-linked starches from different cultivars during frequency sweep.

Cultivars	G′ (Pa)	G′′ (Pa)	tan δ
HC-10	5076 ± 6.1^f	219 ± 2.1^c	0.04 ± 0.001^a
HHB-67	4139 ± 4.5^c	182 ± 1.8^b	0.04 ± 0.003^a
HHB-223	3641 ± 2.7^b	223 ± 3.2^cd	0.06 ± 0.003^a
HHB-226	4661 ± 3.9^e	227 ± 4.6^cd	0.05 ± 0.002^a
W-445	4236 ± 4.0^d	174 ± 2.0^a	0.04 ± 0.003^a
GHB-732	3264 ± 5.1^a	240 ± 3.7^d	0.07 ± 0.001^a

Data are presented as mean± SD (n = 3). Values within the same column followed by the same superscript are not significantly different (p < 0.05)

Table 5. Steady shear properties of cross-linked starches from different cultivars fitted with Herschel-Bulkley model.

Sample	σο (Pa)	K (Pa.s)	n	R^2
HC-10	3.20 ± 0.17^c	0.27 ± 0.002^b	0.852 ± 0.01^e	0.999
HHB-67	0.27 ± 0.02	0.65 ± 0.006^d	0.654 ± 0.04^b	0.991
HHB-223	1.12 ± 0.05^b	0.16 ± 0.005^a	0.810 ± 0.03^d	0.991
HHB-226	1.10 ± 0.06^b	0.38 ± 0.004^c	0.700 ± 0.04^c	0.997
W-445	1.17 ± 0.08^b	0.67 ± 0.006^d	0.692 ± 0.03^c	0.994
GHB-732	0.38 ± 0.06^a	0.77 ± 0.007^e	0.486 ± 0.04^a	0.996

Data are presented as mean± SD (n = 3). Values within the same column followed by the same superscript are not significantly different (p < 0.05)

Figure 2a. Changes in G’ of cross-linked starches from different cultivars during heating.

Figure 2b. Changes in G” of cross-linked starches from different cultivars during heating.

Cultivars are denoted by: A: HC-10; B: HHB-67; C: HHB-223;D: HHB-226; E: W-445; F: GHB-732.

Figure 3a. Angular frequency dependence of G’ at 25°C for different cross-linked starches.

Figure 3b. Angular frequency dependence of G” at 25°C for cross-linked starches.

Figure 3c. Angular frequency dependence of tanδ at 25°C for cross-linked starches.

Cultivars are denoted by: A: HC-10; B: HHB-67; C: HHB-223; D: HHB-226; E: W-445; F: GHB-732.

Figure 4. Steady shear properties of cross-linked starches from different pearl millet cultivars.

Cultivars are denoted by: A: HC-10; B: HHB-67; C: HHB-223; D: HHB-226; E: W-445; F: GHB-732.

Figure 5. Morphological properties of cross-linked starches from different pearl millet cultivars.

Cultivars are denoted by: A: HC-10; B: HHB-67; C: HHB-223; D: HHB-226; E: W-445; F: GHB-732.

Table 6. In vitro digestibility of cross-linked starch from different cultivars.

Sample	RDS(%)	SDS(%)	RS(%)
HC-10	48.3 ± 0.18^c	36.4 ± 0.14^c	15.3 ± 0.17^b
HHB-67	48.7 ± 0.32^c	36.1 ± 0.22^bc	15.2 ± 0.12^b
HHB-223	47.0 ± 0.27^b	35.5 ± 0.33^b	17.5 ± 0.18^d
HHB-226	48.0 ± 0.32^c	36.0 ± 0.17^bc	16.0 ± 0.11^c
W-445	50.6 ± 0.24^d	35.8 ± 0.21^b	13.6 ± 0.13^a
GHB-732	46.1 ± 0.13^a	34.5 ± 0.16^a	19.4 ± 0.09^e

Data are presented as mean± SD (n = 3). Values within the same column followed by the same superscript are not significantly different (p < 0.05)