Physicochemical, thermal, rheological, and morphological properties of flour from different guar seed (Cyamopsis tetragonoloba) cultivars

Figures & data

Figure 1. Flowsheet for extraction of guar gum from guar seeds.

Table 1. Proximate composition of flours from different guar seed flour cultivars (dry basis).^A,B

Cultivar	Protein^C (%)	Fat (%)	Fiber (%)	Ash (%)	Carbohydrates (%)
G 80	24.55 ± 0.94^b	3.06 ± 0.21^a	14.37 ± 1.23^a	3.59 ± 0.43^b	54.72 ± 1.32^a
Ageta 112	26.78 ± 0.49^a	2.98 ± 0.27^a	11.59 ± 0.98^b	5.29 ± 0.39^a	53.33 ± 0.67^b
HG 365	25.68 ± 0.93^b	2.70 ± 0.11^a	13.81 ± 1.00^ab	3.76 ± 0.64^b	53.65 ± 1.10^b

^AMeans followed by same letter within a column do not differ significantly (p < 0.05).

^BMeans (±SD) of triplicate analyses.

^CTotal nitrogen × 6.25.

Table 2. Hunter color values of flours from different chickpea cultivars.^A,B

Cultivar	L*	a*	b*	C*	Hue angle
G 80	76.51 ± 0.71^b	–2.03 ± 0.14^b	8.96 ± 0.14^b	9.19 ± 0.13^a	102.7 ± 0.25^b
Ageta112	79.26 ± 0.52^a	–2.68 ± 0.17^a	9.06 ± 0.11^a	9.45 ± 0.15^a	106.5 ± 0.27^a
HG 365	76.97 ± 0.62^b	–2.07 ± 0.11^a	9.20 ± 0.21^a	9.43 ± 0.18^a	102.7 ± 0.25^b

^AMeans followed by same letter within a column do not differ significantly (p < 0.05).

^BMeans (±SD) of triplicate analyses.

Table 3. Chemical composition and yield of guar seed gum.^A,B

Cultivar	Protein (%)	Fat (%)	Ash (%)	Carbohydrates (%)	Gum* (%)
G 80	5.66 ± 0.51^b	0.30 ± 0.10^a	0.40 ± 0.07^a	93.64 ± 0.76^a	41.19
Ageta 112	6.88 ± 0.42^a	0.20 ± 0.16^a	0.44 ± 0.05^a	92.48 ± 0.85^a	31.19
HG 365	5.21 ± 0.73^b	0.23 ± 0.13^a	0.42 ± 0.05^a	94.14 ± 0.77^a	37.32

^AMeans followed by same letter within a column do not differ significantly (p < 0.05).

^BMeans (±SD) of triplicate analyses.

*Means of triplicate analyses.

Table 4. Thermal properties of guar seed flour cultivars.^A,B

Cultivar	To (ºC)	Tp (ºC)	Te (ºC)	∆Hgel (J/g)	PHI	Range
G 80	69.07 ± 0.03^a	75.70 ± 0.01^a	81.38 ± 0.01^a	5.2 ± 0.02^a	0.78 ± 0.02^b	13.26 ± 0.03^a
Ageta 112	66.36 ± 0.03^b	72.22 ± 0.02^b	78.23 ± 0.03^b	4.1 ± 0.01^b	0.70 ± 0.02^a	11.72 ± 0.01^a
HG 365	67.88 ± 0.02^a	74.15 ± 0.02^ab	79.94 ± 0.04^a	4.8 ± 0.04^a	0.77 ± 0.01^b	12.54 ± 0.04^a

To: onset temperature, Tp: peak temperature, Te: endset temperature, ∆Hgel: enthalpy of gelatinization (dwb), PHI: peak height index ∆Hgel /(Tp – To), R: gelatinization range (Te – To).

^AMeans followed by same letter within a column do not differ significantly (p < 0.05).

^BMeans (±SD) of triplicate analyses.

Table 5. Pasting properties of guar flour cultivars.^A,B

Sample	Paste temperature (ºC)	Peak viscosity (cp)	Hold viscosity (cp)	Final viscosity (cp)	Breakdown viscosity (cp)	Setback viscosity (cp)
G 80	75.2 ± 0.03^b	763 ± 13^c	750 ± 18^c	2423 ± 28^c	13 ± 3^c	1673 ± 10^c
Ageta 112	86.3 ± 0.02^a	2321 ± 22^a	2276 ± 25^a	4894 ± 19^b	45 ± 3^a	2618 ± 16^b
HG 365	54.5 ± 0.03^c	2198 ± 17^b	2171 ± 23^b	5909 ± 21^a	27 ± 2^b	3738 ± 19^a

^AMeans followed by same letter within a column do not differ significantly (p < 0.05).

^BMeans (±SD) of triplicate analyses.

Figure 2. Scanning electron micrographs of guar seed flour of different cultivars, 2a: G 80; 2b: Ageta 112; and 2c: HG 365 showing long shreds of epidermis and he scattered granules of galactomannan deposits originating from the inclusions in the endosperm cells.

Table 6. Pearson’s correlation coefficients between composition, gum yield and thermal properties.

	Protein	Fat	Fiber	Ash	Carbohy	Gum yield	Onset temperature	Peak temperature	Endset temperature	Enthalpy	PHI
Fat	–0.454
Fiber	–0.83**	–0.12
Ash	0.767**	0.223	–0.995**
Carbohy	–0.991**	0.056	0.75**	–0.676**
Gum Yield	–0.925**	0.082	0.98**	–0.953**	0.867**
Onset Temp	–0.946**	0.142	0.966**	–0.933**	0.895**	0.998*
Peak Temp	–0.948**	0.149	0.964**	–0.931**	0.899**	0.998*	1.000*
Endset Temp	–0.953**	0.162	0.96**	–0.926**	0.904**	0.997*	1.000*	1.000**
Enthalpy	–0.915**	0.056	0.985**	–0.961**	0.854**	1.000*	0.996*	0.996**
PHI	–0.785**	–0.195	0.997*	–1.000*	0.697**	0.961*	0.943*	0.941**	0.936**	0.968**
Range	–0.984**	0.287	0.917**	–0.87**	0.952**	0.978*	0.989*	0.99**	0.992**	0.973**	0.884**

*Correlation is significant at the 0.05 level (2-tailed).

**Correlation is significant at the 0.01 level (2-tailed).