Rheological Characterization of Low Fat Sesame Paste Blended With Date Syrup

Figures & data

Figure 1 Hysteresis loop of the flow curves of low fat sesame paste/date syrup blend at different temperatures for fat substitution with 0.01% xanthan gum.

Table 1 The parameters of the Weltman model for a shearing period of 10 min evaluated as a function of starch substitution at 25°C ∗.

	Starch %
	0			0.75			1.25			1.75
Shear rate (s^−1)	A	−B	R^2	A	−B	R^2	A	−B	R^2	A	−B	R^2
4.18	189.2	0.278	0.75	290.5	0.253	0.73	316.3	0.539	0.73	341.1	0.495	0.64
8.36	254.0	0.462	0.89	466.4	0.641	0.79	492.6	0.871	0.72	556.7	0.944	0.73
12.54	316.3	0.824	0.91	608.9	0.824	0.78	616.6	1.571	0.79	730.6	1.214	0.70
∗A (Pa) and B (Pa) parameters were obtained by fitting experimental data to Weltman model (τ = A + B In t).

Table 2 The parameters of the Weltman model for a shearing period of 10 min evaluated as a function of xanthan gum substitution at 25°C ^∗.

		Xanthan gum %
		0			0.01			0.015			0.02
Shear rate (s^−1)	rpm	A	−B	R^2	A	−B	R^2	A	−B	R^2	A	−B	R^2
4.18	20	189.2	0.278	0.75	290.1	0.154	0.71	289.3	0.330	0.98	348.6	0.143	0.88
8.36	40	254.0	0.462	0.89	426.3	0.228	0.79	476.9	0.545	0.85	530.25	0.259	0.72
12.54	60	316.3	0.824	0.91	554.2	0.243	0.60	600.8	0.845	0.95	648.5	0.385	0.81
∗A (Pa) and B (Pa) parameters were obtained by fitting experimental data to Weltman model (τ = A + B In t).

Table 3 The parameters of the Weltman model for a shearing period of 10 min evaluated as a function of guar gum substitution at 25°C ^∗.

		Guar gum %
		0			0.01			0.015			0.02
Shear rate (s^−1)	rpm	A	R^2	−B	A	−B	R^2	A	−B	R^2	A	−B	R^2
4.18	20	189.2	0.75	0.278	210.0	0.090	0.72	380.7	0.295	0.64	365.3	0.354	0.86
8.36	40	254.0	0.89	0.462	489.0	0.306	0.92	529.2	0.480	0.98	518.2	1.210	0.85
12.54	60	316.3	0.91	0.824	597.1	0.394	0.98	665.9	0.749	0.99	—	—	—
∗A (Pa) and B (Pa) parameters were obtained by fitting experimental data to Weltman model (τ = A + B In t).

Table 4 The parameters of the First-order stress decay model, with a zero equilibrium stress value, for a shearing period of 10 min evaluated as a function of starch substitution at 25°C ^∗.

		Starch %
		0			0.75			1.25			1.75
Shear rate (s^−1)	rpm	τ0	K	R^2	τ0	K	R^2	τ0	K	R^2	τ0	K	R^2
4.18	20	197.0	0.007	0.81	304.9	0.008	0.70	342.0	0.014	0.77	368.2	0.014	0.79
8.36	40	265.8	0.008	0.73	500.7	0.010	0.69	534.7	0.014	0.79	597.6	0.014	0.73
12.54	60	330.8	0.008	0.70	654.0	0.012	0.71	648.2	0.018	0.75	794.0	0.015	0.77
∗τ0 (Pa) and K (s^−1) parameters were obtained by fitting experimental data to First-order stress decay model (τ = τ0 e ^−Kt).

Table 5 The parameters of the First-order stress decay model, with a zero equilibrium stress value, for a shearing period of 10 min evaluated as a function of xanthan gum substitution at 25°C ^∗.

		Xanthan gum %
		0			0.01			0.015			0.02
Shear rate (s^−1)	rpm	τ0	K	R^2	τ0	K	R^2	τ0	K	R^2	τ0	K	R^2
4.18	20	197.0	0.007	0.81	298.1	0.005	0.68	438.5	0.005	0.72	353.8	0.002	0.40
8.36	40	265.8	0.008	0.73	438.5	0.005	0.72	494.2	0.006	0.53	538.9	0.002	0.25
12.54	60	330.8	0.008	0.70	570.3	0.005	0.81	623.9	0.006	0.42	665.2	0.004	0.51
∗τ0 (Pa) and K (s^−1) parameters were obtained by fitting experimental data to First-order stress decay model (τ = τ0 e ^−Kt).

Table 6 The parameters of the First-order stress decay model, with a zero equilibrium stress value, for a shearing period of 10 min evaluated as a function of guar gum substitution at 25°C ^∗.

		Guar gum %
		0			0.1			0.15			0.2
Shear rate (s^−1)	rpm	τ0	K	R^2	τ0	K	R^2	τ0	K	R^2	τ0	K	R^2
4.18	20	197.0	0.007	0.81	212.1	0.002	0.69	386.5	0.002	0.31	396.8	0.008	0.74
8.36	40	265.8	0.008	0.73	495.4	0.002	0.48	538.8	0.003	0.37	549.7	0.010	0.61
12.54	60	330.8	0.008	0.70	606.4	0.003	0.58	680.4	0.003	0.34	—	—	—
∗τ0 (Pa) and K (s^−1) parameters were obtained by fitting experimental data to First-order stress decay model (τ = τ0 e ^−Kt).

Figure 2 Shear stress of low fat sesame paste/date syrup blends containing 1.25% starch at 25°C as a function of shearing time (10 min period) and shear rate (4.18, 8.36 & 12.54 s⁻¹), (Experimental data, °; Weltman model predictions, —; Kinetic model predictions, —).

Figure 3 Shear stress of low fat sesame paste/date syrup blends containing 0.02% xanthan gum at 25°C as a function of shearing time (10 min period) and shear rate (4.18, 8.36 & 12.54 s⁻¹), (Experimental data, °; Weltman model predictions, —; Kinetic model predictions, —).

Figure 4 Shear stress of low fat sesame paste/date syrup blends containing 0.15% guar gum at 25°C as a function of shearing time (10 min period) and shear rate (4.18, 8.36 & 12.54 s⁻¹), (Experimental data, °; Weltman model predictions, —; Kinetic model predictions, —).