Granular Structure and Physicochemical Properties of Starches from Amaranth Grain

Figures & data

FIGURE 1 Scanning electron photograph of starch from amaranth grain seeds: (A1) = 10,000 times; (A2) = 50,000 times.

FIGURE 2 X-ray diffraction pattern of starch from amaranth grain seeds.

TABLE 1 Particle size distribution and differential scanning calorimetry results of amaranth starch

Particle size distribution		DSC parameters
d(0.5) (μm)	d(0.9) (μm)	To (°C)	TP (°C)	Tc (°C)	ΔH (J/g)	ΔT1/2 (°C)
2.91	22.93	66.5	72.2	78.4	22.93	129

Note: d(0.5) (μm) = 50% of diameters shorter than; d(0.9) (μm) = 90% of diameters shorter than; T_o = Onset temperatures; T_p = Peak temperatures; T_c = Conclusion temperatures; ΔH = Enthalpy; ΔT_1/2 = Width at half the peak height.

FIGURE 3 Particle size distribution of starch from amaranth grain seeds.

TABLE 2 Blue value, enzymatic digestibility, and key parameters of Brabender viscosity of different starches

			Brabender viscosity
			A	B	tA-B	B–D	E–D
Starch sources	Blue value	Absorbance	(°C)	(BU)	(min)	(BU)	(BU)
Amaranth	0.085^c ± 0.0012	0.41^a ± 0.013	70.7^a	181^c	21.06^a	2^c	129^d
Corn	0.126^b ± 0.0036	0.15^b ± 0.002	70.1^a	326^b	7.9^b	150^b	335^a
Cassava	0.118^b ± 0.0018	0.18^b ± 0.002	61.4^b	417^a	1.86^c	272^a	200^c
Sweet potato	0.201^a ± 0.0037	0.12^b ± 0.003	69.4^a	430^a	11.68^b	251^a	272^b

Note: Values are means ± standard deviations, n = 3. Different letters within a column indicate significant differences at p < 0.05. The absorbance corresponds to enzymatic digestibility.

BU: Brabender Units; Evaluation point: A: Beginning of gelatinization; B: Maximum viscosity; D: Start of cooling period; E: End of cooling period; B–D: Breakdown; E–D: Setback.