Gadung (Dioscorea hispida) tuber starch modified by freeze moisture treatment and heat moisture treatment: a study of functional, pasting, and physicochemical properties

Figures & data

Figure 1. Swelling volume of modified gadung starch by FMT and HMT. Graphs marked with different letters indicate significant differences at p < .05.

Figure 2. Solubility of modified gadung starch by FMT and HMT. Graphs marked with different letters indicate significant differences at p < .05.

Figure 3. WAC of modified gadung starch by FMT and HMT. Graphs marked with different letters indicate significant differences at p < .05.

Table 1. Color chromaticity of modified gadung starch by FMT and HMT.

Treatment	Color Chromaticity
	L*	a*	b*	$\mathrm{\Delta }$E
Native starch	94.79 ± 0.01^f	−0.29 ± 0.01^b	5.62 ± 0.01^a	0.00 ± 0.00^a
FMT	94.67 ± 0.02^e	−0.34 ± 0.01^a	6.07 ± 0.02^b	0.49 ± 0.02^b
HMT 100${ }^{\circ }\mathit{C}$	93.26 ± 0.01^d	0.44 ± 0.01^d	9.24 ± 0.02^e	3.98 ± 0.26^e
HMT 110${ }^{\circ }\mathit{C}$	91.55 ± 0.00^a	0.48 ± 0.00^e	9.48 ± 0.03^f	5.09 ± 0.03^f
FMT + HMT 100${ }^{\circ }\mathit{C}$	93.20 ± 0.01^c	0.37 ± 0.01^c	9.08 ± 0.01^d	3.29 ± 0.02^d
FMT + HMT 110${ }^{\circ }\mathit{C}$	92.30 ± 0.02^b	0.73 ± 0.01^f	7.72 ± 0.02^c	3.41 ± 0.01^c

The treatment means marked by different letters for the same column indicate differences between treatments (p < .05).

Figure 4. Morphological characteristics of modified gadung starch by FMT and HMT at a magnification of 7000X. Pores and cracks were marked by red arrows.

Figure 5. Pasting curves of modified gadung starch by FMT and HMT.

Table 2. Pasting properties of modified gadung starch by FMT and HMT.

Treatment	Pasting Point (°C)	Peak Viscosity (cP)	Hold Viscosity (cP)	Final Viscosity (cP)	Breakdown Viscosity (cP)	Setback Viscosity (cP)
Native starch	75.67 ± 0.29^a	3671.00 ± 143.54^c	682.00 ± 124.45^a	873.50 ± 170.41^a	2989.50 ± 267.99^b	191.00 ± 45.96^b
FMT	75.50 ± 1.15^a	3658.00 ± 52.33^c	919.00 ± 2.83^a	1475.00 ± 4.95^ab	2739.00 ± 49.50^b	556.00 ± 7.78^c
HMT 100 °C	82.24 ± 1.68^b	3075.50 ± 496.39^a	2015.00 ± 436.99^b	2015.00 ± 436.99^bc	113.00 ± 53.40^a	0.00 ± 0.00^a
HMT 110 °C	79.44 ± 0.04^ab	2477.00 ± 79.20^ab	2442.00 ± 80.61^bc	2599.00 ± 33.94^cd	38.00 ± 1.41^a	157,00 ± 46.67^b
FMT + HMT 100°C	81.13 ± 0.59^b	3484.00 ± 134.35^a	3446.00 ± 111.72^c	3384.50 ± 113.84^d	35.00 ± 22.63^a	1504.500 ± 1.41^It is
FMT + HMT 110°C	81.50 ± 0.08^b	2288.00 ± 284.26^bc	2257.00 ± 274.36^b	4950.50 ± 232.64^It is	31.00 ± 9.90^a	1150.00 ± 9.90^d

The treatment means marked with the same lowercase letter are not significantly different at the 5% level according to the Duncan test.

Figure 6. The diffractogram of native and modified gadung starch by FMT + HMT 110°C.

Figure 7. FTIR spectra of native and modified gadung starch by FMT + HMT 110°C.