Process Optimization and Characterization of Popped Brown Rice

Figures & data

TABLE 1 Code and levels of independent factors used for central composite design

Independent factors	Symbol	Code and levels
		–α	–1	0	+1	+α
Salt (g/100 g)	X1	0.49	1	1.75	2.50	3.01
Moisture (g/100 g)	X2	11.64	13	15	17	18.36
Popping temperature (°C)	X3	200	210	225	240	250

FIGURE 1 Response surface plots for expansion ratio of popped rice. (a) Effect of moisture and salt content; (b) Effect of popping temperature and moisture content; (c) Effect of popping temperature and salt.

TABLE 2 Physical properties and mineral analysis of raw and popped brown rice

Property	Raw brown rice	Popped brown rice
Hardness (N)	97.97 ± 4.3	15.68 ± 1.3
L*	63.30 ± 1.7	67.78 ± 2.5
a*	9.19 ± 0.3	7.13 ± 0.5
b*	28.05 ± 1.2	23.27 ± 1.2
L/B ratio	2.43 ± 0.2	1.87 ± 0.4
Bulk density (kg/m^3)	584.60 ± 5.8	137.85 ± 2.8
Calcium (mg/100 g)	6.94 ± 0.5	7.14 ± 0.3
Iron (mg/100 g)	2.63 ± 0.1	2.68 ± 0.2
Potassium (mg/100 g)	107.91 ± 1.3	119.70 ± 4.5
Magnesium (mg/100 g)	18.12 ± 0.6	20.05 ± 0.9
Manganese (mg/100 g)	2.67 ± 0.4	2.96 ± 0.3
Phosphorus (mg/100 g)	78.74 ± 1.3	85.68 ± 3.7
Sulphur (mg/100 g)	27.53 ± 0.7	28.65 ± 0.6
Silicon (mg/100 g)	2.94 ± 0.5	3.23 ± 0.2
Zinc (mg/100 g)	2.59 ± 0.2	2.63 ± 0.1

Values are expressed as mean ± standard deviation.

FIGURE 2 Cross section scanning electron microscopy of (a) raw brown rice; (b) popped brown rice.

FIGURE 3 FT-IR spectrogram of (a) raw brown rice; (b) popped brown rice.

FIGURE 4 X-ray diffractrographs of (a) raw brown rice; (b) popped brown rice.

FIGURE 5 Differential scanning calorimetry thermogram of (a) raw brown rice; (b) popped brown rice.