AN APPLICATION OF IMAGE ANALYSIS FOR THE STUDY OF KINETICS OF HYDRATION OF MILLED RICE IN HOT WATER

Figures & data

Figure 1. Configuration of equipment used in image analysis.

Figure 2. Flowchart of the algorithm for area measurement.

Figure 3. Parity plot for image and physical measurements of the area of 3 replicates of rice.

Figure 4. Influence of heating on the swelling ratio.

Table 1. Statistical Parameters

Statistical Parameters	RMSD	SD	% Error	R ^2
Physical Vs Image measurements	0.59	0.26	1.63	0.99

Table 2. Reaction Rate Constants at Various Temperatures

Temperature (°C)	Reaction Rate Constant (min^−1)
60 ± 1	0.01597
65 ± 1	0.01983
70 ± 1	0.02256
75 ± 1	0.02965

Table 3. Comparison of E_a Values with Literature Values

Material	E a (kJ/mole)	Reference
Rice Cooking	38.213	Present study
Rice starch gelatinization	103.3, 79.55	[9], [15]
Carrot blanching	28.2	[44]
Rice drying	28.5–44.8	10-11
Sorghum drying	31.4–35.3	[45]
Toria drying	61.8	[46]
Cottonseed drying	13.8	[47]
Soybean drying	8.7	[45]

Table 4. Comparison of E_a Values During Starch Gelatinization Determined from Different Methods

Type of Study	Method	Temperature Range (°C)	Ea (kJ/mole)	Reference
Gelatinization of rice grains	Image analysis	60–75	38.213	Present study
Gelatinization of rice starch	Flow consistency with viscometer	70–85	58.62	[48]
Rice Cooking	Compressibilty with plastometer	75–110	79.55	[15]
Gelatinization of brown rice	Amylose/Iodine blue	50–85	103.3	[9]
Gelatinization of rice starch	DSC isothermal	65–75	104.67	[49]
	DSC non isothermal	70–75	185–305

Table 5. Swelling Ratios at Various Cooking Time and Temperatures

		Swelling Ratio
Temperature (°C)	Time (minutes)	Actual	Predicted ^*
60	0	1.00	1.00
60	3	1.08	1.05
60	6	1.12	1.10
60	9	1.15	1.15
65	0	1.00	1.00
65	3	1.07	1.06
65	9	1.20	1.19
65	12	1.23	1.26
70	0	1.00	1.00
70	3	1.12	1.07
70	6	1.19	1.15
70	10	1.23	1.27
75	0	1.00	1.00
75	5	1.13	1.16
75	10	1.28	1.33
75	12	1.36	1.41

^*From equation 7.

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