Table 1.
Central composite rotatable design and the technological properties of the black rice (a) and the red rice (b) extrudates
| Run | Coded level | Actual value | Technological properties | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| x1 | x2 | Feed moisture (g/100 g) | Temperature (°C) | SME (KW/kg)a | WSI (%)b | WAI (g/g)c | Cold viscosity (cP) | Expansion Index | Specific volume (mL/g) | Compression force (N) | |
| (a) | |||||||||||
| 1 | − 1 | − 1 | 15.9 | 117 | 70.67 ± 0.84 | 3.46 ± 0.13 | 6.22 ± 0.10 | 60.00 ± 1.00 | 2.56 ± 0.06 | 3.63 ± 0.16 | 32.62 ± 4.14 |
| 2 | 1 | − 1 | 20.1 | 117 | 50.13 ± 0.65 | 2.48 ± 0.10 | 6.24 ± 0.05 | 36.00 ± 2.00 | 1.99 ± 0.08 | 0.85 ± 0.04 | 90.95 ± 8.58 |
| 3 | − 1 | 1 | 15.9 | 153 | 64.27 ± 1.00 | 4.26 ± 0.15 | 5.47 ± 0.23 | 74.00 ± 2.00 | 3.02 ± 0.08 | 3.81 ± 0.24 | 28.23 ± 2.31 |
| 4 | 1 | 1 | 20.1 | 153 | 44.27 ± 1.00 | 2.40 ± 0.16 | 6.61 ± 0.15 | 48.00 ± 1.00 | 1.97 ± 0.07 | 1.79 ± 0.08 | 106.30 ± 6.33 |
| 5 | − 1.41 | 0 | 15.0 | 135 | 66.67 ± 0.84 | 4.61 ± 0.23 | 5.47 ± 0.38 | 81.00 ± 2.00 | 2.87 ± 0.14 | 4.32 ± 0.04 | 21.58 ± 2.67 |
| 6 | 1.41 | 0 | 21.0 | 135 | 42.13 ± 0.65 | 2.66 ± 0.16 | 6.32 ± 0.07 | 42.00 ± 1.00 | 2.09 ± 0.09 | 1.81 ± 0.12 | 131.80 ± 12.31 |
| 7 | 0 | − 1.41 | 18.0 | 110 | 62.67 ± 0.84 | 2.76 ± 0.17 | 6.40 ± 0.05 | 49.00 ± 1.00 | 2.22 ± 0.07 | 2.57 ± 0.08 | 58.72 ± 5.34 |
| 8 | 0 | 1.41 | 18.0 | 160 | 55.47 ± 1.36 | 2.77 ± 0.06 | 6.32 ± 0.05 | 51.00 ± 1.00 | 2.48 ± 0.08 | 3.25 ± 0.31 | 42.24 ± 2.94 |
| 9 | 0 | 0 | 18.0 | 135 | 50.67 ± 0.84 | 2.86 ± 0.04 | 6.25 ± 0.10 | 50.00 ± 0.01 | 2.39 ± 0.10 | 2.38 ± 0.24 | 68.04 ± 6.48 |
| 10 | 0 | 0 | 18.0 | 135 | 50.40 ± 1.00 | 2.76 ± 0.10 | 6.23 ± 0.08 | 54.00 ± 1.00 | 2.34 ± 0.02 | 2.75 ± 0.20 | 67.56 ± 3.61 |
| 11 | 0 | 0 | 18.0 | 135 | 50.93 ± 1.00 | 2.73 ± 0.19 | 6.26 ± 0.08 | 51.00 ± 2.00 | 2.35 ± 0.04 | 2.59 ± 0.21 | 67.65 ± 5.30 |
| 12 | 0 | 0 | 18.0 | 135 | 50.13 ± 1.36 | 2.66 ± 0.10 | 6.27 ± 0.10 | 54.00 ± 0.01 | 2.38 ± 0.05 | 2.91 ± 0.08 | 68.59 ± 2.13 |
| (b) | |||||||||||
| 1 | − 1 | − 1 | 15.9 | 117 | 64.00 ± 0.84 | 8.47 ± 0.30 | 6.82 ± 0.21 | 197.00 ± 12.00 | 3.01 ± 0.10 | 2.52 ± 0.04 | 21.18 ± 2.64 |
| 2 | 1 | − 1 | 20.1 | 117 | 50.67 ± 0.84 | 3.31 ± 0.04 | 7.58 ± 0.14 | 86.00 ± 2.00 | 2.24 ± 0.05 | 1.80 ± 0.16 | 82.80 ± 9.66 |
| 3 | − 1 | 1 | 15.9 | 153 | 62.13 ± 1.36 | 8.63 ± 0.21 | 6.70 ± 0.21 | 228.00 ± 12.00 | 3.20 ± 0.04 | 5.91 ± 0.09 | 16.44 ± 2.32 |
| 4 | 1 | 1 | 20.1 | 153 | 52.80 ± 1.36 | 3.74 ± 0.02 | 7.53 ± 0.06 | 111.00 ± 3.00 | 2.21 ± 0.08 | 1.01 ± 0.14 | 73.79 ± 4.88 |
| 5 | − 1.41 | 0 | 15.0 | 135 | 75.47 ± 1.07 | 10.94 ± 0.09 | 6.91 ± 0.06 | 271.00 ± 4.00 | 3.30 ± 0.04 | 4.55 ± 0.17 | 20.84 ± 2.11 |
| 6 | 1.41 | 0 | 21.0 | 135 | 43.47 ± 0.65 | 2.48 ± 0.04 | 7.74 ± 0.10 | 111.00 ± 6.00 | 2.25 ± 0.04 | 1.87 ± 0.10 | 82.55 ± 11.80 |
| 7 | 0 | − 1.41 | 18.0 | 110 | 65.33 ± 0.84 | 5.87 ± 0.16 | 7.18 ± 0.09 | 114.00 ± 5.00 | 2.49 ± 0.03 | 1.93 ± 0.08 | 37.18 ± 4.23 |
| 8 | 0 | 1.41 | 18.0 | 160 | 67.47 ± 1.36 | 7.92 ± 0.02 | 7.77 ± 0.05 | 177.00 ± 10.00 | 2.54 ± 0.03 | 2.68 ± 0.15 | 19.99 ± 2.67 |
| 9 | 0 | 0 | 18.0 | 135 | 58.67 ± 0.84 | 7.37 ± 0.13 | 7.39 ± 0.30 | 164.00 ± 11.00 | 2.76 ± 0.08 | 2.38 ± 0.07 | 26.67 ± 2.68 |
| 10 | 0 | 0 | 18.0 | 135 | 58.40 ± 1.00 | 7.33 ± 0.10 | 7.55 ± 0.28 | 163.00 ± 4.00 | 2.78 ± 0.04 | 2.88 ± 0.08 | 26.48 ± 2.58 |
| 11 | 0 | 0 | 18.0 | 135 | 57.33 ± 0.84 | 7.56 ± 0.04 | 7.23 ± 0.04 | 176.00 ± 4.00 | 2.78 ± 0.03 | 2.98 ± 0.22 | 26.39 ± 3.28 |
| 12 | 0 | 0 | 18.0 | 135 | 58.93 ± 1.00 | 7.22 ± 0.29 | 7.33 ± 0.07 | 154.00 ± 7.00 | 2.76 ± 0.07 | 2.83 ± 0.13 | 27.42 ± 2.12 |
| Run | Technological properties | ||
|---|---|---|---|
| L* (lightness) | C* (chroma) | h* (hue angle) | |
| (a) | |||
| 1 | 25.09 ± 0.32 | 2.31 ± 0.03 | 81.82 ± 0.71 |
| 2 | 19.17 ± 0.44 | 2.03 ± 0.02 | 69.01 ± 0.62 |
| 3 | 25.19 ± 0.64 | 2.39 ± 0.05 | 78.91 ± 0.39 |
| 4 | 19.79 ± 0.61 | 2.20 ± 0.03 | 74.64 ± 1.28 |
| 5 | 25.64 ± 0.37 | 2.21 ± 0.01 | 86.47 ± 0.23 |
| 6 | 19.13 ± 0.59 | 2.10 ± 0.07 | 67.98 ± 1.91 |
| 7 | 22.25 ± 0.83 | 2.16 ± 0.04 | 74.74 ± 0.71 |
| 8 | 21.77 ± 0.30 | 2.50 ± 0.02 | 75.35 ± 0.70 |
| 9 | 21.12 ± 0.89 | 2.23 ± 0.04 | 78.53 ± 0.34 |
| 10 | 21.24 ± 1.00 | 2.25 ± 0.02 | 78.51 ± 0.62 |
| 11 | 21.66 ± 0.53 | 2.22 ± 0.03 | 78.37 ± 0.94 |
| 12 | 21.79 ± 0.55 | 2.26 ± 0.01 | 78.29 ± 0.76 |
| (b) | |||
| 1 | 38.29 ± 1.04 | 4.55 ± 0.03 | 40.55 ± 0.65 |
| 2 | 32.69 ± 0.46 | 4.38 ± 0.05 | 41.35 ± 0.43 |
| 3 | 37.60 ± 0.58 | 4.45 ± 0.03 | 40.14 ± 0.44 |
| 4 | 31.68 ± 0.49 | 4.37 ± 0.03 | 42.48 ± 0.92 |
| 5 | 40.53 ± 1.00 | 4.51 ± 0.02 | 40.39 ± 0.62 |
| 6 | 30.43 ± 0.28 | 4.25 ± 0.07 | 43.07 ± 0.80 |
| 7 | 35.08 ± 1.17 | 4.43 ± 0.03 | 41.23 ± 0.54 |
| 8 | 34.46 ± 0.61 | 4.59 ± 0.06 | 40.64 ± 0.39 |
| 9 | 36.11 ± 0.47 | 4.52 ± 0.03 | 40.69 ± 1.10 |
| 10 | 36.45 ± 0.28 | 4.52 ± 0.08 | 41.24 ± 0.41 |
| 11 | 35.96 ± 0.28 | 4.55 ± 0.04 | 40.93 ± 0.67 |
| 12 | 35.98 ± 0.15 | 4.58 ± 0.04 | 40.62 ± 0.14 |
Values are means of at least three replicates and the standard errors of values
aSpecific mechanical energy
bWater Solubility Index
cWater Absorption Index