Figure 1.
Representation of dimensions measured for each grain kernel: width (W), length (L), and thickness (T).
Figure 1.
Representation of dimensions measured for each grain kernel: width (W), length (L), and thickness (T).
Figure 2.
Grain position between parallel plates: length (L), thickness (T).
Figure 2.
Grain position between parallel plates: length (L), thickness (T).
Figure 3.
The dependencies between moisture content and thickness: (a) maize, T = 0.0205 MC + 4.438, R2 = 0.923, (b) rice, T = −5.95 × 10−4 MC2 + 0.0306 MC + 1.522, R2 = 0.999, (c) soybeans, T = 0.00602 MC + 5.887, R2 = 0.786; length: (d) maize, L = 0.00272 MC2 − 0.0463 MC + 13.253, R2 = 0.996, (e) rice, L = 0.0209 MC + 5.605, R2 = 0.928, (f) soybeans, L = 0.00374 MC2 − 0.0736 MC + 7.747, R2 = 0.994; width: (g) maize, W = 0.0448 MC + 7.700, R2 = 0.895, (h) rice, W = 0.0925 MC + 2.663, R2 = 0.796, (i) soybean, W = 0.0273 MC + 6.382, R2 = 0.874; equivalent diameter: (j) maize, De = 0.00233 MC2 − 0.0534 MC + 8.536, R2 = 0.997, (k) rice, De = 0.0120 MC + 2.988, R2 = 0.877, (l) soybeans, De = 0.00283 MC + 6.314, R2 = 0.808; ○—data, ▲—mean, ─—fitted curve, ----—95% confidence band.
Figure 3.
The dependencies between moisture content and thickness: (a) maize, T = 0.0205 MC + 4.438, R2 = 0.923, (b) rice, T = −5.95 × 10−4 MC2 + 0.0306 MC + 1.522, R2 = 0.999, (c) soybeans, T = 0.00602 MC + 5.887, R2 = 0.786; length: (d) maize, L = 0.00272 MC2 − 0.0463 MC + 13.253, R2 = 0.996, (e) rice, L = 0.0209 MC + 5.605, R2 = 0.928, (f) soybeans, L = 0.00374 MC2 − 0.0736 MC + 7.747, R2 = 0.994; width: (g) maize, W = 0.0448 MC + 7.700, R2 = 0.895, (h) rice, W = 0.0925 MC + 2.663, R2 = 0.796, (i) soybean, W = 0.0273 MC + 6.382, R2 = 0.874; equivalent diameter: (j) maize, De = 0.00233 MC2 − 0.0534 MC + 8.536, R2 = 0.997, (k) rice, De = 0.0120 MC + 2.988, R2 = 0.877, (l) soybeans, De = 0.00283 MC + 6.314, R2 = 0.808; ○—data, ▲—mean, ─—fitted curve, ----—95% confidence band.
Figure 4.
The dependencies between moisture content and weight: (a) maize, m = 0.00578 MC + 0.305, R2 = 0.914, (b) rice, m = 0.000233 MC + 0.0180, R2 = 0.953, (c) soybeans, m = 0.00243 MC + 0.164, R2 = 0.939; ○—data, ▲—mean, ─—fitted curve, ----—95% confidence band.
Figure 4.
The dependencies between moisture content and weight: (a) maize, m = 0.00578 MC + 0.305, R2 = 0.914, (b) rice, m = 0.000233 MC + 0.0180, R2 = 0.953, (c) soybeans, m = 0.00243 MC + 0.164, R2 = 0.939; ○—data, ▲—mean, ─—fitted curve, ----—95% confidence band.
Figure 5.
The dependencies between moisture content and bulk density: (a) maize, ρB = −0.00555 MC + 0.833, R2 = 0.946, (b) rice, ρB = −0.00664 MC + 0.905, R2 = 0.950, (c) soybeans, ρB = −0.00379 MC + 0.795, R2 = 0.991; ○—data, ▲—mean, ─—fitted curve, ----—95% confidence band.
Figure 5.
The dependencies between moisture content and bulk density: (a) maize, ρB = −0.00555 MC + 0.833, R2 = 0.946, (b) rice, ρB = −0.00664 MC + 0.905, R2 = 0.950, (c) soybeans, ρB = −0.00379 MC + 0.795, R2 = 0.991; ○—data, ▲—mean, ─—fitted curve, ----—95% confidence band.
Figure 6.
The relationship between moisture content and selected shape characteristics for maize: (a) sphericity, f = 0.000353 MC + 0.602, R2 = 0.922, (b) aspect ratio, AR = 0.00105 MC + 0.617, R2 = 0.781, (c) flatness ratio, FR = −0.00132 MC + 0.577, R2 = 0.873; ○—data, ▲—mean, ─—fitted curve, ----—95% confidence band.
Figure 6.
The relationship between moisture content and selected shape characteristics for maize: (a) sphericity, f = 0.000353 MC + 0.602, R2 = 0.922, (b) aspect ratio, AR = 0.00105 MC + 0.617, R2 = 0.781, (c) flatness ratio, FR = −0.00132 MC + 0.577, R2 = 0.873; ○—data, ▲—mean, ─—fitted curve, ----—95% confidence band.
Figure 7.
The relationship between moisture content and selected shape characteristics for rice: (a) sphericity, f = −0.000021 MC + 0.515, R2 = 0.999, (b) aspect ratio, AR = −0.00058 MC + 0.483, R2 = 0.887, (c) flatness ratio, FR = 0.00147 MC + 0.632, R2 = 0.945; ○—data, ▲—mean, ─—fitted curve, ----—95% confidence band.
Figure 7.
The relationship between moisture content and selected shape characteristics for rice: (a) sphericity, f = −0.000021 MC + 0.515, R2 = 0.999, (b) aspect ratio, AR = −0.00058 MC + 0.483, R2 = 0.887, (c) flatness ratio, FR = 0.00147 MC + 0.632, R2 = 0.945; ○—data, ▲—mean, ─—fitted curve, ----—95% confidence band.
Figure 8.
The relationship between moisture content and selected shape characteristics for soybeans: (a) sphericity, f = −0.000158 MC2 + 0.00249 MC + 0.900, R2 = 0.998, (b) aspect ratio, AR = −0.000193 MC2 + 0.00357 MC + 0.904, R2 = 0.999, (c) flatness ratio, FR = −0.00254 MC + 0.918, R2 = 0.891; ○—data, ▲—mean, ─—fitted curve, ----—95% confidence band.
Figure 8.
The relationship between moisture content and selected shape characteristics for soybeans: (a) sphericity, f = −0.000158 MC2 + 0.00249 MC + 0.900, R2 = 0.998, (b) aspect ratio, AR = −0.000193 MC2 + 0.00357 MC + 0.904, R2 = 0.999, (c) flatness ratio, FR = −0.00254 MC + 0.918, R2 = 0.891; ○—data, ▲—mean, ─—fitted curve, ----—95% confidence band.
Figure 9.
The breakage force (a), stress (b), and deformation (c) during maize grain compression at five levels of moisture content and two loading rates. Letters below the box charts are the interaction grouping letters from the post hoc Fisher least significant difference means comparison test. Means that do not share a letter are significantly different. □—mean, ──—median, ◆—outliers.
Figure 9.
The breakage force (a), stress (b), and deformation (c) during maize grain compression at five levels of moisture content and two loading rates. Letters below the box charts are the interaction grouping letters from the post hoc Fisher least significant difference means comparison test. Means that do not share a letter are significantly different. □—mean, ──—median, ◆—outliers.
Figure 10.
The breakage force (a), stress (b), and deformation (c) during rice grain compression for five levels of moisture content and two loading rates. Letters below the box charts are the interaction grouping letters from the post hoc Fisher least significant difference means comparison test. Means that do not share a letter are significantly different. □—mean, ──—median, ◆—outliers.
Figure 10.
The breakage force (a), stress (b), and deformation (c) during rice grain compression for five levels of moisture content and two loading rates. Letters below the box charts are the interaction grouping letters from the post hoc Fisher least significant difference means comparison test. Means that do not share a letter are significantly different. □—mean, ──—median, ◆—outliers.
Figure 11.
The breakage force (a), stress (b), and deformation (c) during soybean compression for five levels of moisture content and two loading rates. Letters below the box charts are the interaction grouping letters from the post hoc Fisher least significant difference means comparison test. Means that do not share a letter are significantly different. □—mean, ──—median, ◆—outliers.
Figure 11.
The breakage force (a), stress (b), and deformation (c) during soybean compression for five levels of moisture content and two loading rates. Letters below the box charts are the interaction grouping letters from the post hoc Fisher least significant difference means comparison test. Means that do not share a letter are significantly different. □—mean, ──—median, ◆—outliers.
Figure 12.
The dependencies between moisture content and selected mechanical properties for maize (circle), rice (triangle), and soybean (square) kernels at two loading rates: 1.25 mm/min (black) and 125 mm/min (white).
Figure 12.
The dependencies between moisture content and selected mechanical properties for maize (circle), rice (triangle), and soybean (square) kernels at two loading rates: 1.25 mm/min (black) and 125 mm/min (white).
Figure 13.
The dependence between moisture content and energy needed for single grain compression; (a) maize, (b) rice, (c) soybeans.
Figure 13.
The dependence between moisture content and energy needed for single grain compression; (a) maize, (b) rice, (c) soybeans.
Table 1.
Moisture content of cereal grains after conditioning to predetermined levels.
Table 1.
Moisture content of cereal grains after conditioning to predetermined levels.
Moisture Content, % w.b. |
---|
| Maize | Rice | Soybeans |
---|
Level 1: 10% | 10.02 | 9.98 | 9.76 |
Level 2: 14% | 13.95 | 13.96 | 14.10 |
Level 3: 18% | 18.02 | 17.91 | 17.92 |
Level 4: 22% | 22.09 | 21.80 | 21.94 |
Level 5: 26% | 26.40 | 25.71 | 26.19 |
Table 2.
Results of correlation analysis between moisture content and physical properties of grain kernels.
Table 2.
Results of correlation analysis between moisture content and physical properties of grain kernels.
| | Thickness | Length | Width | Equivalent Diameter | Weight | Bulk Density |
---|
Maize | Pearson Corr. | 0.961 * | 0.968 * | 0.946 * | 0.939 * | 0.956 * | −0.972 * |
p-value | 0.009 | 0.007 | 0.015 | 0.018 | 0.011 | 0.005 |
Rice | Pearson Corr. | 0.956 * | 0.963 * | 0.892 * | 0.937 * | 0.976 * | −0.975 * |
p-value | 0.011 | 0.008 | 0.042 | 0.019 | 0.004 | 0.005 |
Soybeans | Pearson Corr. | 0.889 * | 0.958 * | 0.935 * | 0.899 * | 0.969 * | −0.996 * |
p-value | 0.045 | 0.010 | 0.020 | 0.038 | 0.007 | 0.000 |
Table 3.
Results of correlation analysis between moisture content and selected shape characteristics (based on average values).
Table 3.
Results of correlation analysis between moisture content and selected shape characteristics (based on average values).
| | Sphericity | Aspect Ratio | Flatness Ratio |
---|
Maize | Pearson Corr. | 0.960 * | 0.884 * | −0.934 * |
p-value | 0.009 | 0.047 | 0.020 |
Rice | Pearson Corr. | 0.953 * | −0.942 * | 0.972 * |
p-value | 0.012 | 0.017 | 0.006 |
Soybeans | Pearson Corr. | −0.973 * | −0.965 * | −0.944 * |
p-value | 0.005 | 0.008 | 0.016 |
Table 4.
Results of correlation analysis between moisture content and mechanical characteristics (based on average values).
Table 4.
Results of correlation analysis between moisture content and mechanical characteristics (based on average values).
| | Loading Rate 1.25 mm/min | Loading Rate 125 mm/min |
---|
Breakage Force | Breakage Stress | Deformation | Breakage Force | Breakage Stress | Deformation |
---|
Maize | Pearson Corr. | 0.930 * | 0.940 * | 0.974 * | 0.959 * | 0.907 * | 0.968 * |
p-value | 0.022 | 0.017 | 0.005 | 0.010 | 0.033 | 0.006 |
Rice | Pearson Corr. | −0.980 * | −0.965 * | 0.777 | −0.997 * | −0.995 * | 0.949 * |
p-value | 0.003 | 0.008 | 0.122 | 1.81 × 10−4 | 4.19 × 10−4 | 0.014 |
Soybeans | Pearson Corr. | −0.825 # | −0.908 * | 0.847 # | −0.759 | −0.797 | 0.957 * |
p-value | 0.086 | 0.033 | 0.070 | 0.137 | 0.106 | 0.011 |
Table 5.
The means comparison of energy needed to induce breakage at different moisture contents and loading rates.
Table 5.
The means comparison of energy needed to induce breakage at different moisture contents and loading rates.
| Energy (mJ) |
---|
| Maize | Rice | Soybeans |
---|
Loading rate | | | |
1.25 | 61.14(a) | 1.01(b) | 58.02(a) |
125 | 62.36(a) | 3.02(a) | 53.88(b) |
MC | | | |
10% | 29.53(e) | 2.69(a) | 43.80(e) |
14% | 46.25(d) | 2.21(b) | 61.86(b) |
18% | 56.39(c) | 1.87(c) | 65.17(a) |
22% | 80.62(b) | 1.61(d) | 57.36(c) |
26% | 99.76(a) | 1.53(d) | 51.40(d) |
Table 6.
The means comparison of energy needed to induce the breakage for interactions effect of moisture content and loading rates.
Table 6.
The means comparison of energy needed to induce the breakage for interactions effect of moisture content and loading rates.
| Energy (mJ) |
---|
| Maize | Rice | Soybeans |
---|
Loading Rate | 1.25 mm/min | 125 mm/min | 1.25 mm/min | 125 mm/min | 1.25 mm/min | 125 mm/min |
---|
MC | | | | | | |
10% | 31.57(e) | 27.29(e) | 1.58(f) | 3.90(a) | 53.01(c) | 34.79(e) |
14% | 46.96(d) | 45.54(d) | 0.98(g) | 3.48(b) | 73.26(a) | 50.58(c,d) |
18% | 53.68(c,d) | 59.10(c) | 0.72(g) | 3.00(c) | 64.07(b) | 66.16(b) |
22% | 77.74(b) | 83.82(b) | 0.84(g) | 2.58(d) | 48.19(d) | 65.87(b) |
26% | 98.62(a) | 100.98(a) | 0.93(g) | 2.14(e) | 51.57(c,d) | 51.22(c,d) |