Thermal and Dielectric Properties of Wolfberries as Affected by Moisture Content and Temperature Associated with Radio Frequency and Microwave Dehydrations
Abstract
:1. Introduction
2. Materials and Methods
2.1. Sample Preparation
2.2. Measurements of True Density
2.3. Measurement of Thermal Properties
2.4. Measurement of Dielectric Properties
2.5. Statistical Analysis
3. Results and Discussion
3.1. Thermal Properties of Wolfberries
3.2. Dielectric Properties of Wolfberries
3.2.1. Frequency-Dependent DPs
3.2.2. Moisture Content- and Temperature-Dependent DPs
3.2.3. Regression Models
3.3. Penetration Depth
4. Conclusions
Author Contributions
Funding
Data Availability Statement
Acknowledgments
Conflicts of Interest
References
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Moisture Content (w.b.) | True Density (g/cm3) |
---|---|
15.2 ± 1.2% | 1.193 ± 0.019 a * |
30.3 ± 1.1% | 1.166 ± 0.004 ab |
45.3 ± 1.4% | 1.147 ± 0.012 b |
59.8 ± 1.8% | 1.126 ± 0.042 b |
75.1 ± 1.3% | 0.947 ± 0.004 c |
Frequency (MHz) | Dielectric Properties | Equations |
---|---|---|
27 | ε′ = 20.64 + 0.16T − 19.81M + 0.82TM + 330.70M2 − 1.77M2T − 227.30M3 | (4) |
ε″ = 212.80 − 2.44T − 1295.00M + 13.38TM + 1962.00M2 | (5) | |
40 | ε′ = 25.10 − 0.14T − 82.66M + 0.83TM + 495.85M2−1.77M2T−356.02M3 | (6) |
ε″ = 151.70 − 1.71T − 901.23M + 9.39TM + 1369.00M2 | (7) | |
915 | ε′ = −3.72 + 72.69M + 0.93TM−1.57M2T + 66.77M3 | (8) |
ε″ = 1.54 − 0.04T + 54.95M + 0.33TM − 36.79M2 | (9) | |
2450 | ε′ = 30.99−276.90M + 0.91TM + 770.70M2−1.67M2T−438.21M3 | (10) |
ε″ = −5.99 + 0.05T + 78.81M − 52.21M2 | (11) |
Variance and R2 | 27 MHz (Equation (4)) | 40 MHz (Equation (6)) | 915 MHz (Equation (8)) | 2450 MHz (Equation (10)) | ||||
---|---|---|---|---|---|---|---|---|
F-Value | p-Value | F-Value | p-Value | F-Value | p-Value | F-Value | p-Value | |
T | 7.246 | 0.0226 | 13.608 | 0.0042 | 0.995 | 0.3420 | 0.737 | 0.4109 |
M | 215.363 | <0.0001 | 581.503 | <0.0001 | 169.904 | <0.0001 | 119.065 | <0.0001 |
TM | 73.438 | <0.0001 | 160.598 | <0.0001 | 14.337 | 0.0036 | 5.007 | 0.0492 |
T2 | 0.001 | 0.9799 | 0.157 | 0.7004 | 0.063 | 0.8069 | 0.019 | 0.8922 |
M2 | 41.620 | <0.0001 | 116.886 | <0.0001 | 0.693 | 0.4247 | 25.166 | 0.0005 |
T2M | 0.123 | 0.7335 | 0.0001 | 0.9905 | 0.041 | 0.8444 | 0.001 | 0.9765 |
TM2 | 12.091 | 0.0059 | 27.172 | 0.0004 | 6.431 | 0.0296 | 6.215 | 0.0318 |
T3 | 0.125 | 0.7307 | 0.183 | 0.6776 | 0.013 | 0.9122 | 0.020 | 0.8896 |
M3 | 9.251 | 0.0124 | 51.168 | <0.0001 | 25.777 | 0.0005 | 11.137 | 0.0075 |
Model | 191.722 | <0.0001 | 420.048 | <0.0001 | 91.154 | <0.0001 | 68.785 | <0.0001 |
R2 | 0.994 | 0.997 | 0.988 | 0.984 |
Variance and R2 | 27 MHz (Equation (5)) | 40 MHz (Equation (7)) | 915 MHz (Equation (9)) | 2450 MHz (Equation (11)) | ||||
---|---|---|---|---|---|---|---|---|
F-Value | p-Value | F-Value | p-Value | F-Value | p-Value | F-Value | p-Value | |
T | 55.004 | <0.0001 | 117.475 | <0.0001 | 59.110 | <0.0001 | 17.160 | 0.0010 |
M | 789.362 | <0.0001 | 1199.657 | <0.0001 | 751.532 | <0.0001 | 532.508 | <0.0001 |
TM | 73.609 | <0.0001 | 73.709 | <0.0001 | 25.173 | 0.0002 | 0.277 | 0.6070 |
T2 | 0.077 | 0.7860 | 0.071 | 0.7938 | 0.050 | 0.8266 | 0.005 | 0.9459 |
M2 | 99.675 | <0.0001 | 98.608 | <0.0001 | 20.259 | 0.0005 | 45.142 | <0.0001 |
Model | 297.693 | <0.0001 | 297.904 | <0.0001 | 171.225 | <0.0001 | 119.018 | <0.0001 |
R2 | 0.991 | 0.991 | 0.984 | 0.977 |
Moisture Content (% w.b.) | T (°C) | Penetration Depth (cm) | |||
---|---|---|---|---|---|
27 MHz | 40 MHz | 915 MHz | 2450 MHz | ||
15.1 | 25 | 38.84 ± 0.73 | 30.68 ± 0.59 | 2.16 ± 0.01 | 0.85 ± 0.00 |
45 | 34.36 ± 0.75 | 27.64 ± 0.42 | 2.13 ± 0.01 | 0.81 ± 0.02 | |
65 | 30.74 ± 0.87 | 25.21 ± 0.71 | 2.06 ± 0.01 | 0.79 ± 0.02 | |
85 | 25.51 ± 0.75 | 20.92 ± 0.57 | 1.99 ± 0.01 | 0.75 ± 0.01 | |
30.3 | 25 | 22.71 ± 1.38 | 18.55 ± 1.15 | 1.74 ± 0.12 | 0.61 ± 0.04 |
45 | 20.44 ± 0.24 | 16.83 ± 0.11 | 1.70 ± 0.06 | 0.60 ± 0.02 | |
65 | 18.70 ± 0.31 | 15.49 ± 0.26 | 1.56 ± 0.01 | 0.53 ± 0.00 | |
85 | 16.43 ± 0.12 | 13.73 ± 0.10 | 1.51 ± 0.00 | 0.51 ± 0.00 | |
45.3 | 25 | 11.75 ± 0.19 | 9.85 ± 0.16 | 1.33 ± 0.05 | 0.46 ± 0.02 |
45 | 9.60 ± 0.06 | 8.03 ± 0.04 | 1.31 ± 0.03 | 0.43 ± 0.01 | |
65 | 8.26 ± 0.01 | 6.87 ± 0.03 | 1.28 ± 0.02 | 0.42 ± 0.01 | |
85 | 7.52 ± 0.09 | 6.25 ± 0.09 | 1.26 ± 0.01 | 0.40 ± 0.00 | |
59.8 | 25 | 9.86 ± 0.02 | 8.37 ± 0.02 | 1.65 ± 0.02 | 0.59 ± 0.01 |
45 | 7.57 ± 0.09 | 6.32 ± 0.08 | 1.48 ± 0.01 | 0.56 ± 0.01 | |
65 | 5.97 ± 0.07 | 4.94 ± 0.06 | 1.31 ± 0.01 | 0.53 ± 0.00 | |
85 | 5.36 ± 0.18 | 4.42 ± 0.15 | 1.20 ± 0.04 | 0.48 ± 0.01 | |
75.1 | 25 | 5.80 ± 0.03 | 4.80 ± 0.02 | 1.69 ± 0.01 | 0.63 ± 0.00 |
45 | 4.97 ± 0.01 | 4.10 ± 0.01 | 1.45 ± 0.01 | 0.61 ± 0.00 | |
65 | 4.50 ± 0.02 | 3.69 ± 0.01 | 1.24 ± 0.01 | 0.56 ± 0.01 | |
85 | 4.09 ± 0.03 | 3.34 ± 0.03 | 1.06 ± 0.03 | 0.50 ± 0.01 |
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Bai, S.; Liu, L.; Yu, H.; Guan, X.; Li, R.; Hou, L.; Ling, B.; Wang, S. Thermal and Dielectric Properties of Wolfberries as Affected by Moisture Content and Temperature Associated with Radio Frequency and Microwave Dehydrations. Foods 2022, 11, 3796. https://doi.org/10.3390/foods11233796
Bai S, Liu L, Yu H, Guan X, Li R, Hou L, Ling B, Wang S. Thermal and Dielectric Properties of Wolfberries as Affected by Moisture Content and Temperature Associated with Radio Frequency and Microwave Dehydrations. Foods. 2022; 11(23):3796. https://doi.org/10.3390/foods11233796
Chicago/Turabian StyleBai, Shunqin, Li Liu, Haibo Yu, Xiangyu Guan, Rui Li, Lixia Hou, Bo Ling, and Shaojin Wang. 2022. "Thermal and Dielectric Properties of Wolfberries as Affected by Moisture Content and Temperature Associated with Radio Frequency and Microwave Dehydrations" Foods 11, no. 23: 3796. https://doi.org/10.3390/foods11233796