Dielectric properties of sorghum seeds in the radio frequency range
Dielectric properties of sorghum
DOI:
https://doi.org/10.21921/jas.v8i04.7756Keywords:
Dielectric properties, hygroscopic material, radio frequency, dielectric relaxationAbstract
The dielectric parameters of hygroscopic materials such as seeds and grains vary greatly when subjected to varying electric field. The values of dielectric parameters such as dielectric constant, dielectric loss factor and other related parameters along with dielectric relaxation spectrum has tremendous application in in processing industries, as it helps in determine online and instantaneous moisture content of seed lots during harvesting, processing, handling and transportation and in controlled heating without quality damage. For these operations the effect of frequency moisture and temperature of the material over wide frequency range is required. This paper presents the dielectric properties of sorghum seed (Sorghum bicolour) over the radio frequency range of 0.50 kHz to 10 MHz, determined by Hewlett-Packard (HP-4194A) impedance/gain phase analyzer over the moisture range of 2.9% to 18.5% with corresponding bulk density and temperature range of 0.812-0.760 gm/ cm3 and 30-45oC , respectively.
References
Agrwal, R.L.1999.Seed Technology.: Oxford and IBH publishing Co. Pvt. Ltd. New Delhi.
ASAE-Standard, 1999. S352.2: ASAE Standards, St. Joseph Mich: ASAE.
Barrow, G.M.1988. Physical Chemistry. 5th ed. Japanese edition. New York, NY, McGraw-Hill
Beighley, D. H., and N. W. Hopper. 1981. The relationship of chemical composition and electrical conductivity of cowpea seed to field performance. Agronomy Abstract, 117.
Couto, S. M., M. A. Silva, A. J. Regazzi. 1998. An electrical conductivity method suitable for quantitative mechanical damage evaluation. Trans ASAE 41 (2): 421-426
Dutta, A. K., E. Sun, and A. Solis. 1995. Food dielectric property data and their composition based prediction, Ch. 9. In: Eng. Properties of foods: 457-494, Eds. M.A. Rao and S.S.H. Rizvi. New York, NY; Marcel Dekkor, Inc.
Gracia, A., J.L.Torres, E. Prieto, and M. De Blas. 2001. Dielectric properties of grape juice at 0.2 to 3 GHz. J. Food Eng. 203-211.
Hansen, J. D. 1992. Heating curve model of quarantine treatments against insect pest. J. Econ. Entomol. 85 (5): 1846-1854
Headlee, T. J., and R. C. Burdette. 1929. Some facts relative to the effect of high frequency radio waves on insect activity. J. New York, Entmol. Soc. 37 (1): 59-64
Heslehurst, M. R. 1988. Quantifying initial quality and vigour of wheat seeds using regression analysis of conductivity and germination data from aged seed. Seed Sci. Tech. 16: 175-185
Hunt, W. H., M. H. Neustadt, Joe R. Hart and Lawrence Z. 1952. A rapid Dielectric method for determine oil content of Soybeans. J. Amer. Oil. Chem. Soc. 29 (7): 258
Ikediala, J. N., J. Tang, L. G. Neven, and S. R. Darake. 1999. Quarantine treatment of cherries bug at 915 MHz microwave: Tempt mapping, codling moth mortality.
Jones, R.N., H.E. Bussey, W.E. Little, R.F. Metzker.1978. Electrical characteristics of corn, wheat, and soya in the 1-200 MHz range. Gaithersburg, MD : U.S. Dept. of Commerce, National Institute of Standards and Technology, 1978. NBSIR 78-897
Kent, M.1987. Electric and dielectric properties of food materials. Hornchuch, Essex, UK. Sci and Tech. Publishers.
Lawrence, K. C., S. O. Nelson and A. Kraszewski. 1992. Temperature dependence of the dielectric properties of pecans. Transactions of the ASAE 35(1):251-255
Magario, K. and I. Yamaura. 1988. Temperature dependence of microwave dielectric properties in saline solution. Denki-Joho-Tsushin Gakkai Gihou. EMCJ 88(11): 21-26.
Mudgett, R. E. 1995. Electrical properties of foods, Ch. 8,Engineering Properties of Foods, eds. M. A. Rao, and S. S. H.Rizvi, 389-455. New York: Marcel Dekker, Inc.
Nelson S. O., Haverne, E. Stateson, 1985. Germination of seed responses of selected plants species to RF electrical seed treatments. Trans. ASAE 28 (6) Nov-Dec-1985
Nelson, S. O. 1987. Models for the dielectric constant of cereal grains and soybeans, J. microwave power 22(1): 35-39.
Nelson, S. O. and A. J. Payne. 1982. RF dielectric heating for pecan weevil control. Trans. of ASAE 25 (2): 456-458.
Nelson, S.O., W.R. Forbus Jr, and K.C. Lawrence.1995.Assesemennt of microwave permittivituy for sensing peach maturity. Trans.of ASAE 38(2): 579-589.
Nelson, S.O., W.R. Forbus Jr., and K.C. Lawrence.1994. Microwave permittivity of fresh fruit and vegetables from0.2 to 20 GHz.Trans. of ASAE 37(1): 183-189
Nelson, S.O.1979b. RF and microwave dielectric properties of shelled, yellow-dent field corn.Trans. of ASAE 22(6): 1451-1457.
Nelson. S. O. and L. F. Charity, 1972. Frequency dependence of energy absorption by insect and grains in electric field: Trans. of ASAE 15 (6): 1099-1102.
Nelson. S. O., and W. W. Wolf .1964. Reducing hard seed in alfalfa by radio frequency electrical seed treatment. Trans. of ASAE 7 (2): 116-119, 122.
Nelson. S. O., C-Y. Lu, L. R. Beuchat, and M. A. Harrison. 2002. Radio frequency heating of alfalfa seed for reducing human pathogens. Trans. ASAE 45 (6): 1937-1942
Stetson. L. E., and S. O. Nelson, 1972. Effective hot air, 39 MHz dielectric and 2450 MHz microwave heating for hard seed reduction in alfalfa. Trans. of ASAE 15 (3): 530-535.
Sun. E., A. Dutta, and S. Lobo. 1995. Composition based prediction of dielectric properties of foods. J. Int. Microwave Power and Elec. Magnt. Energy 30 (4): 205-212
Tang. J., J. N. Ikediala, S. Wang, J. D. Hansen and R. P. Cavalieri. 2000. High tempt – short-time thermal quarantine methods. Postharvest Bio. Technol. 21 (1): 129-145.
Wang. S, J. N. Ikediala, J. Tang, and J. D. Hansen, E.Mitcham, R.Mao and B. Swanson.2001a. Postharvest Bio. Technol. 22(2):257-270.
Wang. S, J. Tang,,J.A.Johnson,E.Mitcham , J. D. Hansen, R. P. Cavalieri, J.Bower andB. Biasi. 2002b. Process protocols based on radio frequency energy to control field and storage pests in in-shell walnuts. Postharvest Bio. Technol. 26(3):265-273.
Wang. S., J. Tang and R. Cavalieri. 2001b. Modeling fruit internal heating rates for hot air and hot water treatment. Postharvest Bio. Technol. 22 (2): 257-270.
