Electrohydrodynamic, oven and natural drying of mint leaves and effects on the physiochemical indices of the leaves
Electrohydrodynamics (EHD) enhanced the thin-layer drying of mint (Mentha Spicata Huds) leaves using multiple point-to-plate electrodes. Its configurations were carried out under DC high voltage and its effects were compared to oven drying at 40 °C and open-air-drying with natural convection at 25 °C. The EHD was run in an optimum electric field of 3.2 kV·cm–1 using positive ionising conical needles to a plate electrode covered by a steel screen grid to prevent the leaves drifting. The samples subjected to the EHD and oven exhibited faster drying kinetics than natural convection. Compared to the oven drying, the EHD electrical power consumption was negligible. The EHD method developed fewer undesirable changes in the colour features and the leaves’ total chlorophyll, whereas the oven-dried sample colour underwent a significant change in colour. The samples dried by EHD had lower active microorganisms. The empirical modelling, based on the maximum value of R2 and the minimum value of RMSE and SSE between the experimental and predicted moisture ratios, showed that the diffusion and logarithmic models were the best models for describing the EHD and oven drying behaviour of the mint leaves.
Akonor P.T., Amankwah E.A. (2012): Thin layer drying kinetics of solar-dried Amaranthus hybridus and Xanthosoma sagittifolium leaves. Journal of Food Processing and Technology, 3: 1–4. https://doi.org/10.4172/2157-7110.1000174
Al-Hilphy A.R.A. (2014): Effect of electric field, ultrasonic and microwave on the microorganisms. Progress in Biotechnology for Food Applications. In: Wing-Fu L. (ed): Foster City, OMICS International.
Alemrajabi A.A., Rezaee F., Mirhosseini M., Esehaghbeygi A. (2012): Comparative evaluation of the effects of electrohydrodynamic, oven and ambient air on carrot cylindrical slices during drying process. Drying Technology, 30: 88–96. https://doi.org/10.1080/07373937.2011.608913
AOAC (2019): Official Methods of Analysis of AOAC International. Washington, Association of Official Analytical Chemists.
Bai Y., Li X., Sun Y., Shi H. (2011): Thin layer electrohydrodynamic (EHD) drying and mathematical modeling of fish. International Journal of Applied Electromagnetics, 36: 217–228. https://doi.org/10.3233/JAE-2011-1361
Bajgai T.R., Raghavan G.S.V., Hashinaga F., Ngadi M.O. (2006): Electrohydrodynamic drying- a concise overview. Drying Technology, 24: 905–910. https://doi.org/10.1080/07373930600734091
Brodowska A.J., Smigielski K., Nowak A., Czyzowska A., Otlewska A. (2015): The impact of ozone treatment in dynamic bed parameters on changes in biologically active substances of Juniper berries. Plos One, 10(12): e0144855 https://doi.org/10.1371/journal.pone.0144855
Cassol D., Silva F.S.P., Falqueto A.R., Bacarin M.A. (2008): An evaluation of nondestructive methods to estimate total chlorophyll content. Photosynthetica, 46: 634–636. https://doi.org/10.1007/s11099-008-0109-6
Correa P.C., Botelho F.M., Oliveira G.H.H., Goneli A.L.D., Resende O., Campos S.C. (2011): Mathematical modeling of the drying process of corn ears. Acta Scientiarum Agronomy, 33: Available at http://dx.doi.org/10.4025/actasciagron.v33i4.7079 https://doi.org/10.4025/actasciagron.v33i4.7079
Ding C., Lu J., Song Z., Bao S. (2014): The drying efficiency of electrohydrodynamic (EHD) systems based on the drying characteristics of cooked beef and mathematical modeling. International Journal of Applied Electromagnetics, 1: 1–7. https://doi.org/10.3233/JAE-141781
Doymaz I. (2006): Thin-layer drying behavior of mint leaves. Journal of Food Engineering, 74: 370–375. https://doi.org/10.1016/j.jfoodeng.2005.03.009
Esehaghbeygi A., Basiry M. (2011): Electrohydrodynamic (EHD) drying of tomato slices (Lycopersicon esculentum). Journal of Food Engineering, 104: 628–631. https://doi.org/10.1016/j.jfoodeng.2011.01.032
Hashinaga F., Bajgai T.R., Isobe S., Barthakur N.N. (1999): Electrohydrodynamic (EHD) drying of apple slices. Drying Technology, 17: 479–495. https://doi.org/10.1080/07373939908917547
Kadam D.M., Goyal R.K., Singh K.K., Gupta M.K. (2011): Thin layer convective drying of mint leaves. Journal of Medicinal Plants Research, 5: 164–170.
Kavak-Akpinar E. (2010): Drying of mint leaves in a solar dryer and under open sun: Modelling, performance analyses. Energy Conversion and Management, 51: 2407–2418. https://doi.org/10.1016/j.enconman.2010.05.005
Kirschvink-Kobayashi A., Kirschvink J.L. (1986): Electrostatic enhancement of industrial drying processes. Industrial and Engineering Chemistry Process Design and Development, 25: 1027–1030. https://doi.org/10.1021/i200035a030
Lai F.C., Sharma R.K. (2005): EHD-enhanced drying with multiple needle electrode. Journal of Electrostatic, 63: 223–237. https://doi.org/10.1016/j.elstat.2004.10.004
Leistritz W. (1997): Methods of bacterial reduction in spices. Spices, 660: 7–10.
Maharaj V., Sankat C.K. (1996): Quality changes in dehydrated dasheen leaves: effect of blanching pre-treatments and drying conditions. Food Research International, 29: 563–568. https://doi.org/10.1016/S0963-9969(96)00021-X
Mizeraczyk J., Podlinski J., Dors M., Kocik, M. (2002): Electrohydrodynamic transport of ozone in a corona radical shower non-thermal plasma reactor. Czechoslovak Journal of Physics, 52: 413–420.
Ohshima T., Tamura T., Sato M. (2007): Influence of pulsed electric field on various enzyme activities. Journal of Electrostatic, 65: 156–161. https://doi.org/10.1016/j.elstat.2006.07.005
Ozbek B., Dadali G. (2007): Thin-layer drying characteristics and modeling of mint leaves undergoing microwave treatment. Journal of Food Engineering, 83: 541–549. https://doi.org/10.1016/j.jfoodeng.2007.04.004
Rathore S.V., Kumar M.S. (2012): Colour based image segmentation using L*a*b* colour space based on genetic algorithm. The International Journal of Emerging Technology and Advanced Engineering, 6: 2250–2459.
Rayaguru K., Routray W. (2012): Mathematical modeling of thin layer drying kinetics of stone apple slices. International Food Research Journal, 19: 1503–1510.
Sacilik K., Keskin R., Elicin A.K. (2006): Mathematical modeling of solar tunnel drying of thin layer organic tomato. Journal of Food Engineering, 73: 231–238. https://doi.org/10.1016/j.jfoodeng.2005.01.025
Sharma G.P., Prasad S. (2001): Drying of garlic (Allium sativum) cloves by microwave-hot air combination. Journal of Food Engineering, 50: 99–105. https://doi.org/10.1016/S0260-8774(00)00200-4
Therdthai N., Zhou W. (2009): Characterization of microwave vacuum drying and hot air drying of mint leaves (Mentha cordifolia Opiz ex Fresen). Journal of Food Engineering, 91: 482–489. https://doi.org/10.1016/j.jfoodeng.2008.09.031
Togrul T.T., Pehlivan D. (2004): Modeling of thin layer drying kinetics of some fruits under open air sun drying process. Journal of Food Engineering, 65: 413–425. https://doi.org/10.1016/j.jfoodeng.2004.02.001
Zheng D.J., Cheng Y.Q., Liu H.J., Li L.T. (2011): Electrode configuration and polarity effects on water evaporation enhancement by electric field. International Journal of Food Engineering, 7: 231–240. https://doi.org/10.2202/1556-3758.1794