Holy Basil Leaves Drying using Combined Microwave and Hot Air Conveyer Belt Dryer
DOI: 10.14416/j.ind.tech.2021.03.003
Keywords:
Holy basil leaves, Hot air drying, Microwave-hot air drying, Specific energy consumptionAbstract
Holy basil is an important ingredient of Thai food. However, it cannot preserve for a long time since the use of a suitable drying process is necessary to prolong the shelf-life of holy basil. This research aimed to investigate the drying kinetics, specific energy consumption and quality (in term of color) of dried holy basil leaves using a microwave-hot air conveyer belt dryer. The holy basil leaves was dried at temperature range 60 to 80°C and microwave powers range 300 to 500 watt. Air velocity was set at 0.3 m/s with 80% of recycled air while the belt conveyor velocity (forward-backward) was 0.02 m/s. The results showed that the rate of moisture reduction increased with an increase in drying temperature and microwave power. For hot air drying, it was found that the lightness (L*) and yellowness (b*) decreased with an increase in temperature. For microwave-hot air drying, the L* and b* value increased with and increased in microwave power. The specific energy consumption decreased with an increase in the microwave power. Based on this experiment, the optimum condition for holy basil drying using microwave-hot air drying was the use of an air velocity 0.3 m/s, temperature of 80oC and microwave power of 500 watt (2x250 W).
References
[2] F. Gulcimen, H. Karakaya and A. Durmus, Drying of sweet basil with solar air collectors, Renewable Energy, 2016, 93, 77-86.
[3] T. Wang, R. Khir, Z. Pan and Q. Yuan, Simultaneous rough rice drying and rice bran stabilization using infrared radiation heating, LWT-Food Science and Technology, 2017, 78, 281-288.
[4] S. Srisuriyawong, S. Wanlapa, W. Phromjan, and N. Chankamma, Drying kinetics of paddy dried with the small-scale paddy dryer, Agricultural Science Journal, 2014, 45(2)(Suppl.), 345-348. (in Thai)
[5] A. Chen, G. Achkar, B. Liu and R. Bennacer, Experimental study on moisture kinetics and microstructure evolution in apples during high power microwave drying process, Journal of Food Engineering, 2020, 292, 1-7.
[6] J. Jareanjit, A solar dryer technology and its development, KKU Research Journal, 2012, 17(1), 110-124. (in Thai)
[7] W. Sriariyakul, T. Swasdisevi, S. Devahastin and S. Soponronnarit, Drying of aloe vera puree using hot air in combination with far-infrared radiation and high-voltage electric field: Drying kinetics, energy consumption and product quality evaluation, Food and Bioproducts Processing, 2016, 100, 391-400.
[8] A. Elmizadeh, M. Shahedi and N. Hamdami Comparison of electrohydrodynamic and hot-air drying of the quince slices, Innovative Food Science and Emerging Technologies, 2017, 43, 130-135.
[9] P. Toomthong, S. Suayklang and P. Toomthong, Study of wolffia drying using hot air, Rajamangala Surin Conference (RSC 2016), Proceeding, 2016, 365-370. (in Thai)
[10] S. Pangkanya, A. Nathakaranakule and S. Soponronnarit, Durian Chips Drying Using Combined Microwave-Hot Air with Step-Down Microwave Power Input Technique, KKU Research Journal (Graduate Studies), 2016, 16(3), 102-111. (in Thai)
[11] K. Sittichaitaweekul, T. Swasdisevi, and S. Soponronnarit, Kaffir lime leave drying using combined microwave and hot air, 15th Conference on Energy Network of Thailand, (E-NETT-Thailand 2019), Proceeding, 2019, 889-903. (in Thai)
[12] A. Chahbani, N. Fakhfakh, M.A. Balti, M. Mabrouk, H.E. Hatmi, N. Zouari and N. Kechaou, Microwave drying effects on drying kinetics, bioactive compounds and antioxidant activity of green peas (Pisum sativum L.), Food Bioscience, 2018, 25, 32-38.
[13] T. Tipyavimol and S. Chirnaksorn, Hot air-microwave combination drying of chili, Thai Agricultural Research Journal, 2007, (25)1, 46-57. (in Thai)
[14] Y. Pu and D. Sun, Drying for improving drying uniformity of mango slices based on hyperspectral imaging visualisation of moisture content distribution, Biosystem Engineering, 2017, 156, 108-119.
[15] Y. Jia, I. Khalifa, L. Hu, W. Zhu, J. Li, K. Li and C. Lia, Influence of three different drying techniques on persimmon chips’ characteristics: A comparison study among hot-air, combined hot-air-microwave, and vacuum-freeze drying techniques, Food and Bioproducts Processing, 2019, 118, 67-76.
[16] K. Apinyavisit, A. Nathakaranakule and S. Soponronnarit, Design of prototype of combined microwave-hot air conveyor belt dryer, KKU Science Journal, 2017, 45(3), 628-638. (in Thai)
