Effect of combined microwave-hot air under microwave pretreatment on drying kinetics of Myrtus fruit

Document Type : Complete scientific research article

Authors

1 Department of Chemical Engineering, Jundi-Shapur University of Technology, Dezful, Iran.

2 Department of Chemical Engineering, Jundi-Shapur University of Technology, Dezful,, Iran

Abstract

Background and objectives: A decoction of leaves and fruit of Myrtus is used to solve problems such as stomach ailments at the folk medicine. Fruits and vegetables are highly susceptible to microbial spoilage due to their high moisture content. For this reason, drying method have been expanded in order to prevent microbial spoilage of them. The most common method is hot air drying, but combination of this method with other such as microwave drying is developed to solve hot air method disadvantages such as low drying rate and high energy consumption in this method. Therefore, the aim of this study was to investigate effect of combined microwave-hot air method on mass transfer and drying kinetics of Myrtus fruit and to find the best experimental drying conditions in terms of time, rate and mass transfer.
Materials and methods: In present study, drying process of the Myrtus fruit by combined microwave-hot air under microwave pretreatment was investigated. Drying experiments were performed at combined powers of 180, 300 and 450W and three temperatures of 60°C, 70°C and 80°C under microwave pretreatment at powers of 300, 450 and 600W in a domestic microwave device. Experimental data were fitted to 10 mathematical models to study drying kinetics of Myrtus fruit. Also, fitting quality of equations was evaluated by using coefficient detemination (R2) and root mean square error (RMSE). The effect of the combined method on mass transfer coefficient and activation energy of samples was also investigated.
Results: kinetic analysis of process showed that among 10 common kinetic models, exponential Two-term model fits well the present combined method in mentioned power range. The results showed that at a certain temperature with increasing microwave power, drying rate constant (k) of exponential two-parameter equation describing drying behavior of the Myrtus fruit increased. According to results, at a certain temperature, with increasing microwave power, drying time decreased and drying rate increased. The highest drying time was obtained 46 minutes at combined power of 180W and temperature of 60 °C. The lowest drying time was obtained at 450W and 80°C equal to 19min, which was 58.7% lower than the maximum drying time. The results revealed that with increasing microwave power at a certain temperature, diffusion coefficient of Myrtus fruit increased and activation energy decreased. The highest effective moisture diffusivity and lowest activation energy was obtained at 450W and 80°C and it was 11.59 ×10-8 (m2/s) and 13.14 (kj/mol), respectively.
conclution: Temperature and combined power are two main factors affecting Myrtus fruit drying. Increasing the combined microwave power at a certain temperature as well as increasing the hot air temperature at a specific combined power have dramatically reduced time and significantly increased drying rate. The drying of the Myrtus fruit occured at falling rate. Microwave power also affect drying rate constants and it increased with increasing combined power. In addition, increasing combined microwave power increases mass transfer and thus effective diffusion coefficient of moisture.
keywords: Activation energy, Drying kinetics, Microwave-hot air, Myrtus fruit, Moisture diffuisivity.

Keywords

References

  1. Ahmed, N., Singh, J., Chauhan, H., Anjum, P. G. A., and Kour, H. 2013. Different drying methods: Their applications and recent advances. Int. J. Food. Nutr. Saf. 434-42.
  2. Akpinar, E. K., and Toraman, S. 2016. Determination of drying kinetics and convective heat transfer coefficients of ginger slices. Heat and Mass Transfer. 52: 10. 2271-2281.
  3. Andrés, A., Bilbao, C., and Fito, P. 2004. Drying kinetics of apple cylinders under combined hot air–microwave dehydration. J. of Food Engineering. 63:1. 71-78.
  4. Aydın, C., and Özcan, M. M. 2007. Determination of nutritional and physical properties of myrtle (Myrtus communis L.) fruits growing wild in Turkey. J. of Food Engineering. 79: 2. 453-458.
  5. Aykın-Dinçer, E., Kılıç-Büyükkurt, Ö., and Erbaş, M. 2019. Influence of drying techniques and temperatures on drying kinetics and quality characteristics of beef slices. Heat and Mass Transfer1-6.
  6. Doymaz, İ., and Altıner, P. 2012. Effect of pretreatment solution on drying and color characteristics of seedless grapes. Food Science and Biotechnology. 21 :1. 43-49.
  7. Doymaz, I., Kipcak, A. S., and Piskin, S. 2015. Microwave drying of green bean slices: drying kinetics and physical quality. Czech J. of Food Sciences. 33: 4. 367-376.

8.Feng, H., and Tang, J. 1998. Microwave finish drying of diced apples in a spouted bed. J. of Food Science. 63: 4. 679-683.

9.Henderson, S. 1974. Progress in developing the thin layer drying equation. Transactions of the ASAE. 17: 6.1167-1168.

10.Hendorson, S. 1961. Grain Drying Theory (I) Temperature Effect on Drying Coefficient. J. of Agricultural Engineering Research. 6: 3.169-174.

  1. Horuz, E., Bozkurt, H., Karataş, H., and Maskan, M. 2017. Drying kinetics of apricot halves in a microwave-hot air hybrid oven. Heat and Mass Transfer. 53: 6. 2117-2127.
  2. İlter, I., Akyıl, S., Devseren, E., Okut, D., Koç, M., and Ertekin, F. K. 2018. Microwave and hot air drying of garlic puree: drying kinetics and quality characteristics. Heat and Mass Transfer. 54: 7. 2101-2112.
  3. Jia, Y., Khalifa, I., Hu, L., Zhu, W., Li, J., Li, K., and Li, C. 2019. 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. 11867-76.
  4. Karathanos, V. T. 1999. Determination of water content of dried fruits by drying kinetics. J. of Food Engineering. 39: 4. 337-344.
  5. Kaya, A., Aydın, O., and Demirtaş, C. 2007. Drying kinetics of red delicious apple. Biosystems Engineering. 96: 4. 517-524.

16.Kesbi, O.M., Sadeghi, M., and Mireei, S.A. 2016. Quality assessment and modeling of microwave-convective drying of lemon slices. Engineering in agriculture, environment and food. 9: 3. 216-223.

17.Lee, J.H., and Kim, H.J. 2009. Vacuum drying kinetics of Asian white radish (Raphanus sativus L.) slices. LWT-Food Science and Technology. 42: 1.180-186.

18.Lemus‐Mondaca, R., Vega‐Gálvez, A., Moraga, N. O., and Astudillo, S. 2015. Dehydration of S tevia rebaudiana B ertoni Leaves: Kinetics, Modeling and Energy Features. J. of Food Processing and Preservation. 39: 5.508-520.

  1. Lewis, W.K. 1921. The rate of drying of solid materials. Industrial & Engineering Chemistry. 13: 5.427-432.
  2. Maisnam, D., Rasane, P., Dey, A., Kaur, S., and Sarma, C. 2017. Recent advances in conventional drying of foods. J. of Food Technology and Preservation. 1:1.
  3. Maskan, M. 2000. Microwave/air and microwave finish drying of banana. Journal of food engineering. 44: 2. 71-78.

22.Maskan, M. 2001. Drying, shrinkage and rehydration characteristics of kiwifruits during hot air and microwave drying. J. of Food Engineering. 48: 2. 177-182.

23.Midilli, A., Kucuk, H., and Yapar, Z. 2002. A new model for single-layer drying. Drying Technology. 20: 7.1503-1513.

24.Mujaffar, S., and Sankat, C. 2015. Modeling the Drying Behavior of Unsalted and Salted Catfish (A rius sp.) Slabs. J. of Food Processing and Preservation. 39: 6.1385-1398.

25.Ozgen, F. 2015. Experimental investigation of drying characteristics of cornelian cherry fruits (Cornus mas L.). Heat and Mass Transfer. 51: 3.343-352.

26.Page, G.E. 1949. Factors influencing the maximum rates of air drying shelled corn in thin layers.

27.Sagar, V., and Kumar, P.S. 2010. Recent advances in drying and dehydration of fruits and vegetables: a review. J. of food science and technology. 47: 1.15-26.

28.Sharaf-Eldeen, Y.I., Blaisdell, J., and Hamdy, M. 1980. A model for ear corn drying. Transactions of the ASAE. 5: 4. 1261-1265.

29.Sharma, G., and Prasad, S. 2001. Drying of garlic (Allium sativum) cloves by microwave–hot air combination. J. of Food Engineering. 50: 2. 99-105.

30.Torringa, E., Esveld, E., Scheewe, I., van den Berg, R., and Bartels, P. 2001. Osmotic dehydration as a pre-treatment before combined microwave-hot-air drying of mushrooms. J. of food engineering. 49: 2-3. 185-191.

31.Tulasidas, T., Raghavan, G., and Mujumdar, A. 1995. Microwave drying of grapes in a single mode cavity at 2450 Mhz-11: quality and energy aspects. Drying Technology. 13: 8-9. 1973-1992.

32.Verma, L.R., Bucklin, R., Endan, J., and Wratten, F. 1985. Effects of drying air parameters on rice drying models. Transactions of the ASAE. 28: 1. 296-301.

33.Yagcioglu, A. 1999. Drying characteristic of laurel leaves under different conditions. Paper presented at the Proceedings of the 7th International congress on agricultural mechanization and energy.

34.Zogzas, N., Maroulis, Z., and Marinos-Kouris, D. 1996. Moisture diffusivity data compilation in foodstuffs. Drying Technology. 14: 10. 2225-2253.

Food Processing and Preservation Journal
Volume 13, Issue 1
September 2021
Pages 125-138

Files

Share

How to cite

Statistics