Determination of Some Vegetable Drying Characteristics in Convectional and Fluidized Bed Drying Systems (Turkish with English Abstract)

Öz

Drying characteristics of spinach, swiss chard and leek were determined both in convectional and fluidized bed dryers at 70 oC and experimental moisture data were fitted into thin layer drying models. Percentage of weight loss of spinach, swiss chard and leek samples were 49.30, 40.85 ve 23.97% in convectional drying whereas 81.50, 80.90 ve 81.70% in fluidized bed drying, respectively. Initial water activity of spinach, swiss chard and leek samples were 0.99, 0.97 and 0.96 while final water activities were 0.93, 0.93 and 0.91 for convectional drying and 0.30, 0.27 and 0.48 for fluidized bed drying at the end of drying period. Fluidized bed drying was found to be more efficient than convectional drying. Wang-Singh model for convectional drying and logarithmic model for fluidized bed drying provided a good fit for the experimental data (R2>0.999). Water activity and percentage of weight loss values were in good agreement.

Anahtar Kelimeler

• Vegetable, convectional drying, fluidized bed drying, model.  

Konveksiyonel ve Akışkan Yataklı Sistemlerde Bazı Sebzelerin Kuruma Karakteristiklerinin Belirlenmesi

Öz

Bu çalışmada konveksiyonel ve akışkan yataklı kurutma sistemleri kullanılarak ıspanak, pazı ve pırasanın 70 oC'deki kuruma karakteristikleri belirlenmiş ve deneysel veriler 6 farklı ince tabaka kurutma modeline uyarlanmıştır. Kuruma periyodu sonunda ıspanak, pazı ve pırasanın konveksiyonel kurutucudaki % ağırlık (su) kayıpları sırasıyla % 49.30, 40.85 ve 23.97 iken akışkan yataklı kurutucuda ise % 81.50, 80.90 ve 81.70 olmuştur. Ispanak, pazı ve pırasada 0.99, 0.97 ve 0.96 olan başlangıç su aktivitesi değerleri konveksiyonel kurutma sonunda 0.93, 0.93 ve 0.91 ve akışkan yataklı kurutma sonunda 0.30, 0.27 ve 0.48 olmuştur. Akışkan yataklı kurutma sistemi konveksiyonel sisteme göre daha efektif bir kuruma sağlamıştır. Kurutma karakteristikleri konveksiyonel kurutmada en iyi Wang-Singh modeli ve akışkan yataklı kurutmada logaritmik model ile ifade edilmiştir (R2>0.999). Örneklerin su aktivitesi değerleri ve ağırlık kaybı ilişkisi uyum içindedir.

Anahtar Kelimeler

• Sebze, konveksiyonel kurutma, akışkan yataklı kurutma, model.  

Kaynakça

1. Ataseven E, fiahin A ve Yazıcı K. 2002. Bazı üzümsü meyvelerin (Frenküzümü, ahududu, bö¤ürtlen ve nar) ekolojik yetifltiricili¤e uygunlu¤u, Türkiye 2. Ekolojik Tarım Sempozyumu, Antalya, Türkiye, 286-295.
2. TUIK. (2012). Bitkisel Üretim ‹statistikleri. www.tuik.gov.tr/PreHaberBultenleri.do?id= 13661. Eriflim tarihi: 22.07.2013.
3. Karim MA and Hawlader MNA. 2005. Mathematical modeling and experimental investigation of tropical fruits drying, Int J Heat Mass Trans, 48:4914-4925.
4. Doymaz ‹. 2006 . Drying kinetics of black grapes treated with different solutions, J Food Eng, 76:212-217.
5. Çınar ‹. 2006. Meyve ve sebzelerin kurutulması. Akademik Gıda, v:21, s:32-34.
6. Çınar ‹. 2009. Ozmotik dehidrasyon, mekanizması ve uygulamaları. GIDA, 34(5):325-329.
7. Rajkumar P, Kulanthaisami S, Raghavan GSV, Gariepy Y and Orsat V. 2007. Drying kinetics of tomato slices in vacuum assisted solar and open sun drying methods, Drying Tech, 25:1349-1357. 8. Guine RPF, Pinho S and Barroca MJ. 2011. Study of the convective drying of pumpkin (Cucurbita maxima). Food Bioprod Proc, 89:422-428.
8. Miranda M, Maureira H, Rodriguez K and Vega- Galvez A. 2009. Influence of temperature on the drying kinetics, physicochemical properties and antioxidant capacity of Aloe vera (Aloe Barbadensis Miller) gel. J Food Eng, 91:297-304.

9. Brasiello A, Adiletta G, Russo P, Crescitelli S, Albanese D and Di Matteo M. 2013. Mathematical modeling of eggplant drying: shrinkage effect. J Food Eng, 114, 99-105.
10. Singh NJ and Pandey RK. 2011. Convective air drying characteristics of sweet potato cube (Ipomoea batatas L.). Food Bioprod Proc, in press. 12. Zielinska M and Markowski M. 2010. Air drying characteristics and moisture diffusivity of carrots. Chem EngProc, 49:212-218.
11. Lewicki PP. 2006. Design of hot air drying for better foods. Trends Food Sci Tech., 17:153-163.
12. Doymaz I, Tugrul N and Pala M. 2006. Drying characteristics of dill and parsley leaves. J Food Eng, 77:559-565.
13. Mota CL, Luciano C, Dias A, Barroca MJ and Guine RPF. 2010. Convective drying of onion: Kinetics and nutritional evaluation. Food Bioprod Proc, 88:115-123.
14. Meziane S. 2011. Drying kinetics of olive pomace in a fluidized bed dryer. Energy Cons Manag, 52:1644-1649.
15. Jaiboon P, Prachayawarakorn S, Devahastin S and Soponronnarit S. 2009. Effects of fluidized bed drying temperature and tempering time on quality of waxy rice. J Food Eng, 95:517-524.
16. Senadeera W, Bhandari BR, Young G and Wijesinghe B. 2003. Influence of shapes of selected vegetable materials on drying kinetics during fluidized bed drying. J Food Eng, 58:277-283.
17. Hatamipour MS and Mowla D. 2002. Shrinkage of carrots during drying in an inert medium fluidized bed. J Food Eng, 55:247-252.
18. Nazghelichi T, Kianmehr MH and Aghbashlo M. 2010. Thermodynamic analysis of fluidized bed drying of carrot cubes. Energy, 35:4679-4684.
19. Srinivasakannan C and Balasubramanian N. 2008. An analysis on modeling of fluidized bed drying of granular material. Adv Powder Tech, 19:73-82.
20. Jaros M and Pabis S. 2006. Theoretical models for fluid bed drying of cut vegetables. Biosys Eng, 93(1):45-55.
21. Bialobrzewski I, Zielinska M, Mujumdar AS and Markowski M. 2008. Heat and mass transfer during drying of a bed of shrinking cles - Simulation for carrot cubes dried in a spout-fluidized-bed drier. Int J Heat Mass Trans, 51, 4704-4716.
22. Bacelos MS, Camargo CFS, Silveira AM and Freire JT. 2011. Local heat-transfer coefficient of immersed cylindrical surface in fluidized and vibrated fluidized beds. Chem Eng Proc, (in press). 25. Karaca H and Velioglu YS. 2014. Effects of ozone treatments on microbial quality and some chemical properties of lettuce, spinach and parsley. Postharvest Bio Tech, 88:46-53.
23. Kholmanskiy AS, Tilov AZ and Soronika EY. 2013. Drying kinetics of plant products: Dependence on chemical composition. J Food Eng, 117:378-382.
24. Dadali G, Demirhan E and Özbek B. 2008. Effect of drying conditions on rehydration kinetics of microwave dried spinach. Food Bioprod Proc, 86(4):235-241.
25. Huang Y, Ye M and Chen H. 2012. Efficacy of washing with hydrogen peroxide followed by aerosolized antimicrobials as a novel sanitizing process to inactivate Escherichia coli O157:H7 on baby spinach. Int J Food Micro, 153(3):306-313.
26. Vazquez E, Garcia-Risco MR, Jaime L, Reglero G and Fornari T. Simultaneous extraction of rosemary and spinach leaves and its effect on the antioxidant activity of products. The J Supercritical Fluids, 82:138-145.
27. Bernaert N, De Clercq H, Van Bockstaele E, De Loose M and Van Droogenbroeck B. 2013. Antioxidant changes during postharvest processing and storage of leek (Allium ampeloprasum var. Porrum). Postharvest Bio Tech, 86:8-16.
28. Bernaert N, De Paepe D, Bouten C, De Cler- cq H, Stewart D, Van Bockstaele E, De Loose M and Van Droogenbroeck B. 2012. Antioxidant capacity, total phenolic and ascorbate content as a function of genetic diversity of leek (Allium ampeloprasum var. Porrum). Food Chem, 134(2): 669-677.
29. Tsoukalas DS, Katsanidis E, Marantidou S and Bloukas JG. 2011. Effect of freeze-dried leek powder (FDLP) and nitrite level on processing and quality characteristics of fermented sausages. Meat Sci, 87(2):140-145.
30. Doymaz, I. 2008. Influence of blanching and slice thickness on drying characteristics of leek slices. Chem Eng Proc, 47:41-47.
31. Murcia MA, Jimenez-Monreal AM, Garcia-Diz L, Carmona M, Maggi L and Martinez M. 2009. Antioxidant activity of minimally processed (in modified atmospheres), dehydrated and ready-to- eat vegetables. Food Chem Toxicology, 47(8): 2103-2110.
32. Aguero MV, Pereda J, Roura SI, Moreira MR and Del Valle CE. 2005. Sensory and biochemical changes in swiss chard (Beta vulgaris) during blanching. LWT- Food Sci Tech, 38(7):772-778.
33. Krokida MK, Karathanos VT, Maroulis ZB and Marinos-Kouris D. 2003. Drying kinetics of some vegetables. J Food Eng, 59:391-403.
34. Alibas O, Akbudak, B and Akbudak N. 2007. Microwave drying characteristics of spinach. J Food Eng, 78:577-583.
35. Karaaslan SN and Tunçer ‹K. 2013. Development of drying model for combined microwave-fan assisted convection drying of spinach. Biosystems Eng, (in press):www.elsevier.com/locate/issn/ 15375110.
36. To¤rul ‹ and Pehlivan D. 2004. Modelling of thin tayer drying Kinetics of some fruits under open-air sun drying process. J Food Eng, 65:413-425. 40. Goyal RK, Kingsly ARP, Manikantan MR, ‹lyas SM. 2007. Mathematical modelling of thin tayer drying kinetics of plum in a tunnel dryer. J Food Eng, 79:176-180.
37. Özdemir O, Devres YO. 1999. The thin layer drying characteristics of hazelnuts during roasting. J Food Eng, 42:225-233.
38. Babalis S, Papanicolaou E, Kyriakis N and Belessiotis V. 2006. Evaluation of thin layer drying models for describing drying kinetics of figs. J Food Eng, 75:205-214.
39. Kumar PS, Kanwat M and Choudhary VK. 2012. Mathematical modeling and thin layer drying kinetics of bamboo slices on convective tray drying at varying temperature. J Food Proc Preservation, 37:914-923.