Özge SÜFER, Ömer Faruk GAMLI, Tülin EKER

Mikrodalga ile Kurutulmuş Zeytin Yapraklarının Kurutma Kinetikleri ve Demleme Özellikleri

Zeytin yaprakları, sağlık üzerindeki olumlu etkilerinden dolayı araştırmacıların ve tüketicilerin ilgisini çekmektedir. Bu çalışmada, zeytin yaprakları mikrodalga uygulaması ile 52, 90, 167, 290, 347 W gerçek etkin güç seviyelerinde kurutulmuş ve kurutma kinetikleri, kurutma davranışını en iyi betimleyen matematik modelin belirlenebilmesi maksadıyla incelenmiştir. Page model, diğerlerinin içerisinde en uygun model olarak tespit edilmiştir. Difüzyon katsayıları 2,65×10-10 – 6,87×10-10 m2/s aralığında hesaplanmış olup, güç düzeyindeki artışın, difüzyon katsayısında da artışa sebep olduğu görülmüştür. Kurutulmuş zeytin yaprakları çay elde etmek amacıyla kullanılmış ve farklı demleme sıcaklıklarının, çayın toplam polifenol (mg GAE/kg) ve radikal süpürme aktivitesi (%) üzerindeki etkileri araştırılmıştır. Demleme sıcaklığındaki artışın, özellikle 100°C’de polifenollerin özütlenmesini arttırdığı görülmüştür. 167 W’da kurutulmuş olan zeytin yapraklarının (2282,9 mg GAE/kg) diğer güçlerde kurutulanlara oranla daha fazla fenolik içeriğine sahip olduğu açığa çıkmıştır.

Dehydration Kinetics and Infusion Attributes of Microwave Dried Olive Leaves

Olive leaves have been catching consumers’ and researchers’ great interest because ofbenefits on human health. In this study, the olive leaves were dried by microwave methodat different powers (52, 90, 167, 290, 347 W real effective power levels) and dryingkinetics of olive leaves were examined to find the best mathematical model. Page modelwas the most suitable model rather than the others. Diffusion coefficients were rangedbetween 2.65×10-10 to 6.87×10-10 m2/s and an increment in power level promotedmoisture diffusivities. Dried olive leaves were used to get leave tea and different infusiontemperatures were investigated to recover the total polyphenols (mg GAE/kg) and radicalscavenging activities (%). Rising in infusion temperature, especially at 100°C enhancedthe extraction levels of polyphenols from leave tea. Olive leaves dried at 167 W hadhigher phenolic contents (2282.9 mg GAE/kg) among all samples.

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Anoynmous. 1983. Black tea. The institue of Turkish standardization. TS 3907, ICS 67.140.10,67,240.
Boudhrioua N, Bahloul N, Ben Slimen I, Kechaou N. 2009. Comparison on the total phenol contents and the color of fresh and infrared dried olive leaves. Ind Crops Prod., 29(2– 3): 412–419.
Chua KJ, Mujumdar AS, Hawlader MNA, Chou SK, Ho JC. 2001. Batch drying of banana pieces-effect of stepwise change in drying air temperature on drying kinetics and product colour. Food Res Int., 34: 721-731.
Değirmencioğlu N, Gürbüz O, Herken EN, Yıldız AY. 2016. The impact of drying techniques on phenolic compound, total phenolic content and antioxidant capacity of oat flour tarhana. Food Chem., 194: 587-594.
El SN, Karakaya S, 2009. Olive tree (Olea europaea) leaves: potential beneficial effects on human health. Nutr Rev., 67: 632-638.
Erbay Z, Icier F. 2009. Optimization of hot air drying of olive leaves using response surface methodology. J Food Eng., 91(4): 533–541.
Erbay Z, Icier F. 2010. Thin‐layer drying behaviors of olive leaves (Olea europaea L.). J Food Process Eng., 33: 287-308.
Fernandes de Oliveira AM, Sousa Pinheiro L, Souto Pereira CK, Neves Matias W, Albuquerque Gomes R, Souza Chaves O, Simões de Assis T. 2012.
Total phenolic content and antioxidant activity of some Malvaceae family species. Antioxid., 1(1): 33-43.
Ferreira IC, Barros L, Soares ME, Bastos ML, Pereira JA. 2007. Antioxidant activity and phenolic contents of Olea europaea L. leaves sprayed with different copper formulations. Food Chem., 103(1): 188-195.
Figiel A. 2010. Drying kinetics and quality of beetroots dehydrated by combination of convective and vacuum-microwave methods. J Food Eng., 98(4): 461-470.
Gamlı ÖF. 2011. Effective moisture diffusivity and drying characteristics of tomato slices during convectional drying. Gıda, 36(4): 201-208.
Gamli ÖF, Süfer Ö, Eker T. 2016. Convective drying kinetics and phenolic contents of olive leaves. J Food Phys., 28: 14-20.
Gaware TJ, Sutar N, Thorat BN. 2010. Drying of tomato using different methods: comparison of dehydration and rehydration kinetics. Dry Technol., 28: 651-658.
Ghanem N, Mihoubi D, Kechaou N, Mihoubi NB. 2012. Microwave dehydration of three citrus peel cultivars: Effect on water and oil retention capacities, color, shrinkage and total phenols content. Ind Crops Prod., 40(1): 167-177.
Goncalves LT, Pereira NR, Almeida SB, Freitas SD, Waldman WR. 2017. Microwave-hot air drying applied to selected cassava cultivars: drying kinetics and sensory acceptance. Int J Food Sci Technol., 52(2): 389-397.
Hamrouni-Sellami I, Rahali FZ, Rebey IB, Bourgou S, Limam F, Marzouk B. 2013. Total phenolics, flavonoids, and antioxidant activity of sage (Salvia officinalis L.) plants as affected by different drying methods. Food Bioprocess Technol., 6: 806-817.
Huang D, Ou B, Prior RL. 2005. The chemistry behind antioxidant capacity assays. J Agric Food Chem., 53(6): 1841-1856.
Kumar PS, Kanwat M, Choudhary VK. 2013. Mathematical modeling and thin‐layer drying kinetics of bamboo slices on convective tray drying at varying temperature. J Food Process Preserv., 37(5): 914-923.
Lewicki PP. 2006. Design of hot air drying for better foods. Trends Food Sci Technol., 17: 153-163.
Li X, Wu X, Huang L. 2009. Correlation between antioxidant activities and phenolic contents of radix Angelicae sinensis (Danggui). Molecules, 14(12): 5349-5361.
Malik NS, Bradford JM. 2008. Recovery and stability of oleuropein and other phenolic compounds during extraction and processing of olive (Olea europaea L.) leaves. J Food Agric Environ., 6(2): 8.
Maskan M. 2001. Kinetics of colour change of kiwifruits during hot air and microwave drying. J Food Eng., 48(2): 169-175.
Mkaouar H, Zalila B, Hugues J, Jmaiel M. 2015. From AADL Model to LNT Specification. In: de la Puente J., Vardanega T. (eds) Reliable Software Technologies – Ada-Europe 2015. Ada-Europe 2015. Lecture Notes in Computer Science, vol 9111. Springer, Cham.
Midilli A, Kucuk H, Yapar Z. 2002. A new model for single-layer drying. Dry Technol., 20(7): 1503-1513.
Minaei S, Motevali A, Ahmadi E, Azizi MH. 2012. Mathematical models of drying pomegranate arils in vacuum and microwave dryers. J Agr Sci Tech., 14: 311-325.
Nourhène B, Mohammed K, Nabil K. 2008. Experimental and mathematical investigations of convective solar drying of four varieties of olive leaves. Food Bioprod Process., 86: 176–184.
Nurs Lokman Hekim Company. www.nurs.com.tr, Adana, Turkey.
Omar SH. 2010. Oleuropein in olive and its pharmacological effects. Sci Pharm., 78(2): 133–154.
Omolola AO, Jideani AIO, Kapila PF. 2014. Modeling microwave drying kinetics and moisture diffusivity of Mabonde banana variety. Int J Agr Biol Eng., 7(6): 107-113.
Paiva-Martins F, Pinto M. 2008. Isolation and characterization of a new hydroxytyrosol derivative from olive (Olea europaea) leaves. J Agric Food Chem., 56(14): 5582–5588.
Puente-Díaz L, Ah-Hen K, Vega-Gálvez A, Lemus-Mondaca R, Di Scala K. 2013. Combined infrared-convective drying of murta (Ugni molinae Turcz) berries: kinetic modeling and quality assessment. Dry Technol., 31: 329-38.
Sharma GP, Prasad S. 2004. Effective moisture diffusivity of garlic cloves undergoing microwave-convective drying. J Food Eng., 65(4): 609-617.
Sharma SR, Arora S, Chand T. 2011. Air drying kinetics of pomegranate seeds. Int J Food Eng., 7(2).
Souilem S, Fki I, Kobayashi I, Khalid N, Neves MA, Isoda H, Sayadi S, Nakajima M, 2017. Emerging technologies for recovery of value-added components from olive leaves and their applications in food/feed industries. Food Bioprocess Technol., 10: 229-248.
Şahin S, Bilgin M. 2012. Study on oleuropein extraction from olive tree (Olea europaea) leaves by means of SFE: Comparison of Water and Ethanol as Co-Solvent. Sep Sci Technol., 47: 2391-2398.
Toujani M, Hassini L, Azzouz S, Belghith A. 2013. Experimental study and mathematical modeling of silverside fish convective drying. J Food Process Preserv., 37: 930-938.
T.S.M.S. (2015). Turkish State Meteorological Service.
Tuck KL, Hayball PJ. 2002. Major phenolic compounds in olive oil: metabolism and health effects. J Nutr Biochem., 13(11): 636-644.
Visioli F, Bellomo G, Montedoro G, Galli C. 1995. Low density lipoprotein oxidation is inhibited in vitro by olive oil constituents. Atherosclerosis, 117(1): 25-32.
Wiktor A, Iwaniuk M, Śledź M, Nowacka M, Chudoba T, Witrowa-Rajchert D. 2013. Drying kinetics of apple tissue treated by pulsed electric field. Dry Technol., 31(1): 112-119.
Yateem H, Afaneh I, Al-Rimawi F. 2014. Optimum conditions for oleuropein extraction from olive leaves. Int J Appl Sci Technol., 4(5): 153-457.
Zhang M, Jiang H, Lim RX. 2010. Recent developments in microwave-assisted drying of vegetables, fruits, and aquatic product-Drying kinetics and quality considerations. Dry Technol., 28(11): 1307-1316.