The Effect of Ultrasound-Assisted Osmotic Dehydration Pretreatment on the Convective Drying of Apple Slices (var.Golab)

Document Type: Research Paper


1 Ph.D. Student of the Department of Food Science, Mamaghan Branch, Islamic Azad University, Mamaghan, Iran.

2 Associate Professor of the Department of Food Hygiene, Biotechnology Research Center, Tabriz Branch, Islamic Azad University, Tabriz, Iran.


Drying is one of the widely used methods of food preservation and it is a sensitive food processing operation due to undesirable changes in the quality of dried product. In this study the effect of osmotic dyhedration and ultrasound pretreatment prior to convective drying on quality properties of apple slices was investigated. Apple slices were pretreated by osmotic dehydration in two concentration levels of sucrose solution (30, 60ºBrix) at 25 ºC for 15 and 30 minutes and were subjected to ultrasound pretreatment modulates osmotic dehydration by ultrasonic waves in a water bath at the frequency of 60 kHz in osmotic sucrose solution (30, 60ºBrix) at 25 ºC for 15 and 30 minutes. The quality of dehydrated apple was analyzed by rehydration ratio, shrinkage and color changes. The results showed that the application of ultrasound-assisted osmotic dehydration led to a decrease in rehydration ratio as compared to the control samples and observed more decrease in the samples of ultrasound-assisted osmotic than osmotic samples. Most of shrinkage belonged to the control samples and the least shrinkage was related to the samples of ultrasound-assisted osmotic. Control samples had darker color whereas the treated samples had higher lightness (L*) and lower redness (a*), yellowness (b*) and colour intensity () were represented. Based on the findings it can be concluded that the ultrasound-assisted osmotic dehydration led to improves in the color and shrinkage and obtained a decrease in rehydration ratio in the dried samples.


Ahmed, I., Mabood Qazi, I. & Jamal, S. (2016). Developments in osmotic dehydration technique for the preservation of fruits and vegetables. Innovative Food Science and

Emerging Technologies, 34, 29-43.

Amami, E., Khezami, W., Mezrigui, S., Badwaik, L. S., Bejar, A. K., Perez, C. T. & Kechaou, N. (2017). Effect of Ultrasound – assisted osmotic dehydration pretreatment on the convective drying of strawberry. Ultrasonics sonochemistery, 36, 286-300.

Azarpazhooh, E. & Ramaswamy, S. H. (2011). Optimization of microwave-osmotic pretreatment of apples with subsequent air-drying for preparing high-quality dried product. International Journal of Microwave Science and Technology, 1-12.

AOAC. (1990). Official methods of analysis. Washington: Association of Official Analytical Chemists.

Bakalis, S. & Karathanos, V. T. (2005). Study of rehydration of osmotically pretreated dried fruit samples. Drying Technology, 23(3), 533–549.

Barman, N. & Badwaik, L. S. (2017). Effect of ultrasound and centrifugal force on carambola (Averrhoa carambola L.) slices during osmotic dehydration. Ultrasonics Sonochemistry, 34, 37-44.

Cárcel, J. A., Benedito, J., Rossello, C. & Mulet, A. (2007). Influence of ultrasound intensity on mass transfer in apple immersed in a sucrose solution. Journal of Food Engineering, 78(2), 472-479.

Dehghannya, J., Gorbani, R. & Ghanbarzadeh, B. (2016). Shrinkage of mirabelle plum during hot air drying as influenced by ultrasound-assisted osmotic dehydration. International Journal of Food Properties, 19(5), 1093-1103

Doymaz, I. (2009). An experimental study on drying of green apples. Drying Technology, 27(3), 478–485.

Falade, O. K., Igbeka, J. C. & Ayanwuyi, F. A. (2007).Kinetics of mass transfer, and colour changes during osmotic dehydration of watermelon. Journal of Food Engineering, 80, 979–985.

Fernandes, F. A. N., Gallão, M. I. & Rodrigues, S. (2008). Effect of osmotic dehydration and ultrasound pre-treatment on cell structure: Melon dehydration. Journal of LWT Food Science and Technology, 41(4), 604-610.

Fernandes, F. A. N., Gallão, M. I. & Rodrigues, S. (2009). Effect of osmosis and ultrasound on pineapple cell tissue structure during dehydration. Journal of Engineering,

90(2), 186-190.

Garcia-Noguera, J., Oliveira, F. I. P., Weller, C. L., Rodrigues, S. & Fernandes, F. A. N. (2014). Effect of ultrasonic and osmotic dehydration pre-treatments on the colour of freeze dried strawberries. Journal Food Science and Technology, 51(9), 2222–2227.

Ispir, A. & Toğrul, D.T. (2009). Osmotic dehydration of apricot: Kinetics and the effect of process parameters. Chemistry of Engineering Research and Design, 87(2), 166-180.

Jambrak, A. R., Mason, T. J., Paniwnyk, L. & Lelas, V. (2007). Accelerated drying of button mushrooms, Brussels sprouts and cauliflower by applying power ultrasound and its rehydration properties. Journal of Food Engineering, 81(1), 88-97.

Kaleta, A. & Górnicki, K. (2010). Evaluation of drying models of apple (var. Mclntosh) dried in a convective dryer. Food Science and Technology, 45(5), 891-898.

Khanizadeh, S., Tsao, R., Rekika, D., Yang, R., Charles, M. T. & Rupasingh, H. P.V. (2008). Polyphenol composition and total antioxidant capacity of selected apple genotypes for processing, Journal of Food Composition and Analysis, 21(5), 396–401

Krokida, M. K., Karathanos, V. T. & Maroulis, Z. B. (2000). Effect of osmotic dehydration on color and sorption characteristics of apple and banana. Drying Technology, 18(4-5), 937-950.

Kowalski, S. J. & Szadzińska, J. (2014). Convective-intermittent drying of cherries preceded by ultrasonic assisted osmotic dehydration. Chemical Engineering and Processing, 82, 65-70.

Mavroudis, N. E., Gidley, M. J. & Sjoholm, I. (2009). Osmotic processing: Effects of osmotic medium composition on the kinetics and texture of apple tissue. Food Research International, 48(2), 839-847.

Mayor, L. & Sereno, A. M. (2004). Modelling shrinkage during convective drying of food materials: a review. Journal of Food Engineering, 61(3), 373–386.

Mandala, I. G., Anagnostaras, E. F. & Oikonomou, C. K. (2005). Influence of osmotic dehydration conditions on apple air drying kinetics and their quality characteristics. Journal of Food Engineering, 69(3), 307–316.

Mundada, M., Hathan, B. S. & Maske, S. (2011). Mass transfer kinetics during osmotic dehydration of pomegranate arils. Journal of Food Science, 76(1), 31–39.

Noshad, M., Mohebbi, M., Shahidi, F. & Mortazavi, S. A. (2012). Multi-objective optimization of osmotic-ultrasonic pretreatments and hot-air drying of quince using response surface methodology. Food and Bioprocess Technology, 5(6), 2098–2110.

Nawacka, M., Tylewicz, U., Laghi, L., Dalla Rosa, M. & Witrowa-Rajchert, D. (2014). Effect of ultrasound treatment on the water state in kiwifruit during osmotic dehydration. Food Chemistry, 144, 18-25.

Onwude, D. I., Hashim, N. & Chen, G. (2016). Recent advances of novel thermal combined hot air drying of agricultural crops. Trends in food science and Technology, 57, 132-145.

Ramallo, L. A. & Mascheroni, R. H. (2012). Quality evaluation of pineapple fruit during drying process. Food and Bioproducts Processing, 90(2), 275-283.

Rastogi, N. K., Nayak, C. A. & Raghavarao, K. S. M. S. (2004). Influence of osmotic pre-treatments on rehydration characteristics of carrots. Journal of Food Engineering, 65(2), 287–292.

Rastogi, N. K., Raghavarao, K. S. M. S., Niranjan, K. & Knorr, D. (2002). Recent developments in osmotic dehydration: methods to enhance mass transfer. Trends in Food Science and Technology, 13(2), 48-49.

Ricce, C., Rojas, M. L., Miano, A. C., Siche, R. & Augusto, P. E. D. (2016). Ultrasound pre-treatment enhances the carrot drying and rehydration. Food Research International, 89,701-708.

Riva, M., Campolongo, S., Leva, A. A., Maestrelli, A. & Torreggiani, D. (2005). Structure–property relationships in osmo-air-dehydrated apricot cubes. Food Research International, 38(5), 533–542.

Rodrigues, A. C. C., Cunha, R. L. &

Hubinger, M. D. (2003). Rheological properties and colour evaluation of papaya during osmotic dehydration processing. Journal of Food Engineering, 59(2-3), 129–135.

Shukla, B. D. & Singh, S. P. (2007). Osmo-convective drying of cauliflower, mushroom and greenpea. Journal of Food Engineering, 80(2), 741–747.

Silva, S. K., Fernandes, A. M. & Mauro, A. M. (2014). Effect of calcium on the osmotic dehydration kinetics and quality of pineapple. Journal of Food Engineering, 134, 37–44.

Silva, S. K., Caetano, L. C., Garcia, C. C., Romero, J. T., Santos, A. B. & Mauro, M. A. (2011). Osmotic dehydration process for low temperature blanched pumpkin. Journal of Food Engineering, 105(1), 56-64.

Singh, B., Panesar, P. S., Gupta, A. K. & Kennedy, J. F. (2007). Optimisation of osmotic dehydration of carrot cubes in sucrose-salt solutions using response surface methodology. European Food Research and Technlogy, 225(2), 157–165.

Sturm, B., Vega, A. N. & Hofacker, W. C. (2014). Influence of process control strategies on drying kinetics, colour and shrinkage of air dried apples. Applied Thermal Engineering, 62(2), 455-460.

Tao, Y., Wang, P., Wang, Y., Kadam, S.U., Han, Y., Wang, J. & Zhou. J. (2016). Power ultrasound as a pretreatment to convective drying of mulberry (Morus alba L.) leaves: Impact on drying kinetics and selected quality properties. Ultrasonic Sonochemistry, 31, 310-318.

Unal, G. H. & Sacilik, K. (2011). Drying characteristics of hawthhorn fruit in a convective hot-air drying. Journal of Food Processing and Preservation, 35(2), 272-279.

Yadav, K. A & Singh, S. V. (2014). Osmotic dehydration of fruits and vegetables: a review. Journal of Food Science and Technology, 51 (9), 1654–1673.

Yan, Z., Sousa-Gallagher, M. J. & Oliveira, F. A. R. (2008). Shrinkage and porosity of banana, pineapple and mango slices during air-drying. Journal of Food Engineering, 84(3), 430-440.