Drying of stanley plum with some post-harvest applications

This study was conducted to observe the effects of some physical, chemical and microwave pretreatments on drying period and prune colour of Stanley plums dried in the sun. For this aim, seven pretreatments including piercing with thin needle, cutting fruit layer by knife, microwave application, dipping into solutions of NaOH and K2CO3 with or without olive oil addition were compared with untreated samples. Microwave application was the most effective pretreatment in reducing drying time (95 h) while control was the slowest drying application (401 h). Microwave and other chemical applications negatively affected colour by increasing redness of prunes. Olive oil addition decreased this negative effect but decelerated drying process. Layer cutting were concluded to be a promising method since it significantly accelerated drying while saving colour of prunes.

The Effects of Some Physical, Chemical and Microwave Pretreatments on Plum Drying

This study was conducted to observe the effects of some physical, chemical and microwave pretreatments on drying period and prune quality of Stanley plums dried under open sun. For this aim, seven pretreatments including piercing with thin needle, cutting fruit layer by knife, microwave application, dipping into solutions of NaOH and K2CO3 with or without olive oil addition were compared with untreated samples. Microwave application was the most effective pretreatment in reducing drying time and was followed by dipping into 5% K2CO3. Microwave and other chemical applications negatively affected quality by increasing redness of prunes. Olive oil addition decreased this negative effect but decelerated drying process. Layer cutting were concluded to be a promising method since it significantly accelerated drying while saving quality of prunes.

Keywords:

drying curve, plum, prune pretreatment,

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Abdelhaq, E. H., Labuza, T. P., 1987. Air drying characteristics of apricots. Journal of Food Science, 52(2): 342-345.
Cinquanta, L., DiMatteo, M., Esti, M., 2002. Physical pretreatment of plums (Prunus domestica). Part 2. Effect of the quality characteristics of different prune cultivars. Food Chemistry, 79: 233-238.
Çağlar, A., Toğrul, İ. T., Toğrul, H., 2009. Moisture and thermal diffusivity of seedless grape under infrared drying. Food and Bioproducts Processing, 87(4): 292-300.
Dev, S. R. S., Padmini, T., Adedeji, A., Gariépy, Y., Raghavan, G. S. V., 2008. A comparative study on the effect of chemical, microwave, and pulsed electric pretreatments on convective drying and quality of raisins. Drying Technology, 26(10): 1238-1243.
Dincer, I., 1996. Sun drying of sultana grapes. Drying Technology, 14 (7-8): 1827-1838.
Doymaz, İ., 2004. Effect of dipping treatment on air drying of plums. Journal of Food Engineering, 64(4): 465-470.
Güneyli, A., Onursal, C.E., 2014. Ilıman iklim meyve türlerinde hasat kriterleri (Harvest criteria in temperate fruits). – Gıda, Tarım ve Hayvancılık Bakanlığı, Meyvecilik Araştırma Enstitüsü (Minisry of Food, Agriculture and Livestock, Fruit Research Institute)
http://arastirma.tarim.gov.tr/marem/Belgeler/Yeti%C5%9Ftiricilik%20Bilgileri/Il%C4%B1man%20%C4%B0klim%20Meyvelerinde%20Hasat%20Kriterleri.pdf (Available Date: 17.05.2019).
INC, 2019. Nuts and Dried Fruits Statistical Yearbook 2017-2018, International Nut&Dried Fruit Council.
Jazini, M. H., Hatamipour, M. S., 2010. A new physical pretreatment of plum for drying. Food and Bioproducts Processing, 88(2): 133-137.
Karathanos, V. T., Belessiotis, V. G., 1997. Sun and artificial air drying kinetics of some agricultural products. Journal of Food Engineering, 31(1): 35-46.
Kostaropoulos, A. E., Saravacos, G. D., 1995. Microwave pretreatment for sun-dried raisins. Journal of Food Science, 60(2): 344-347.
McGuire, R. G., 1992. Reporting of objective color measurements. HortScience, 27(12): 1254-1255.
MGM, 2019. Resmi İstatistikler, T.C. Tarım ve Orman Bakanlığı, Meteoroloji Genel Müdürlüğü (Cities & Holiday Resorts, Turkish State Meteorological Service).
Nijhuis, H. H., Torringa,, H. M., Muresan, S., Yuksel, D., Leguijt, C., Kloek, W., 1998. Approaches to improving the quality of dried fruit and vegetables. Trends in Food Science & Technology, 9(1): 13-20.
Pala, M., Mahmutoglu, T., Saygi, B., 1996. Effects of pretreatments on the quality of open-air and solar dried apricots. Nahrung, 40(3), 137-141.
Sabarez, H. T., Price, W.E., Korth, J., 2000. Volatile changes during dehydration of d'Agen prunes. Journal of Agricultural and Food Chemistry, 48(5), 1838-1842.
Tarhan, S., 2007. Selection of chemical and thermal pretreatment combination for plum drying at low and moderate drying air temperatures. Journal of Food Engineering, 79(1): 255-260.
Turan, A., 2018. Effect of drying methods on nut quality of hazelnuts (Corylus avellana L.). Journal of Food Science and Technology, 55(11): 4554–4565. Zhang, B., Zheng, A., Zhou, L., Huang, Z., Wang, S., 2016. Developing hot air-assisted radio frequency drying protocols for in-shell walnuts. Emirates Journal of Food and Agriculture, 28(7): 459.
Zhang, M., Tang, J., Mujumdar, A. S., Wang, S., 2006. Trends in microwave-related drying of fruits and vegetables. Trends in Food Science & Technology, 17(10): 524-534.