The effect of washing solutions on reduction of microbial load in Mazafati rutab

Authors
1 Assistant Professor, Food and Postharvest Technology Division, Agricultural Engineering Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran
2 M.Sc., Plant Protection Research Department, Kerman Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Kerman, Iran
Abstract
In this study, the effect of water and Sodium diacetate solutions on reduction of pollutions in Mazafati rutab was investigated. Date branches were washed at the last stage of Khalal by spraying of pure water and Sodium diacetate solution (4000 ppm). Total microbial and fungal counts were determined before washing as well as two, three and four weeks after washing of the fruits on tree. Mazafati rutab samples were packed after harvest and stored in cold room and also at ambient temperature for 6 months. The results showed that surface and microbial pollutions significantly (P<0.05) decreased after washing of the fruits with pure water and Sodium diacetate solution. Total microbial and fungal counts gradually increased during stage of fruit maturity. Rotting rate was significantly (P<0.05) high in the dates treated with Sodium diacetate at harvest time. The moisture content of the dates decreased but total soluble solids (TSS) increased during storage at ambient temperature. In all treatments, pH content decreased and percent acidity (as lactic acid) increased during storage. Total microbial counts in the dates treated with Sodium diacetate was significantly (P<0.05) lower than other treatments during storage. The results indicated that washing of Mazafati date bunches at the last stage of Khalal by spraying of pure water can be effective in reduction of surface pollutions on the fruits. Mazafati rutab should be stored in cold rooms to prevent the activity of microorganisms and pests and increase the storage life.
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Fallahi, M. (1998). Development, handling and storage of the dates. Mashhad, Barsava Publishing House, 124 PP. [in persian].
Saif Kordi, A. A. (1999). Study of cleaning and preparing methods of date fruits for packaging. Final Report, Agricultural Engineering Research Institute. [in persian].
Golshan Tafti, A. (2005). Study on artificial maturation of Mazafati date. Final Report, Agricultural Engineering Research Institute. [in persian].
Khatri, N. K. (1991). Efficacy of different fungicides against fruit rot of date palm cultivar Halawi. Indian Journal of Mycology and Plant Pathology, 21:197-199.
Kamal, H. M. (1996). Comparative effect of some fungicides on the keeping quality and physical and chemical properties of date palm fruits. Bulletin of Faculty of Agriculture, University of Cario, 47: 305-317.
Golshan Tafti, A., Fooladi, M. H. (2006). Preservation of Mazafati Rutab by antimicrobial agents. Iranian Journal of Agriculture Science, 1: 137-131. [in persian].
Glabe, E. F., Maryanski, J. K. (1981). Sodium diacetate: An effective mold inhibitor. Cereal Foods World, 26: 285-289.
Jay, J. M., Loessner, M.J., Golden, D.A. (2005). Modern food microbiology. 7th edition, Van Nostrand Reinhold, USA, 790 PP.
Karim, G. (2015). Food microbial tests. Tehran, Tehran University Press, 517 PP. [in persian].
Hosseini, Z. (2007). Current methods in food analysis. Shiraz, Shiraz University Press, 232 PP. [in persian].
Golshan Tafti, A., Fooladi, M. H. (2005). Changes in physical and chemical characteristic of Mazafati date fruit during development. Journal of Biological sciences, 5: 319-322.
Peirson, M. D., Guan, T. Y., Holley, R. A. (2003). Thermal resistances and lactate and diacetate sensitivities of bacteria causing bologna discolouration. International Journal of Food Microbiology, 86: 223-230.
Cheraghi Dehdezi, S., Hamdami, N. (2012). Effect of storage at different temperatures on moisture content, total soluble solids, acidity and pH of dates (Kabkab variety). Journal of Food Research, 22: 131-140.
Mortazavi, A., Razavizadeh, M.,Karajiyan, H. (2006). Effect of different storage temperatures on chemical properties of date varieties. Journal of Food Technology and Nutrition, 2: 27-34.
Barreveld, W. H. (1994). Date palm products. FAO Agricultural Services Bulletin.