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

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.