The Assessment of Physical and Microbial Properties of Traditional Fruit Leathers in Tehran

Fruit leathers are nutritional products that are made by dehydrating a thin layer of fruit puree or juice under specific conditions, to obtain a chewy snack. Usually, the sun drying system is used to make traditional leathers, consequently takes a relatively long time and infections may occur during this period. The aim of this work was to assess the chemical and microbial quality of traditional fruit leathers. In this study, 30 traditional sample leathers were obtained from the local market of Tehran. The pH, moisture, and microbiological load were measured in calculated samples. The pH was determined using a pH meter and moisture content values of all fruit leather samples were determined using the AOAC official method. For the assessment of aerobic mesophilic bacteria, yeast, and mold, dilutions were prepared and inoculated, followed by incubation for two and seven days at 37°C and 25°C, respectively. Also, this research used Green Bile Broth Brilliant Culture medium and most probable number (MPN) method for E. coli detection. The measured pH of the samples was in the range of 2.3 to 3.6 and 56% of the samples had a higher moisture content than the standard. Measuring the microbial load of the samples showed that they were over-contaminated in 16% of cases. Also, E. coli was identified in four samples. This study showed that the high microbial load of traditional leathers, due to unhealthy production, is predictable. Thus, the correction of the traditional method for this product is recommended.