Effectiveness of wood ash in extending the shelf life of fresh tomatoes

Abstract

In Uganda, tomato is the most widely grown vegetable crop and is popular among all communities. Income from tomatoes is mainly constrained by post-harvest losses. Some farmers in Teso region keep their tomatoes in ash. However, no research has been carried out on the use of cultural measures such as ash which is affordable by small holder farmers to extend the shelf life of tomatoes. The main objective of this study was to determine the effectiveness of wood ash in extending the shelf life of fresh tomatoes. The study was conducted in the chemistry laboratory at the Department of Technology and nutrition, School of Food Technology, Nutrition and Bioengineering, Makerere University. Texture, physiological weight loss (%), colour change, decay (%), total soluble solids (oBrix) and pH were evaluated over the 5 weeks storage period. Data collected was subjected to analysis using Genstat statistical software package 14th edition and an analysis of variance (ANOVA) was performed to determine significant differences within the treatments of ash at 5% (P ≤ 0.05). Significant differences (P ≤ 0.01) were observed among tomatoes treated with different levels of wood ash over the storage period. Tomato rotting generally increased over the storage period. The rate of rotting in tomatoes (% decay) was highest in control (100%) while the lowest (20%) was recorded in tomatoes treated with 1.5 kg ash. Total soluble solids were not significantly different between different ash treatments. The firmness of the tomatoes reduced with time for all the ash treatments. The percentage physiological weight loss was not significant between treatments but was lowest in the control (30.56%) and highest for the 1.5 kg ash treatments (33.47%). The pH of the tomatoes generally increased over the storage period. Treatment with 1.5 kg ash per 1 kg of tomatoes was most effective in extending shelf life and is therefore recommended for application as an affordable technology for preserving tomatoes especially in rural areas where access to electricity is limited.