Sustainable Reduction of Post-harvest Losses in Gelila Tomatoes through Sodium Hydroxide-Assisted Oven Drying

Abstract

Postharvest losses of Gelila tomatoes are estimated to exceed 40%. To mitigate these losses, drying the tomatoes to optimal storage moisture levels using appropriate drying techniques is essential. While oven dry-ing is a sustainable and promising method, it is energy-intensive and of-ten leads to longer drying times, which can negatively affect product quality. This study investigates the effect of sodium hydroxide pretreat-ment on enhancing the drying process of Gelila tomatoes in an oven dry-er. Sodium hydroxide treatment helps break down the tomato's waxy cu-ticular surface, reducing moisture resistance without compromising fla-vor. The experiment was conducted using an oven dryer at temperatures of 50 °C, 60 °C, and 70 °C, with sodium hydroxide concentrations of 2%, 4%, and 6%, and dipping times of 5, 10, and 15 minutes. A 600 g sample of Gelila tomatoes was used for each test. The drying performance was evaluated by fitting the experimental data to ten thin-layer drying models using R², sum of square error, and root mean square error as performance metrics. Among these models, the Modified Page I model best predicted the drying behavior. The study concluded that sodium hydroxide pre-treatment significantly enhances the drying efficiency of Gelila tomatoes in an oven dryer. This method reduces drying time, minimizes contami-nation risk, and improves the overall quality of the dried product. Con-sequently, it presents a viable approach to reducing postharvest losses and supporting sustainable tomato preservation for growers.