The tomato (Solanum lycopersicum L.) is a widely consumed yet highly perishable product, necessitating the development of traditional preservation methods accessible to the general population. This study aims to evaluate the effect of local preservatives on the nutritional and microbiological quality of tomato paste. Following production, the paste was divided into four batches: those treated with salt (TPSP), lemon (TPLP) or oil (TPOP) and a control group with no preservative (TPNP). Nutritional and microbiological characteristics were determined using standardized methods. Analysis of the results revealed that salt, lemon and oil influenced biochemical compounds in varying ways. These preservatives also affected levels of polyphenols (3.35 to 4.91 mg GAE/100g), flavonoids (0.48 to 1.42 mg QE/100g), vitamin A (1.33 to 3.10 mg/100g), tannins (1.41 to 2.55 mg TAE/100g) and lycopene (1.61 to 4.85 mg/100g). Antioxidant activity was also influenced by the treatments applied. From a microbiological perspective, the preservatives inhibited microorganism growth compared to the control. These results demonstrate that local preservatives contribute to improving the quality and shelf life of traditional tomato paste.
