Impact of Fertilization on Antioxidant Activity, Microbiological Quality, and Sensory Attributes of Tomato ( L.) Cultivated in Ethiopia's Central Rift Valley.

Tomatoes, known for their antioxidant capacity, are mostly recommended by health professionals. Despite their nutritional significance, progress in enhancing their nutritional qualities and safety has been limited. This study evaluated the effects of compost-based (organic) and chemical-based (conventional) fertilization on the antioxidant activity, microbiological quality, and sensory attributes of four commonly cultivated tomato varieties (, , , and ) in Ethiopia's Central Rift Valley. Compost fertilization significantly increased vitamin C, flavonoids, total phenolics, DPPH radical scavenging activity, and FRAP antioxidant capacity. However, chemical fertilization primarily enhanced ß-carotene and lycopene content across both growing seasons. Microbiological analysis revealed that the highest total plate count (TPC) and coliform bacteria levels were observed in the unfertilized treatment, whereas no was detected in any of the samples. Sensory evaluation indicated no significant differences in tomato quality among the treatments. Overall, these findings suggest that compost fertilization can enhance the production of bioactive compounds and improve the antioxidant activity of tomatoes, particularly in the Gelilema and Galilea varieties.