Assessment of nutritive and antinutritive status of tomato and brinjal under different fertilizer management practices

Tomato (Solanum lycopersicum) and brinjal (Solanum melongena) are nutritionally rich vegetables whose composition can be influenced by fertilizer management. The study evaluated the effect of four treatments, T1 (Control), T2 (Vermicompost), T3 (NPK, a combination of Nitrogen, Phosphorus, and Potassium), and T4 (50% Vermicompost + 50% NPK), on the nutritive and antinutritive composition of both crops in two consecutive Rabi seasons (2021–22 and 2022–23) in a randomized complete block design experiment. Proximate, mineral, and phytochemical analyses were conducted according to AOAC procedures.

Results showed significant variations in macronutrients, minerals, and bioactive compounds. In tomatoes, T4 enhanced lycopene (6.7±0.75 µg/100 g), dietary flavonoids (25.05±3.45 mg/100 g), and iron (0.58±0.03 mg/100 g) with appreciable protein (1.23±0.07 g/100 g) and fat (0.46±0.07 g/100 g) content. T3 and T4 increased protein to 2.20±0.07 g/100 g, iron (1.8±0.06 mg/100 g), and magnesium to 18±1.72 mg/100 g in brinjal, but T2 had highest antioxidant activity (79.39±3.21%). T4 also increased oxalate content (243±4.02 mg/100 g), and T2 had highest tannin (432±6.32 mg/100 g), both of which reduce the bioavailability of nutrients. Combined fertilization (T4) generally enhanced nutrient accumulation compared to sole organic or inorganic application, which was likely due to synergistic effects on nutrient uptake and secondary metabolite production. Properly balanced organic–inorganic fertilizer use can enhance vegetable quality and nutrient status but should be controlled to manage antinutritional compounds. Future studies need to maximize fertilizer formulation and post-harvesting operations to reduce oxalates and tannins and preserve favorable compounds to provide safe and sustainable production.