The Effects of Bio-Fertilizer Applications on Post-Harvest Fruit Quality in Soilless-Grown Tomatoes

Tomatoes (Solanum lycopersicum) are widely cultivated for nutrition and economic importance; quality losses of 25%-45% during cold storage pose a significant problem. In soilless cultivation, bio-fertilization using beneficial microorganisms can extend shelf life by enhancing nutrient uptake and physiological resilience. This study investigated the efficacy of bacterial (AG: Arthrobacter globiformis; SG: Streptomyces griseus) and fungal (AO: Aspergillus oryzae) bio-fertilizers applications on cluster tomatoes (Cletego F1) grown in soilless culture and during cold storage. Using a randomized complete block design with three replications, fruits harvested at the pink-ripe stage were stored in Modified Atmosphere Packaging (MAP) at 8°C and 90% humidity for 21 days. Weight loss, respiration, firmness, pH, titratable acidity, SSC, vitamin C, phenolic/flavonoid content, and antioxidant activity were measured on days 0, 7, 14, and 21. Weight loss was highest in AO (0.11%) and lowest in AG (0.07%) on day 7. Respiration was highest in control (5.96 mL CO₂ kg^-1 h^-1) and lowest in AG (3.58 mL CO₂ kg^-1 h^-1) on day 21; AG (2.14%) maintained higher firmness than control (1.90%). SSC peaked in control on day 7 (5.90%), while microbial treatments reduced this value; vitamin C was highest in AG on day 21 (23.60 mg 100 g^-1). AG showed highest values for phenolics (16.43 mg GAE 100 g^-1) and flavonoids (13.57 mg QE 100 g^-1) on day 21. DPPH was highest in AO (11.72), FRAP highest in control (20.04). Microbial fertilization, particularly with AG, supports nutritional quality by slowing respiration and enhancing bioactive compounds, while AO and SG influence antioxidant capacity.