Exogenous Melatonin Application Retains Bioactive Compounds, Enhances Antioxidant Activity, Reduces Softening and Prolongs Shelf Life of Cherry Tomato (Solanum lycopersicon var. Cerasiformaeae) During Cold Storage

• 120 µM MT effectively maintains cherry tomatoes' quality and shelf life up to 35 days. • MT suppressed respiration and ethylene evolution, reduced softening and delayed oxidative stress. • MT treatment preserved the structural integrity, sensory appeal and retained overall consumer acceptability. Cherry tomatoes are a widely grown salad crop with global commercial significance. However, their quality and shelf life are often compromised due to rapid deterioration during storage. This study examined the efficacy of melatonin (MT) treatments (0, 70, 120, 170, and 220 µM) on postharvest quality and shelf-life of cherry tomatoes stored at 10°C and 85–90% RH for 35 days. Fruit treated with 120 µM MT significantly lowered respiration and ethylene production rates, slowed down softening, and helped elevate bioactive compounds and antioxidant activity retention compared to untreated fruit. 120 µM MT also enhanced antioxidant enzyme activity, reduced softening enzymes, and limited malondialdehyde accumulation. High-performance liquid chromatography revealed higher sugar retention in treated tomatoes, with fructose as the dominant sugar. Fourier transform infrared analysis showed increased intensity of functional groups at 120 µM MT, while scanning electron microscopy imaging indicated better-preserved cell wall structure. Notably, 120 µM MT treatment extended shelf-life by 15 days, maintaining quality and consumer acceptability.