Physiological Factors Associated with Yellow Shoulder Expression in Tomato Fruit

Yellow shoulder (YS) expression was associated with differences in composition, respiration rate, and ethylene evolution between the yellow and normal red tissue in tomato ( Lycopersicon esculentum Mill.) fruit. The YS tissue was higher in pH, dry matter, alcohol-insoluble solids (AIS), calcium content, respiration rate, and ethylene evolution than the red blossom-end tissue. The YS tissue had less phosphorus, potassium, citric acid, and a lower titratable acidity than the red tissue. Expression of YS was not associated with imbalances in fructose, glucose, malic acid, nitrogen, or magnesium concentration. Substantial YS development occurred in fruit of nonuniform ripening gene cultivars allowed to vine-ripen. Yellow shoulder was alleviated by harvesting fruit in the mature-green stage and room-ripening.