Salicylic acid influences lenticel discolouration and physiological and biochemical attributes of mango (Mangifera indica L.) fruits

Abstract

Lenticel discolouration (LD) has now emerged as a leading postharvest threat in mango, which interferes with the face value of fruits, thereby affecting the trade and causing huge monetary losses to our country. For its management, we designed an experiment using salicylic acid at 200, 400 and 600 ppm concentration along with control fruits, as a dip treatment for 5 min. Our results revealed that salicylic acid at 200 ppm was not only effective in reducing LD significantly but also reduced the activities of polyphenol oxidase (PPO) (0.397 ∆A₄₁₀ O.D min⁻¹ g⁻¹ FW), peroxidase (POD) (0.050 ∆ A₄₇₀ O.D min⁻¹ g⁻¹ FW), and lipoxigenase (LOX) (3.227 µmol min⁻¹ g⁻¹ FW) enzymes and helped in increasing the total phenolics (15.46 mg gallic acid equivalent 100 g⁻¹). This treatment also suppressed the rates of ethylene evolution (0.521 µL kg⁻¹ h⁻¹) and respiration (34.46 mL CO₂ kg⁻¹ h⁻¹) over untreated mango fruits. With respect to quality parameters, the significant decrease in postharvest decay (23.3%) occurred without any adverse effect on soluble solids concentrates (16° B) and total carotenoids (4.1 mg 100 g⁻¹pulp). Thus, keeping all parameters (physical, physiological, biochemical and quality) in view, salicylic acid at 200 ppm was most effective as a postharvest dip treatment for reducing LD in mango during storage or marketing without adversely affecting the fruit quality.