The effects of salicylic acid on quality control of horticultural commodities

Fresh fruits and vegetables are important dietary sources of fibres, minerals and antioxidant compounds. However, post-harvest transportation, storage and processing of horticultural crops are usually accompanied by quality deterioration, leading to the loss of commodity value. Previously used methods of post-harvest preservation may adversely affect quality properties, and have harmful chemical residues. Therefore, some plant endogenous signalling molecules are examined as non-toxic alternatives. Salicylic acid (SA), a natural phenolic acid, was first recognised as a defence-related plant hormone, which provides benefits to post-harvest storability and alleviation of injury for horticultural commodities. In recent years, studies in the application of SA have suggested a critical role in regulating post-harvest quality. In this paper, with a focus on quality control, we review the effects of pre-harvest and post-harvest applications of SA and its combination with other post-harvest technologies on horticultural commodities. Exogenous SA treatment exhibits excellent potential in quality control, which is attributed to (1) delaying fruit ripening, altering pigment composition, alleviating fruit browning; (2) reducing cell wall degrading enzyme activity, maintaining cell membrane properties; (3) reducing fruit aroma loss, improving fruit taste and (4) retaining nutrient content and enhancing antioxidant activity.