Effects of preharvest monopotassium phosphate applications on tomato fruit quality during cold storage

During the postharvest period, tomatoes are frequently exposed to suboptimal temperatures, adversely affecting their quality attributes, including the concentration of volatile organic compounds (VOCs). To mitigate this concern, the impact was investigated of preharvest foliar sprays of KH2PO4 (20 mmol L-1) on the quality and volatile composition of ‘Kaucana’ cherry tomatoes, following storage for 0 (S0), 7 (S7), and 14 days (S14) at 8.0±0.5°C. The application of KH2PO4 promoted fruit firmness (+14%), tomato color index (TCI, +12%) and total carotenoid content (TCC, +18%), when compared to control fruits. Except for TCI, storage time significantly influenced all the carpometric variables and, within the S0-S14 period, control fruits showed the highest reductions in fruit firmness and TCC (-30 and -27%, respectively). Five out of six VOCs investigated were promoted following KH2PO4 application, including benzaldehyde, 6-methyl-5-hepten-2-one, (E)-citral, geranyl acetone and β-ionone. Proceeding to S7 and S14, hexanal in control fruits provided the most marked reduction among all volatiles (-40%), whereas at S14 treated fruits had significant higher concentrations of benzaldehyde, 6-methyl-5-hepten-2-one, (E)-citral and geranyl acetone. These results suggest that tailored preharvest KH2PO4 applications can preserve specific quality traits of cold-stored cherry tomatoes.