Effects of post-harvest putrescine and calcium treatments on reducing mechanical damage and polyamines and abscisic acid levels during lemon storage

Abstract

The role of post-harvest putrescine and calcium (at 1 mM), exogenously applied during storage of lemon at 15 °C, in relation to fruit firmness (fruit deformation force) and peel resistance (puncture force) was investigated. Also, the levels of endogenous polyamines (putrescine, spermidine and spermine) and abscisic acid (ABA) and the colour development in mechanically damaged fruits (50N) were studied. Fruits under putrescine and calcium treatments maintained higher firmness values and more resistance to peel rupture than control ones during storage. Treated lemons showed also less deformation when the compression force (50N) to induce mechanical damage was applied. Treated and damaged fruits showed a decline in polyamine content while ABA and colour changed in parallel with maturation during storage. In damaged control fruits, an increase of spermine and ABA levels as a consequence of mechanical damage was observed. From the results reported, spermine and ABA could be considered physiological markers of mechanical stress.