FLAVEDO AND ALBEDO CHANGES IN EUREKA LEMONS CAUSED BY STATIC COMPRESSION AND IMPACT LOADING

Mature lemons (Citrus limon (L.) Burnt.. 'Eureka') were subjected to i ncreasing compression, impact and static loading, then stored at eithe r 1C, 13C or 20C for 14 or 28 days. Following storage, fruit were asse ssed for cellular damage associated with the site of loading. Slow com pression (1.7 cm plunger driven at a loading rate of 200 mm min(-1)) r esulted in cell damage in the mid to lower flavedo tissue. Tissue fail ure was characterised by cell rupture, with minor cell deformation and compression associated with damage to the oil glands. Impact loading caused relatively little lower flavedo damage, with most of the injury associated with the albedo, the upper flavedo and tissue surrounding the oil glands. Damaged albedo cells formed a distinct zone of rupture d and laterally compressed tissue which increased in area with drop he ight. Static loading (3.7 kg top weight) resulted in a similar mode of failure to that of impact loading, with extensive cellular damage obs erved in the lower albedo. Injury was distinct in that cells were not laterally compressed and flavedo damage was far more pronounced While most of the tissue damage was directly