Evaluation of the Effect of Different Map Box Liners on the Quality and Shelf Life of ‘friar’ Plums

Non-destructive firmness sensors have recently become available for packers and fruit handlers although they demand more information on their performance and reliability. A commercial sensor, aimed both for in-line or bench-top usage, based on low mass impact has been tested on kiwifruit. Correlation between the firmness index given by the device and Magness-Taylor force was low (R 2 = 0.594 and a standard error of prediction of 3.4N). Classifications modeled with discriminant analysis showed that it is feasible to sort samples into two firmness groups, with percentages of correctly classified fruits ranging from 97% to 76% depending on the firmness threshold set. However, classification into three classes yielded lower scores (71 to 65%, depending on the threshold between soft, medium and hard classes).