MODIFIED ATMOSPHERE PACKAGING OF LAPINS SWEET CHERRY

'Lapins' sweet cherries (Prunus avium L.) were stored at 0 degrees C under modified atmospheres for 10 weeks. Atmospheres within low density polyethylene bags of 38 mu thickness equilibrated to 0.8% O-2 and 4.5% CO2 by the second week of storage. Brightness of the fruit (L values) declined after 6 weeks and firmness decreased after 8 weeks. Titratable acidity declined steadily over the storage period. Stems remained green during the 10-week storage period. Sixty volatile compounds were isolated by a purge and trap method. Two principal components (PC) accounted for 73.5% of the total variation in volatile production. PC1 accounted for the variation between the first 6 weeks of storage and weeks 8-10 and PC2 accounted for the variation between weeks 8 and 10. The variation in volatiles involved aldehydes, alcohols, ketones and esters. Sensory evaluation by a trained panel revealed a significant decline (P less than or equal to 0.05) in external appearance with each sampling date relative to all previous sampling dates. Flavour also declined in value with each removal date except for week 1 which did not differ from that at harvest. Texture after two weeks of storage was perceived as crunchier and did not change with subsequent removal dates. Off flavours were present at week 8. Acceptability remained high for 4-6 weeks of storage but decreased appreciably thereafter.