Physiology of pre-cut mango. I. ACC and ACC oxidase activity of slices subjected to osmotic dehydration

Physiologically mature mangoes were ripened For 6 days at 24 degreesC and 9 8% relative humidity. Slices from these fruits were osmotically dehydrated by immersion in sucrose 65 degrees Brix at 30 degreesC and 211 mbar vacuum during 30 min. Slices not subjected to osmotic dehydration (NOD) and slices with osmotic dehydration (OD) were stored at 24, 13 or 5 degreesC. The res piration rate of both slice types was affected by the storage temperature. I-Aminocyclopropane l-carboxylic acid (ACC) synthesis indicated activity of ACC synthase in both slices as well as in the whole fruit. ACC oxidase act ivity was greater in OD slices as compared to NOD and that was associated t o better membrane stability. OD favored compaction of external layer in sli ces. No ethylene was detected in slices; however, the tissues did not lose their ability to synthesize ethylene. Results suggest that OD under vacuum may be beneficial as a pre-treatment of mango slices for longer shelf life under refrigeration. (C) 2001 Elsevier Science Ltd. All rights reserved.