VOLATILE PRODUCTION AND FRUIT-QUALITY DURING DEVELOPMENT OF SUPERFICIAL SCALD IN RED-DELICIOUS APPLES

To evaluate potential differences in quality between normal and scald- developing apples, volatile components and tissue integrity of Red Del icious apples were analyzed. Solid-phase micro-extraction (SPME) of he ad-space volatiles coupled with GC-MS (gas chromatography-mass spectro metry) revealed the presence of several fatty acyl esters and the terp ene, alpha-farnesene. Development of superficial scald in Red Deliciou s apples was not associated with any major qualitative changes in vola tiles. However, unscalded Red Delicious apples evolved much higher amo unts of volatiles such as hexyl acetate, butyl hexanoate, propyl octan oate, hexyl hexanoate and alpha-farnesene. Proton magnetic resonance i maging of scalded Red Delicious apples revealed an increase in the mob ility of water protons or an increase in the ratio of free to bound wa ter in the epidermal layer and peripheral cortical tissue. The results show that scald development may be associated with changes in volatil e emission and tissue integrity in Red Delicious apples. (C) 1997 Cana dian Institute of Food Science and Technology. Published by Elsevier S cience Ltd.