A MODIFIED HYPOTHESIS ON THE ROLE OF CONJUGATED TRIENES IN SUPERFICIAL SCALD DEVELOPMENT ON STORED APPLES

Three experiments were conducted using 'Cortland' and 'Delicious' apples (Malus domestica Borkh.). Fruit varying widely in superficial scald susceptibility, because of either endogenous or experimentally induced conditions, were stored for various intervals at OC and evaluated for scald development at 20C. Samples were extracted periodically in hexane, and ultraviolet absorption spectra of the extracts were used to evaluate alpha-farnesene and conjugated triene (CT) relationships to scald development. CT concentrations were calculated using each of the three CT absorption maxima (258-290 nm, 269-290 nm; and 281-290 nm) and expressed accordingly as CT258, CT269, and CT281. The poor association of CT281 concentrations with scald development led us to propose that metabolic products of CT281 species are more likely to be associated with scald development than the species themselves.