SPECTROPHOTOMETRIC CHARACTERIZATION OF SUPERFICIAL AND SENESCENT SCALD IN PEAR FRUITS RELATIVE TO DIFFERENT STAGES OF MATURITY

Scald development in ‘Anjou’, ‘Packham’s Triumph’ and ‘Bartlett’ pear fruits was characterized by spectrophotometry.
Fruit harvested at several stages of maturity produced different degrees of susceptibility to scald.
Ultraviolet absorption spectra of hexane extracts from fruit peel discs showed a main peak at 232 nm and secondary peaks at 258, 269 and 281 nm during storage at 0 °C, regardless of variety and maturity.
This spectrum was similar to that of farnesene (232 nm) and its conjugated trienes (CT281, CT258, CT269), compounds referred in the literature as responsible for scald damage of apples.
In all varieties studied, scald disorder coincided with decreases of farnesene, but the proportion of conjugated trienes varied.
Late harvested ‘Anjou’ and Packham’s Triumph fruits were the most resistant to superficial scald and had the highest CT258/CT281 ratio.
Senescent scald developed in Bartlett pear fruit during storage at low temperature.
Early maturity Bartlett fruit was the most resistant to the disorder and it was characterized by low level of conjugated form.
The CT258 was the main form of conjugated compounds in this variety.

VII International Symposium on Pear Growing

J.P. Zoffoli, D. Richardson, P. Chen, D. Sugar

Scald, α-farnesene, conjugated trienes

https://doi.org/10.17660/ActaHortic.1998.475.66