INQUIMAE   12526
INSTITUTO DE QUIMICA, FISICA DE LOS MATERIALES, MEDIOAMBIENTE Y ENERGIA
Unidad Ejecutora - UE
artículos
Título:
A model considering light reabsorption processes to correct in vivo chlorophyll fluorescence spectra in apples
Autor/es:
MARÍA E. RAMOS AND M. GABRIELA LAGORIO
Revista:
Photochemical and Photobiological Sciences
Editorial:
RSCPublishing
Referencias:
Lugar: Cambridge; Año: 2006 vol. 5 p. 508 - 512
ISSN:
1474-905X
Resumen:
Chlorophyll-a contained in the peel of Granny Smith apples emits .uorescence upon excitation with
blue light. The observed emission, collected by an external detector and corrected by its spectral
response, is still distorted by light reabsorption processes taking place in the fruit skin and differs
appreciably from the true spectral distribution of .uorescence emerging from chlorophyll molecules in
the biological tissue. Reabsorption processes particularly affect the ratio of .uorescence intensities at
680 nm and at 730 nm. A model to obtain the correct spectral distribution of the emission, from the
experimental .uorescence recorded at a .uorometer detector and corrected for the detector spectral
sensitivity, is developed in the present work. Measurements of the whole fruit re.ectance, the peel
transmittance and the .esh re.ectance allow the calculation of the reabsorption-corrected spectra. The
model is validated by comparing the corrected emission spectra with that obtained for a thin layer of
apple-peel-chloroplasts, where no reabsorption takes place. It is recommended to correct distortions in
emission spectra of intact fruits due to light reabsorption effects whenever a correlation between the
physiological state of the fruit and its .uorescence spectra is investigated.