Fruit-Enhanced Resistance to Microbial Infection Induced by Selective Laser Excitation

Autor: Alicia G. Gonzálvez, Jorge B. Jiménez, Ángel González Ureña
Jazyk: angličtina
Rok vydání: 2013
Předmět:
Zdroj: Journal of Spectroscopy, Vol 2013 (2013)
Druh dokumentu: article
ISSN: 2314-4920
2314-4939
DOI: 10.1155/2013/789159
Popis: Table grapes were irradiated with laser pulses at two different wavelengths: one selected at 302.1 nm, that is, resonant with the transresveratrol biphoton absorption band, and another selected at 300 nm, that is a nonresonant wavelength where trans-resveratrol two-photon absorption is negligible. Attenuated total reflectance Fourier transformed infrared spectroscopic analyses of the irradiated grapes' skin showed an enhancement of polyphenols' content when the resonant wavelength was employed. Furthermore, microbiological analysis performed with nontreated (control), nonresonant, and resonantly irradiated grapes demonstrated how the last samples developed a significantly lower number of colony forming units. Since the only difference between the two (resonant and nonresonant) irradiation conditions was just a couple of nanometres in the employed UV-B laser wavelengths, the germicidal effect should be considered very similar. As a result, the observed difference in the table grape resistance to microbial infection was attributed to a wavelength-dependent-induced photochemistry. Finally, the potentiality of this method to enhance the postharvest health status of table grapes is remarked.
Databáze: Directory of Open Access Journals
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