RESUMO

Photoacoustic spectroscopy is applied to evaluate the impact of Moringa at different concentrations (0, 1.25, 2.5, 5 and 10%) on the elaboration, sanity, texture, and color of wheat bread. It was found that: i) Photoacoustic signal amplitude values of bread significantly increase from 37 to 90% when moringa powder concentration raises from 1.25% to 10%, at 300 nm wavelength. ii) Comparing the photoacoustic signal values at 300, 330, and 370 nm wavelengths, produced by the different bread types, there were statistically significant differences. iii) The sanitary quality of bread mixed with a 2.5% of moringa is relatively higher than the ones obtained for other concentrations, such that the number of fungal colonies were reduced by 99% in comparison with the control bread without moringa, after six days of storage. Moringa at 2.5% of concentration could thus improve the sanitary quality of wheat bread. iv) The addition of moringa for making bread slows down its textural changes (hardness, elasticity, cohesiveness, resilience, and chewiness) during storage. v) Finally, the highest correlation between the photoacoustic amplitude and the moringa concentration occurs at the wavelengths of 300 and 330 nm, which could be related to significant changes in the content of flavonoids and phenolic acids.

RESUMO

Resumen: La Espectroscopia Fotoacústica (EFA), ha destacado de entre las técnicas fototérmicas por su versatilidad para la caracterización de diversos tipos de muestras, incluyendo las de tipo biológicas. En este estudio, se compararon y analizaron mediante EFA, las diferencias entre los espectros de absorción ópticos de sangre de ratas macho Fisher en tres casos, control (ratas sanas), con daño hepático, y con daño hepático tratadas con Curcuma longa. Los resultados experimentales demostraron diferencias en los espectros de absorción ópticos de cada caso analizado, por lo que EFA se propondría como una técnica complementaria, no convencional para el estudio del efecto de la Curcuma longa en daño hepático inducido en modelo animal.

Abstract: Photoacoustic Spectroscopy (PAS) stand outs among Photothermal techniques due to its versatility for the characterization of different types of materials, including biological samples. In this study, were compared and analyzed by PAS, the differences between the optical absorption spectra of blood of male Fisher rats, in three cases, control (healthy rats), liver damage and liver damage treated with Curcuma longa. The experimental results show differences in the optical absorption spectra of each analysed case, therefore PAS would be proposed as a non conventional complementary technique, to study the effect of Curcuma longa in induced liver damage for an animal model.