This work explores the feasibility of applying in situ Raman spectroscopy for the online monitoring of the supercritical carbon dioxide (SC-CO₂) drying of fruits. Specifically, we investigate two types of fruits: mango and persimmon. The drying experiments were carried out inside an optical accessible vessel at 10 MPa and 313 K. The Raman spectra reveal: (i) the reduction of the water from the fruit slice and (ii) the change of the fruit matrix structure during the drying process. Two different Raman excitation wavelengths were compared: 532 nm and 785 nm. With respect to the quality of the obtained spectra, the 532 nm excitation wavelength was superior due to a higher signal-to-noise ratio and due to a resonant excitation scheme of the carotenoid molecules. It was found that the absorption of CO₂ into the fruit matrix enhances the extraction of water, which was expressed by the obtained drying kinetic curve.
In Situ Raman Analysis of CO₂-Assisted Drying of Fruit-Slices / Braeuer, Andreas Siegfried; Schuster, Julian Jonathan; Gebrekidan, Medhanie Tesfay; Bahr, Leo; Michelino, Filippo; ZAMBON, ALESSANDRO; SPILIMBERGO, SARA. - In: FOODS. - ISSN 2304-8158. - STAMPA. - 6:37(2017), pp. 1-11. [10.3390/foods6050037]
In Situ Raman Analysis of CO₂-Assisted Drying of Fruit-Slices
ZAMBON, ALESSANDRO;
2017
Abstract
This work explores the feasibility of applying in situ Raman spectroscopy for the online monitoring of the supercritical carbon dioxide (SC-CO₂) drying of fruits. Specifically, we investigate two types of fruits: mango and persimmon. The drying experiments were carried out inside an optical accessible vessel at 10 MPa and 313 K. The Raman spectra reveal: (i) the reduction of the water from the fruit slice and (ii) the change of the fruit matrix structure during the drying process. Two different Raman excitation wavelengths were compared: 532 nm and 785 nm. With respect to the quality of the obtained spectra, the 532 nm excitation wavelength was superior due to a higher signal-to-noise ratio and due to a resonant excitation scheme of the carotenoid molecules. It was found that the absorption of CO₂ into the fruit matrix enhances the extraction of water, which was expressed by the obtained drying kinetic curve.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.