Application of SPR Method as an Approach to Gas Phase Sensing of Volatile Compound Profile in Mezcal Spirits Conferred by Agave Species

Abstract

Mezcal is a traditional Mexican spirit produced by distilling fermented agave, with a unique taste directly related to its volatile compound composition. Thus, the present research proposed the surface plasmon resonance (SPR) technique as a potential method to differentiate mezcals, studying several parameters at angular interrogations and at a fixed angle. The study evaluated eight mezcals from different agave species using SPR and gas chromatography-mass spectrometry (GC-MS). Despite the similarities in mezcal spirits corresponding to the same ethanol content and the same artisanal method, it was possible to obtain well-differentiated characteristics by SPR parameters, such as the width of the curve, the resonant angle, and reflectance intensities. Therefore, it was possible to demonstrate the potential use of the SPR technique as a rapid first approach to a screening test to differentiate types of spirits.

Review of Predator Emitted Volatile Organic Compounds and Their Potential for Predator Detection in New Zealand Forests

“…Electrochemical signals measure the current resulting from the electrochemical reaction between the analyte and a redox electrode, or the potential difference between two electrodes resulting from ion-selective interactions between the analyte and a sensing membrane [162][163][164][165][166][167][168] Surface plasmon resonance (SPR) measure changes in the refractive index near a metal surface due to the binding of analytes [169][170][171][172] Optical signals measure the emission of fluorescent light by a fluorophore attached to the analyte, the emission of light from excited states of a molecule, or the absorption of light by the analyte at specific wavelengths [173][174][175] Electrical signals measure resistance/conductance changes of the sensing material due to analyte adsorption or interaction [176][177][178][179] Colourimetric signals measure changes in colour due to reactions between the analyte and reagents [180][181][182] Acoustic Signals measure changes in sound frequency, amplitude, or velocity attributed to interactions between VOC and sensor [183][184][185] These biosensors can be categorized into distinct types based on the variation in sensing materials and the measuring signals they employ, such as chemiresistors [186] electrochemical biosensors [187][188][189] and optical VOC biosensors [190][191][192]. Diverse VOC biosensors manifest unique sets of advantages and drawbacks.…”