Effects of electrostatic field treatment on the maturation characteristics of rum and its mechanism

The effect of applying an electrostatic field treatment to rum and its underlying reaction mechanism based upon a model system were investigated in this study. A field intensity of 1 kV·cm−1 and processing time of 30 min were the optimal treatment conditions, the content of (desirable) ester was increased to 219.57 ± 4.61 μg·mL−1, and the content of (undesirable) fusel oil was decreased to 643.37 ± 15.26 μg·mL−1, compared with the control (208.42 ± 2.31 μg·mL−1 and 707.04 ± 2.21 μg·mL−1, respectively). In addition, Odorant Activity Value (OAV) analysis showed that there were 15 main flavor components (OAV  > 1) in rum, and the concentrations of 13 flavor components were increased after 1 kV·cm−1 electrostatic field treatment, indicating that the flavor quality of rum was improved. When the electrostatic field intensity was 0.5, 1, and 2 kV·cm−1, the rate constant (k) of the esterification reaction increased in the ethanol-acetic acid model system, and the activation energy decreased from 47.7 kJ·mol−1 to 46.1, 40.6 and 38.6 kJ·mol−1, respectively. This showed that the electrostatic field treatment was helpful to the esterification reaction in the rum simulation system. 1H NMR results showed that δET-OH, δH-OH, δCH3, and δCH3 in the ethanol–water model system were all increased when the electrostatic field strength was 0.5, 1, 2, and 4, respectively. This showed that the electrostatic field treatment promoted the hydrogen bond association between ethanol and water molecules in the rum simulation system. Therefore, the maturation process in rum was accelerated and the quality of the rum was improved by electrostatic field treatment.