Testing the Efficacy of a Prototype That Combines Ultrasound and Pulsed Electric Field for Extracting Valuable Compounds from Mitragyna speciosa Leaves

This work aimed to test the efficacy of an ultrasound (US) and pulsed electric field (PEF) apparatus to extract mitragynine from dried Mitragyna speciosa cv. Karn Dang leaves. Four modes of the device were tested: PEF, US, US + PEF, and PEF + US, and the modes were compared using a conventional technique (maceration, as the control). The liquid chromatography/mass spectrometry (LC-MS/MS) analysis revealed that the mitragynine contents from M. speciosa leaves using the four different modes were significantly different (p < 0.05). The highest extraction (106.63 ± 0.85 mg/L) of mitragynine was obtained by the mode using a combination of PEF + US, followed by US + PEF (97.27 ± 1.33 mg/L), with increased extraction efficiencies of 45.81 ± 0.59% and 33.00 ± 1.85%, respectively. Moreover, the total energy consumption under the combination technique was 25.0% lower than that with PEF assistance. Scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) were used to analyze the structural and functional features of the alterations in M. speciosa leaves. This study demonstrated that a combination of PEF and US devices may be regarded as a green alternative technique and can assist in streamlining the implementation of agricultural products.