This study aims to improve the efficiency of lycopene extraction from gac (Momordica cochinchinensis Spreng.) by the Z‐isomerization induced with microwave irradiation pre‐treatment. Although 93.6% of lycopene exist as all‐E‐isomers in dried gac aril, the total Z‐isomer content reaches 35.6 and 58.5% by microwave irradiation at 900 W for 40 s and at 1050 W for 60 s, respectively. The 35.6 and 58.5% Z‐isomerization treatment improves lycopene content of extract (by 6.0 or 8.5 times for press extraction, 7.8 or 13.5 times for ethanol extraction, and 4.5 or 6.1 times for supercritical CO2 (SC‐CO2)extraction, respectively) compared with no treatment. In addition, the extracts containes high amounts of lycopene Z‐isomers, which have higher bioavailability and antioxidant capacity than (all‐E)‐lycopene. Practical Applications: This study clearly shows that lycopene recovery by press, organic solvent, and SC‐CO2 extraction from dried gac aril improved by the increase in the Z‐isomer content. It indicates that the Z‐isomers are more soluble in oil, organic solvent, and SC‐CO2 than the all‐E‐isomer. Moreover, the thermal Z‐isomerization pre‐treatment increases the content of lycopene Z‐isomers in the extract. Therefore, this procedure is important not only for improving the productivity of lycopene, but also for providing a highly functionalized extract. The effect of the Z‐isomerization, induced by microwave irradiation pre‐treatment of gac (Momordica cochinchinensis Spreng.) aril, on the lycopene recovery and lycopene content of the extracts obtained using press, ethanol, and SC‐CO2 extractions is investigated. For all extraction methods, as the content of Z‐isomers in the raw material increases, the recovery and lycopene content of gac extracts improve.

In this study, an atmospheric‐pressure nanosecond impulse discharge initiated above the pyrrole microemulsion surface is applied to polymerize pyrrole and obtain a polypyrrole film. The films obtained under different number of plasma discharge times and duration of argon gas input time are investigated using a field emission scanning electron microscope. Results show that the roughness and thickness of the polypyrrole film can be tuned by controlling discharge times and the gas feed time. Four‐point sheet resistance measurements of the films reflect that those with a smoother and more complete surface have better electrical conductivity. The films are identified as polypyrrole by Fourier‐transform infrared spectroscopy, X‐ray diffraction, and X‐ray photoelectron spectrometry. Also, N2 is a critical factor in polymerizing polypyrrole and the gas–liquid plasma polymerization mechanism, which has three steps, is discussed.

Chemical reactions of amino acids induced by discharge plasma are important for understanding the mechanism of biological effects of discharge plasma in biomedical applications. In this study, we generated a nano-second pulsed discharge plasma under atmospheric pressure over an aqueous solution containing glycine. The reaction products after the pulsed discharge plasma treatments were analyzed by high-performance liquid chromatography and matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy. The oligomerization reaction of glycine was induced in aqueous solution and produced glycine oligomers at the beginning of the discharge plasma. However, the glycine oligomers were decomposed into products with low molecular weight by excessive pulsed discharge plasma. According to comparative experiments, physical force of the plasma is believed to induce the glycine reaction. Moreover, the reactions depended on the pH, but not the conductivity, of the glycine solution. Glycine in aqueous solution was reacted by the discharge plasma only at neutral pH because the reaction proceeded only when glycine ions were in the zwitterionic state. Anions and cations of glycine reacted very little under the discharge plasma.

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