Abstract Black pepper oils have been investigated frequently in the recent years. However, there is a significant variation in physicochemical properties and bioactivity of oils depended on extraction techniques. In this study, the systemic investigation of four various extraction methods was performed to evaluate the physicochemical characterizations, antioxidant and antibacterial activity. The investigation of 1H NMR, FTIR and UV–Vis spectra confirmed presence of non-volatile components in oils extracted through supercritical CO2 and hexane-soaking extractions which induced their typical thermal properties. The isothermal behaviour of extracted oils related to evaporation was within range of 3.2–7.3% (w/w) at 27 °C. The SEM images of the black pepper confirmed different operation manners of mechanism between extractions using the solvents and heating process. The lowest MIC for both essential oils from conventional hidrodistillation and microwave-assisted hidrodistillation against two bacteria including E. coli and B. subtilis were found to be 137 µg mL−1. The non-isothermal decomposition kinetics were investigated on the essential oil of microwave-assisted hydrodistillation extraction. The activation energies and pre-exponent factors of non-isothermal decomposition were found to be in range of 36.5–73.7 KJ mol−1 and 4.98 × 103–1.97 × 108 s−1, respectively, dependent on conversional fractions of the oil. The results revealed that chemical components, physicochemical properties and bioactivity of black pepper essential oils depended on the extraction techniques.

中文翻译：

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提取物对黑胡椒油理化特性和生物活性的影响：非等温分解动力学研究

摘要 近年来，人们对黑胡椒油进行了频繁的研究。然而，取决于提取技术，油的物理化学性质和生物活性存在显着差异。在本研究中，对四种不同的提取方法进行了系统研究，以评估其理化特性、抗氧化和抗菌活性。1H NMR、FTIR 和 UV-Vis 光谱的研究证实，通过超临界 CO2 和己烷浸泡提取的油中存在非挥发性成分，这导致了它们的典型热特性。与蒸发相关的提取油的等温行为在 27°C 时在 3.2-7.3% (w/w) 的范围内。黑胡椒的 SEM 图像证实了使用溶剂和加热过程提取之间机制的不同操作方式。发现来自常规水蒸馏和微波辅助水蒸馏的两种精油对两种细菌（包括大肠杆菌和枯草芽孢杆菌）的最低 MIC 为 137 µg mL-1。研究了微波辅助水蒸馏提取精油的非等温分解动力学。发现非等温分解的活化能和指数前因子分别在 36.5-73.7 KJ mol-1 和 4.98 × 103-1.97 × 108 s-1 的范围内，这取决于油的转化率。结果表明，化学成分，