College of Food Science and Engineering & Institute of Special Oilseed Processing and Technology, Henan University of Technology.
J Oleo Sci. 2022 Dec 3;71(12):1799-1811. doi: 10.5650/jos.ess22258. Epub 2022 Nov 7.
In this study, tigernut oil was extracted from tigernut meal by subcritical n-butane extraction with the assistance of microwave pretreatment. Effects of microwave pulse duration, particle size of tigernut meal, and subcritical extraction variables (temperature, time, solid-liquid ratio, number of extraction cycles) on extraction efficiency were examined by single-factor experiments and Response Surface Methodology (RSM) modeling. The results indicate that microwaving (560 W, 6 min) significantly increased the subcritical extraction efficiency. The variation of extraction yield could be interpreted as a nonlinear function of extraction time, temperature and liquid-solid ratio. Changing the independent variables could affect the oil extraction efficiency. The subcritical extraction of tigernut oil with a liquid-solid ratio of 3.62 kg/(kg of tigernut meal) at a temperature of 52°C for 32 min after three extraction cycles produced the most oil, and a maximum yield (24.736%) of tigernut oil was achieved. The ratio of unsaturated to saturated fatty acids (4.68 UFA/SFA), low acid value (3.30 mg KOH/g oil), low peroxide value (0.28 meq.kg), and preponderance of oleic acid indicate a high-quality oil. To describe the extraction kinetics, a modified Brunner's mathematical model was used. The model fit the experimental data well over the entire operating range, and the explanation coefficient exceeds 96%. Our results can be used to develop an optimized method for subcritical fluid extraction of tigernut oil and can move industry further toward implementing microwave-assisted subcritical extraction in oil processing.
在这项研究中，采用亚临界正丁烷萃取法，并辅以微波预处理，从菱角粉中提取菱角油。通过单因素实验和响应面法（RSM）建模，考察了微波脉冲持续时间、菱角粉粒径和亚临界萃取变量（温度、时间、固液比、萃取循环数）对萃取效率的影响。结果表明，微波处理（560 W，6 min）显著提高了亚临界萃取效率。萃取产率的变化可以解释为萃取时间、温度和液固比的非线性函数。改变自变量会影响油的萃取效率。在 3 次萃取循环后，在固液比为 3.62 kg/（kg 菱角粉）、温度为 52°C、时间为 32 min 的条件下进行亚临界萃取，可获得最多的油，菱角油的最大产率（24.736%）。不饱和脂肪酸与饱和脂肪酸的比值（4.68 UFA/SFA）、低酸值（3.30 mg KOH/g 油）、低过氧化物值（0.28 meq.kg）和油酸优势表明，这是一种高质量的油。为了描述萃取动力学，使用了改进的 Brunner 数学模型。该模型在整个操作范围内很好地拟合了实验数据，解释系数超过 96%。我们的研究结果可用于开发优化的亚临界流体萃取菱角油的方法，并进一步推动微波辅助亚临界萃取在油脂加工中的应用。
