Mohseni Nazanin Maryam, Mirzaei Habibollah, Moghimi Masoumeh
Department of Food Science and Technology Sari Branch Islamic Azad University Sari Iran.
Department of Food Materials and Process Design Engineering University of Agricultural Sciences and Natural Resources Gorgan Iran.
Food Sci Nutr. 2020 Jan 28;8(3):1383-1393. doi: 10.1002/fsn3.1396. eCollection 2020 Mar.
In this study, oil extraction from Niger seeds was evaluated with different microwave irradiation times (0-200 s) and pulsed electric fields (PEF) intensities (0-5 kV/cm) as pretreatments. Then, oil extraction was completed with a screw press at different rotation speeds (11-57 rpm). Quality parameters including extraction efficiency, acidity and peroxide values (PVs), chlorophyll, and phenolic contents along with fatty acid profiles and tocopherol levels of the extracted oils were determined as responses. With enhancements in microwave time, PEF intensity and press rotation, the chlorophyll contents, acidity/PVs, and total phenolics of oils increased similar to oil extraction efficiency although it was reduced later. The optimized conditions selected by response surface methodology were determined as 156.23 s, 1.18 kV/cm, and 20 rpm for microwave time, PEF intensity and press speed, respectively. Fatty acid analysis revealed that linoleic acid was the most predominant fatty acid in the extracted oil. Application of the mentioned pretreatments may lead to a reduction in unsaturated fatty acids and escalation of saturated ones ( < .05). High-performance liquid chromatography results indicated that α-tocopherols are the most common tocopherols in Niger seed oil and microwave-PEF pretreatments may lead to 2.79% increase in tocopherols content.
在本研究中，以不同的微波辐照时间（0 - 200秒）和脉冲电场（PEF）强度（0 - 5 kV/cm）作为预处理，对从黑芝麻中提取油脂进行了评估。然后，使用螺旋压榨机在不同转速（11 - 57转/分钟）下完成油脂提取。测定了包括提取效率、酸度和过氧化值（PVs）、叶绿素、酚类含量以及提取油脂的脂肪酸谱和生育酚水平等质量参数作为响应指标。随着微波时间、PEF强度和压榨转速的增加，油脂的叶绿素含量、酸度/PVs和总酚类物质与油脂提取效率相似地增加，尽管后期有所降低。通过响应面法选择的优化条件分别确定为微波时间156.23秒、PEF强度1.18 kV/cm和压榨速度20转/分钟。脂肪酸分析表明，亚油酸是提取油脂中最主要的脂肪酸。上述预处理的应用可能导致不饱和脂肪酸减少，饱和脂肪酸增加（P < 0.05）。高效液相色谱结果表明，α - 生育酚是黑芝麻油中最常见的生育酚，微波 - PEF预处理可能使生育酚含量增加2.79%。
