Al-Hilphy Asaad Rehman, Al-Musafer Alaa M, Gavahian Mohsen
Department of Food Science, College of Agriculture, University of Basrah, Iraq.
Quality Control Department, General Company for Grain Processing, Baghdad, Iraq.
Food Res Int. 2020 Nov;137:109649. doi: 10.1016/j.foodres.2020.109649. Epub 2020 Sep 1.
Recent studies introduced ohmic heating-assisted extraction (OHAE) as a promising emerging technology at laboratory-scales. The objectives of the present study were, first, to investigate the applicability of OHAE at pilot-scale for extraction of bioactive compounds from wheat bran immersed in a polar solvent (salted water containing 0.1% NaCl) at the electric field strengths (EFS) of 4.28, 7.90, and 15.71 V/cm and, second, to evaluate the effects of the wheat extracts on the corn oil stability during 30 days of storage at 45 °C. The results showed that OHAE saved 63% of energy consumption compared with the conventional extraction method. Also, the scaled-up OHAE unit yielded extracts with high quantities of bioactive compounds (110-460 ppm total phenolics) and higher antioxidant activities (antioxidant effectiveness of 56-84%) than those of the extract obtained through the conventional extraction method, i.e., 95 ppm total phenolics with antioxidant effectiveness of 51%. Increasing the EFS increased total phenolics and antioxidant effectiveness of extracts. The incorporation of 250 ppm of the extract obtained at the highest EFS effectively postponed the oxidation of corn oil during one month of storage (peroxide value of 7 vs. 19 meq/kg compared with the control sample) and extended the half-life of oil from 11 to 26 days. Besides, mathematical models proposed in this study well-predicted the oxidation stability of the oil samples mixed with the extract.
最近的研究将欧姆加热辅助提取（OHAE）作为一种在实验室规模上很有前景的新兴技术。本研究的目的，首先是在中试规模下研究OHAE在从浸泡在极性溶剂（含0.1% NaCl的盐水）中的麦麸中提取生物活性化合物的适用性，电场强度（EFS）分别为4.28、7.90和15.71 V/cm；其次是评估小麦提取物在45℃储存30天期间对玉米油稳定性的影响。结果表明，与传统提取方法相比，OHAE节省了63%的能源消耗。此外，放大后的OHAE装置所得到的提取物含有大量生物活性化合物（总酚含量为110 - 460 ppm），且抗氧化活性更高（抗氧化效果为56 - 84%），高于通过传统提取方法得到的提取物，即总酚含量为95 ppm，抗氧化效果为51%。提高EFS可增加提取物的总酚含量和抗氧化效果。添加250 ppm在最高EFS下获得的提取物可有效延缓玉米油在一个月储存期内的氧化（与对照样品相比，过氧化值为7 vs. 19 meq/kg），并将油的半衰期从11天延长至26天。此外，本研究中提出的数学模型能很好地预测与提取物混合的油样的氧化稳定性。
