Tavakoli Atefeh, Sahari Mohammad Ali, Barzegar Mohsen, Ahmadi Gavlighi Hassan, Marzocchi Silvia, Marziali Sara, Caboni Maria
Faculty of Agriculture, Department of Food Science and Technology, Tarbiat Modares University, Tehran, Iran.
Interdepartmental Centre for Agri-Food Industrial Research, Alma Mater Studiorum, University of Bologna, Cesena, Italy.
J Food Sci. 2022 Oct;87(10):4363-4378. doi: 10.1111/1750-3841.16312. Epub 2022 Sep 14.
In this study, the high voltage electric field (HVEF) method was used for deodorization of sunflower oil to omit drawbacks of an established industrial method including long time, high energy, chemicals and water consumption, loss of bioactive compounds, and formation of some contaminants due to exposure to heat. Response surface methodology (RSM) was employed to find the optimal values of processing parameters. The effects of voltage (5-15 kV), clay (0-1%), electrolyte concentration (0-50 mM), the number of electrodes (1-5 pairs), and electrodes distance (1-3 cm) on the volatile compounds and tocopherols content were investigated by HS-SPME-GC/MS and HPLC, respectively. The optimal processing conditions were determined to be a voltage of 5 kV, a distance of 1 cm between the electrodes and a number of five pairs of electrodes. The amount of bleaching clay and electrolyte concentration were zero under optimal conditions. The refining process by HVEF removed 32.33% of the volatile compounds from crude sunflower oil, while the industrial refining process reduced the volatile compounds by only 17.78%. Results indicated no change was observed in the tocopherols content of refined sunflower oil by HVEF method. Based on PCA results, HVEF-treated sample not only contained the lowest concentration of volatile compounds but also was the most similar to crude sample in terms of volatile compounds composition. PRACTICAL APPLICATION: The oil refining process consists of four main stages, the last of which is deodorization. This step involves injecting steam at a temperature of about 240°C, under vacuum for about 50 min. High voltage electric field (HVEF) was able to reduce the number of volatile compounds, while no change was made in the tocopherol content of sunflower oil samples. It also does not form contaminant such as 3-monochloropropane-1,2-diol fatty acid esters and glycidyl fatty acid esters. There is no need to apply the vacuum in HVEF refining, which reduces the production cost and makes the process flow straightforward as well as rapid. This research helps to propagate green refining procedures of vegetable oils in food plants.
在本研究中，采用高压电场（HVEF）法对葵花籽油进行脱臭，以克服现有工业方法的缺点，如时间长、能耗高、消耗化学物质和水、生物活性成分损失以及因受热形成一些污染物等问题。采用响应面法（RSM）来确定加工参数的最佳值。分别通过顶空固相微萃取-气相色谱/质谱联用（HS-SPME-GC/MS）和高效液相色谱（HPLC）研究了电压（5 - 15 kV）、白土（0 - 1%）、电解质浓度（0 - 50 mM）、电极对数（1 - 5对）和电极间距（1 - 3 cm）对挥发性化合物和生育酚含量的影响。确定最佳加工条件为电压5 kV、电极间距1 cm和电极对数为5对。在最佳条件下，白土用量和电解质浓度均为零。HVEF精炼工艺去除了粗葵花籽油中32.33%的挥发性化合物，而工业精炼工艺仅将挥发性化合物减少了17.78%。结果表明，采用HVEF法精炼的葵花籽油中生育酚含量未发生变化。基于主成分分析（PCA）结果，经HVEF处理的样品不仅挥发性化合物浓度最低，而且在挥发性化合物组成方面与粗样品最为相似。实际应用：油脂精炼过程包括四个主要阶段，最后一个阶段是脱臭。这一步骤涉及在约240°C的温度下、真空条件下注入蒸汽约50分钟。高压电场（HVEF）能够减少挥发性化合物的数量，同时葵花籽油样品中的生育酚含量没有变化。它也不会形成如3-氯-1,2-丙二醇脂肪酸酯和缩水甘油脂肪酸酯等污染物。HVEF精炼无需抽真空，这降低了生产成本，使工艺流程简单且快速。本研究有助于在食品工厂推广植物油的绿色精炼工艺。
