Institute of Agrophysics Polish Academy of Sciences, Doświadczalna 4, 20-290 Lublin, Poland.
Department of Gastronomy Science and Functional Food, Faculty of Food Science and Nutrition, Poznan, University of Life Sciences, Wojska Polskiego 31, 60-634 Poznan, Poland.
Sensors (Basel). 2021 Jan 5;21(1):303. doi: 10.3390/s21010303.
The process of deep fat frying is the most common technological procedure applied to rapeseed oil. During heat treatment, oil loses its nutritional properties and its original consumer quality is lowered, which is often impossible to determine by organoleptic assessment. Therefore, the aim of the study was to correlate markers of the loss of the nutritional properties by rapeseed oil related to the frying time and the surface area of contact with oxygen with changes in the profile of volatile compounds. The investigations involved the process of 6-, 12-, and 18-h heating of oil with a surface-to-volume ratio (s/v ratio) of 0.378 cm, 0.189 cm, and 0.126 cm. Samples were analysed to determine changes in the content of polar compounds, colour, fatty acid composition, iodine value, and total chromanol content. The results were correlated with the emission of volatile compounds determined using gas chromatography and an electronic nose. The results clearly show a positive correlation between the qualitative degradation of the oil induced by prolonged heating and the response of the electronic nose to these changes. The three volumes, the maximum reaction of the metal oxide semiconductor chemoresistors, and the content of polar compounds increased along the extended frying time.
深度油炸过程是应用于菜籽油最常见的技术程序。在热处理过程中，油会失去其营养价值，其原始的消费质量会降低，这通常通过感官评估无法确定。因此，本研究的目的是将与油炸时间和与氧气接触的表面积相关的菜籽油营养特性损失的标志物与挥发性化合物的特征变化相关联。研究涉及在表面体积比（s/v 比）为 0.378 cm、0.189 cm 和 0.126 cm 的情况下，分别对油进行 6、12 和 18 小时的加热过程。分析样品以确定极性化合物含量、颜色、脂肪酸组成、碘值和总色醇含量的变化。结果与使用气相色谱法和电子鼻测定的挥发性化合物的发射相关联。结果清楚地表明，延长加热时间引起的油的定性降解与电子鼻对这些变化的反应之间存在正相关。三种体积、金属氧化物半导体化学电阻器的最大反应以及极性化合物的含量随着油炸时间的延长而增加。
