Higher Technical School of Agronomy and Forestry Engineering, University of Castilla-La Mancha, Campus Universitario, s/n, 02071 Albacete, Spain.
Technological Institute of Food and Agriculture CICYTEX-INTAEX, Junta of Extremadura, Avda, Adolfo Suárez, s/n, 06007 Badajoz, Spain.
Nutrients. 2022 Dec 27;15(1):130. doi: 10.3390/nu15010130.
Almonds contain around 50% fat with a health-promoting fatty acid profile that can be extracted by pressing to obtain high-quality oils. To improve oil sensory properties, the almonds can be subjected to roasting treatments before oil extraction. However, intense thermal treatments may cause the appearance of undesirable volatile compounds causing unpleasant aromas. Thus, oils from almonds subjected to different roasting treatments (30, 45, 60 and 90 min at 150 °C) were analyzed from sensory and the chemical points of view. In addition, an electronic device (E-nose) was used in order to evaluate its usefulness in discriminating samples according to their aromas. The almonds’ roasting treatments caused changes in the sensory properties, since defects such as a burned, dry smell or wood fragrance appeared when almonds were subjected to roasting treatments (>45 min). These data agree with the analysis of volatile compounds, which showed an increase in the content of aldehyde and aromatic groups in roasted almonds oils while alcohols and terpenes decreased. Partial least squares discriminant analysis and partial least squares obtained from the E-nose were able to classify samples (97.5% success) and quantify the burned defect of the oils (Rp2 of 0.88), showing that the E-nose can be an effective tool for classifying oils.
杏仁含有约 50%的脂肪，其脂肪酸谱有利于健康，可以通过压榨提取得到高质量的油。为了改善油的感官特性，可以对杏仁进行烘烤处理，然后再进行油提取。然而，强烈的热处理可能会导致出现不良挥发性化合物，产生不愉快的气味。因此，对经过不同烘烤处理（150°C 下 30、45、60 和 90 分钟）的杏仁进行了感官和化学分析。此外，还使用了一种电子设备（电子鼻）来评估其根据香气对样品进行区分的有用性。杏仁的烘烤处理会导致感官特性发生变化，因为当杏仁经过烘烤处理（>45 分钟）时，会出现烧焦、干燥的气味或木材香味等缺陷。这些数据与挥发性化合物的分析结果一致，表明烘烤杏仁油中的醛类和芳香族化合物含量增加，而醇类和萜烯类化合物减少。电子鼻获得的偏最小二乘判别分析和偏最小二乘能够对样品进行分类（成功率为 97.5%），并对油的烧焦缺陷进行定量（Rp2 为 0.88），表明电子鼻可以成为一种有效的油分类工具。
