Matthäus B
Institut für Lipidforschung der Bundesanstalt für Getreide-, Kartoffel- und Fettforschung im Forschungsverbund Ernährungsforschung, Piusallee 76, 48165 Münster, Germany.
J Agric Food Chem. 2002 Jun 5;50(12):3444-52. doi: 10.1021/jf011440s.
Residues of the oil-extracting process of oilseeds contain bioactive substances such as phenolic compounds, which could be used as natural antioxidants for the protection of fats and oils against oxidative deterioration. Thus, the extraction of such constituents from residual material can be considered to contribute to the added value of these residues, which could justify their isolation. In the present work the fat-free residues of eight different oilseeds whose oils are usable for nutritional applications, and also as renewable resources, were extracted with 70% methanol, 70% acetone, water, and ethyl acetate/water, respectively. The resulting extracts were investigated regarding their content of total phenolic compounds by the Folin-Ciocalteau assay, sinapine, flavanoids, and the UV-absorption spectra. Further, the antioxidant activity of the extracts was characterized by the DPPH method, the beta-carotene-linoleic acid assay, and ESR investigations. The fat-free residues of the different oilseeds contained considerable amounts of extractable substances. The yields decreased with decreasing polarity of the solvent in the order water, 70% methanol, 70% acetone, and ethyl acetate. The ratio of total phenolic compounds to the extractable compounds ranged from 3 to 19%. There was no significant correlation between the amount of total extractable compounds and the total phenolic compounds (p < 0.001). All extracts showed remarkable antioxidant activities determined with the different methods. The effects depended strongly on the solvent used for the extraction as well as on the extracted residue. A correlation between the methods used for the characterization of the antioxidant activity and the composition of the residues could not be shown.
油料种子榨油过程中的残渣含有酚类化合物等生物活性物质，这些物质可用作天然抗氧化剂，保护油脂免受氧化变质。因此，从残渣中提取此类成分可被视为有助于提高这些残渣的附加值，这也证明了对其进行分离的合理性。在本研究中，分别用70%甲醇、70%丙酮、水以及乙酸乙酯/水对八种不同油料种子的脱脂残渣进行提取，这些油料种子的油可用于营养应用，也可作为可再生资源。通过福林-酚法、芥子碱、类黄酮以及紫外吸收光谱对所得提取物的总酚类化合物含量进行了研究。此外，还通过DPPH法、β-胡萝卜素-亚油酸法以及电子自旋共振研究对提取物的抗氧化活性进行了表征。不同油料种子的脱脂残渣含有大量可提取物质。提取物的产率随着溶剂极性的降低而降低，顺序为水、70%甲醇、70%丙酮和乙酸乙酯。总酚类化合物与可提取化合物的比例在3%至19%之间。可提取化合物总量与总酚类化合物之间无显著相关性（p < 0.001）。所有提取物用不同方法测定均表现出显著的抗氧化活性。其效果在很大程度上取决于用于提取的溶剂以及所提取的残渣。抗氧化活性表征方法与残渣组成之间未显示出相关性。
