A single extraction and HPLC procedure for simultaneous analysis of phytosterols, tocopherols and lutein in soybeans

• Published in: Food chemistry Vol. 135; no. 4; pp. 2789 - 2795
• Main Authors: Slavin, Margaret, Yu, Liangli (Lucy)
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 15.12.2012; Elsevier
• Subjects: Biological and medical sciences; campesterol; Chemical Fractionation; Chromatography, High Pressure Liquid - methods; ELSD HPLC; Food engineering; Food industries; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; General aspects; Glycine max - chemistry; high performance liquid chromatography; light scattering; Lutein; Lutein - analysis; Lutein - isolation & purification; methanol; Phenyl column; Phytosterol; Phytosterols - analysis; Phytosterols - isolation & purification; Plant Extracts - analysis; Plant Extracts - isolation & purification; saponification; Soy; soybeans; stigmasterol; Tocopherol; tocopherols; Tocopherols - analysis; Tocopherols - isolation & purification; Lutein; Phenyl column; ELSD HPLC; Soy; Tocopherol; Phytosterol; Xanthophyll; HPLC chromatography; Lipids; Soybean; Grain legume; Analysis; Pigments; Tocopherols; Extraction; Carotenoid
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2012.06.043

► New HPLC method developed to measure sterols, tocopherols and lutein in soybeans. ► Direct saponification of ground soybeans is used to simplify extraction. ► The ELSD was used to analyze tocopherols and sterols, and UV to quantify lutein. ► Phenyl column may produce better resolution through π–π interactions. A saponification/extraction procedure and high performance liquid chromatography (HPLC) analysis method were developed and validated for simultaneous analysis of phytosterols, tocopherols and lutein (a carotenoid) in soybeans. Separation was achieved on a phenyl column with a ternary, isocratic solvent system of acetonitrile, methanol and water (48:22.5:29.5, v/v/v). Evaporative light scattering detection (ELSD) was used to quantify β-sitosterol, stigmasterol, campesterol, and α-, δ- and γ-tocopherols, while lutein was quantified with visible light absorption at 450nm. Peak identification was verified by retention times and spikes with external standards. Standard curves were constructed (R2>0.99) to allow for sample quantification. Recovery of the saponification and extraction was demonstrated via analysis of spiked samples. Also, the accuracy of results of four soybeans using the described saponification and HPLC analytical method was validated against existing methods. This method offers a more efficient alternative to individual methods for quantifying lutein, tocopherols and sterols in soybeans.