Determination of phytosterols in Oryza sativa L. cultivars by liquid chromatography atmospheric chemical ionization time-of-flight mass spectrometer (LC-APCI-TOF-MS) coupled with a modified QuEChERS method

Seung Rok Lee, Dong Cheon Yun, Seung Ho Lee, Si Young Yang, In Seon Kim

Division of Applied Bioscience and Biotechnology, Institute of Environmentally-Friendly Agriculture, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, Republic of Korea.

DOI: 10.4236/jacen.2012.11003                

Abstract

Development of analytical methods for the determination of phytosterols in whole grains is one of growing interests due to their clinical and nutritional functions in human. In this study, we examined simultaneous determination of β-si tosterol, stigmasterol and campesterol in Korean rice cultivars by liquid chromatography atmospheric chemical ionization time-of-flight mass spectrometer (LC-APCI-TOF-MS). The hulled rice samples were extracted using a modified QuEChERS and analyzed by LC-APCI -TOF-MS. The method was validated by low limit of detection (LOD) and limit of quantification (LOQ) values and high recovery values with low relative standard deviation (RSD). The highest concentration of sitosterol was detected in Hwasung and Undu rice cultivars, exhibiting approximately 195.5 and 191.7 mg/Kg, respectively. Stigmasterol and campesterol were detected at the highest level in Hwasung rice cultivar, giving the concentrations of approximately 70.0 and 53.9 mg/Kg, respectively. Sitosterol was determined to be a main phytosterol detected in the rice samples. Our data demonstrated that LC/APCI-TOF- MS coupled with QuEChERS method can be used as a simple tool for the determination of phytosterols in rice samples.

Keywords

Campesterol; Phytosterols; QuEChERS; Sitosterol; Stigmasterol; Rice

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Tham, D.M. (1998) Potential health benefits of dietary phytoestrogens: A review of the clinical, epidemiological, and mechanistic evidence. The Journal of Clinical Endocrinology and Metabolism, 83, 2223-2235. doi:10.1210/jc.83.7.2223
[2]	Piironen, V., Lindsay, D., Miettinen, T., Toivo, J. and Lampi A.-M. (2000) Plant sterols: Biosynthesis, biological function and their importance to human nutrition. Journal of the Science of Food and Agriculture, 80, 939-966. doi:10.1002/(SICI)1097-0010(20000515)80:7<939::AID-JSFA644>3.0.CO;2-C
[3]	Awd, A.B. and Fink, C.S. (2000) Phytosterols as anticancer dietary components: Evidence and mechanism of action. Journal of Nutrition, 130, 2127-2130.
[4]	Andersson, S.W., Skinner, J., Ellegard, L., Welch, A.A., Bingham, S., Mulligan, A., Andersson, H. and Khaw, K.T. (2004) Intake of dietary plant sterols in inversely related to serum cholesterol concentration in men and women in the EPIC Norfolk populations: A cross-sectional study. European Journal of Clinical Nutrition, 58, 1378-1385. doi:10.1038/sj.ejcn.1601980
[5]	Akihisa, T., Kokke, W. and Tamura, T. (1991) Naturally occurring sterols and related compounds from plants. In: Patterson, G.W. and Nes, W.D., Eds., Physiology and Biochemistry of Sterols, American Oil Chemists’ Society, Champaign, 172-228.
[6]	Eussen, S.R.B.M., Feenstra, T.L., Toxopeus, I.B., Hoekstra, J., Klungel, O.H., Verhagen, H., Van Karen, H.J. and Rompelberg, C.J.M. (2011) Costs and health effects of adding functional foods containing physterols/-stanols to statin therapy in the prevention of cardiovascular disease. European Journal of Pharmacology, 668, S91-S100. doi:10.1016/j.ejphar.2011.05.081
[7]	Choudhary, S.P. and Tran, L.S. (2011) Phytosterols: Perspectives in human nutrition and clinical therapy. Current Medicinal Chemistry, 18, 4557-4567. doi:10.2174/092986711797287593
[8]	Jones, P.J. and Abumweis, S.S. (2009) Phytosterols as functional food ingredients: Linkages to cardiovascular disease and cancer. Current Opinion in Clinical Nutrition and Metabolic Care, 12, 147-151. doi:10.1097/MCO.0b013e328326770f
[9]	Liu, R.H. (2007) Whole grain phytochemicals and health. Journal of Cereal Science, 46, 207-219. doi:10.1016/j.jcs.2007.06.010
[10]	Lu, T.-J., Chen, H.-N. and Wang, H.-J. (2011) Chemical constituents, dietary fiber, and γ-oryzanol in six commercial varieties of brown rice from Taiwan. Cereal Chemistry, 88, 463-466. doi:10.1094/CCHEM-09-10-0132
[11]	Gani, A., Wani, S.M., Masoodi, F.A. and Hameed, G. (2012) Whole-grain cereal bioactive compounds and their health benefits: A review. Food Processing and Technology, 3, 1-10.
[12]	Lloyd, B.J., Siebenmorgen, T.J. and Beers, K.W. (2000) Effect of commercial processing on antioxidants in rice ban. Cereal Chemistry, 77, 551-555. doi:10.1094/CCHEM.2000.77.5.551
[13]	Phillips, K.M., Ruggio, D.M. and Bailey, J.A. (1999) Precise quantitative determination of phytosterols, stanols, and cholesterol metabolites in human serum by capillary gas-liquid chromatography. Journal of Chromatography B, 732, 17-29. doi:10.1016/S0378-4347(99)00257-1
[14]	Kasama, T., Byun, D.-S. and Seyama, Y. (1987) Quantitative analysis of sterols in serum by high performance liquid chromatography: Application to the biochemical diagnosis of cerebrotendinous xanthomatosis. Journal of Chromatography A, 400, 214-246.
[15]	Chevy, F., Humbert, L. and Woilf, C. (2005) Sterol profiling of amniotic fluid: A routine method for the detection of distal cholesterol synthesis deficit. Prenatal Diagnosis, 25, 1000-1006. doi:10.1002/pd.1254
[16]	Careri, M., Elviri, L. and Mangia, A. (2001) Liquid chromatography-UV determination and liquid chromatography-atmospheric pressure chemical ionization mass spectrometric characterization of sitosterol and stigmasterol in soybean oil. Journal of Chromatography A, 935, 249-257. doi:10.1016/S0021-9673(01)01079-2
[17]	Anastassiades, M., Lehotay, S.J., Stajnbaher, D. and Schenck, F.F. (2003) Fast and easy multiresidue method employing acetonitrile extraction/partitioning and “dispersive solidphase extraction” for the determination of pesticide residues in produce. Journal of AOAC International, 86, 412-431.
[18]	Gilbert-López, B., García-Reyer, J.F., Mezcua, M., Milina-Díaz, A. (2009) Sample treatment and determination of pesticide residues in fatty vegetable matrices. Talanta, 79, 109-128. doi:10.1016/j.talanta.2009.04.022
[19]	Bong, M.S., Yang, S.Y., Lee, S.H., Seo, J.M. and Kim, I.S. (2011) Simultaneous analysis of conazole fungicides in garlic by Q-TOF mass spectrometer coupled with a modified QuEChERS method. Korean Journal of Environmental Agriculture, 30, 324-330.
[20]	Lehotay, S., Son, K., Kwon, H., Koesukwiwat, U., Fu, W., Mastovska, K., Hoh, E. and Leepipatpiboon, N. (2010) Comparison of QuEChERS sample preparation methods for the analysis of pesticide residues in fruit and vegetables. Journal of Chromatography A, 1217, 2548-2560. doi:10.1016/j.chroma.2010.01.044