Determination of Melatonin in Rice (Oryza sativa) Grains by Pressurized Liquid Extraction

作者:Setyaningsih Widiastuti; Estiono Saputro Irfan; Fernandez Barbero Gerardo; Palma Miguel*; Garcia Barroso Carmelo
来源:Journal of Agricultural and Food Chemistry, 2015, 63(4): 1107-1115.
DOI:10.1021/jf505106m

摘要

Melatonin provides a number of benefits for human health. The study reported here concerns the optimization, validation, and application of analytical pressurized liquid extraction and high-performance liquid chromatography coupled to a fluorescence detector for the determination of melatonin in rice grains. The factors that are most likely to affect the extraction efficiency were optimized with a 2(IV)(7-2) fractional factorial design. The optimum extraction conditions were achieved by applying 70% EtOAc in MeOH at 200 degrees C and 200 atm for a static time of 5 min in two cycles with 50% flushing and a 60 s purge to extract a 2.5 g rice sample. The method validation ensured excellent linearity, limit of detection, limit of quantification, precision, and recovery. Furthermore, the method was applied to various rice products composed of polished, whole grain, aromatic, black, black glutinous, red, and parboiled rice. All kinds of pigmented rice grains showed high levels of melatonin (>100 mu g kg(-1)), and the highest levels were found in red rice.

  • 出版日期2015-2-4