Simultaneous detection of monacolins and citrinin of angkak produced by monascus purpureus strains using liquid chromatography-mass spectrometry (LC-MS/MS)

Abstract

Angkak or red mold rice is produced from the fermentation of white rice using Monascus purpureus, which results in the red color of the fermented rice. Angkak has been used as a natural coloring agent for food, spices, and medicine. The active compound in angkak that contributes to lower blood cholesterol is known as monacolin (monacolin K). However, the presence of citrinin, the byproduct of angkak fermentation, needs to be considered as it can cause hepato-nephrotoxic mycotoxin. The contents of pigments, monacolins, and citrinin as secondary metabolites depends on the Monascus strain and fermentation conditions. This study aims to analyze simultaneously monacolins and citrinin in angkak produced by M. purpureus strains using Liquid Chromatography-Mass Spectrometry (LC-MS/MS). The angkak was prepared by fermentation using M. purpureus FNCC 6008 and M. purpureus JK2. A total of 107 M. purpureus spores/mL was inoculated into the rice. The fermentation was carried out at room temperature (25-30oC) for 14 days. The detection using LC-MS/MS showed that the monacolin K in angkak from both strains was below LOQ (