Lee Chun-Lin, Chen Wen-Pei, Wang Jyh-Jye, Pan Tzu-Ming
Institute of Microbiology and Biochemistry, National Taiwan University, Taipei, Taiwan, Republic of China.
J Agric Food Chem. 2007 Dec 26;55(26):11101-8. doi: 10.1021/jf071640p. Epub 2007 Nov 30.
Monascus species-fermented red mold rice (RMR) has been regarded as a popular hypolipidemic functional food because it contains monacolin K, an inhibitor of de novo cholesterol synthesis. However, the safety of RMR is always an issue because citrinin is present in RMR and is reported to be hepatotoxic and nephrotoxic. The present study was therefore to develop a postprocess to remove citrinin yet retain monacoln K in the RMR preparation. We found that phosphate-ethanol extraction was effective for the removal citrinin, yet it could retain monacolin K, because the former was more hydrophilic than the latter in phosphate-ethanol solution. Ethanol, phosphate, and extraction time were optimized as factors of response surface methodology (RSM). It was found that the optimal RSM condition was 45% ethanol, 1.5% phosphate, and extraction for 70 min. Under this optimal condition, 91.6% citrinin was removed and 79.5% monacolin K was retained in the final RMR.
红曲霉菌发酵的红曲米（RMR）因其含有莫纳可林K（一种从头合成胆固醇的抑制剂）而被视为一种广受欢迎的降血脂功能性食品。然而，RMR的安全性一直是个问题，因为RMR中存在桔霉素，据报道桔霉素具有肝毒性和肾毒性。因此，本研究旨在开发一种后处理方法，以去除RMR制剂中的桔霉素，同时保留莫纳可林K。我们发现磷酸 - 乙醇萃取法对去除桔霉素有效，且能保留莫纳可林K，因为在磷酸 - 乙醇溶液中，桔霉素比莫纳可林K更具亲水性。乙醇、磷酸盐和萃取时间作为响应面法（RSM）的因素进行了优化。结果发现，RSM的最佳条件是45%乙醇、1.5%磷酸盐，萃取70分钟。在此最佳条件下，最终的RMR中91.6%的桔霉素被去除，79.5%的莫纳可林K得以保留。
