Studies On Functional Monacsus-nata Complex

Nata de coco is composed of bacterial cellulose, which has such physiological effects as improving digestion, preventing colon cancer, detoxification, keeping fit and so on. On the other hand, when Monascus sp. is fermented in a medium containing nata de coco, some metabolites, such as red koji pigment, monacolin k, will penetrated into nata de coco. And therefore the product, Monascus-nata complex, will have some physiological functions of red koji and nata de coco.Two processes of making monascus-nata complex, including liquid state fermentation (LSF) and solid state fermentation(SSF) were explored. The appearance quality,color value and monacolin k content in the complex were compared, and the results showed that monascus-nata complex produced by LSF was better than that by SSF. The conditions of LSF was optimized as follows: glucose 5%, potatoes 15%, NaNO₃ 0.2%, MgSO₄ 0.1%, ZnSO₄ 0.1%, pH6.0, inoculum 6.5%, and 40 pieces nata (1×1×1cm) in the fermentation liquid, fermented for 13 days at 26℃. Monacolin k content in the product was 152mg/L, and color value was 128.38u/g.The effects of various factors were studied on stability of monacolin k and red koji pigment. The results showed: monacolin k was very unstable to high temperature and high pressure (HTHP, 121℃, 0.1MPa) in autoclave, stable in pH 4⁸, flowing water, boiling water and low temperature (0⁴℃). Red koji pigment was very stable to UV-light, stable to HTHP and pH(3⁹) and boiling water, but not stable to flowing water. The color value dropped to 64.75% when exposed to sunlight for 1 day.