Monascus pilosus BCRC 31526發酵黑豆麴中γ-胺基丁酸、酚酸之組成及其對一些生理活性之影響

Abstract

本研究利用Monascus pilosus BCRC 3152在30℃下進行黑豆之固態發酵十天，進而探討所製備黑豆麴之機能性成分 (酚酸、γ-胺基丁酸) 並測試黑豆麴中麩胺酸脫羧酶 (glutamate decarboxylase, GAD )活性，胺基態氮 (amino nitrogen) 之含量及其對脂多醣誘發NO、TNF-α發炎因子之影響。結果顯示，在30℃下所製備之黑豆麴中，其酚酸 (phenolic acid) 、胺基態氮含量隨著發酵天數之延長而提高。酚酸含量於發酵期間第十天時達最高，與未發酵黑豆相比其含量顯著提升2.04倍 (p < 0.05)。在發酵過程中麩胺酸脫羧酶活性在發酵時間第六天達到最高，其所生成之γ-胺基丁酸含量亦為最高。胺基態氮含量則隨著發酵天數增加而顯著增加。不論黑豆或黑豆麴甲醇萃取物在濃度為15 μg/mL時，均能顯著降低由脂多醣誘導RAW264.7所產生之NO及TNF-α之生成，當濃度為15 μg/mL時，抑制能力隨發酵天數增加而提升，其中又以發酵十天之黑豆麴甲醇萃取物效果最佳。

In this study, a solid fermentation was performed on black soybeans with Monascus pilosus BCRC 31526 at 30℃ for a period up to 10 days. The functional components including phenolic acids, γ-aminobutyric acid (GABA) and amino nitrogen of black soybean koji were examined. The change of glutamate decarboxylase activity was also investigated. Inhibitory effect of methanol extracts of fermented or non-fermented black soybean on the production of NO and TNF-α in the LPS-induced macrophages were also compared. It was found that the 10 day-fermented black soybean contained the highest amount of phenolic acids which is ca 2.04 times that of the unfermented black soybean. Content of GABA was found closely related to the glutamate decarboxylase activity noted in the fermented black soybean. They all increased as the fermentation was extended and reached their maxima after 6 days of fermentation. Further extension of fermentation resulted in the reduction of GABA content and glutamate decarbosylase activity. Fermentation was also found to enhance the amino nitrogen content of black soybean. Methanol extracts of the fermented or non-fermented black soybean at a dosage of 15 ug/mL showed inhibitory effect on the production of NO and TNF-α in the LPS-induced macrophages. Furthermore, the inhibitory effect exerted by the fermented black soybean extract was generally significant higher (p<0.05) than that of the non-fermented black soybean extract.