本文關(guān)鍵詞： 紅曲霉 麥麩培養(yǎng)基 發(fā)酵工藝 抗氧化性　出處：《浙江工業(yè)大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：紅曲是以大米為原料經(jīng)紅曲霉(Monascus)發(fā)酵而成的一種紅色米曲,論文以麥麩為基質(zhì)進行紅曲霉的發(fā)酵,一方面是擴大了紅曲霉發(fā)酵基質(zhì)的種類,另外一方面更重要的是麥麩自身的特點對于紅曲霉發(fā)酵的影響。麥麩本身含有豐富的活性物質(zhì),如p-葡聚糖,是公認(rèn)的降血脂物質(zhì),和紅曲霉發(fā)酵出來的洛伐他汀功能相同,所以二者在一起具有協(xié)同降脂的效果。同時麥麩還富含多酚,具有很強的抗氧化作用,以麥麩為基質(zhì)發(fā)酵紅曲霉,得到的最終發(fā)酵產(chǎn)物的抗氧化活性也能得到增強。實驗首先篩選出抗氧化活性較佳的紅曲霉菌株,從來自山東、麗水、江蘇、福建四個地方出廠的紅曲米中分離單個紅曲霉菌株,經(jīng)固態(tài)發(fā)酵后,利用DPPH和ABTS方法測定各發(fā)酵產(chǎn)物的抗氧化活性,并結(jié)合生物量篩選最優(yōu)菌株,篩選得到的菌株Y221,其ABTS清除率為90.44%,DPPH抑制率為為89.51%,生物量為0.077mg/mL,并對這支菌株進行鑒定,確定其為紫色紅曲霉菌株。然后對篩選出來的菌株Y221通過改變培養(yǎng)基成分、發(fā)酵溫度,考察發(fā)酵產(chǎn)物的抗氧化性能,最終確定培養(yǎng)基成分為：菌液量10%,含水量50%,2%蛋白胨,2%冰醋酸,培養(yǎng)溫度30℃；在此培養(yǎng)條件下,對菌株Y221各方面的抗氧化性進行考察,結(jié)果為：濃度為5mg/mL的發(fā)酵產(chǎn)物提取液400μL,其Trolox當(dāng)量為2.62mmol/L,Fe3+還原能力在700 nm吸光值為0.313；HPLC法測定發(fā)酵產(chǎn)物中阿魏酸含量為44.7 mg/g；總酚含量為450μg/mL。發(fā)酵前后游離型酚酸含量從106 μg/mL升高到：208μg/mL。最后,在此培養(yǎng)條件下,分別用麥麩和大米進行發(fā)酵,不同濃度麥麩發(fā)酵產(chǎn)物明顯高于大米發(fā)酵產(chǎn)物的抗氧化性活力。篩選出來的紅曲霉菌株抗氧化活性表現(xiàn)良好,發(fā)酵產(chǎn)物的液相結(jié)果表明其中阿魏酸含量豐富,無論是定性還是定量上,麥麩作為紅曲霉發(fā)酵的基質(zhì),有利于產(chǎn)物抗氧化活性的提高,而且抗氧化活性優(yōu)于利用大米等其他基質(zhì)發(fā)酵,是紅曲霉固態(tài)發(fā)酵的更好選擇。
[Abstract]:Monascus is a kind of red rice koji fermented from rice by Monascus. The fermentation of Monascus was based on wheat bran. On the one hand, it expanded the variety of fermentation substrate of Monascus. On the other hand, more important is the effect of the characteristics of wheat bran on the fermentation of Monascus. Wheat bran itself is rich in active substances, such as p-dextran, which is recognized as a lipid lowering substance. The function of lovastatin fermented by Monascus is the same, so the two have synergistic effect of reducing lipid. Meanwhile, wheat bran is rich in polyphenols and has strong antioxidant effect, and fermented Monascus on the basis of wheat bran. The antioxidation activity of the final fermentation product can also be enhanced. Firstly, Monascus strains with better antioxidant activity were selected from Shandong, Lishui and Jiangsu. A single Monascus strain was isolated from four local Monascus rice plants in Fujian Province. After solid state fermentation, the antioxidant activity of each fermentation product was determined by DPPH and ABTS methods, and the optimum strain was screened by combining with biomass. The ABTS clearance rate of strain Y221 was 90.44 and the inhibition rate of DPPH was 89.51, the biomass was 0.077 mg / mL, and the strain was identified. The strain Y221 was determined to be Monascus purplicus. The antioxidant activity of the fermentation product was investigated by changing the composition of culture medium and fermentation temperature. The composition of the culture medium was determined as follows: the amount of liquid was 10, the water content was 50% peptone and 2% acetic acid, and the culture temperature was 30 鈩，

本文編號：1476014