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乳酸是一种重要的有机酸,利用木质纤维素生物炼制乳酸已经成为研究热点。与传统乳酸生产菌相比,凝结芽孢杆菌(Bacillus coagulans)具有高温发酵、己糖/戊糖共利用、糖酸转化率高等特点。该文简要介绍了乳酸生物炼制过程,分析了技术难点,重点阐述凝结芽孢杆菌用于乳酸生物炼制的技术优势,并指出了目前存在的技术瓶颈和解决策略,最后对乳酸生物炼制的工业化应用提出了技术展望。 相似文献
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Hui Juan Zhang Jing Wang Bing Hua Zhang Hui Zhang 《International Journal of Food Science & Technology》2014,49(5):1330-1336
The hydrolysates from heat stable rice bran (HSDRB) treated by Alcalase 2.4L and Protease 500G were desalted and fractionated by hydrophobicity using a nonpolar, styrene divinylbenzene resin and macroporous adsorption resin DA201‐C. The antioxidant activities of HSDRB hydrolysates (HSDRBH) eluted by 25%, 50%, 75% and 100% ethanol were investigated using 2, 2‐di (4‐tertoctylphenyl)‐1‐picrylhydrazyl free radical‐scavenging activity assay, reducing power assay, ferrous ion‐chelating activity assay and lipid peroxidation inhibition assay. The HSDRBH‐75 had the highest reducing power assay and inhibition ratio of linoleic acid autoxidation, which might be associated with reduced molecular weight, amino acid composition and hydrophobicity. The highest metal‐chelating activity of four different fractions (at the concentration of 4 mg mL?1) had a positive correlation (r = 0.768, P = 0.116) with the total content of basic amino acid (Lys, Arg, and His) and a negative correlation (r = ?0.886, P = 0.057) with the range of molecular weight (Mw < 1000 Da). The HSDRBH‐75 had the highest antioxidant activities in many assays, which suggests that it may become a good natural antioxidant as a food additive. 相似文献
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利用响应面分析法优化了脱脂米糠中植酸的提取工艺条件,建立了植酸提取的二次多项式数学模型。在单因素试验基础上,选择pH、液料比、提取时间和提取温度为自变量,植酸得率和残渣蛋白质量为响应值,响应面优化得出最佳工艺条件为:pH3.9,液料比9∶1,提取时间4.4h,提取温度50℃。在最佳工艺条件下,植酸得率为5.27%,残渣蛋白质量为1.4034g(10g原料脱脂米糠)。在响应面优化工艺的基础上,选择了一浸一洗的浸提方式,并利用阴、阳离子交换树脂纯化了植酸粗溶液,浓缩得到了50%植酸溶液,植酸纯度为94.72%。 相似文献
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以糯米酶解液、奶粉为原料进行乳酸发酵,制得一种新型凝固酸奶——糯米酸奶。通过单因素试验初步确定加工工艺参数,再用正交试验得出制作糯米酸奶的最佳工艺条件。试验结果表明最佳工艺条件为:糯米酶解液与奶粉液体积比72∶28、白砂糖2.8%、发酵剂3%,在42℃发酵4h。在此最佳条件下获得的酸奶产品品质最好,兼具糯米和酸奶的风味特点。 相似文献
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Kun Yao Dong-Mei Liu Charles S. Brennan 《International Journal of Food Science & Technology》2021,56(5):2384-2394
L-lactic acid is an important organic acid widely used in pharmaceutical, food and textile industries. Bacillus coagulans BCS13002 can efficiently produce L-lactic acid with two kinds of carbon sources. BCS13002 produced L-lactic acid at a content of 10.23 ± 0.16 g/L and 11.67 ± 0.22 g/L, when glucose and gelatinised and hydrolysed corn starch (GHCS) were used, respectively. GHCS exhibits several advantages, including high yield of L-lactic acid and low cost. Proteomics analyses identified several key enzymes, which contributed to the higher production of L-lactic acid when GHCS was used as the carbon source. Those key enzymes were involved in the two-component system (SpoOF), pantothenate and CoA biosynthesis (pantothenate synthetase, 1.584-fold; dihydroxy-acid dehydratase, 1.517-fold), beta-alanine metabolism (1.605-fold) and valine, leucine and isoleucine biosynthesis (1.517-fold) pathways. This study provides a biological basis for using GHCS as a substitute of glucose in the production of L-lactic acid. 相似文献
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该研究拟考察凝结芽孢杆菌(Bacillus coagulans)利用玉米秸秆生物炼制乳酸的效果。以凝结芽孢杆菌CGMCC No.7635为菌种,利用2%硫酸预处理后的玉米秸秆为碳源、20 g/L酵母粉为氮源,添加20 FPU/g纤维素酶后开展糖化发酵生产乳酸实验。结果表明,发酵65 h后可获得乳酸含量为(38.38±1.03) g/L,其中L-乳酸光学纯度为(99.23±0.22)%。进一步使用补料发酵工艺,添加经预处理的玉米秸秆,可最终获得乳酸含量为(82.56±1.28) g/L。建立的玉米秸秆生物炼制乳酸工艺操作简单、产物浓度高,具有工业应用潜力。 相似文献
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凝结芽孢杆菌CICIM B1821发酵生产L-乳酸的研究 总被引:1,自引:1,他引:0
凝结芽孢杆菌(Bacillus coagulans)CICIM B1821是一株实验室前期筛选获得的产L-乳酸的嗜热菌。该菌株在34~55℃范围内均表现出良好的生长特性和产酸特性,50℃时获得最高的比生长速率和最大的乳酸积累量。CICIMB1821能够在pH为5.0~7.5的范围内保持高的菌体活性。氧气的存在有利于CICIMB1821的快速生长.但会导致副产物的积累,而在不通氧的条件下该菌株也生长良好,同时产酸速率可高达5.63g/L·h。控制残糖浓度不高于10%的发酵条件下,发酵48h,可积累乳酸107.5g/L,副产物总和仅为1.05g/L,葡萄糖对乳酸的得率为97.5%,所产L-乳酸光学纯度高于99%。此外,高浓度葡萄糖发酵实验显示,该菌株可在高渗透压下利用20%葡萄糖发酵生产L-乳酸,发酵100h.可积累乳酸134g/L,副产物总和仅为1.12g/L,葡萄糖对乳酸的得率为92.0%。 相似文献
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BACKGROUND: Rice bran, containing about 100–150 g kg?1 protein, is a by‐product of rice milling that has only become an available ingredient in recent years owing to the centralisation of rice milling. Rice bran, but not its protein fraction or hydrolysates, has been shown to have a hypocholesterolaemic effect. Peptides from soy, milk and other foods have been proposed to have hypocholesterolaemic effects based on their ability to lower cholesterol solubility in bile acid/phosphotidyl choline micelles. RESULTS: Rice bran protein hydrolysates (RBPHs) were prepared and investigated for their potential to lower cholesterol concentration in micelles. The RBPHs were produced by digestion using four different peptidases, alcalase 2.4L®, neutrase 0.8L®, papaya latex papain and porcine pancreas trypsin, and then fractionated by hydrophobicity using styrene/divinylbeneze resins. Alcalase 2.4L® produced the highest degree of hydrolysis, and the resulting hydrolysates had the highest micellar cholesterol inhibition ability in an in vitro hypocholesterolaemic test. The adsorption dynamics of four different macroporous resins, DA201‐C, Sepabeads SP207 and SP825 and Diaion HP20, were determined using the Langmuir isotherm model. DA201‐C had the highest adsorption capacity with an equilibrium concentration of 220 mg g?1. The hydrolysates eluted with 25, 50, 75 and 95% (v/v) ethanol lowered the micellar cholesterol concentration by 11.88, 14.76, 19.37 and 7.56% respectively. CONCLUSION: A hydrophobic fraction of RBPH had the highest inhibitory activity on micellar cholesterol, which suggests that it may have hypocholesterolaemic properties. Copyright © 2011 Society of Chemical Industry 相似文献
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Smerjai Bureenok Tomoyuki Namihira Susumu Mizumachi Yasuhiro Kawamoto Tadashi Nakada 《Journal of the science of food and agriculture》2006,86(7):1073-1077
A fermented juice from macerated napiergrass containing epiphytic lactic bacteria (FJLB) and napiergrass was prepared, mixed with defatted rice bran (FJLB + DRB) or dried green tea waste (FJLB + DTW) and freeze‐dried. Silage was treated with FJLB + DRB, FJLB + DTW, DRB or DTW in powder form at levels of 2, 10 and 50 g kg?1 fresh matter (FM). FJLB in liquid form was added at a level of 10 mL kg?1 FM. All treated silages were well preserved, with lower pH, acetic acid and NH3‐N content and higher lactic acid content than that of the control. Butyric acid was present only in the control silage and those treated with DRB or DTW. Without powdered FJLB additives, napiergrass silages had higher pH values, butyric acid and NH3‐N content, but low lactic acid content compared with powdered FJLB silages. Increasing the amount of all powdered additives had effect on lactic acid and NH3‐N content. It may thus be concluded that the powder form of FJLB was as effective in improving the fermentative quality of napiergrass as the liquid form. Copyright © 2006 Society of Chemical Industry 相似文献
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利用米糠制备阿魏酸的研究 总被引:1,自引:0,他引:1
阿魏酸(Ferulic acid,简称FA)在医药和食品工业中具有广泛用途。米糠中阿魏酸含量较高,是获取天然阿魏酸较为理想的原料。主要研究了以米糠为原料制备阿魏酸的技术路线,首先采用淀粉酶和蛋白酶除去米糠中部分淀粉和蛋白质,然后通过正交试验确定了碱解米糠制备阿魏酸的最佳工艺条件:氢氧化钠浓度0.5%,水解温度55℃,水解时间6h,添加0.03%亚硫酸钠。以该优化条件进行制备,最终可获得阿魏酸427.3mg。制备过程中添加亚硫酸钠可减少阿魏酸损失,增加阿魏酸回收率。 相似文献
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米糠发酵过程中脂肪酸组分及含量变化的研究 总被引:1,自引:0,他引:1
以新鲜米糠为原料,以料水比1:9(w:v)配成培养基,接入红曲(Monascus anka)M180和木耳(Auricularia auricular)A900,在30℃、200r/min摇床培养,培养时间分别为4d和7d。利用气相色谱法,对米糠发酵过程中脂肪酸组分及含量的变化进行分析。结果显示,米糠中主要脂肪酸为C16:0、C18:1、C18:2,占总脂肪酸的95.05%,C16:1、C18:1、C18:2等不饱和脂肪酸占总脂肪酸的80.09%,在红曲和木耳发酵过程中,脂肪酸含量一直呈下降趋势,总脂肪酸含量由最初的200.75mg/g分别下降至68.35mg/g和79.95mg/g,红曲M180比木耳A900利用脂肪酸速度快。发酵结束后,红曲发酵米糠和木耳发酵米糠中不饱和脂肪酸占总脂肪酸的比例分别为83.76%和80.84%,与发酵前相比,没有得到明显提高。利用红曲和木耳发酵米糠不能达到富集不饱和脂肪酸的目的,但可作为除去米糠中脂肪,抑制酸败的潜在途径。 相似文献
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Radha Renuka Devi Ananthasankaran Jayalekshmy & Chaml Arumughan 《International Journal of Food Science & Technology》2008,43(5):878-885
Defatted rice bran (DRB) is the byproduct of rice bran oil extraction. On HPLC analysis, methanolic extracts prepared from DRB was found to contain oryzanols (OYL), tocols and ferulic acid (FA). Solvent fractionation was employed to prepare extracts enriched with beneficial phytochemicals from crude methanolic extract (CME). The antioxidant potential of DRB extracts and their phytochemical constituents in emulsified media were evaluated by linoleic acid emulsion system and β‐carotene bleaching test. In linoleic acid model, the activity indexed as percent inhibition values followed the order TBHQ (83.9) > BHT (60.1) > AE‐PP = AE‐LP = OYL = tricin (51.7) > Tmix (48.0) > FA (44.1) > AE (36.0) > CME (29.9) > sterol (22.8) with inhibition percentages at 200 ppm levels given in parentheses. The order for the β‐carotene model was TBHQ (75.2) > BHT (54.1) > OYL = tricin = AE‐LP = AE‐PP (47.2) > Tmix (43.9) > FA (41.0) > AE (29.9) > CME (25.1) > sterol (20.1), with inhibition percentages at 200 ppm levels given in parentheses. The results demonstrated that DRB extracts could be used as antioxidant substitutes in heterogeneous food matrix and could also be used in protecting both linoleic acid and β‐carotene against oxidation. The increase in activity with purification might be due to enhanced levels of antioxidants in purified extracts as compared to CME. 相似文献
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以95%乙醇为萃取剂,采用溶剂法对高酸值米糠原油进行同步脱酸脱蜡,以脱酸率、脱蜡率为指标,通过单因素试验和正交试验优化高酸值米糠油同步脱酸脱蜡工艺条件。结果表明:高酸值米糠油脱酸脱蜡最佳工艺条件为卵磷脂添加量0.15%(以95%乙醇质量计)、萃取时间40 min、萃取温度60 ℃、料液比1∶ 2.5、萃取次数4次,在最佳工艺条件下米糠油的脱酸率和脱蜡率分别为99.45%和99.86%,精炼得率为65.67%,谷维素、植物甾醇和维生素E保留率分别为87.88%、9764%和95.15%。 相似文献
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以产L-乳酸光学纯度为99.3%的粪肠球菌(Enterococcus faecium)HY-38作为出发菌株,通过Plackett-Burman试验设计确定影响L-乳酸的产量的主要因素,筛选出3个有显著影响效应的因素,分别为葡萄糖、酵母膏及乙酸钠,最陡爬坡试验逼近影响因素最佳值区域,采用Box-Behnken设计及响应面分析对L-乳酸发酵培养基成分进行优化。结果表明,L-乳酸发酵培养基成分确定为葡萄糖148 g/L、酵母膏12.4 g/L、碳酸钙80 g/L、乙酸钠5.0 g/L、磷酸二氢钾1.0 g/L、硫酸镁1.2 g/L、硫酸锰0.04 g/L,在此条件下,L-乳酸的产量达到134.7g/L,比优化前(108.3 g/L)提高了24.3%。 相似文献