麦麸阿魏酸糖酯微生物发酵工艺优化及体外抗氧化和益生活性评价

以麦麸为原料,对固态发酵制备麦麸阿魏酸糖酯（Feruloylated glycosides,FGs）的工艺进行优化,并对其体外抗氧化及益生活性进行评价。以植物乳杆菌、枯草芽孢杆菌、地衣芽孢杆菌、酿酒酵母为发酵菌种,采取单菌发酵和混菌发酵筛选最优菌种组合,考察接种量、发酵温度、发酵时间、料水比对麦麸FGs产量的影响,通过响应面试验设计优化发酵工艺。结果表明:以枯草芽孢杆菌:地衣芽孢杆菌:酿酒酵母=1:1:1发酵麦麸时,FGs产量最高;最佳固态发酵工艺条件为发酵温度42.5℃,发酵时间58.5 h,接种量10.7%,料水比1:1.16（g/mL）,在此条件下FGs产量为1273.18 nmol/g;抗氧化实验结果表明,DPPH自由基清除率高达87.42%（1 mg/mL）,羟基自由基清除率为33.68%（4 mg/mL）,还原力为1.078（4 mg/mL）。发酵麦麸FGs可有效促进嗜热链球菌和植物乳杆菌的增殖。综上所述,以枯草芽孢杆菌、地衣芽孢杆菌和酿酒酵母混菌发酵制备的麦麸FGs有一定的抗氧化和益生活性。     

乳酸菌固态发酵过程中麦麸组分的动态变化

麦麸是小麦加工的主要副产物,营养丰富且产量大,采用乳酸菌处理麦麸可提高其附加值。为明确乳酸菌发酵对麦麸各组分的影响,作者采用植物乳杆菌、鼠李糖乳杆菌、戊糖片球菌和布氏乳杆菌分别对麦麸进行固态发酵,在48 h内每隔8 h取样,分析可溶性膳食纤维、粗蛋白质、淀粉、总酚、植酸等成分的质量分数及DPPH自由基清除能力的动态变化。结果表明,在麦麸基质中,4株乳酸菌在24 h内生长较为迅速;麦麸经乳酸菌发酵后可溶性膳食纤维质量分数显著提高,其中布氏乳杆菌发酵48 h后可溶性膳食纤维质量分数由4.72%增加至6.58%;随着发酵时间的增加,麦麸中淀粉质量分数逐渐降低,粗蛋白质量分数先增加后降低最后趋于稳定;植物乳杆菌在提高麦麸多酚质量分数方面有更好的效果,多酚质量分数由1.34 mg/g增加至3.86 mg/g,麦麸抗氧化活性显著增加;此外,乳酸菌发酵麦麸可显著降低其植酸质量分数。综合而言,植物乳杆菌和布氏乳杆菌在提高麦麸的营养特性方面具有较好的效果,可有效改善麦麸的综合利用价值。     

麸皮多糖微生物发酵工艺优化及其抗炎活性

对麸皮多糖发酵制备工艺进行优化,并对其抗炎活性进行研究。以酿酒酵母以及枯草芽孢杆菌为发酵菌种固态发酵制备麸皮多糖,通过响应面法优化发酵工艺条件（发酵温度、发酵时间、总接种量和料水比）,并研究其对敌草快攻毒大鼠血浆和肝脏组织中TNF-α、IL-6、IL-2和IL-1β炎性因子水平的影响。结果表明,1）麸皮多糖最佳固态发酵工艺条件为发酵温度35.4?℃、发酵时间52.7?h、总接种量10.4%、料水比1∶1.16（g/mL）,该条件下麸皮多糖产量为130.21?mg/g;2）腹腔注射敌草快显著升高大鼠血浆和肝脏组织中TNF-α、IL-6、IL-2和IL-1β炎性因子水平（P＜0.05）;3）在敌草快引起的应激状态下,灌胃麦麸多糖可以显著降低大鼠血浆和肝脏组织中TNF-α、IL-6、IL-2和IL-1β炎性因子水平（P＜0.05）,并且随着灌服剂量的升高,大鼠血浆和肝脏组织中炎性因子水平可恢复到正常生理状态。综上所述,以响应面法优化后发酵工艺制备的麸皮多糖有一定的抗炎作用。     

Effect of various types of fermentation on in vitro protein and starch digestibility of differently processed pearl millet

Pearl millet (Pennisetum typhoideum) grains were fermented with Lactobacilli and yeast alone, in combination and with natural flora at 30 °C for 48 h after giving various processing treatments viz, fine and coarse grinding, soaking, debranning, dry heat treatment, germination and autoclaving after adding of water. Fermentation was carried out with Lactobacillus acidophilus and Rhodotorula isolated from naturally fermented pearl millet and Lactobacillus acidophilus, Candida utilis and natural fermentation using freshly ground pearl millet flour as inoculum. All the processing treatments except coarse grinding improved the protein and starch digestibility. Autoclaving enhanced the digestibilities of processed samples which was further improved by different types of fermentation, the maximum being in case of germinated and naturally fermented pearl millet. A combination of Lactobacilli and yeast was more effective in increasing the protein as well as starch digestibility as compared to pure culture fermentation.     

灵芝发酵麸皮粗多糖的组成及抗氧化活性分析

为研究灵芝发酵麸皮粗多糖组成及抗氧化活性,对比分析了灵芝发酵前后麸皮粗多糖的体外抗氧化活性和组分,并通过高效液相色谱、傅里叶红外光谱初探灵芝发酵麸皮粗多糖的结构。结果表明:灵芝发酵麸皮粗多糖（GWBP）在4.0 g/L浓度下的DPPH、羟基自由基清除率和还原力分别为91.37%、95.74%和0.92,显著高于未发酵麸皮粗多糖（WBP）（P<0.05）。GWBP组分中黄酮、多酚、蛋白含量分别为5.41、12.74和206.41 mg/g,显著高于WBP（P<0.05）。GWBP是一种吡喃糖,主要由葡萄糖、木糖和核糖等组成,分子量为4.172×103 Da。灵芝液态发酵可以提高麸皮粗多糖的抗氧化活性,改变粗多糖的组成成分。本研究为灵芝发酵麸皮粗多糖天然抗氧化的开发提供参考。     

纳豆芽孢杆菌固态发酵小米糠产抗氧化肽工艺优化

为提高小米糠蛋白资源的利用率,为小米糠的深加工提供参考,采用纳豆芽孢杆菌对小米糠进行固态发酵以获得小米糠抗氧化肽。在单因素试验的基础上以小米糠发酵后水提液的总抗氧化能力(total antioxidant capacity,T-AOC)为指标,使用Plackett-Burman试验对发酵条件进行筛选,然后使用响应面法对发酵条件进行优化,并测定优化后小米糠水提液的多肽含量和1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除能力。结果显示最适发酵条件为:小米糠平均粒径0.22 mm(60~80目)、菌液接种量0.4 mL(约108 CFU/mL)、初始pH 6.7、发酵时间26 h、发酵温度35℃。此条件下小米糠固态发酵后提取液的T-AOC实际值为(344.51±8.02)U/g小米糠,多肽提取量为(68.37±0.92)mg/g小米糠,清除DPPH自由基IC50为0.12 mg/mL。该研究表明,小米糠固态发酵条件经过优化后能够获得具有较高抗氧化能力的生物活性肽。     

Solid-state fermentation by S. cerevisiae with high resistance to ferulic acid improves the physicochemical properties of wheat bran and quality of bran-rich Chinese steamed bread

Wheat bran has numerous health benefits, but its poor processing and sensory properties limit its application in the staple food industry. Fermentation by S. cerevisiae changes the performance of wheat bran. However, high levels of ferulic acid (FA) inhibit S. cerevisiae. The effects of solid-state fermentation of S. cerevisiae with high resistance to FA on the physicochemical properties of wheat bran and the quality of bran-rich Chinese steamed bread (CSB) were investigated. The results showed that the growth of S. cerevisiae was inhibited by FA in a dose-dependent manner. Short-term adaptation strategies efficiently improved the tolerance of S. cerevisiae to FA stress. Compared with the parental strain (PS), fermentation of the short-term adapted strains (adapted strains) significantly increased the FA, total phenol, and soluble dietary fiber content in wheat bran. Wheat bran fermented by the adapted strains had a higher antioxidant capacity than wheat bran fermented by PS. In addition, compared with the PS, the wheat bran fermented by the adapted strains can decrease the hardness, improve the specific volume, and the quality of CSB. Thus, solid-state fermentation of the adapted strain is a potentially effective method to improve the nutritional and physicochemical properties of wheat bran as a cereal food ingredient.     

Evaluation of Solid-State Fermentation by Ganoderma lucidum Using Soybean Curd Residue

The effects of fermentation conditions on the production of polysaccharides from Ganoderma lucidum using soybean curd residue (SCR) as a substrate were investigated. Based on the optimum conditions of solid-state fermentation, the fermentation time, the inoculum size, and the C/N ratio were optimized by response surface methodology. The optimal fermentation conditions for G. lucidum polysaccharide were determined to be the following: 14.53 % of the inoculum size, 10.49 of the C/N ratio, and 21.18 days incubation. The maximum polysaccharide yield of 48.14?±?1.47 mg/g was obtained in the verification experiment. Furthermore, treatment with 20 μg/mL of G. lucidum polysaccharide from fermented SCR showed significant stimulation for the macrophage proliferation and higher nitric oxide production. Compared with the unfermented soybean curd residue, the total phenolic compounds increased fourfold, and various amino acids were increased significantly in the fermented soybean curd residue. Therefore, a nutritious functional food or food additives could be produced using fermented soybean curd residue.     

利用谷物进行类胡萝卜素固态发酵

研究了 7种谷物培养基及相关因素对青霉PT95菌株进行类胡萝卜素固态发酵的影响作用。结果表明 ,谷物培养基的组成对PT95菌株在固态发酵条件下的菌核生物量和菌核中的类胡萝卜素含量都有明显的影响 ;接种方式和接种量能明显影响谷物培养基上的菌核生物量 ,但对菌核中的类胡萝卜素含量没有明显的影响 ;在谷物培养基里添加麸皮有利于菌核的形成。在选择最佳接种方式、接种量 ,并在培养基里添加 2 0 %麸皮 (干重 )的固态发酵条件下 ,大米培养基上得到的菌核生物量最高 ,达到 1 5 0 0 g/1 0 0 g(干料 ) ;荞麦培养基上 ,菌核中的类胡萝卜素含量最高 ,达到82 6μg/g(干菌核 ) ;而在谷子培养基上 ,类胡萝卜素产率最高 ,达到 1 1 45 7μg/1 0 0 g(干料 )。     

Development of a solid-state fermentation process for production of an alpha amylase with potentially interesting properties

Ca-independency with potential activity and stability at low pH are among the most interesting characteristics of α-amylase in starch industry. In this attempt the synergetic effect of low pH on activity of crude Ca-independent α-amylase isolated from a native Bacillus sp. KR-8104 in solid-state fermentation (SSF) was studied using wheat bran (WB) as a substrate. The effects of different parameters including moisturizing agents, solid substrate to moisture ratio, particle size, incubation temperature and period, inoculum (v/w) and supplementation with 1% (w/w) different carbon and nitrogen sources on enzyme production were investigated. Maximum enzyme production of 140 U/g dry fermented substrate was obtained from wheat bran moistened with tap water at a ratio of 1:1.5 and supplemented with 1% (w/w) NH₄NO₃ and 1% (w/w) lactose after 48 h incubation at 37 °C. Even though the production of α-amylase was lower at 40 and 45 °C, the viable cell count was higher. In addition response surface methodology (RSM) was applied to find optimum conditions of temperature and pH on crude amylase activity. Using central composite design (CCD) a quadratic mathematical model equation was derived for the prediction of enzyme activity. The results showed that the model was in good agreement with experimental results, with R² = 0.90 (p < 0.0001) and the low pH has a synergetic effect on enzyme activity at higher temperature.     

In vitro DNA damage protection and anti‐inflammatory effects of Tartary buckwheats (Fagopyrum tataricum L. Gaertn) fermented by filamentous fungi

The present work was designed to investigate the phenolic profiles, DNA damage protection and anti‐inflammatory effects of Tartary buckwheat fermented by Rhizopus oryzae 40469, Rhizopus oryzae 40503 and Rhizopus oligosporus 3152. Six phenolic compounds were characterised and quantified. Regardless of fermentation, rutin was the dominant phenolic substance in Tartary buckwheat. Fermentation significantly enhanced total phenolic and flavonoid contents, as well as DNA scission protection. Rhizopus oryzae 40469‐fermented sample had the highest content of phenolics, while R. oligosporus 3152‐fermented sample had the strongest inhibitory effect on DNA scission. Tartary buckwheat, regardless of fermentation, inhibited nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) mRNA levels in LPS‐induced RAW 264.7 cells. Moreover, the sample fermented with R. oryzae 40503 had the strongest inhibitory activity. Those results indicated that fermented Tartary buckwheat has potential applications as a novel nutraceutical or functional food for preventing DNA damage‐induced disease and inflammation.     

香菇菌丝体液体发酵的研究

利用麸皮浸提液配制发酵培养基,研究了香菇菌丝体发酵培养基对胞外内多糖和菌丝体生物量的影响.结果表明,最适宜培养基配方为麦麸60％、蔗糖1％、MgSO40.15％、KH2PO40.2％.研究了香菇液体菌种发酵过程中菌丝体生物量、pH值、胞外多糖含量的变化,确定了最佳接种量为12％,最佳发酵时间为11d,发酵液的最终pH值在4.2左右.     

Characteristic of filamentous fungal diversity and dynamics associated with wheat Qu and the traditional fermentation of Chinese rice wine

Chinese rice wine, a traditional alcoholic beverage, is fermented from steamed rice with a starter culture of wheat Qu which is either inoculated spontaneously with various microorganisms in natural environment or inoculated artificially with certain microorganisms. The diversity of filamentous fungi in wheat Qu and the fermentation mashes of Chinese rice wine was studied by high‐throughput sequencing. The results indicated that filamentous fungi varied in wheat Qu and fermentation periods. Moreover, Aspergillus was the dominant filamentous fungi at genus levels. On that basis, quantitative real‐time PCR was used to quantify some dominant Aspergillus species. It was found that Aspergillus species in wheat Qu were more abundant than that in various fermentation mashes and continually decreased until the end of rice wine fermentation. Furthermore, it was found that different organic acids were produced by microorganisms at different fermentation stages might due to the changes of oxygen and nutrient content.     

Isoflavone Conversion of Black Soybean by Immobilized Rhizopus spp.

Isoflavones exhibit many bioactive benefits, such as antioxidation, antimutagenic effects, and reduction of symptoms of postmenopause conditions. Aglycone forms of isoflavone have shown more biological effects over their glycosylated ones. Most isoflavones in nature, however, exist as glycosylated forms and cannot easily be absorbed in the intestines. The purpose of this study was to develop a fermentation process of black soybean to produce functional food using a Luffa cylindrical fiber biofilm reactor. Three filamentous-fungi, including Rhizopus oligosporus (BCRC 31996), Rhizopus oligosporus (NTU-5), and Rhizopus oryzae (BCRC 30894), were cultivated in black soybean medium. The assay using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging effect of fermented broth and isoflavone aglycosylation rate of genistin and daidzin were evaluated as indicators to determine the most suitable strain. After a 2-day cultivation in flasks, DPPH radical scavenging effect of R. oligosporus NTU-5 reached 83%, which is the maximum value among three strains. R. oligosporus NTU-5 was subsequently chosen as target strain and used for the scale-up of fungal-based aerobic growth. The optimal cultivation condition obtained in a 5-L bioreactor with Luffa cylindrical fiber was 30°C, 0.1 vvm aeration, 100 rpm agitation, 10% inoculum volume, and 6% (w/v) black soybean as medium. After a 6-day cultivation, R. oligosporus NTU-5 converted isoflavones to their aglycones, daidzein and genistein, and these were 59.7 and 23.6 μM, respectively. Isoflavone aglycosylation rate of daidzin and genistin were 77.6 and 31.8%, respectively. The DPPH scavenging effect was 62%.     

基于两步法制备生物发酵蛋白工艺的研究

该研究通过单因素、正交试验优化米曲霉（Aspergillus oryzae）固态发酵、酶解两步法协同处理农副加工产物（菜籽粕、豆粕）制备发酵蛋白,以达到改善蛋白质品质、降低抗营养因子的目的。结果表明,最佳发酵原料组成为70%菜籽粕+30%豆粕;固态发酵的最佳条件为发酵蛋白原料初始含水量45%,米曲霉麸皮种子接种量3%,发酵时间40 h,发酵温度30 ℃;最佳酶解条件为酶解时间32 h,酶解初始含水量56%,酶解温度50 ℃。在此工艺条件下,发酵蛋白的蛋白溶解度（65.80%）提高97.49%,酸溶蛋白/粗蛋白（44.13%）提高779.75%,硫苷含量（8.63 μmol/g）降低69.14%。表明利用两步法处理农产品加工副产物,能在改善蛋白品质的同时,降低抗营养因子水平。     

Bioavailability of Zinc in Fermented Soybeans

The bioavailability of zinc in soybean meal fermented by lactic acid-producing bacteria (LAPB) and by Rhizopus oligosporus in tempeh fermentation was evaluated with the rat bioassay, using the slope ratio method and log total femur zinc or weight gain versus zinc intake as response parameters. Fermentation significantly increased (P < 0.05) the RBV of zinc from 73.0% in boiled non-fermented soybeans (pH 6.7) to 84.5% in boiled LAPB fermented soybeans. The highest RBV (95.3%) was found in the autoclaved and LAPB fermented product (pH 6.5). Rhizopus oligosporus fermentation resulted in a RBV of 89.0%. Thus, fermentation in the processing of soybeans will improve zinc bioavailability in this food.     

Optimization of enzymatic extraction of ferulic acid from wheat bran,using response surface methodology,and characterization of the resulting fractions

BACKGROUND: The agro‐industries generate thousands of tons of by‐products, such as bran or pulps, each year. They are, at best, used for cattle feeding. Through biocracking, this biomass may constitute a renewable source for various molecules of interest for the industry. For instance, ferulic acid, a compound showing antioxidant ability, is found in abundance in cereal bran. Its release depends mainly on the breaking of its ester linkage to other constitutive elements of the cell wall, such as arabinoxylans. Response surface methodology was used to evaluate the effects of ferulic acid esterase (FAE) and xylanase activities, as well as incubation time and temperature, on ferulic acid extraction yield from wheat bran. Under optimized conditions, the composition of the hydrolysate and of residual bran were compared to native bran. RESULTS: Experiments carried out under the predicted optimal conditions (FAE amount, 27 U g^?1; xylanase amount, 304 U g^?1; incubation time, 2 h; and temperature, 65 °C) led to an extraction yield of 52.8%, agreeing with the expected value (51.0%). The crude ferulic acid fraction was purified with Amberlite XAD16, leading to a final concentration of 125 µg mL^?1 of ferulic acid in ethanol. The antioxidant capacity of this purified fraction was evaluated by the DPPH· scavenging method: it exhibited better efficiency (EC₅₀ = 10.6 µmol L^?1 in ferulic acid) than the ferulic acid standard (EC₅₀ = 13.7 µmol L^?1). CONCLUSION: These results confirm the potential of wheat bran valorization in the field of natural antioxidant extraction, possibly viable in an industrial scheme. Copyright © 2009 Society of Chemical Industry     

玉米芯多糖的微生物发酵工艺及其单糖组成和体外益生活性研究

以玉米芯多糖含量为指标,对玉米芯发酵工艺进行优化,测定玉米芯多糖的单糖组成,并对其体外益生活性进行评价。确定最终发酵条件为:接种8%枯草芽孢杆菌,添加10%麸皮,纤维素酶添加量为500 U/g,料水比1:1.25(g/mL),发酵时间96 h,发酵温度35℃,该发酵条件下使用苯酚硫酸法测得玉米芯多糖含量为162.61 mg/g,较未发酵玉米芯多糖含量提高了20.16%。HPLC法分析单糖组成结果显示,发酵后玉米芯粗多糖中木糖、阿拉伯糖、半乳糖和甘露糖含量分别增加了152.17%、118.12%、64.73%、36.30%,葡萄糖含量降低57.29%;体外益生活性研究显示,在等量碳源的基础上,添加玉米芯粗多糖后对植物乳杆菌和嗜热链球菌的促生长作用显著优于仅葡萄糖作为碳源组(P<0.05),且添加发酵玉米芯粗多糖组对两种菌的益生作用比添加未发酵玉米芯粗多糖组显著升高(P<0.05)。综上所述,通过微生物发酵技术可增加玉米芯中多糖的含量并改变其单糖组成,同时提高其体外益生活性。     

发酵麦麸对面包膳食纤维组成及烘焙特性的影响

采用马克斯克鲁维酵母发酵麦麸制得富含天然酶的功能配料,分析麦麸发酵过程中纤维素酶活力变化,比较制作的麦麸面包(B₁)、发酵麦麸面包(B₂)、木聚糖酶麦麸面包(B₃)和复合麦麸面包(B₄)的膳食纤维组成及烘焙特性的差异。结果表明:马克斯克鲁维酵母具有较强的胞外β-葡萄糖苷酶生产能力,其酶活为6.98 U/g;在48 h麦麸发酵过程中,外切葡聚糖酶和β-葡萄糖苷酶的酶活不断提高,其酶活分别增加至6.06和21.70 U/g,不溶性膳食纤维(IDF)也持续降解至38.30 g/100 g。面团搅拌、醒发过程中,还原糖含量不断增加,且添加发酵麦麸的面包效果最明显。相比未发酵麦麸面包,添加发酵麦麸的面包体积、弹性及持水力都显著提升(p<0.05),气孔结构更加细腻。制作的4种面包中总膳食纤维(TDF)和阿拉伯木聚糖(AX)含量没有显著差异,而添加发酵麦麸及木聚糖酶都能促进面包中IDF和AX溶解。     

Amylase production in solid state fermentation by the thermophilic fungus Thermomyces lanuginosus

The production of extracellular amylase by the thermophilic fungus Thermomyces lanuginosus was studied in solid state fermentation (SSF). Solid substrates such as wheat bran, molasses bran, rice bran, maize meal, millet cereal, wheat flakes, barley bran, crushed maize, corncobs and crushed wheat were studied for enzyme production. Growth on wheat bran gave the highest amylase activity. The maximum enzyme activity obtained was 534 U/g of wheat bran under optimum conditions of an incubation period of 120 h, an incubation temperature of 50 degrees C, an initial moisture content of 90%, a pH of 6.0, an inoculum level of 10% (v/w), a salt solution concentration of 1.5:10 (v/w) and a ratio of substrate weight to flask volume of 1:100 with soluble starch (1% w/w) and peptone (1% w/w) as supplements.