混合菌种发酵对豆豉抗氧化性影响的研究

通过混合菌种发酵豆豉,提高豆豉的抗氧化能力.选用高产蛋白酶菌株枯草芽孢杆菌D2、D8、D10和β-葡萄糖苷酶产生菌枯草芽孢杆菌U35进行单菌种和混合菌种发酵豆豉,测定其中的抗氧化成分黄酮类化合物含量,比较豆豉铁氰化钾还原能力、自由基清除能力、抗氧化能力差异,同时分析其抗氧化成分含量和抗氧化活性的关系.混菌豆豉的苷元型异黄酮含量明显提高,D2U35、D8U35、D10U35混菌豆豉比D2、D8、D10单菌豆豉分别增加了59.71％、68.18％、54.83％.豆豉中抗氧化成分黄酮类化合物的含量比蒸煮大豆高31.20％～45.19％.混菌豆豉铁氰化钾还原能力、对[·OH]自由基清除能力分别比单菌豆豉高约22.02％、38.62％,对[DPPH·]自由基清除能力与单菌豆豉基本相同.混菌豆豉苷元型异黄酮含量对抗氧化性质影响较大.     

多菌种固态发酵去除菜籽粕中的植酸

以普通菜籽粕为原料,选用枯草芽孢杆菌、蜡样芽孢杆菌、植物乳酸菌及酪酸梭状芽孢杆菌多个菌种,通过单菌与混菌发酵,研究发酵对菜籽粕中植酸含量的影响.结果表明,单菌发酵中枯草芽孢杆菌对植酸降解效果优于其他菌种,其降解率可达62.4%;混菌发酵效果优于单菌发酵,当混菌接种量分别为枯草芽孢杆菌6%,蜡样芽孢杆菌4%,植物乳酸菌6%,水料比为1.3:1,pH 6.9,30℃发酵48 h时,菜籽粕植酸含量从2.26%(干基)降至0.221%(干基),降解率达90.15%,粗蛋白含量提高5.19%(干基).     

豆豉与淡豆豉的成分测试及微生物菌群分析

目的 测试食品豆豉和中药淡豆豉样本中的药典成分,分离培养其留存的微生物菌株,分析微生物类别、发酵过程与功能成分的关系。方法 平板筛选培养、菌苔外观和显微镜鉴别微生物菌株,液相色谱法测定大豆异黄酮及苷元成分的含量,纤维平板法测试纤溶酶活性。结果 中药淡豆豉和食品豆豉的微生物以枯草芽孢杆菌最多,其次是霉菌和酵母;样本大豆异黄酮和苷元成分差异较大,有些中药材淡豆豉低于药典标准;个别食品豆豉样本具有纤溶酶活性,中药材淡豆豉少有纤溶酶活性。结论 留存于淡豆豉或豆豉中的微生物丰度顺序如下：枯草芽孢杆菌、霉菌和酵母;大豆异黄酮和苷元成分的含量与发酵过程有关,样本的差异较大;溶栓不是中药材淡豆豉的主要功效。     

固态发酵菜籽粕生产多肽及降解硫苷菌种的筛选

以两种细菌(Bacillus subtilis W1-3、Bacillus subtilis 10160)和三种真菌(毕赤酵母、酿酒酵母和黑曲霉)为出发菌种,菜籽粕为原料,硫代葡萄糖苷(硫苷)降解率和菜籽多肽得率为发酵菜籽粕品质的评价指标,进行单菌、混菌固态发酵实验。结果表明:最优的单菌发酵菌种为枯草芽孢杆菌W1-3;比较枯草芽孢杆菌W1-3的单菌及与其他菌种的双菌和三菌发酵方式,单菌发酵优于混菌发酵。由枯草芽孢杆菌W1-3发酵所得的菜籽粕,其中多肽、粗蛋白、氨基酸含量有益物质含量分别增加453.47%、10.39%、17.76%,硫苷和植酸两种抗营养物质含量分别降低62.14%和31.58%。     

微生物两步联合发酵对豆渣主要营养品质及抗氧化性影响

以雅致放射毛霉、枯草芽孢杆菌单独预发酵和分别联合植物乳杆菌发酵豆渣,测定发酵前后豆渣的主要营养品质和抗氧化特性的变化。结果表明,以未发酵豆渣为对照,分别经雅致放射毛霉和枯草芽孢杆菌预发酵后,豆渣的粗纤维和糖苷型大豆异黄酮含量均显著降低(P<0.05),其他主要营养物质均显著升高(P<0.05),纤维素酶活性分别提高了21.6倍和8.5倍,蛋白酶活性分别提高了7.3倍和29.6倍;相较于预发酵组,植物乳杆菌联合雅致放射毛霉和植物乳杆菌联合枯草芽孢杆菌发酵豆渣后,糖苷型大豆异黄酮含量分别降低了67.2%和68.3%、苷元型大豆异黄酮升高了2.2倍和2.3倍、β-葡萄糖苷酶活性增加了154.5%和299.3%,总酚含量均显著降低。预发酵和联合发酵均可显著提升豆渣的总还原力和DPPH自由基清除能力,而后者更为显著。豆渣的抗氧化性与其大豆异黄酮的生物转化有较高的相关性。与单独预发酵相比,植物乳杆菌联合雅致放射毛霉或枯草芽孢杆菌发酵对豆渣主要营养品质、关键酶活性和抗氧化能力的提升效果更好。     

微生物发酵生产高蛋白多肽菜籽粕的研究

以菜籽粕为原料,以菜籽粕粗蛋白质含量和多肽含量为评价指标,通过植物乳酸菌、黑曲霉菌、枯草芽孢杆菌的单菌发酵和混菌发酵实验,进行最佳菌种组合和发酵条件的研究。结果表明:单菌发酵黑曲霉菌效果最好,菜籽粕粗蛋白质含量和多肽含量分别为38.4%和3.682%;混菌发酵最佳菌种组合为植物乳酸菌、黑曲霉菌、枯草芽孢杆菌,其接种量分别为4%、6%、6%,优化发酵条件为水料比1.7∶1、34℃下发酵48 h。在上述条件下菜籽粕粗蛋白质含量和多肽含量分别为42.5%和7.86%,硫甙含量降至21.637μmol/g、植酸含量为0.27%、单宁含量为0.41 mg/g,得到高蛋白、多肽、低毒的菜籽粕饲料。     

不同菌种发酵对辣木茎叶粉的营养价值及其抗氧化活性的影响

以黑曲霉、产朊假丝酵母、枯草芽孢杆菌为发酵菌种进行固态好氧发酵,在相同条件下比较单一菌种或混菌组合对辣木茎叶粉的营养成分、抗营养成分及抗氧化活性的影响。结果表明,混菌发酵的效果优于单一菌种。与添加等量无菌水的对照组相比较,黑曲霉和枯草芽孢杆菌组合发酵,黑曲霉、枯草芽孢杆菌和产朊假丝酵母三菌混合发酵后的辣木茎叶粉粗蛋白、酸溶蛋白、还原糖、体外蛋白消化率、中性洗涤纤维以及酸性洗涤纤维含量均发生显著变化(p0.05)。抗营养因子如水解单宁、皂苷、植酸的含量均有所降低,抗氧化活性则显著性提高(p0.05)。综合考虑,混菌发酵会比单菌发酵具有更广泛的应用前景。选择黑曲霉、枯草芽孢杆菌、产朊假丝酵母三菌混合发酵改善辣木茎叶粉的营养品质,提高其抗氧化活性的能力最佳。     

两步固态发酵对发酵大豆功能成分的影响研究

研究经枯草芽孢杆菌DC-12-步发酵所得发酵大豆Ⅰ(FBB Ⅰ)和经曲霉前发酵、DC-12后发酵两步发酵所得发酵大豆Ⅱ(FBB Ⅱ)中含氮成分、含糖成分、脂类成分、异黄酮苷元含量及豆豉纤溶酶酶活力的变化.结果表明:FBB Ⅱ中非蛋白氮含量为黑豆的8.0倍,FBB Ⅰ的2.0倍;氨基酸态氮含量为黑豆的6.4倍,为FBB Ⅰ的2.1倍;游离脂肪酸含量为黑豆的63.2倍,为FBB Ⅰ的14.0倍;还原糖和总糖含量均低于FBB Ⅰ;异黄酮类组分大豆苷元和染料木素含量分别为黑豆中的25.6倍和15.5倍,为FBB Ⅰ的3.2倍和1.9倍;豆豉纤溶酶产量略低于FBB Ⅰ.结论:两步发酵法所得产品优于一步发酵法.     

一株细菌型豆豉发酵菌种的筛选及鉴定

从临沂细菌型豆豉中筛选出一株适于豆豉生产的高产蛋白酶菌种,并对此菌种进行鉴定。结果表明：采用酪蛋白平板初筛,制曲复筛,根据曲样蛋白酶酶活以及游离态含量共选出5株优良菌株用于豆豉的制作,由成品豆豉的理化指标和感官评定认为D2号菌种发酵的豆豉风味好,滋味鲜美。结合生理生化和16SrDNA序列分析初步鉴定D2号菌种为枯草芽孢杆菌,该菌株来源于豆豉,属于安全菌种,具有研究开发价值。     

混菌固态发酵米糠产谷维素的工艺及抗氧化活性评估

目的:提高米糠谷维素的得率。方法:以米糠为研究对象，经单因素试验筛选出酿酒酵母和枯草芽孢杆菌作为固态发酵菌种，以谷维素含量为指标，通过单因素试验结合Box-Behnken响应面法优化混菌固态发酵工艺，采用DPPH自由基和ABTS自由基清除试验对发酵提取物抗氧化活性进行评价，并通过扫描电镜(SEM)分析混菌固态发酵法富集谷维素的原理。结果:在酿酒酵母和枯草芽孢杆菌混菌处理下，米糠谷维素最优发酵工艺为发酵时间44 h,发酵温度34℃,接种量10%,含水量40%,在此条件下谷维素含量为(7.816±0.038) mg/g,是未发酵米糠谷维素含量的1.9倍。混菌固态发酵法制备的提取物具有较强的DPPH自由基和ABTS自由基清除活性，其IC₅₀值分别为(0.220±0.007),(0.409±0.014) mg/mL,与未发酵米糠相比，其IC₅₀值分别降低了28.6%和39.7%。SEM分析结果显示，混菌固态发酵后米糠组织表面油脂更少，结构疏松多孔，更加有利于米糠中谷维素的释放。结论:米糠经混菌固态发酵后，谷维素含量和抗氧化活性均得到显著提高。     

响应面法优化贝莱斯芽孢杆菌发酵水豆豉的工艺条件

发酵产品的质量与微生物的产酶能力和发酵条件息息相关。为提高水豆豉的发酵品质,采用单因素法结合响应面法对一株高产豆豉纤溶酶的贝莱斯芽孢杆菌发酵水豆豉的条件进行优化,以获取最佳的发酵条件。首先利用单因素法缩小发酵时间、温度和接种量的范围,然后通过响应面法以水豆豉中的氨基酸态氮含量和豆豉纤溶酶活性为指标,确定最优发酵条件为:时间5d,温度35℃,接种量0.01%。最终发酵的水豆豉氨基酸态氮含量为8.95g/kg,豆豉纤溶酶活性为420.05IU/g,与市售相比,豆豉纤溶酶活性升高约400倍。该研究为贝莱斯芽孢杆菌发酵水豆豉提供了理论依据。     

Use of Bacillus subtilis to enrich isoflavone aglycones in fermented natto

BACKGROUND: Natto is a food made by fermenting cooked soybeans with Bacillus subtilis. Soybean isoflavones are reported to provide many health benefits, including oestrogenic effects. However, isoflavone aglycones may be absorbed faster and in higher amounts in the human intestine than their glucosides. This study aimed to investigate the content of isoflavone components in commercial natto products as well as the use of B. subtilis strains to ferment cooked soybeans to produce a high level of isoflavone aglycones in natto. RESULTS: The content and composition of isoflavones in commercial natto products were predominantly (>76%) isoflavone glucosides. Fermentation of cooked soybeans with B. subtilis BCRC 14718 at 37 °C for 48 h was more effective in converting glucosides to aglycones than with other strains of B. subtilis, increasing the proportion of isoflavone aglycones from 12 to 68% of the total isoflavones in the fermented natto. The proportions of the isoflavone aglycones daidzein and genistein in cooked soybeans fermented with B. subtilis BCRC 14718 for 48 h increased from 6 to 54% and from 5 to 13% respectively. CONCLUSION: Bacillus subtilis BCRC 14718 incubated with cooked soybeans produces higher levels of isoflavone aglycones, which may enhance health benefits over traditional fermented natto. Copyright © 2008 Society of Chemical Industry     

Cereal bars functionalised with tempeh: nutritional composition,isoflavone content and consumer acceptance

The aim of this study was to produce cereal bars (CB) added with tempeh flour (TF) and evaluate the nutritional composition, fatty acids profile, isoflavone content and sensory acceptance. Tempeh was produced from organic soya beans cotyledons fermented by Rhizophus oligosporus followed by freeze-drying and milling in order to obtain the TF. The addition of 10%, 15% and 20% TF to CB resulted in both protein and lipid content increase and a higher polyunsaturated/saturated fatty acids ratio. The content of isoflavone aglycones, the forms considered to have higher biological activity, was higher in TF than in soya bean, which was also reflected in the CB chemical composition. An acceptance test showed that CB added with TF (up to 15%) were sensory accepted. Overall results suggest that the addition of TF as an ingredient in cereal bars allows improving the chemical and functional characteristics of this type of ready-to-eat foods.     

米糠饮料发酵条件的研究

采用纳豆芽孢杆菌对米糠进行发酵,通过交互试验比较接种量、发酵温度和发酵时间对纳豆激酶活性和饮料感官评分的影响,确定最佳发酵条件为:接种量4%、发酵温度35℃和发酵时间24h。在此条件下可以获得酶活性达到621.5U/mL、口感较好、兼具米糠营养成分和纳豆营养产物的新型发酵饮料。     

Fermentation of commercial soy beverages with lactobacilli and bifidobacteria strains featuring high β-glucosidase activity

An increase of isoflavone aglycone content in soy foods can be attained through fermentation with food-grade bacteria. In this study, two commercial soy beverages with distinctive chemical composition (AS and VS) were fermented by strains of lactobacilli (eight strains) and bifidobacteria (two strains) with a high β-glucosidase activity. Along fermentation, growth of the strains and isoflavone deglycosylation in the soy beverages were monitored. Large differences in growth, aglycone content and chemical parameters in AS and VS beverages fermented by different species and strains were observed. Isoflavone glycosides were completely transformed into their corresponding aglycones by most strains during fermentation of AS beverage, whereas large amounts of undeglycosilated isoflavones were still present in fermented VS. Four strains showing strong deglycosylation activity and appropriate technological properties (Lactobacillus casei LP71, Lactobacillus plantarum E112, Lactobacillus rhamnosus E41 and Bifidobacterium pseudocatenulatum C35) were proposed as industrial starters to improve functionality in soy-based fermented foods.     

Transformation of isoflavone phytoestrogens during the fermentation of soymilk with lactic acid bacteria and bifidobacteria

In the present study, soymilk is fermented with lactic acid bacteria (Streptococcus thermophilus BCRC 14085, Lactobacillus acidophilus BCRC 14079) and bifidobacteria (Bifidobacterium infantis BCRC 14633, B. longum B6) individually, and in combination. The change in the content of various isoflavones (aglycones, glucoside, acetyl- and malonyl-glucosides) and the beta-glucosidase activity in soymilk during fermentation is investigated. It is observed that fermented soymilk contains a lower total isoflavone content (81.94-86.61 microg/ml) than soymilk without fermentation (87.61 microg/ml). Regardless of starter organism employed, fermentation causes a major reduction in the contents of glucoside, malonylglucoside and acetylglucoside isoflavones along with a significant increase of aglycone isoflavones content. The level of change in the content of various isoflavones and beta-glucosidase activity after fermentation varies with the starter organism. Among all the fermented soymilks tested, soymilk fermented with S. thermophilus showed the highest beta-glucosidase activity and the greatest increase in the contents of aglycones. The percentage of daidzein, genistein and glycitein to total isoflavone content in S. thermophilus-fermented soymilk increases from an initial 14.24%, 6.89% and 2.45%, respectively, to 36.20%, 28.80% and 12.44% after 24h of fermentation. Finally, the increase of aglycones and decrease of glucoside isoflavones during fermentation coincides with the increase of beta-glucosidase activity observed in fermented soymilk.     

Production of beta-glucosidase and hydrolysis of isoflavone phytoestrogens by Lactobacillus acidophilus, Bifidobacterium lactis, and Lactobacillus casei in soymilk

ABSTRACT:  The study determined β-glucosidase activity of commercial probiotic organisms for hydrolysis of isoflavone to aglycones in fermenting soymilk. Soymilk made with soy protein isolate (SPI) was fermented with Lactobacillus acidophilus LAFTI^® L10, Bifidobacterium lactis LAFTI^® B94, and Lactobacillus casei LAFTI^® L26 at 37 °C for 48 h and the fermented soymilk was stored for 28 d at 4 °C. β-Glucosidase activity of organisms was determined using ρ-nitrophenyl β-D-glucopyranoside as a substrate and the hydrolysis of isoflavone glycosides to aglycones by these organisms was carried out. The highest level of growth occurred at 12 h for L. casei L26, 24 h for B. lactis B94, and 36 h for L. acidophilus L10 during fermentation in soymilk. Survival after storage at 4 °C for 28 d was 20%, 15%, and 11% greater ( P < 0.05) than initial cell counts, respectively. All the bacteria produced β-glucosidase, which hydrolyzed isoflavone β-glycosides to isoflavone aglycones. The decrease in the concentration of β-glycosides and the increase in the concentration of aglycones were significant ( P < 0.05) in the fermented soymilk. Increased isoflavone aglycone content in fermented soymilk is likely to improve the biological functionality of soymilk.     

Preparation and characterisation of soya milk enriched with isoflavone aglycone fermented by lactic acid bacteria combined with hydrothermal cooking pretreatment

A fermented soya milk (FSM) enriched with isoflavone aglycone (FSM‐SPIA) was prepared from heated soya protein isolate (SPI)‐isoflavone complex. After 48 h of fermentation, FSM‐SPIA contained higher contents of living bacteria, free amino acids and aglycone compared with the FSM of SPI (FSM‐SPI) and the FSM of SPI‐isoflavone complex (FSM‐Mix). In the in‐vitro digestion experiment, FSM‐SPIA showed higher antioxidant capacity and isoflavones (ISO) bioavailability than FSM‐SPI and FSM‐Mix. This was likely due to the soya milk containing a higher level of amino acid, peptides and the presence of soya bean isoflavone. The improved protein digestibility, the interaction and binding ability between proteins and ISO may affect the properties of the protein and the fermented products. The FSM enriched with isoflavone aglycone can be used as a functional fermented drink, as well as an auxiliary food for menopausal women during a specific pathological period.     

Biotransformation of phenolics (isoflavones,flavanols and phenolic acids) during the fermentation of cheonggukjang by Bacillus pumilus HY1

Changes in β-glycosidase, esterase activities, isoflavone, flavanols and phenolic acid during the fermentation of Korean whole soybean fermented food cheonggukjang by Bacillus pumilus HY1 were investigated. The levels of aglycones, flavanols and gallic acid increased, while the β-glucosidase activity, esterase activity, glycosides content (except for acetylglycosides) and flavanol gallates decreased. Total isoflavone content slightly decreased after 60 h of fermentation, while total flavanol and phenolic acid content increased. The highest levels of daidzein (aglycone type) and acetyldaidzin (glycoside type) were recorded after 48 h of fermentation. The levels of catechin, epicatechin and gallic acid also increased during fermentation. However, total contents of glycosides, malonylglycosides and flavanol gallates decreased by about 80%, 90% and 60% during 60 h of fermentation, respectively. In addition, total phenolic content increased markedly during fermentation, while levels of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity increased. Hence, it would be beneficial for the food industry if components of cheonggukjang could be separated and developed into functional products.     

植物乳杆菌58发酵豆乳产大豆异黄酮苷元条件的优化

本研究通过测定植物乳杆菌58在不同碳源中的生长和产β-葡萄糖苷酶情况,筛选菌株的最适碳源,并确定接种至豆乳的最佳时间.在接种量、糖含量、发酵时间和发酵温度等单因素实验基础上,根据Box-Behnken中心组合原理进行响应面实验设计,以大豆异黄酮苷元含量为指标,进一步优化菌株58发酵豆乳产大豆异黄酮苷元条件.结果显示,植...