共查询到19条相似文献，搜索用时 478 毫秒
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以铁皮石斛为原料,利用乳酸菌发酵生产风味饮料,对铁皮石斛汁发酵前后多糖、石斛碱、总酚、总黄酮含量及抗氧化能力变化情况进行研究。结果表明,植物乳杆菌对石斛多糖的消耗最高,比原汁减少了41.63%。植物乳杆菌与保加利亚乳杆菌按1∶1混合发酵对石斛碱的消耗最高,比原汁减少了4.92%。经乳酸菌发酵,总酚、总黄酮含量均比发酵前有提高,其中以植物乳杆菌与保加利亚乳杆菌按比例1∶1混合发酵提高幅度最大,总酚与总黄酮含量分别提高了24.17%和31.87%。铁皮石斛汁发酵后对羟基自由基、DPPH自由基和超氧阴离子自由基的清除能力均比发酵前有所增强。本研究说明,利用乳酸菌发酵可提高铁皮石斛活性物质的溶出率,从而提高铁皮石斛乳酸菌饮品抗氧化功能。 相似文献
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以西番莲果皮为对象,研究酿酒酵母菌、乳酸菌二步发酵工艺,制备乳酸菌和酿酒酵母菌活菌数高、多酚保留好、风味醇和的果皮浆。通过单因素和正交优化实验,以酿酒酵母菌和乳酸菌活菌数、总酚、乙醇生成量为指标,分别优选了单一乳酸菌和酿酒酵母菌发酵的工艺参数,在此基础上,通过测定总酸含量、活菌数、总酚含量等指标的变化,确定二步法发酵西番莲果皮浆的工艺参数为：发酵总时间40 h,酿酒酵母菌初始接种量1.5%,在29 ℃下发酵16 h后,再接入2.0%复合乳杆菌（干酪乳杆菌∶植物乳杆菌=1∶1）,在37 ℃下继续发酵24 h至终点。制备的西番莲果皮发酵液中,复合乳杆菌活菌数为8.93 lg CFU/mL,酿酒酵母菌活菌数为7.78 lg CFU/mL,总酚含量为24.00 μg/mL,总酸含量为4.40 mg/mL。二步发酵法发挥了酿酒酵母菌产香、产乙醇抑制杂菌,以及乳酸菌提高酸度、保留多酚物质的优点。 相似文献
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为提高酸茶B族维生素含量，试验通过减少发酵时长和添加外源菌剂发酵制备酸茶。测定发酵过程中酸茶不同维生素B的含量，采用SPSS 12.0对所得试验结果进行统计学处理。结果表明：与其他茶类相比，厌氧发酵的酸茶维生素B2含量较高，而其他B族维生素含量均较低，尤其是维生素B3和B5。缩短发酵时长有利于酸茶维生素B3和B5的积累，外源添加酵母菌和乳杆菌有助于提高酸茶维生素B3含量，接混合菌能够增加维生素B3含量但显著降低维生素B2和B6含量水平。表明缩短发酵时长与添加外源酵母菌或乳杆菌有助于提升酸茶B族维生素含量。 相似文献
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对传统发酵蔬菜汁中筛选出的酵母菌SCY1进行了豆乳凝固条件与机理的研究,经生理生化、分子生物学鉴定该菌株为酿酒酵母属,将其接种于豆乳中可在发酵7h后发生凝固,最佳凝固温度为35℃,最佳初始pH值为6．2。采用HPLC对微生物凝乳的测定表明,凝固的豆乳中乳酸和醋酸含量分别为0．099％和0．098％,而采用合成底物测得菌株的内肽酶活力不高。研究表明酵母菌SCY1凝固豆乳的机理主要为产酸凝乳,内肽酶对凝固豆乳的风味形成可能起到促进作用。 相似文献
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《大豆科学》2020,(3)
为快速检测发酵豆乳中主要乳酸菌植物乳杆菌、副干酪乳杆菌含量,建立实时荧光定量聚合酶链式反应检测方法。根据植物乳杆菌、副干酪乳杆菌保守区域设计特异性引物和探针,验证建立的实时荧光定量PCR法的特异性、灵敏度和重复性,并与国标法进行比较。结果表明:引物特异性强,实时荧光定量PCR法特异性及重复性较好;植物乳杆菌和副干酪乳杆菌的检验灵敏度分别达到1.3×10~(-4)和1.0×10~(-5) ng·μL~(-1)。分别建立植物乳杆菌和副干酪乳杆菌标准菌株的实时荧光定量PCR检验法的标准曲线,得出R~2分别为0.994 3和0.999 6,表明线性关系较好,可进行发酵豆乳中2种菌株含量的检测,测得供试发酵豆乳中植物乳杆菌与副干酪乳杆菌比例为4∶1。实时荧光定量PCR法测得发酵豆乳中乳酸菌总量为(5.5±0.26)×10~9 CFU·mL~(-1),国标法检测为(5.3±0.43)×10~9 CFU·mL~(-1),2种方法检测结果无差异(P0.05),表明建立的实时荧光定量PCR方法可快速、准确地检测出发酵豆乳中植物乳杆菌和副干酪乳杆菌的含量。 相似文献
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豆渣固体发酵产纳豆激酶的工艺优化及其部分酶学性质研究 总被引：2，自引：1，他引：1
研究纳豆菌固体发酵产纳豆激酶的工艺及其部分酶学性质.采用单因素和正交试验,对以豆渣为原料纳豆菌固体发酵生产纳豆激酶的工艺条件进行优化,并利用最佳发酵工艺制备纳豆激酶粗品,对纳豆激酶的部分性质进行研究.结果表明固体发酵培养基最佳配比:豆渣:麸皮=5:2,初始含水量65%,接种量为10%,初始pH为8.0,培养温度30℃.采用最适培养基和优化工艺,在250 m1三角瓶中进行验证实验,纳豆激酶的酶的产率可达到1577U·g-1.酶学性质研究表明,最适反应温度为60℃,37℃以下稳定,最适反应pH为8.0,在pH7-9溶液中基本稳定.体外溶栓作用表明,纳豆激酶溶解纤维蛋白的方式是直接溶解,而不是通过激活纤溶酶原. 相似文献
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Fermentation by selected sourdough lactic acid bacteria to decrease coeliac intolerance to rye flour 总被引：2，自引：0，他引：2
Maria De Angelis Rossana Coda Marco Silano Fabio Minervini Carlo G. Rizzello Raffaella Di Cagno Olimpia Vicentini Massimo De Vincenzi Marco Gobbetti 《Journal of Cereal Science》2006,43(3):301-314
A pool of selected lactic acid bacteria was used to ferment suspensions of rye flour. Two-dimensional electrophoresis showed that 109 of the 129 ethanol-soluble rye polypeptides were hydrolysed almost totally by lactic acid bacteria. Matrix-assisted laser desorption ionization—time of flight mass spectrometry and reversed-phase high performance liquid chromatography analysis confirmed the hydrolysis of prolamins. After 48 h fermentation, no prolamin polypeptides were recognized by R5-Western analysis. HPLC analysis of glutelin polymers showed a very low bacterial proteolysis but a pH dependent hydrolysis probably due to activation of rye enzymes. Prolamins were extracted from rye flour and used to produce a peptic–tryptic (PT)-digest for in vitro tests with K 562 (S) sub-clone and Caco-2/TC7 cells of human origin. The PT-digest was also treated with lactic acid bacteria before assay. The Minimal Agglutinating Capacity increased ca. 8-times when K 562 (S) sub-clone cells were exposed to rye PT-digest treated with lactic acid bacteria. Hydrolysis of rye PT-digest by lactic acid bacteria decreased the toxicity of PT-digest itself towards Caco-2/TC7 cells as estimated by cell viability, caspase-3 activity and release of nitric oxide. Rye prolamins and glutelins were extracted from doughs and subjected to PT digestion. Compared to PT-digests from chemically acidified dough, coeliac jejunal biopsies exposed to the PT-digest from the dough fermented by lactic acid bacteria did not show an increase of the infiltration of CD3+ intraepithelial lymphocytes. The same was found for epithelial cell Fas expression. Long-time fermentation of dough by selected lactic acid bacteria could be considered as a potential tool to decrease the risk of rye contamination of gluten-free products for coeliac patients. 相似文献
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J. H. HARRISON R. L. KINCAID K. A. LONEY R. E. RILEY J. CRONRATH 《Grass and Forage Science》1994,49(2):130-137
The effect of adding rolled barley on the ensiling characteristics and nutritive value of lucerne and corn ( Zea mays ) forage was studied using 19-1 plastic mini-silos. Other factors evaluated with lucerne were the effect of wilting and added lactic acid bacteria. Rolled barley was added at rates of 0, 50, 100 and 150gkg−1 (wet weight) to lucerne or corn forage. Lucerne was ensiled at 170–330 g kg−1 dry matter (DM) and lactic acid bacteria were applied at 105 g−1 wet forage. Addition of rolled barley consistently improved the fermentation of lucerne by lowering the pH and decreasing the concentration of acetate and ammonia nitrogen. Wilting of lucerne had variable effects on fermentation in two experiments. The addition of lactic acid bacteria improved fermentation by decreasing the concentrations of acetate and ammonia nitrogen, improved the nutritive value by increasing the in vitro dry matter digestibility (IVDMD), and was associated with decreased amounts of lactic acid. Corn was ensiled at 250 g kg−1 DM, and added rolled barley had little effect on the fermentation of corn silage. The digestibility of all silages determined in vitro was improved by the addition of rolled barley. 相似文献
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Aderiye B. I. Ogunjobi A. A. 《Plant foods for human nutrition (Dordrecht, Netherlands)》1998,52(1):49-54
The microflora of white yam ( Dioscorea rotundata L.) slices fermented anaerobically in 1.5 percent brine for five days at room temperature were studied. The hydrolysis of the carbohydrate and the subsequent conversion of sugars and minerals by the fermenting microbes contributed much to the increased microbial load especially within the first 72 hours of fermentation. The organisms implicated in the fermentation include the species of Pediococcus, Lactobacillus and Pseudomonas, Bacillus subtilis and two other Gram negative coccal cells, yet to be identified. The decrease in microbial counts at the latter stage of fermentation was attributed to the high total acidity of the medium, which was about 2.67 times the initial value of 0.027% lactic acid. Meanwhile, the lactic acid bacteria increased continuously throughout the period of fermentation. 相似文献
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香蕉营养丰富、活性物质含量高，可作为深加工产品的优质原料。香蕉果酒是香蕉精深加工产品中的重要一类。由于香蕉果浆碳水化合物含量较高、酸度低、糖分高，其酿造过程中适宜各种微生物的生长繁殖，特别是乳酸菌数量的变化与酸类物质的产生密切相关。乳酸菌群落的变化容易增加发酵过程的风险，造成香蕉酒挥发酸含量超标、品质低下等不良结果。因此明确香蕉果酒发酵过程中自然存在的乳酸菌的生长繁殖规律及其对有机酸代谢的影响，可为精准调控发酵过程、提高产品质量提供理论依据。试验设置商业酵母Lalvin K1TM接种发酵过程（K1）与香蕉果汁自然发酵过程（SF）2组对比，采用实时定量PCR方法和高效液相色谱法对香蕉汁接种发酵（K1）与自然发酵过程（SF）中酵母菌、乳酸菌的生长规律以及有机酸的含量变化进行监测。结果表明：2种发酵处理下，酵母菌和乳酸菌的生长规律有差异；K1酵母菌主导的发酵过程中，乳酸菌的生长受到显著抑制，最大生长量仅为4.0×106 CFU/mL，而酵母菌生物量为1.2×107 CFU/mL；在自然发酵过程中，乳酸菌与酵母菌的生长周期完全错开，但对乳酸菌的生物量无显著影响，乳酸菌与酵母菌的生长量分别达到1.0×107 CFU/mL和1.6×107 CFU/mL。2种发酵过程均表明，酵母菌和乳酸菌的生长存在竞争与抑制关系；有机酸代谢主要与乳酸菌菌落数量相关，不同有机酸的总体变化趋势一致；在发酵过程中，乳酸含量逐渐增加，乙酸含量呈先增后降的趋势，二者在自然发酵样品中的累积量均高于接种发酵；柠檬酸、苹果酸、酒石酸含量整体呈下降趋势。 相似文献
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C. E. Müller 《Grass and Forage Science》2005,60(2):109-118
The fermentation quality of small‐bale silage and haylage for feeding to horses in Sweden, and using a conventional high‐density hay baler, was investigated in two experiments. Treatments studied were use of additives (inoculants containing lactic acid bacteria and a chemical additive consisting of hexamethylenetetramine, sodium nitrate, sodium benzoate and sodium propionate), the influence of dry‐matter (DM) content of wilted herbage and the effect of number of stretch film layers on fermentation pattern and aerobic stability. All silages and haylages were made from predominantly Timothy swards and were well fermented as indicated by low levels of ammonia and butyric acid. Values of pH were higher and concentrations of organic acids were lower in haylages than in the silages. This was not considered to be indicative of a poor fermentation in the haylage but of a restricted fermentation due to the high DM content of the herbage. The additives enhanced aerobic storage stability because of inhibition of mould growth. The only statistically significant effect of varying the number of stretch film layers was a higher content of CO2 inside the bales when ten layers of stretch film were applied compared with six layers. 相似文献
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A simulation model of the growth and fermentation of lactic acid bacteria and clostridia in silage is described. The model is used to predict the occurrence of a well-preserved lactate silage or a poorly-preserved clostridial silage. Results of the model are compared with published experimental studies not used in the model's development. The results are summarized with maps showing the combinations of initial water-soluble-carbohydrate content, crop buffering capacity, dry matter content, temperature, initial pH, and initial population of lactic acid bacteria which result in a clostridial silage. The specific processes modelled include the growth and death of lactic acid bacteria and clostridia; the use of substrate and accumulation of fermentation end products; release of ammonia; and change in silage pH. 相似文献
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The effect of addition of sugar and inoculation with two commercial inoculants on the fermentation of lucerne silage in laboratory silos 总被引：10，自引：0，他引：10
Lucerne (DM 236 g kg-1 , WSC 49 g (kg DM)-1 ) was ensiled in test-tube silos with or without either glucose or fructose and with or without one of two commercial inoculants. The WSC content of the forage as ensiled was too low to obtain a well preserved untreated silage. By day 4 the pH values of the silages with added sugar or inoculant were significantly lower (P< 0·001) than the control silage. A satisfactory fermentation was attained only in the silages to which sugar and an inoculant had been added. These silages had a lower pH, more protein-N (P< 0·001), less ammonia-N (P<0·001), a faster increase in counts of lactic acid bacteria, and decrease in counts of coliforms than the other silages. Homo-fermentative lactic acid bacteria dominated the fermentation in the inoculated silages while leuconostocs dominated the early stages of fermentation in the control silages. The results indicate that if there is insufficient sugar in the original crop, then the bacteria in an inoculant will not be able to produce enough lactic acid to lower the pH to an acceptable level. This has important implications for the ensilage of lucerne and other highly buffered low sugar crops. 相似文献
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Zvauya R. Mygochi T. Parawira W. 《Plant foods for human nutrition (Dordrecht, Netherlands)》1997,51(1):43-51
Biochemical and microbiological changes that occur during production of masvusvu and mangisi, both traditional Zimbabwean beverages made from malted finger millet flour were investigated in this study. During cooking to produce masvusvu, amylase was active within the first 20 minutes but its activity decreased drastically at temperatures of above 60 °C. Free reducing sugars increased from 3.8 to 308.1 mg/ml. During fermentation to produce mangisis, total aerobic mesophilic bacteria, lactic acid bacteria and yeast and molds increased with fermentation time. Total titratable acidity increased from 0.13 to 0.67 percent, lactic acid from 0.51 t 4.10 g/l and pH decreased from 6.10 to 3.98. 相似文献
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从海南鱼酸中分离出4株优势乳酸菌L2、L3、L8、L11,根据形态、生理生化特征和分子生物学特征鉴定为植物乳杆菌(Lactobacillus plantarum)。其中L2菌株产酸速率最快,可用于鱼酸纯种发酵。 相似文献