一种新型乳酸菌复合发酵剂的应用及效果

从众多菌株中筛选出4株乳酸菌,分别为产乳酸菌胞外多糖菌株Lvan04、产Nisin菌株LA02、嗜热链球菌1和保加利亚乳杆菌2,组成复合发酵剂。该种复合发酵剂通过乳酸菌发酵产生乳酸菌胞外多糖,提高了产品的黏度、稳定性及口感,取代传统的向产品中添加稳定剂的方法,这样不但降低了产品的成本,还提高了产品品质和安全性,延长了产品货架期,同时也为nisin的应用提供了新思路。     

常用食品乳酸菌发酵蔬菜的研究

对Streptococcus lastic,Lactobacillus brevis,Lactobacillus casei等9种食品常用乳酸菌种进行发酵蔬菜研究,通过对发酵菜及汤汁中V_C、氨基酸、总酸、总糖、挥发酸、硝酸盐、亚硝酸盐等指标的测定,结合产品的感官评价,筛选出适合作为蔬菜发酵剂用的菌种Streptococcus lastic。从研究结果看,接种Streptococcus lastic菌种的发酵蔬菜既可以很好地降解发酵菜中亚硝酸盐的含量,又可与其他菌种制成复合发酵菌剂,用于发酵制品生产,且产品营养较丰富。     

螺旋藻乳酸菌发酵饮料的研制

通过向发酵乳中添加螺旋藻提取液,研究螺旋藻乳酸菌发酵饮料的加工工艺及配方;试制出一种色泽浅绿,风味独特、酸甜适口、细腻润滑且营养全面的新型螺旋藻乳酸菌发酵饮料。通过4因素3水平正交试验确定各种成分的最佳剂量。实验结果表明发酵乳最佳工艺条件为：接种量4％、发酵温度40℃、发酵时间3．5h;螺旋藻乳酸菌发酵饮料最佳配方为：发酵乳35％、10％螺旋藻液20％、葡萄糖8％、瓜尔豆胶0．25％。所得产品是一种富含蛋白质、维生素、乳酸菌等,集营养、保健于一体的新型螺旋藻乳酸菌发酵饮料。     

几株应用于发酵肉制品的乳酸菌的筛选

为了筛选出符合发酵肉制品优质乳酸菌发酵剂,对不同乳酸菌发酵性能进行研究,通过实验筛选出耐盐、耐亚硝酸盐、不分解蛋白质和脂肪、适于肉类发酵的优质乳酸菌。试验表明,植物乳杆菌、发酵乳杆菌和乳酸乳球菌三株乳酸菌均能在6%食盐溶液和1.5×10-4亚硝酸盐溶液下能够很好生长,因而这三种乳酸菌可耐受食盐和亚硝酸盐,并且均不分解蛋白质和脂肪。得出结论,植物乳杆菌、发酵乳杆菌、干酪乳杆菌和德氏乳杆菌均为适宜于使用在发酵肉制品中的发酵剂。     

乳酸菌及其发酵乳制品的发展趋势

综述了乳酸菌的生物学特性、功能及用于乳制品发酵生产的乳酸菌种类。概述了发酵乳制品的种类、生产流程、特点、功能及其发展趋势，以及乳酸菌发酵乳制品保健功能、风味物质及其生产技术的发展趋势。     

乳酸菌的降胆固醇作用及其在发酵制品中的应用

乳酸菌是益生菌,已经受到广泛的关注。本文综述了乳酸菌降胆固醇作用的发展和作用机理,以及在发酵制品中的应用进展。     

乳酸菌发酵鱼的研制

研究了乳酸菌发酵鱼的制作工艺.通过研究表明,利用浸泡发酵方式在12℃的条件下发酵5d,经150℃烘烤20min所得的产品风味良好.     

Production of fermented chestnut purees by lactic acid bacteria

The objective of this study was to develop a new chestnut-based puree, in order to seasonally adjust the offer and use the surplus of undersized production, providing, at the same time, a response to the growing demand for healthy and environmentally friendly products. Broken dried chestnuts have been employed to prepare purees to be fermented with six different strains of Lactobacillus (Lb.) rhamnosus and Lactobacillus casei. The fermented purees were characterized by a technological and sensorial point of view, while the employed strains were tested for their probiotic potential. Conventional in vitro tests have indicated the six lactobacilli strains as promising probiotic candidates; moreover, being the strains able to grow and to survive in chestnut puree at a population level higher than 8 log(10) CFU/mL along 40days of storage at 4°C, the bases for the production of a new food, lactose-free and with reduced fat content, have been laid.     

乳酸菌发酵酸豆乳生产工艺的研究

以大豆为原料,对生产酸豆乳的工艺进行了研究。纯豆乳经浸泡、磨浆、脱腥后制成,通过正交试验,获得最佳的发酵工艺,豆水比为大豆：水=1：10。嗜热链球菌：保加利亚乳杆菌=1：1,85℃杀菌30min,蔗糖的添加量为8％,前发酵温度为40℃,前发酵时间为4h,接种量5％,后发酵温度4℃。     

发酵型大米乳酸菌饮料加工工艺研究

以大米为主要原料,经过粉碎、糊化、糖化、过滤等处理后得到米浆原液,加入一定量蔗糖、脱脂乳,接入两种乳酸菌进行发酵,制备发酵型大米饮料。通过预实验确定了最佳米/水比为1∶16,并且对乳酸菌进行了定向驯化。通过正交实验确定了产品最佳制备工艺,即蔗糖添加量4%、脱脂乳添加量5%、鼠李糖乳杆菌接种量3%、保加利亚乳杆菌接种量为4%,在37℃下发酵8 h。     

核桃乳酸菌饮料的研制

主要通过实验筛选出在核桃、大豆等植物蛋白中适宜生长且产酸产香良好的乳酸菌种,研究出复合植物蛋白原料的最佳配比与最适接种量,经过发酵、调配,研制出品质达标的核桃乳酸菌饮料。     

传统发酵乳制品中乳酸菌和酵母菌的互作关系

论述了传统发酵乳制品(酸马奶酒、开菲尔、西藏灵菇)的产品特点、微生物分布规律,并对国内外传统发酵乳制品中乳酸菌和酵母菌的互作关系的研究进展进行综述,期望为我国研究乳酸菌和酵母菌的共生机理提供新的思路.     

Influence of sodium chloride, pH, and lactic acid bacteria on anaerobic lactic acid utilization during fermented cucumber spoilage

Cucumbers are preserved commercially by natural fermentations in 5% to 8% sodium chloride (NaCl) brines. Occasionally, fermented cucumbers spoil after the primary fermentation is complete. This spoilage has been characterized by decreases in lactic acid and a rise in brine pH caused by microbial instability. Objectives of this study were to determine the combined effects of NaCl and pH on fermented cucumber spoilage and to determine the ability of lactic acid bacteria (LAB) spoilage isolates to initiate lactic acid degradation in fermented cucumbers. Cucumbers fermented with 0%, 2%, 4%, and 6% NaCl were blended into slurries (FCS) and adjusted to pH 3.2, 3.8, 4.3, and 5.0 prior to centrifugation, sterile-filtration, and inoculation with spoilage organisms. Organic acids and pH were measured initially and after 3 wk, 2, 6, 12, and 18 mo anaerobic incubation at 25 °C. Anaerobic lactic acid degradation occurred in FCS at pH 3.8, 4.3, and 5.0 regardless of NaCl concentration. At pH 3.2, reduced NaCl concentrations resulted in increased susceptibility to spoilage, indicating that the pH limit for lactic acid utilization in reduced NaCl fermented cucumbers is 3.2 or lower. Over 18 mo incubation, only cucumbers fermented with 6% NaCl to pH 3.2 prevented anaerobic lactic acid degradation by spoilage bacteria. Among several LAB species isolated from fermented cucumber spoilage, Lactobacillus buchneri was unique in its ability to metabolize lactic acid in FCS with concurrent increases in acetic acid and 1,2-propanediol. Therefore, L. buchneri may be one of multiple organisms that contribute to development of fermented cucumber spoilage. PRACTICAL APPLICATION: Microbial spoilage of fermented cucumbers during bulk storage causes economic losses for producers. Current knowledge is insufficient to predict or control these losses. This study demonstrated that in the absence of oxygen, cucumbers fermented with 6% sodium chloride to pH 3.2 were not subject to spoilage. However, lactic acid was degraded by spoilage microorganisms in reduced salt, even with pH as low as 3.2. Efforts to reduce salt in commercial brining operations will need to include control measures for this increased susceptibility to spoilage. Lactobacillus buchneri was identified as a potential causative agent and could be used as a target in development of such control measures.     

抗氧化乳酸菌L4的SOD活性及其发酵乳的抗氧化作用

从30株乳酸菌中筛选出的抗氧化活性相对较高的乳酸菌L3和L4进行实验,发现乳酸菌L4的抗H2O2的能力明显要高于乳酸菌L3和保加利亚乳杆菌。并检测到乳酸菌L4无细胞提取物SOD活性为(73.70±1.77)U/mg。但未检测到乳酸菌L3和L4具有GSH-Px活性。利用PCR技术扩增了乳酸菌L4的SOD基因,通过DNA序列测定,发现乳酸菌L4的SOD基因与E.coli的Mn-SOD基因有高度的同源性。并发现乳酸菌L4发酵乳的还原活性和螯合Fe2+作用均明显高于未发酵乳。     

乳酸菌对发酵豆豉品质的影响

目的研究4株不同乳酸菌对豆豉发酵产生氨基态氮含量、γ-氨基丁酸(γ-aminobutyric acid,GABA)以及挥发性成分的影响。方法将高密度培养后的4株乳酸菌:植物乳杆菌(Lactobacillus plantarum,LP)、发酵乳杆菌(Lactobacillus plantarum,LF)、嗜酸乳杆菌(Lactobacillus acidophilus,LA)、瑞士乳杆菌(Lactobacillus casei,LH)分别接入豆豉成曲进行发酵,与未添加乳酸菌的对照组作比较,测定发酵完成后氨基态氮含量、γ-氨基丁酸含量,并用气相色谱质谱联用法(gas chromatography-mass spectrometry,GC-MS)检测各豆豉挥发性成分。结果添加乳酸菌发酵的豆豉氨基态氮含量都高于对照组豆豉,以LF、LP、LA效果明显,其中LF最为明显,达到2.355 g/100 g;添加LH、LP发酵豆豉产GABA含量高于对照组豆豉,其中LH最高,达38.2 mg/g;LF豆豉共检测出风味物质46种,LP豆豉共检测出风味物质50种,LH共检测出风味物质58种,LA共检测出风味物质49种,对照组未添加乳酸菌豆豉共检测出风味物质60种。结论本研究的结果为开发保健型发酵豆制品,4株不同乳酸菌发酵豆豉的应用提供信息。     

乳酸菌发酵黄浆水的抗氧化研究

应用鼠李糖乳杆菌和嗜酸乳杆菌发酵豆腐黄浆水,分析了黄浆水和发酵黄浆水还原三价铁、清除DPPH和ABTS+自由基以及螯合二价铁的能力.结果表明,嗜酸乳杆菌发酵黄浆水的还原力最强,显著高于鼠李糖乳杆菌发酵的黄浆水和未发酵的黄浆水;经过发酵的黄浆水清除DPPH和ABTS+自由基的能力明显大于未发酵黄浆水,但是菌种和发酵时间影响不大;螯合二价铁的能力依次为鼠李糖乳杆菌发酵的黄浆水＞嗜酸乳杆菌发酵的黄浆水＞未发酵黄浆水,且延长发酵时间能提高其螯合二价铁的能力.     

乳酸菌发酵蔬菜汁的研究进展

阐述了乳酸菌对发酵蔬菜汁的作用、目前发酵工艺中的一些关键技术及发酵蔬菜汁稳定性和乳酸菌固定化细胞技术的研究进展．     

发酵酸鱼中乳酸菌的鉴定及特性分析

该研究以分离自酸鱼发酵后期的乳酸菌菌株LP224为研究对象,采用形态学观察、生理生化试验和分子生物学技术对其进行菌种鉴定,采用K-B药敏纸片扩散法和聚合酶链式反应（PCR）法对其耐药性和抗性基因进行检测,并研究其生长特性及耐受性。结果表明,菌株LP224被鉴定为植物乳杆菌（Lactobacillus plantarum）,其对头孢曲松、链霉素、环丙沙星、磺胺异噁唑、万古霉素、林可霉素等6类15种抗生素耐药,基因组DNA检测出ermC和tetG2种抗性基因,而细菌质粒未检测到抗性基因,说明该菌株相对安全。菌株LP224经55℃水浴处理30 min后存活率为35.06%;p H2.5环境下存活率为52.60%;0.3%胆盐浓度下存活率为31.67%,说明该菌株具有较强的耐热、耐酸、耐胆盐能力。     

小麦胚芽乳酸发酵饮料的工艺研究

为了得到小麦胚芽乳酸发酵饮料制备的最佳工艺,首先通过单因素试验考察接种量、发酵温度、发酵时间、培养基初始pH值等对乳酸饮料风味的影响,然后在最优范围内对这4个主要影响因素采用正交试验设计优化工艺条件。结果表明,最佳条件为接种量8%,温度45 ℃,发酵时间18 h,初始pH值为6.5,此条件下产品酸度为80～85 °T,总糖为5.3 g/100 mL,pH值为4.43,感官评分为88.5分。