发芽糙米乳中双株复合乳酸菌的发酵特性研究

以发芽糙米为基质,将植物乳杆菌(Lactobacillus plantarum)、鼠李糖乳杆菌(L.rhamnosus)、嗜酸乳杆菌(L.acidophilus)、干酪乳杆菌(L.casei)4种乳酸菌经两两组合后,对发芽糙米乳进行发酵。通过对酸度、活菌数、脱水收缩作用敏感性、蛋白分解力、流变学性质等指标的测定来进行发酵特性评价,最终筛选出适合发酵发芽糙米乳的最佳菌株组合。实验结果表明:各组合在发芽糙米乳中的发酵特性不尽相同,其中嗜酸乳杆菌和干酪乳杆菌对各自组合贮藏过程中酸度的变化起主导作用,每组产品的活菌数均达8 lg cfu/m L以上,发酵特性的组间差异较为明显。综合考虑鼠李糖乳杆菌和干酪乳杆菌以1∶1的体积比组合所得产品品质较好,该发酵乳在4℃贮藏21 d后酸化程度较弱,p H下降了0.65个单位;乳清析出较少,7 d以后低于20%;活菌数变化小且冷藏期间数量一直高于8.5 lg cfu/m L,游离氨基酸增加0.08 mmol/L,流变学性质显示其黏稠度较高,相对易于储运。     

四种乳酸杆菌在全谷物糙米乳中发酵特性的研究

选用植物乳杆菌(Lactobacillus plantarum)、鼠李糖乳杆菌(L.rhamnosus)、嗜酸乳杆菌(L.acidophilus)、干酪乳杆菌(L.casei)4株乳酸菌(Lactic acid bacteria,LAB)分别发酵糙米乳,通过测定发酵乳的p H、滴定酸度、活菌数、脱水收缩敏感性(susceptibility to syneresis,STS)、蛋白分解力、黏弹性等指标进行综合评定。结果表明:4株乳酸杆菌均能耐受酸和胆盐环境。L.rhamnosus的p H在4.45~4.5之间,p H环境更稳定;L.rhamnosus后酸化程度较弱;4℃贮藏21 d活菌数均超过8 lg cfu/g其中L.rhamnosus在贮藏期内乳酸菌的减少量较均匀且脱水收缩敏感性较低,保水性较好;其蛋白分解力维持在0.74~0.76 mmol/L;四种乳酸杆菌发酵的糙米乳都具有良好的黏度和黏弹性,L.rhamnosus的滞后环面积是687.92 Pa/s,发酵乳凝胶结构破坏后较易恢复,具有类固体的性质。综上,各方面均表现较好的L.rhamnosus适合发酵糙米乳。     

蓝莓汁乳酸菌的发酵特性

蓝莓汁中分别接种干酪乳杆菌、保加利亚乳杆菌、植物乳杆菌和嗜酸乳杆菌进行发酵,比较蓝莓汁发酵过程中乳酸菌活菌数、p H值、总滴定酸、总糖、还原糖、总花色苷、总酚、抗氧化能力和色泽等变化。结果表明,蓝莓汁营养丰富,上述各种乳酸菌均能在蓝莓汁中正常生长,发酵24 h,活菌数达8.10 lg cfu/mL以上;此外,植物乳杆菌和嗜酸乳杆菌产酸能力均强于其它两种乳酸菌,可滴定酸含量均超过10.29 g/L,而植物乳杆菌对蓝莓汁中糖的消耗能力最强,总糖的残留量为40.26%;在花色苷和总酚的保留率以及抗氧化能力等方面,植物乳杆菌和嗜酸乳杆菌也要优于其它两种乳酸菌。植物乳杆菌与嗜酸乳杆菌单独发酵和混合发酵时蓝莓汁营养品质的差异分析表明,单独发酵组与混合发酵组在抗氧化能力和总酚的保留上无明显差异,但混合发酵组在花色苷和色泽的保留方面明显优于单独发酵组。综上所述,蓝莓汁应以植物乳杆菌与嗜酸乳杆菌混合发酵为宜。     

羊胎水解液乳酸菌发酵菌种的选择

通过研究嗜酸乳杆菌（Lactobacillus acidophilus）1.1854；乳酸乳球菌（Lactobacillus）11454；短乳杆菌（Lactobacillus brevis）1.12；干酪乳杆菌干酪亚种（Lactobacillus casei)1.62；嗜热链球菌（Lactobacillus Streptococcus thermophilus)1.1855；植物乳杆菌9Lactobacillus plantarum）6种菌种对羊胎水解液菌发酵活力、双菌发酵活力、活菌数及风味的影响，确定了乳酸菌发酵羊水解液的最适菌种组合为嗜酸乳杆菌（Lactobacillus acidophilus)1.1854与嗜热链球菌（Lactobacillus Streptococ-cus thermophilus)1.1855。     

乳酸菌在豆乳中的生长特性及其与酵母菌联合发酵作用

本研究通过分析植物乳杆菌45、植物乳杆菌571、干酪乳杆菌、嗜酸乳杆菌、鼠李糖乳杆菌以及联合增香酵母PL09发酵豆乳过程中的酸度、活菌数、电泳图、胞外多糖含量、黏度等的变化,研究不同乳酸菌在豆乳中的生长特性及乳酸菌和酵母菌联合发酵豆乳时的特性。结果表明:植物乳杆菌45和植物乳杆菌571单独发酵豆乳8 h后pH分别达到4.43和4.42,活菌数分别达到3.11×108和2.78×108 CFU/mL,并且总糖含量降低较快;鼠李糖乳杆菌和干酪乳杆菌能够在豆乳中发酵分别产生胞外多糖180.82和174.45 μg/mL;乳酸菌和增香酵母PL09联合用于发酵豆乳时,增香酵母PL09能够促进乳酸菌在豆乳中的产酸能力,并且提高活菌数及产品的黏度,为开发乳酸菌和酵母菌的联合发酵豆乳提供指导。     

混料设计法优化红枣汁乳酸发酵菌种配比研究

以红枣发酵液的乳酸含量和活菌数为指标,选择嗜酸乳杆菌(NCFM)、干酪乳杆菌(D400)、植物乳杆菌(121)和嗜热链球菌(St)作为发酵菌种,利用混料设计法优化菌种配比。建立了各菌种配比与发酵液活菌数和乳酸含量的数学回归模型,并对此进行分析和预测,得出各菌种最佳体积比为:干酪乳杆菌(D400)∶嗜酸乳杆菌(NCFM)∶植物乳杆菌(121)=1∶1∶2,此时活菌数为1.81×109 CFU/m L,乳酸含量为6.31 g/L。     

益生菌发酵糙米饮料的制作工艺及其营养价值研究

为了开发新型发酵糙米饮料产品,选取干酪乳杆菌、嗜酸乳杆菌、双歧杆菌、唾液乳杆菌、德式乳杆菌、酿酒酵母6株益生菌菌株进行了单菌和多菌复配发酵试验,通过发酵后产品的乳酸含量、p H值、氨基酸、水溶性肽等指标的检测与分析得到了最优发酵菌种组合为:干酪乳杆菌+嗜酸乳杆菌+双歧杆菌。以乳酸含量为主要指标,利用正交试验确定了发酵糙米饮料的最佳发酵工艺为料水比1.2∶10,接种量5%,发酵时间16 h。在此条件下,发酵饮料的乳酸含量为45 mmol/L,产品具有浓郁的发酵香味和米香味,滋味酸度适中,风味独特。通过与市售谷物饮料和市售乳酸菌饮料的营养指标对比发现,发酵糙米饮料综合了谷物饮料和乳酸菌饮料的优点,是一种高蛋白质,高膳食纤维,高活菌数,低脂肪,低能量的全面均衡营养型的饮料。     

益生乳酸菌发酵苹果汁的研究

研究益生乳酸菌对苹果汁发酵的适应性和最优工艺条件。以发酵酸度为考核指标,考察保加利亚乳杆菌、嗜酸乳杆菌和植物乳杆菌单一菌株发酵和混合菌株发酵苹果汁的能力,筛选获得最佳的发酵菌株组合。通过正交实验优化了乳酸菌发酵的最佳工艺条件。结果显示,嗜酸乳杆菌与植物乳杆菌按1:1混合的复合乳酸菌对苹果汁发酵产酸作用较好,其发酵的最佳工艺参数是:苹果汁添加量35%、蔗糖添加量3%、发酵剂接种量4%、发酵温度40℃。在最优条件此时,苹果汁的发酵酸度达到0.952%。冷藏4周后,乳酸菌活菌数为1.12×10~9 cfu/mL,说明采用嗜酸乳杆菌与植物乳杆菌混合发酵苹果汁可行。     

益生菌对发酵乳理化性质影响的研究

通过比较不同菌种发酵乳和酸乳在4℃下贮藏21d的pH、酸度、活菌数与持水力的差异,并对后熟24h的发酵乳和酸乳进行质构特性分析。结果显示,益生菌发酵乳和乳酸菌酸乳的pH、活菌数与酸乳持水力均随时间的延长而降低,酸度呈上升趋势,益生菌发酵乳酸度值比乳酸菌酸乳更高。添加干酪乳杆菌与植物乳杆菌的益生菌发酵乳在硬度、稠度、凝聚性与黏度上与乳酸菌酸乳相比,均有所增加,其中添加植物乳杆菌的益生菌酸乳在硬度与稠度上较乳酸菌酸乳相比有显著增加(p<0.05),为发酵乳制品提供开发导向并为实际生产提供理论依据。     

发酵花生酸奶益生乳杆菌菌株筛选及其蛋白酶活性

以从天然发酵食品及保健品中自行分离选育的14株益生乳杆菌为试验菌株,对花生乳发酵。对发酵前、后的pH值、活菌数、感官特性和蛋白酶活进行分析,经层层筛选,得到繁殖能力强,发酵活力好的2株益生乳酸菌。干酪乳杆菌05-20和植物乳杆菌fs-4发酵后活菌数在8.29 lg(CFU/m L)以上,pH值在4.5以下,蛋白酶活分别为4.417 U/m L和15.638 U/m L。通过SDS-PAGE电泳得出菌株具有蛋白酶活且能将大分子花生蛋白分解为小分子蛋白和花生肽。试验结果表明这两株益生乳杆菌具有发酵花生酸乳的潜力,为进一步开发花生酸奶产品和研究花生酸乳功能性质提供理论和实践依据。     

Physicochemical, microbiological and sensory profiles of fermented milk containing probiotic strains isolated from kefir

A two-strain starter culture containing Lactobacillus plantarum CIDCA 83114, a potential probiotic strain isolated from kefir grains, and Streptococcus thermophilus CIDCA 321 was tested for the preparation of a fermented milk product. Kluyveromyces marxianus CIDCA 8154, a yeast with immunomodulatory properties was included to formulate a three-strain starter culture. Supernatants of enterohaemorragic Escherichia coli, shiga-toxin-producing strain, along with a two-strain or a three-strain starter culture were included in the medium of Vero-cell surface cultures. The results demonstrated that these combinations of microorganisms antagonize the cytopathic action of shiga toxins. The cell concentration of Lb. plantarum did not decrease during fermentation, indicating that the viability of this strain was not affected by low pH, nor did the number of viable bacteria change during 21 days of storage in either fermented products. The number of viable yeasts increases during fermentation and storage. Trained assessors analyzed the general acceptability of fresh fermented milks and considered both acceptable. The milk fermented with the two-strain starter culture was considered acceptable after two week of storage, while the product fermented with the three-strain starter culture remained acceptable for less than one week. The main changes in sensory attributes detected by the trained panel were in sour taste, milky taste and also in fermented attributes. The correlation between different sensory attributes and acceptability indicated that the panel was positively influenced by milky attributes (taste, odour, and flavour) as well as the intensity of flavour. In conclusion, the two-strain starter culture would be the more promising alternative for inclusion of that potential probiotic lactobacillus in a fermented milk product.     

响应面法优化萌发藜麦芽乳发酵工艺

以萌发藜麦芽为原料,研究发酵条件对藜麦芽发酵乳酸度和活菌数的影响。选用植物乳杆菌和干酪乳杆菌2种混合菌进行发酵,通过单因素试验、响应面优化试验探究菌种比例、接种量和发酵时间对发酵的影响。结果表明,萌发藜麦芽乳混合菌发酵最佳工艺条件为植物乳杆菌和干酪乳杆菌比例2.5∶1、接种量3%、发酵时间10.3 h,得到的萌发藜麦芽发酵乳酸度为85.32°T,活菌数为9.21(lg(CFU/m L)),与预测值吻合,表明萌发藜麦芽的匀浆发酵培养基适合乳酸菌生长。     

几种保护剂对干酪乳杆菌代田株保护作用的比较

将活化后的干酪乳杆菌代田株制成冻干发酵剂，通过对其复水后活菌数和乳酸脱氢酶的测定，比较了脱脂奶、葡萄糖、谷氨酸钠、海藻糖4种冻干保护剂对干酪乳杆菌代田株的保护效果。结果表明，10%-15%脱脂奶、10%-15%海藻糖对干酪乳杆菌代田株有较好的保护效果，在12个月的保藏期内，冻干保藏的菌种存活细胞总数保持90%以上，并且随着保护剂浓度的增加其保藏效果更好。     

益生菌混合菌种在发酵豆乳中的优化

采用益生菌混合物AST和TLB分别在42℃进行豆乳的发酵,在发酵豆乳的发酵和贮存过程中(4℃下28d),观察pH值和活菌数的变化情况。在AST益生菌混合物(嗜酸性乳杆菌,双歧杆菌和嗜热链球菌)的培育下,42℃下发酵时间减少到8h。但嗜酸性乳杆菌在冷藏的过程中生存状态较差,其活菌数在冷藏后一周后未达到标准。将豆乳在42℃下用TLB益生菌(嗜热链球菌,保加利亚乳杆菌和动物双歧杆菌乳酸亚种Bb12)进行发酵,结果发酵时间缩短到4h,双歧杆菌活菌数目的对数增加了约一半,而且经过28d的冷藏,细菌数仍然维持在107 CFU/mL以上。     

Effect of milk base and starter culture on acidification,texture, and probiotic cell counts in fermented milk processing

In the present work, the compared effect of milk base and starter culture on acidification, texture, growth, and stability of probiotic bacteria in fermented milk processing, was studied. Two strains of probiotic bacteria were used, Lactobacillus acidophilus LA5 and L. rhamnosus LR35, with two starter cultures. One starter culture consisted only of Streptococcus thermophilus ST7 (single starter culture); the other was a yogurt mixed culture with S. thermophilus ST7 and L. bulgaricus LB12 (mixed starter culture). For the milk base preparation, four commercial dairy ingredients were tested (two milk protein concentrates and two casein hydrolysates). The resulting fermented milks were compared to those obtained with control milk (without enrichment) and milk added with skim milk powder. The performance of the two probiotic strains were opposite. L. acidophilus LA5 grew well on milk but showed a poor stability during storage. L. rhamnosus LR35 grew weakly on milk but was remarkably stable during storage. With the strains tested in this study, the use of the single starter culture and the addition of casein hydrolysate gave the best probiotic cell counts. The fermentation time was of about 11 h, and the probiotic level after five weeks of storage was greater than 106 cfu/ml for L. acidophilus LA5 and 10(7) cfu/ml for L. rhamnosus LR35. However, an optimization of the level of casein hydrolysate added to milk base has to be done, in order to improve texture and flavor when using this dairy ingredient.     

Production and evaluation of a probiotic yogurt using Lactobacillus casei ssp. casei

Skimmed milk was inoculated with the commercial starter and Lactobacillus casei ssp. casei. pH changes, viable counts, and organoleptic properties of the produced control and probiotic yogurts were analysed. The pH decrease during the fermentation period was faster in the milk inoculated with L. casei plus starter. The growth of both starters in probiotic yogurt was significantly lower than their growth in control yogurt during the fermentation period. The viable count of the probiotic bacterium remained higher than the standard limit for probiotic products. There was no significant difference between the organoleptic properties of the control and the probiotic yogurts.     

Viability of probiotic (Bifidobacterium, Lactobacillus acidophilus and Lactobacillus casei) and nonprobiotic microflora in Argentinian Fresco cheese

We evaluated the suitability of Argentinian Fresco cheese as a food carrier of probiotic cultures. We used cultures of Bifidobacterium bifidum (two strains), Bifidobacterium longum (two strains), Bifidobacterium sp. (one strain), Lactobacillus acidophilus (two strains), and Lactobacillus casei (two strains) in different combinations, as probiotic adjuncts. Probiotic, lactic starter (Lactococcus lactis and Streptococcus thermophilus), and contaminant (coliforms, yeasts, and molds) organisms were counted at 0, 30, and 60 d of refrigerated storage. Furthermore, the acid resistance of probiotic and starter bacteria was determined from hydrochloric solutions (pH 2 and 3) of Fresco cheese. The results showed that nine different combinations of bifidobacteria and L. acidophilus had a satisfactory viability (count decreases in 60 d <1 log order) in the cheese. Both combinations of bifidobacteria and L. casei cultures assayed also showed a satisfactory survival (counts decreased <1 log order for bifidobacteria but no decrease was detected for L. casei). On the other hand, the three combinations of bifidobacteria, L. acidophilus, and L. casei tested adapted well to the Fresco cheese environment. When a cheese homogenate at pH 3 was used to partially simulate the acidic conditions in the stomach, the probiotic cultures had an excellent ability to remain viable up to 3 h. At pH 2, the cell viability was more affected; B. bifidum was the most resistant organism. This study showed that the Argentinian Fresco cheese could be used as an adequate carrier of probiotic bacteria.     

核桃粕发酵乳菌种筛选及发酵条件优化研究

该试验对乳酸菌发酵核桃粕乳的不同菌株进行筛选,通过pH值、酸度及感官评定分析,从9株乳酸菌中筛选出嗜酸乳杆菌(Lactobacillus acidophilus)和植物乳杆菌(Lactobacillus plantarum)两株优良菌种。研究两株乳酸菌的复配比例,并与传统发酵剂发酵的核桃粕乳进行品质对比。结果表明,以嗜酸乳杆菌:植物乳杆菌(1∶1)接种发酵后得到的发酵核桃粕发酵乳综合品质最佳,其感官评分90分,氨基酸态氮含量57.0 mg/L,活菌总数7.35×107 CFU/mL,经发酵后的营养价值明显优于传统发酵剂发酵的核桃粕乳。     

Lactobacillus casei HS4胞外多糖对发酵乳组织结构和流变特性的影响

研究干酪乳杆菌（Lactobacillus casei）HS4所产乳酸菌胞外多糖（exopolysaccharide,EPS）及其对发酵乳微观结构和流变性的影响。通过Sephadex G-50柱纯化得到两种类型的EPS,分别命名为HS4-1-EPS和HS4-2-EPS。HS4-1-EPS主要由葡萄糖组成,峰面积为0.940。HS4-2-EPS主要由葡萄糖和甘露糖组成,峰面积比为0.3830.364。红外光谱结果显示,HS4-1-EPS和HS4-2-EPS均为杂多糖。分别采用干酪乳杆菌HS4、嗜热链球菌-保加利亚乳杆菌（11）复合菌株以及复合菌株添加纯化EPS制成的不同发酵乳作为样品,通过测定流变特性及微观结构观察,研究补充纯化EPS和原位EPS对发酵乳流变特性及微观结构的影响。结果显示,其在4 ℃贮存期间显示出不同的流变特性及微观结构。基于扫描电镜下样品的微观结构,可以推知,EPS的类型和空间阻挡效应与发酵乳的流变性质相关。