双歧杆菌发酵酸豆奶的研制

就双歧杆菌以豆奶为培养基的耐氧条件进行了探索,经实验确定了发酵工艺,制作的双歧杆菌发酵酸豆奶具有普通发酵酸豆奶的典型风味,还含有双歧杆菌活菌达１０８ 以上。     

功能性酸乳中每种益生菌的单独计数方法及其混合发酵工艺的研究

通过研究分析功能性酸乳中双歧杆菌和各种乳酸菌在BBL平板培养基上的菌落特征及菌体形态,提出了一种可同时准确对每种益生菌单独计数的新方法,从而可直观地观察到各种益生菌的生长活度,免除了传统方法计数不同有益菌数要用不同培养基的繁琐,为生产和检测提供了依据;还对功能性酸乳的混合发酵生产工艺进行了研究,确定了最佳的菌种比例,按嗜热链球菌3%、保加利亚乳杆菌2%、嗜酸乳杆菌4%、双歧杆菌10%接种,39℃发酵11~13h,酸乳产品既保持了普通酸乳的良好口感和风味,又保证了双歧杆菌和乳酸菌活菌数在贮存期内均大于108cfu/mL,增强了酸乳的保健功能。     

双歧杆菌发酵胡萝卜汁酸乳贮藏稳定性研究

从健康人体中选育出2株发酵活力高、耐氧性和抗逆性强的双歧杆菌优良发酵菌株两歧双歧杆菌Bbm和长双歧杆菌Blm作为试验菌株,制备了双歧杆菌纯种及双歧杆菌与乳酸菌混种发酵胡萝卜汁酸乳,考察了发酵产品在室温(20~30℃)和冷藏(0~4℃)条件下的贮藏稳定性。试验结果表明:0~4℃冷藏21d,活菌含量仍可达1×109cfu/mL以上,pH值降至4.2~4.3,酸甜适宜。因此,确定发酵产品0~4℃下贮藏期为21d。     

以麦麸为原料固态发酵开发多菌种微生态制剂的研究

试验以麦麸为主要原料,采用固态发酵技术,以纳豆芽孢杆菌和嗜酸乳杆菌为发酵菌种,以活茵数为指标,通过单因素和L9(34)正交试验确定了双菌混合发酵的最佳条件.结果表明:先接入纳豆芽孢杆菌,发酵3 d后接入嗜酸乳杆菌再共同培养3 d、培养基初始含水量80%、pH值7.0、纳豆芽孢杆菌和嗜酸乳杆菌接种比例为4:6、接种量10%、发酵温度37℃的发酵效果最好.在此条件下发酵后,纳豆芽孢杆茵数为9.8×109cfu/g,嗜酸乳杆菌数为7.1×109cfu/g.     

两歧双歧杆菌与嗜酸乳杆菌微生态制剂的工业化生产工艺研究

研究了两歧双歧杆菌和嗜酸乳杆菌双联微生态制剂的工业化生产工艺。对发酵培养基及发酵条件进行了研究和优化，并确定了发酵奶的冷冻干燥工艺条件。冻干后的产品中两歧双歧杆菌和嗜酸乳杆菌的活菌数均达到了10^9-10^10g^-1，而且在冻干工艺条件下，发酵产物中的各种活性成分得以最大限度地保存下来，使产品可以达到作为微生态制剂应用的相关标准。     

小米、绿豆发酵乳的研制

以小米、绿豆为主要原料制成发酵培养基，采用耐氧双歧杆菌进行发酵扩大培养，然后发酵小米、绿豆制成酸乳，有消暑解热败火之功效。     

双歧杆菌酸奶制造的中间试验

应用筛选获得的双歧杆菌耐氧菌株发酵制造酸牛奶的工艺进行了中间试验。结果表明:采用双歧杆菌耐氧菌株进行有氧奶质发酵制造酸牛奶是完全可行的。适当添加一些生长促进物质,可使发酵剂制备时间减少到8小时以内。采用由双歧杆菌和其它辅助菌混合而成的组合发酵剂制造酸奶,发酵周期可缩短到5小时;此种酸奶在保质期内双歧杆菌活菌数含量能保持在10~7个/g以上。应用此工艺,只需采用普通酸奶的生产设备即可进行双歧杆菌酸奶的制造。     

含金属硫蛋白鸡蛋水解物对两种乳酸菌体外生长的影响

以乳酸菌生长过程中的pH、OD值和菌落总数为评价指标,研究了普通鸡蛋、含金属硫蛋白鸡蛋、普通鸡蛋水解物以及含金属硫蛋白的鸡蛋水解物对动物双歧杆菌、嗜酸乳杆菌以及两种混合菌的影响。结果表明,鸡蛋水解物作为氮源能够促进乳酸菌的增殖,经比较,最佳氮源为含金属硫蛋白鸡蛋水解物,其动物双歧杆菌、嗜酸乳杆菌和混合菌发酵液OD值为普通鸡蛋水解物的1.05倍、1.08倍和1.09倍。含金属硫蛋白的鸡蛋水解物在动物双歧杆菌、嗜酸乳杆菌以及两种混合菌发酵液的最佳添加量分别为2.0%、1.5%和2.0%,活菌数分别可达7.5×109、3.21×109和2.33×1010 CFU/mL。本研究为开发乳酸菌发酵金属硫蛋白鸡蛋肽产品提供指导。     

乳酸发醇胡萝卜汁的研制

以胡萝卜汁为基质,对若干乳酸发酵菌株进行发酵性能及生长曲线的研究,确定了以嗜酸乳杆菌为主要发酵菌种。并使之与耐氧驯化的青春双歧杆菌混合培养,表现出良好的共发酵特性。以此培养液为发酵剂,对胡萝卜汁进行发酵,即可制得色泽纯正、风味优良、质地细腻的乳酸发酵胡萝卜汁。     

分离双歧杆菌INf和嗜酸乳杆菌PB1要豆乳中共生特性的研究

通过混合培养和纯培养时的生长速率及产酸性能的比较,研究分离的双歧杆菌INf和嗜酸乳杆菌PB1在豆乳中的生长关系,研究这两种菌在混合培养时的微生态关系.研究发现,在豆乳培养基中,两者呈现出一定的混合培养优势,可以混合应用到豆乳的发酵生产中.     

Influence of heat impact in reconstituted skim milk on the properties of yoghurt fermented by ropy or non-ropy starter cultures

The paper describes studies on the influence of heat impact in reconstituted skim milk on chemical and functional properties of yoghurt products. Reconstituted skim milk was heated for 20 min at 85 degrees C, 90 degrees C, or 95 degrees C. Ropy (producing exopolysaccharides, EPS) or non-ropy strains of S. thermophilus and L. delbrueckii subsp. bulgaricus were used as starter culture for yoghurt manufacture. The studies have shown that the fermentation times decreased with increasing heat impact when the ropy starter culture was used, while they remained to a far extent unchanged if the non-ropy starter culture was applied. The lactic acid contents of the yoghurt products were in the same range when the milk was heated at 85 degrees C or 90 degrees C, while they were different when milk was heated at 95 degrees C. There was a tendency visible that an increase in preheating leads to increased L(+)- and decreased D(-)-lactic acid contents if the non-ropy culture was applied. Using the ropy culture, it was vice versa. A slightly decrease in proteolysis with increasing heat impact was to be noted with both starter cultures. Concerning the relation of proteolysis to acidification, the fermentation process could be subdivided into three sections with different slopes if the non-ropy starter culture was used, while a linear relation was found if the ropy starter culture was applied. Regarding final product characteristics it was found that the functional properties of yoghurt decreased with increasing heat impact when the ropy starter culture was applied, while they remained to a far extent unchanged when the non-ropy starter culture was used. It can be concluded from these studies that a preheating of milk at a temperature of 85 degrees C (20 min) is optimal in regard to final yoghurt product characteristics.     

Influence of heat impact in reconstituted skim milk on the properties of yoghurt fermented by ropy or non‐ropy starter cultures

The paper describes studies on the influence of heat impact in reconstituted skim milk on chemical and functional properties of yoghurt products. Reconstituted skim milk was heated for 20 min at 85°C, 90°C, or 95°C. Ropy (producing exopolysaccharides, EPS) or non‐ropy strains of S. thermophilus and L. delbrueckii subsp. bulgaricus were used as starter culture for yoghurt manufacture. The studies have shown that the fermentation times decreased with increasing heat impact when the ropy starter culture was used, while they remained to a far extent unchanged if the non‐ropy starter culture was applied. The lactic acid contents of the yoghurt products were in the same range when the milk was heated at 85°C or 90°C, while they were different when milk was heated at 95°C. There was a tendency visible that an increase in preheating leads to increased L (+)‐ and decreased D (–)‐lactic acid contents if the non‐ropy culture was applied. Using the ropy culture, it was vice versa. A slightly decrease in proteolysis with increasing heat impact was to be noted with both starter cultures. Concerning the relation of proteolysis to acidification, the fermentation process could be subdivided into three sections with different slopes if the non‐ropy starter culture was used, while a linear relation was found if the ropy starter culture was applied. Regarding final product characteristics it was found that the functional properties of yoghurt decreased with increasing heat impact when the ropy starter culture was applied, while they remained to a far extent unchanged when the non‐ropy starter culture was used. It can be concluded from these studies that a preheating of milk at a temperature of 85°C (20 min) is optimal in regard to final yoghurt product characteristics.     

复合乳酸菌在发芽糙米乳中的发酵特性

将植物乳杆菌、鼠李糖乳杆菌、嗜酸乳杆菌、干酪乳杆菌4种乳酸菌经三三组合后作为复合发酵剂对发芽糙米乳进行发酵,通过分析酸度、活菌数、脱水收缩作用敏感性、蛋白质分解力、流变学性质等实验结果,对各乳酸菌组合的发酵特性进行评价,最终筛选出适合发酵发芽糙米乳的最佳菌株组合。结果表明:植物乳杆菌-嗜酸乳杆菌-干酪乳杆菌组合所得到的发酵发芽糙米乳具有较高的品质。该发酵糙米乳在4℃条件下贮藏21 d后酸化程度较弱,下降了0.71个单位;活菌数变化小且冷藏期间数量一直高于8.7(lg(CFU/m L)),游离氨基酸平均含量达0.86 mmol/L,流变学性质显示其剪切稀化作用较弱。故该乳酸菌组合较为适合发酵发芽糙米乳。     

藏灵菇及其优势菌群的发酵性能研究

以藏灵菇为发酵剂生产酸乳的工艺条件为:发酵温度37℃,发酵时间10h。获得的酸乳产品pH较低。用MRS培养基、Elliker培养基、TYC培养基和SL培养基从藏灵菇中分离出乳球菌、乳杆菌、链球菌和明串珠菌。将优选的分离菌组合发酵鲜牛乳,产酸速度更快,黏度较高。     

响应面法优化金银花枸杞风味酸奶的发酵工艺

以金银花、枸杞、全脂奶粉为原料,采用单因素试验研究了金银花汁添加量、枸杞汁添加量、白砂糖添加量、发酵温度、发酵时间、发酵剂接种量对金银花枸杞风味酸奶发酵的影响。以感官评分为响应值,采用响应面法对金银花枸杞风味酸奶的发酵工艺条件进行优化。结果表明,金银花枸杞风味酸奶的最佳发酵工艺条件为金银花汁添加量5%、枸杞汁添加量6%、白砂糖添加量8%,发酵剂接种量10%,发酵温度43 ℃,发酵时间5.1 h。在此优化工艺条件下,发酵的金银花枸杞风味酸奶组织细腻,酸甜可口,具有独特的中药香,感官评分为91分。     

Development of made‐in‐transit set culture yoghurt: effect of increasing the concentration of reconstituted skim milk as the milk base

The fermentation time, yoghurt acidity expressed as lactic acid, starter culture growth, viscosity and firmness of made‐in‐transit (MIT) set culture yoghurt produced using different concentrations of reconstituted skim milk powder (SMP) from 12% to 20% (w/v) as the milk base were investigated. All milk base formulations were ultra‐high temperature sterilised at 138 °C for 6 s. The results revealed that increasing the SMP concentration increased the viscosity and firmness of MIT set culture yoghurt. At 20% SMP, viscosity and firmness were 4650.8 cP and 1.266 N, respectively. Fermentation of MIT set culture yoghurt with 20% SMP was observed to be faster than with the other conditions. The fermentation time for a medium containing from 14% to 20% SMP could be extended to 168 h, reaching a final pH of 4.50–4.37 and at the same time improving the texture of the MIT set culture yoghurt. The SMP concentration had no influence on the total viable counts of starter bacteria in the yoghurt. The texture of MIT set culture yoghurt may be improved by increasing the concentration of SMP.     

黑木耳多糖凝固型酸奶发酵工艺优化

以黑木耳多糖(Auricularia auricular polysaccharide,AAP)和纯牛奶为原料,嗜热链球菌、保加利亚乳杆菌和干酪乳杆菌组成的混合菌为发酵剂,研究AAP凝固型酸奶的最佳发酵工艺。以感官评价为指标,单因素实验探究蔗糖添加量、AAP添加量、明胶添加量、发酵时间、发酵温度、发酵剂接种量对AAP凝固型酸奶的影响,进一步采用响应面试验设计对AAP凝固型酸奶的发酵工艺进行优化,并对其酸奶品质进行评价。结果表明:AAP固体酸奶的最佳发酵工艺参数为0.33%明胶、7.0%蔗糖、3.0%发酵剂、0.1% AAP、发酵时间6.9 h、发酵温度42℃。在此最优工艺下进行验证实验,得到的AAP凝固型酸奶的感官评分为(9.30±0.08)分,与预测值吻合;将其与普通酸奶的感官评分(8.83±0.12)分、持水力(63.83%±2.69%)和质构特性比较,AAP酸奶的持水力(72.14%±3.58%)和质构特性显著提高,感官评分更优;此外,AAP酸奶的游离氨基酸和胞外粗多糖显著(P<0.05)升高,脂肪含量(2.35±0.25 g/100 g)显著(P<0.05)低于普通酸奶(4.16±0.39 g/100 g),具有更高的营养价值和保健功效。因此,AAP凝固型酸奶具备开发成为一种新型功能性酸奶的潜力。     

红枣山楂桂圆酸奶的研制

结合红枣、桂圆、山楂和牛奶的有益作用,研制出集营养与保健功能于一体的红枣山楂桂圆酸奶。以牛奶、红枣、桂圆、山楂为原料,以乳酸菌为发酵剂,通过单因素和正交试验确定红枣山楂桂圆发酵乳的制作工艺。试验表明,果汁最佳添加量为15%,蔗糖添加量为7%,接种量为11%,发酵温度45 ℃,发酵时间为5 h,4 ℃后熟12 h。利用此工艺制备的酸奶风味独特,营养丰富,感官评分为95.6分。     

Milk-based beverages obtained by Kombucha application

This paper investigates the manufacture of milk-based beverages by application of several Kombucha starters. Local Kombucha culture was grown up on three substrates: sweetened black and green tea, and topinambur. Their concentrates were obtained by vacuum-evaporation and amounts of 10% and 15% (v/v) were applied to milk (2.2% fat). The traditional yoghurt starter (B3) was applied for producing control samples. All fermentations were stopped when the pH reached 4.4. Fermentation curves were registered, linear for yoghurt and sigmoidal for Kombucha. Two times faster process was achieved with yoghurt starter. Influence of inoculum concentration on the rate of fermentation was insignificant. Viscosities were higher for Kombucha beverages at lower speeds of spindle, but lower at higher speeds of spindle. Very high sensory scores were achieved for all beverages, after production and after 5-days’ storage.     

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.