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1.
Yogurt products fermented with probiotic bacteria are a consumer trend and a challenge for functional food development. So far, limited research has focused on the behavior of the various probiotic strains used in milk fermentation. In the present study, we characterized folic acid production and the sensory and textural characteristics of yogurt products fermented with probiotic bacteria. Yogurt fermented with Lactobacillus plantarum had improved nutrient content and sensory and textural characteristics, but the presence of L. plantarum significantly impaired the growth and survival of Lactobacillus delbrueckii ssp. bulgaricus during refrigerated storage. Overall, L. plantarum was a good candidate for probiotic yogurt fermentation; further studies are needed to understand the major metabolite path of lactic acid bacteria in complex fermentation.  相似文献   

2.
《Food microbiology》2005,22(1):117-124
Green-table olives, unheated and pasteurized, of Greek cultivar Conservolea were supplemented with glucose or sucrose in various amounts inoculated with Lactobacillus plantarum and fermentation was conducted. Although sugar supplements did not affect the lactic acid bacteria growth rate, they increased the rate of pH drop and the production of acids and lowered the final pH values in all cases. Adequate supplements of sugars (0.5%, 1.0% w v−1), of both types, in unheated olive fermentation, resulted in a fast pH drop, causing a satisfactory halt of Enterobacteriaceae growth in the first days of fermentation, and a subsequent population decline occurred in the following days, eliminating the danger of early stage spoilage and ensuring the safety of the final product. In pasteurized olives, where L. plantarum starter was the only microbial flora, it was considered worth evaluating the fermentation progress without any competition. The rate of pH drop was not as high as in unheated olives, but final pH values and acid development were more pronounced. Lactic acid was the predominant acid developed in both unheated and pasteurized olive fermentation, and increased sugar supplements resulted in faster production and higher yields of this acid. Acetic acid was also produced in low amounts at the end of fermentation, except in the cases of pasteurized olive fermentation supplemented with sucrose, where acetic acid was absent. A switch from homo-fermentative to hetero-fermentative metabolism might have taken place in case of glucose presence, but the same was not observed for sucrose.  相似文献   

3.
Hervé Robert 《LWT》2006,39(3):256-265
The acidification properties, metabolic activity and technological performance of four individual Lactobacillus plantarum or Leuconostoc freeze-dried starters were investigated during a complete wheat sourdough breadmaking process including 0.2 g/100 g baker's yeast. Microbiological contents (lactic acid bacteria and yeasts), acidification characteristics (pH and total titratable acidity), soluble carbohydrates (maltose, glucose and fructose) and fermentative end-products (lactic and acetic acids, ethanol) contents were evaluated during both sourdough and corresponding bread dough fermentation. Biochemical and technological analysis of the resulting bread products are also presented. Some differences among strains in acidification properties and soluble carbohydrates availability were outlined both in sourdough and bread dough. Each individual Leuconostoc or Lb. plantarum starter was able to produce a characteristic fermentation and was found to ensure the production of breads with overall satisfactory acceptance.  相似文献   

4.
杨萍  徐忠 《食品科学》2009,30(3):184-187
本实验以大豆秸秆酶解液为原料,发酵制备L- 乳酸。首先对产L- 乳酸的四株菌进行筛选,选出性能优良、糖利用率和乳酸产量均较高的干酪乳杆菌作为实验用菌种。然后对乳酸菌发酵大豆秸秆酶解液制备L- 乳酸的影响因素进行了研究,研究结果表明:干酪乳杆菌发酵的最佳接种量为10%,最适发酵温度为30℃,最佳pH 值为5.5;在发酵42h 时,大豆秸秆酶解液中残留糖浓度接近于零,此时,随底物浓度的增高,乳酸产量相应增加,并且酶解液浓度达到34.98g/L 时,乳酸生产没有受到抑制。  相似文献   

5.
Two experiments were carried out to study the influence of storage time, glucose and urea additions ( Experiment 1 ) and lactic acid bacteria inoculation with and without glucose addition ( Experiment 2 ) on the production of lactate isomers and fermentation quality of guineagrass (Panicum maximum Jacq) silage. All silages in both experiments were well preserved, as indicated by lower pH and little or no butyric acid. In Experiment 1 , addition of glucose or urea did not significantly affect the pH of silages (P > 0.05). Urea addition tended to reduce acetic acid content and greatly increased NH3 − N content. L (+)‐Lactic acid was produced predominantly in the first 3 days of ensiling, but D (−)‐lactic acid increased gradually until 1 month after ensiling. Thereafter all silages became stable. In Experiment 2 , inoculation of Lactobacillus casei or L rhamnosus with or without glucose reduced D (−)‐lactic acid and increased L (+)‐lactic acid of silages. The proportions of L (+)‐lactic acid in these silages were higher than 80% of total lactic acid. L plantarum alone or in combination with glucose promoted D (−)‐lactic acid production and decreased the proportion of L (+)‐lactic acid. Glucose addition alone tended to reduce the proportion of L (+)‐lactic acid in both experiments. © 2000 Society of Chemical Industry  相似文献   

6.
To protect consumers from Salmonella infection acquired through the consumption of pork meat, it is necessary to eradicate Salmonella from pork. In order to achieve this, the whole pork production chain should be free from Salmonella, including the pigs at the farm. In epidemiological studies it was concluded that the use of fermented feed plays a significant role in the reduction of Salmonella prevalence in pig farms. However, the mechanism of Salmonella reduction in fermented feed is not known. A controlled feed fermentation was performed using a pure culture of Lactobacillus plantarum. pH reduction, organic acid profiles and bacterial counts were determined. In L plantarum‐fermented feed, lactic acid and acetic acid were produced and the pH dropped to a value below 4.0. Antimicrobial products (bacteriocins) could not be detected. The results showed that the produced lactic and acetic acid and the pH in the feed are responsible for Salmonella reduction in fermented feed. L plantarum did not show any other antimicrobial effect on Salmonella. © 2000 Society of Chemical Industry  相似文献   

7.
The aim of this work was to evaluate the performance of spontaneous and Lactobacillus cultures in Spanish style fermentation of olive fruits. A fermentation with Lactobacillus plantarum ATCC 8014 was carried out for comparison. Fermentation was performed at room temperature during 120 days in two different concentrations of NaCl (2.4–13.6 % w/v) and sucrose (0–0.82 % w/v) in the brines. The pH, chlorides, lactic acid, reducing sugar and lactic bacteria in selective medium were investigated during the olive fermentation. After 120 days of fermentation, the formulation with 12 % NaCl in the brine hampered the growth of lactic bacteria, avoiding the consumption of reducing sugars. However, low salt concentrations (≤4 %) promoted a decrease in pH, an increase of the lactic acid and the growth of lactic bacteria, providing best environmentally suitable for the fermentation process. Whereas using concentrations of 12 % NaCl and 0.7 % sucrose showed better chemical conditions, ensuring the safety of the product produced. Multivariate analysis showed that the olives with both cultures were in close relation to lactic acid and reducing sugar and different from lactic bacteria.  相似文献   

8.
The present study aims to evaluate the probiotic potential of lactic acid bacteria (LAB) isolated from naturally fermented olives and select candidates to be used as probiotic starters for the improvement of the traditional fermentation process and the production of newly added value functional foods. Seventy one (71) lactic acid bacterial strains (17 Leuconostoc mesenteroides, 1 Ln. pseudomesenteroides, 13 Lactobacillus plantarum, 37 Lb. pentosus, 1 Lb. paraplantarum, and 2 Lb. paracasei subsp. paracasei) isolated from table olives were screened for their probiotic potential. Lb. rhamnosus GG and Lb. casei Shirota were used as reference strains. The in vitro tests included survival in simulated gastrointestinal tract conditions, antimicrobial activity (against Listeria monocytogenes, Salmonella Enteritidis, Escherichia coli O157:H7), Caco-2 surface adhesion, resistance to 9 antibiotics and haemolytic activity. Three (3) Lb. pentosus, 4 Lb. plantarum and 2 Lb. paracasei subsp. paracasei strains demonstrated the highest final population (>8 log cfu/ml) after 3 h of exposure at low pH. The majority of the tested strains were resistant to bile salts even after 4 h of exposure, while 5 Lb. plantarum and 7 Lb. pentosus strains exhibited partial bile salt hydrolase activity. None of the strains inhibited the growth of the pathogens tested. Variable efficiency to adhere to Caco-2 cells was observed. This was the same regarding strains' susceptibility towards different antibiotics. None of the strains exhibited β-haemolytic activity. As a whole, 4 strains of Lb. pentosus, 3 strains of Lb. plantarum and 2 strains of Lb. paracasei subsp. paracasei were found to possess desirable in vitro probiotic properties similar to or even better than the reference probiotic strains Lb. casei Shirota and Lb. rhamnosus GG. These strains are good candidates for further investigation both with in vivo studies to elucidate their potential health benefits and in olive fermentation processes to assess their technological performance as novel probiotic starters.  相似文献   

9.
The production of lactic acid by Lactobacillus casei B-442 was studied and modeled. Sugar feedstock was provided using cashew apple juice, an alternative glucose and fructose feedstock that proved to yield high concentrations of lactic acid. The fermentations were carried out in a 1-L fermenter under constant agitation (150 rpm) and controlled pH (6.5). Lactic acid production was evaluated through a dynamic study, varying the initial concentration of sugar in the range of 20 to 60 g/L. Biomass, reducing sugars, and lactic acid concentration were measured throughout the experiments. The highest production of lactic acid (59.3 g/L) was obtained operating the fermentation with 60 g/L of reducing sugar from the cashew apple juice. A rigorous kinetic model was developed for batch fermentation of cashew apple juice for lactic acid production by L. casei B-442. The growth of biomass and lactic acid production were affected by substrate limitation, substrate inhibition and lactic acid inhibition. The model assumed growth- and non-growth-associated lactic acid production and a term for microorganism death was also included in the model. Parameters of the kinetic model were determined based on experimental data by using the least mean squares method and Levenberg–Marquardt algorithm. The model validation was performed and the model was statistically able to fit the profiles for growth of biomass, sugar consumption and lactic acid production. The optimization of the process, using the model, was carried out and the optimum operating conditions aiming highest productivity, lowest production cost and highest gross profit are presented.  相似文献   

10.
Alfalfa (approximately 31% DM) was untreated or treated with a silage inoculant containing the lactic acid bacteria Lactobacillus lactis, Lactobacillus plantarum L-54, and L. plantarum Aber F1. The inoculant was added at a normal and a high dose as a freeze-dried powder that had been mixed with water just prior to application, or it was grown with nutrients the day before and added as a fresh culture. The actual application rate of lactic acid bacteria was 1.19 × 105 for the normal dose, 4.30 × 105 for the high dose, and 5.10 × 105 for the fresh culture. All inoculated silages showed a faster increase in the rate of lactic acid production and a decrease in the drop in pH over the first 24 h of ensiling compared with untreated silage. The effect was greatest for silage treated with the fresh culture and was supported by the fact that this treatment had numbers of lactic acid bacteria that increased faster than in other treatments. Inoculation also generally resulted in a fermentation profile that was more homolactic (more lactic acid and less acetic acid, ethanol, and NH3-N) than for untreated silage, but the effect was greatest for the fresh culture. Inoculation did not affect in vitro neutral detergent fiber digestion or the concentrations of neutral detergent fiber or total N in silages. The recovery of dry matter was greater in silage that was treated with a high level of the freeze-dried culture or with the fresh culture when compared with the untreated control. This study showed that application of a silage inoculant as a freeze-dried culture or as a fresh culture resulted in alfalfa silage with a more homolactic fermentation profile. The effect was greatest from addition of the fresh culture.  相似文献   

11.
Pichia guilliermondii was the only identified yeast in pineapple fruits. Lactobacillus plantarum and Lactobacillus rossiae were the main identified species of lactic acid bacteria. Typing of lactic acid bacteria differentiated isolates depending on the layers. L. plantarum 1OR12 and L. rossiae 2MR10 were selected within the lactic acid bacteria isolates based on the kinetics of growth and acidification. Five technological options, including minimal processing, were considered for pineapple: heating at 72 °C for 15 s (HP); spontaneous fermentation without (FP) or followed by heating (FHP), and fermentation by selected autochthonous L. plantarum 1OR12 and L. rossiae 2MR10 without (SP) or preceded by heating (HSP). After 30 days of storage at 4 °C, HSP and SP had a number of lactic acid bacteria 1000 to 1,000,000 times higher than the other processed pineapples. The number of yeasts was the lowest in HSP and SP. The Community Level Catabolic Profiles of processed pineapples indirectly confirmed the capacity of autochthonous starters to dominate during fermentation. HSP and SP also showed the highest antioxidant activity and firmness, the better preservation of the natural colours and were preferred for odour and overall acceptability.  相似文献   

12.
Microorganisms associated with the fermentation of cotton seed and rice were studied using a combination of culture-dependent and -independent methods. Samples of the cotton seed and rice beverage were collected every 8 h during the fermentation process for analysis of the microbiota present over 48 h. The lactic acid bacteria (LAB) population reached values of approximately 8.0 log cfu/mL. A total of 162 bacteria and 81 yeast isolates were identified using polyphasic methods. LAB (Lactobacillus plantarum, Lactobacillus vermiforme, Lactobacillus paracasei) were the most frequently isolated bacteria. Bacillus subtilis was present from 16 h until the end of the fermentation process. A decrease in pH value from 6.92 (0 h) to 4.76 (48 h) was observed, and the concentration of lactic acid reached 24 g/L at the end of the fermentation process. DGGE (denaturing gradient gel electrophoresis) was performed to determine the dynamics of the communities of bacteria and yeast, and the analysis revealed a predominance of LAB throughout the fermentation process. No changes were observed in the yeast community. The yeast species detected were Candida parapsilosis, Candida orthopsilosis, Clavispora lusitaniae and Rhodotorula mucilaginosa. Our studies indicate that the DGGE technique combined with a culture-dependent method is required to discern the dynamics in the fermentation of cotton seed and rice.  相似文献   

13.
Lactobacillus (Lb.) plantarum ST71KS was isolated from homemade goat feta cheese and identified using biochemical and molecular biology techniques. As shown by Tricine-SDS-PAGE, this lactic acid bacterium produces a bacteriocin (ST71KS) with an estimated molecular weight of 5.0 kDa. Bacteriocin ST71KS was not affected by the presence of α-amylase, catalase and remained stable in a wide range of pH and after treatment with Triton X-100, Triton X-114, Tween 20, Tween 80, NaCl, SDS, urea and EDTA. This bacteriocin also remained active after being heated at 100 °C for 2 h and even after 20 min at 121 °C; however, it was inactivated by proteolitic enzymes. Production of bacteriocin ST71KS reached 6400 AU/mL during stationary growth phase of Lb. plantarum cultivated in MRS at 30 °C and 37 °C. Bacteriocin ST71KS displayed a bactericidal effect against Listeria monocytogenes strains 603 and 607 and did not adsorb to the producer cells. Lb. plantarum ST71KS harbors two bacteriocin genes with homology to plantaricin S and pediocin PA-1. These characteristics indicate that bacteriocin ST71KS is a class IIa bacteriocin. The peptide presented no toxic effect when tested in vitro with kidney Vero cells, indicating safe technological application to control L. monocytogenes in foods.  相似文献   

14.
《LWT》2005,38(1):73-75
Red beets were evaluated as a potential substrate for the production of probiotic beet juice by four species of lactic acid bacteria (Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus delbrueckii, Lactobacillus plantarum). All the lactic cultures were found capable of rapidly utilizing beet juice for cell synthesis and lactic acid production. However, L. acidophilus and L. plantarum produced a greater amount of lactic acid than other cultures and reduced the pH of fermented beet juice from an initial value of 6.3 to below 4.5 after 48 h of fermentation at 30°C. Although the lactic cultures in fermented beet juice gradually lost their viability during cold storage, the viable cell counts of these lactic acid bacteria except for L. acidophilus in the fermented beet juice still remained at 106–108 CFU/ml after 4 weeks of cold storage at 4°C.  相似文献   

15.
BACKGROUND: As the processing of amaranth in baked goods is challenging, the use of sourdough fermentation is a promising possibility to exploit the advantages of this raw material. In this study the fermentation properties of Lactobacillus plantarum, Lactobacillus paralimentarius and Lactobacillus helveticus in amaranth‐based sourdough were examined in order to validate them as starter cultures. pH, total titratable acidity (TTA) and lactic/acetic acid ratio of the sourdough and sensory properties of the resulting wheat bread were evaluated using fermentation temperatures of 30 and 35 °C. RESULTS: While fermentation pH, TTA and lactic acid concentration showed small variations with the use of L. plantarum and L. paralimentarius, L. helveticus reached the most intensive acidification after initial adaptation to the substrate. Acetic acid production was independent of lactic acid metabolism. Furthermore, the lactic/acetic acid ratio exceeded recommendation by 10–35 times (fermentation quotient 25–82). Sensory evaluation showed no significant differences between the two fermentation temperatures but differences among the three micro‐organisms. CONCLUSION: The results provide relevant information on the fermentation properties required of a customised starter for amaranth flour. Copyright © 2010 Society of Chemical Industry  相似文献   

16.
A new-type of instant Chinese noodle was developed with the application of lactic acid fermentation by lactobacilli. Since the pH value of the noodle sheets is alkaline with kansui (around 8.5), alkaline tolerance is required for the lactobacilli to ferment noodle sheets. The screening of the lactobacilli strains suitable for the fermentation was conducted using 46 strains from 12 species (including subspecies) of lactobacilli. Several strains of Lactobacillus pentosus and Lactobacillus plantarum were found to be fermenters. Among these, L. plantarum NRIC 0380, that showed the highest fermentation rate and favorable modification of noodle, was selected as the best strain, and was employed for the pilot scale manufacture of instant Chinese noodle. During fermentation, L. plantarum NRIC 0380 produced lactic acid to about 11 g/kg noodle sheet after 24 h with a concomitant pH decrease from an initial of about 7.9 down to 3.9. Sensory test after rehydration with boiled water revealed that the fermented instant Chinese noodle sheets at pH 7.5 had increased hardness, elasticity and light sour taste.  相似文献   

17.
麦麸是小麦加工的主要副产物,营养丰富且产量大,采用乳酸菌处理麦麸可提高其附加值。为明确乳酸菌发酵对麦麸各组分的影响,作者采用植物乳杆菌、鼠李糖乳杆菌、戊糖片球菌和布氏乳杆菌分别对麦麸进行固态发酵,在48 h内每隔8 h取样,分析可溶性膳食纤维、粗蛋白质、淀粉、总酚、植酸等成分的质量分数及DPPH自由基清除能力的动态变化。结果表明,在麦麸基质中,4株乳酸菌在24 h内生长较为迅速;麦麸经乳酸菌发酵后可溶性膳食纤维质量分数显著提高,其中布氏乳杆菌发酵48 h后可溶性膳食纤维质量分数由4.72%增加至6.58%;随着发酵时间的增加,麦麸中淀粉质量分数逐渐降低,粗蛋白质量分数先增加后降低最后趋于稳定;植物乳杆菌在提高麦麸多酚质量分数方面有更好的效果,多酚质量分数由1.34 mg/g增加至3.86 mg/g,麦麸抗氧化活性显著增加;此外,乳酸菌发酵麦麸可显著降低其植酸质量分数。综合而言,植物乳杆菌和布氏乳杆菌在提高麦麸的营养特性方面具有较好的效果,可有效改善麦麸的综合利用价值。  相似文献   

18.
Lactobacillus strains were isolated from kimchi and investigated for their potential use for probiotic yogurt starters. Two of the isolated strains have over 90% survival rate to artificial gastric acid (pH 2.5, 1% pepsin) and artificial bile acid (0.3% oxgall). These strains were identified as Lactobacillus plantarum by 16S rRNA sequencing, and named as L. plantarum SY11 and L. plantarum SY12. The known carcinogenic enzyme, β-glucuronidase was not produced by L. plantarum SY11 and L. plantarum SY12. These 2 strains were found to be resistant to several antibiotics and strongly adhered to intestinal cells. Antiallergic effect of L. plantarum SY11 and L. plantarum SY12 was demonstrated using nitric oxide (NO) and cytokine production. L. plantarum SY11 and L. plantarum SY12 were capable of significantly decreasing NO production, and reduced T helper 2-associated cytokines, cyclooxygenase-2, tumor necrosis factor-α, and inducible nitric oxide synthase compared to control. Yogurt samples produced using L. plantarum SY11 and L. plantarum SY12 did not show significant differences in microbiological, physicochemical, and sensory properties compared with yogurt sample produced using commercial strain. Therefore, these two strains could be used as probiotic yogurt starters with antiallergic effects.  相似文献   

19.
The use of sourdough returned to be popular due to its beneficial nutritional, sensorial properties and physical features. In this study, two types of experiments aimed to evaluate comparatively the efficiency of two Lactobacillus (Lb.) strains, Lactobacillus plantarum ATCC 8014 and Lactobacilus casei ATCC 393, to metabolize different carbohydrates (glucose, fructose, maltose and sucrose) in vitro and to compare their efficiency, combined with/without Saccharomyces cerevisiae on sourdough fermentation. Their efficiency was monitored by cellular growth dynamics, pH values and metabolite production (lactic and acetic acid, volatile derivatives) determined by HPLC and GC–MS analysis. Lb. plantarum ATCC 8014 was, generally, more efficient than Lb. casei for carbohydrate consumption in vitro and release of lactic acid. Unexpected, Lb. casei was able to produce trehalose in vitro, especially when glucose and sucrose were added in media. During sourdough fermentation, Lb. plantarum had a superior growth dynamic and a dominant nonaerobic fermentation, opposite to Lb. casei. By the addition of yeast to lactobacilli after a short-time lactic fermentation, a combined nonaerobic and aerobic fermentation was noticed, reflected by a more complex mixture of volatile derivatives. In vitro, both Lb. strains produced seven volatile compounds (carbonyl derivatives), but during sourdough fermentation, especially after yeast addition, a complex mixture of alcohols, carbonyl derivatives and acetate esters were determined. Lb. strains (especially Lb. plantarum) determined a moderate volatiles production dominated by alcohols, while addition of yeast to Lb. intensified the volatiles’ production and increase the alcohols proportion against carbonyl derivatives.  相似文献   

20.
To speed up research on the usefulness and selection of bacterial starter cultures for cocoa bean fermentation, a benchmark cocoa bean fermentation process under natural fermentation conditions was developed successfully. Therefore, spontaneous fermentations of cocoa pulp-bean mass in vessels on a 20 kg scale were tried out in triplicate. The community dynamics and kinetics of these fermentations were studied through a multiphasic approach. Microbiological analysis revealed a limited bacterial species diversity and targeted community dynamics of both lactic acid bacteria (LAB) and acetic acid bacteria (AAB) during fermentation, as was the case during cocoa bean fermentations processes carried out in the field. LAB isolates belonged to two main (GTG)5-PCR clusters, namely Lactobacillus plantarum and Lactobacillus fermentum, with Fructobacillus pseudofilculneus occurring occasionally; one main (GTG)5-PCR cluster, composed of Acetobacter pasteurianus, was found among the AAB isolates, besides minor clusters of Acetobacter ghanensis and Acetobacter senegalensis. 16S rRNA-PCR-DGGE revealed that L. plantarum and L. fermentum dominated the fermentations from day two until the end and Acetobacter was the only AAB species present at the end of the fermentations. Also, species of Tatumella and Pantoea were detected culture-independently at the beginning of the fermentations. Further, it was shown through metabolite target analyses that similar substrate consumption and metabolite production kinetics occurred in the vessels compared to spontaneous cocoa bean fermentation processes. Current drawbacks of the vessel fermentations encompassed an insufficient mixing of the cocoa pulp-bean mass and retarded yeast growth.  相似文献   

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