Search

Objective: The aim of this study was to characterize the exopolysaccharides (EPS)-producing lactic acid bacteria from Taiwanese ropy fermented milk (TRFM) for developing a clean label low-fat fermented milk.Methods: Potential isolates from TRFM were selected based on the Gram staining test and observation of turbid suspension in the culture broth. Random amplified polymorphic DNA-polymerase chain reaction, 16S rRNA gene sequencing, and API CHL 50 test were used for strain identification. After evaluation of EPS concentration, target strains were introduced to low-fat milk fermentation for 24 h. Fermentation characters were checked: pH value, acidity, viable count, syneresis, and viscosity. Sensory evaluation of fermented products was carried out by 30 volunteers, while the storage test was performed for 21 days at 4°C.Results: Two EPS-producing strains (APL15 and APL16) were isolated from TRFM and identified as Lactococcus (Lc.) lactis subsp. cremoris. Their EPS concentrations in glucose and lactose media were higher than other published strains of Lc. lactis subsp. cremoris. Low-fat fermented milk separately prepared with APL15 and APL16 reached pH 4.3 and acidity 0.8% with a viable count of 9 log colony-forming units/mL. The physical properties of both products were superior to the control yogurt, showing significant improvements in syneresis and viscosity (p

Few studies have documented the effects of fermented milk on intestinal colitis, which are mediated by regulating various microbial and inflammatory processes. Here, we investigated the effects of fermented milk with Lactobacillus paracasei PS23 on intestinal epithelial cells in vitro and dextran sulfate sodium (DSS)-induced colitis in vivo. As L. paracasei PS23 grew poorly in milk, a coculture strategy with yogurt culture was provided to produce fermented milk (FM). The results indicated that the coculture exhibited a symbiotic effect, contributing to the better microbial and physicochemical property of the fermented milk products. We further evaluated the anti-colitis effect of fermented milk with L. paracasei PS23 in vitro. Both PS23-fermented milk (PS23 FM) and its heat-killed counterpart (HK PS23 FM) could protect or reverse the increased epithelial permeability by strengthening the epithelial barrier function in vitro by increasing transepithelial electrical resistance (TEER). In vivo analysis of the regulation of intestinal physiology demonstrated that low-dose L. paracasei PS23-fermented ameliorated DSS-induced colitis, with a significant attenuation of the bleeding score and reduction of fecal calprotectin levels. This anti-colitis effect may be exerted by deactivating the inflammatory cascade and strengthening the tight junction through the modification of specific cecal bacteria and upregulation of short-chain fatty acids. Our findings can clarify the role of L. paracasei PS23 in FM products when cocultured with yogurt culture and can elucidate the mechanisms of the anti-colitis effect of L. paracasei PS23 FM, which may be considered for therapeutic intervention.

Our previous studies indicated that Lactobacillus kefiranofaciens HL1, isolated from kefir grain, has strong antioxidant activities and anti-aging effects. However, this strain is difficult to use in isolation when manufacturing fermented products due to poor viability in milk. Thus, the purpose of this study was to apply a co-culture strategy to develop a novel probiotic fermented milk rich in L. kefiranofaciens HL1. Each of four selected starter cultures was co-cultured with kefir strain HL1 in different media to evaluate their effects on microbial activity and availability of milk fermentation. The results of a colony size test on de Man, Rogosa and Sharpe (MRS) agar agar, microbial viability, and acidification performance in MRS broth and skimmed milk suggested that Lactococcus lactis subsp. cremoris APL15 is a suitable candidate for co-culturing with HL1. We then co-cultured HL1 and APL15 in skimmed milk and report remarkable improvement in fermentation ability and no negative impact on the viability of strain HL1 or textural and rheological properties of the milk. Through a co-culture strategy, we have improved the viability of kefir strain HL1 in fermented skimmed milk products and successfully developed a novel milk product with a unique flavor and sufficient probiotics.

The objective of this study was to develop a novel immobilized system using kefir lactic acid bacteria and sugar cane pieces for the production of fermented milk. Lactobacillus kefiranofaciens HL1, Lactobacillus kefiri HL2, Leuconostoc mesenteroides HL3, and Lactococcus lactis HL4 were isolated from Taiwanese kefir grains and immobilized on pieces of sugar cane using adsorption. Scanning electron micrographs of the cell-immobilized sugar cane pieces (CISCP) showed that the microorganisms were embedded within the porous structures of the sugar cane pieces. During 28 cycles of repeated batch fermentation, viable cells on both sugar cane pieces and fermented products were maintained at 10 log cfu/g (cfu/mL). Random amplified polymorphic DNA PCR analysis revealed that Leu. mesenteroides HL3 (29–43%) and Lc. lactis HL4 (31–49%) were predominant on the CISCP, and the fermented samples had 79% Lc. lactis HL4. When tracking fermentation parameters, the data on the microbial, chemical, and physical properties of the fermented milk suggested that the CISCP had stable fermentative ability over the course of successive fermentations. We found an enhancement of the acid-producing ability of CISCP as the number of fermentations increased, with a significant growth in titratable acidity from 0.65 to 0.81% by the end.

Omega-3 fatty acids are often attempted to incorporate into foods due to their beneficial effects on health. However, their susceptibility to autoxidation limits their utilization. After analyses, rosemary extracts (REs) contained abundant antioxidant phenolics, flavonoids, and condensed tannin. Therefore, the aims of this study were to (1) determine the optimal extraction condition of a natural antioxidant from rosemary leaves; (2) investigate an lipid stability of plant-derived omega-3 fatty-acid rich oil (flaxseed oil) with an RE addition. Rosemary extracts obtained by using 80% ethanol solution extraction for 30 min had higher (p

Most microbiome studies of dairy cows have investigated the compositions and functions of rumen microbial communities in lactating dairy cows. The importance of the relationships among hosts, microbiota, diet composition, and milk production remains unknown in dry dairy cows. Thus, in the present study, the composition of the rumen microbiome in cows from three dairy farms was investigated to identify core bacteria contributing to various physiological roles during rumen fermentation in dry dairy cows. The results indicated that ruminal fluid in dry dairy cows from different regional farms had core rumen microbiota that could be clearly distinguished from that of cows of the other farms. Further identification of key microorganisms associated with each farm revealed that Prevotella, Methanobrevibacter, Pseudobutyrivibrio, Ruminococcus, Bacteroides, and Streptococcus were major contributors. Spearman&rsquo, s correlation indicated that the abundance of genera such as Prevotella and Ruminococcus in dry dairy cows could indicate milk yield in the previous lactating period. Functional pathway analysis of the rumen bacterial communities demonstrated that amino acid metabolism and carbohydrate metabolism were the major pathways. Our findings provide knowledge of the composition and predicted functions of rumen microbiota in dry dairy cows from regional farms, which underscore the importance of the relationships among hosts, microbiota, diet composition, and milk production.

Steroid hormones are often used in animal agriculture but are currently banned for use in domesticated fowl because residual hormones could be present in eggs for human consumption. Egg samples from eight common commercial poultry layer breeds (Hy‐Line W‐36, Hy‐Line Brown, ISA‐White, ISA‐Brown, Lohnmann Ultra‐Lite, Lohnmann‐Brown, Hisex White, Hisex Brown) in Taiwan were screened for a combination of 15 natural and synthetic steroid hormones by liquid chromatography–tandem mass spectrometry (LC‐MS/MS) for consumer assurance. Only natural hormones such as progesterone, 4‐androstene‐3,17‐dione, and testosterone were detected. Regarding each breed, the interaction effect (age × shell color), main effect (age or shell color), and blocking effect (lighting system) were further analyzed by using 2 × 2 factorial arrangement of treatment in a randomized block design. We also discovered associations between yolk steroid hormone levels and laying hen age, as well as lighting conditions. Additionally, we found a correlation between hormone levels and eggshell color, suggesting a potential role in brown pigmentation. Ultimately, we concluded that detectable steroid hormone levels in eggs were not a consumer health risk. Furthermore, these data provide empirical hormone concentrations in various types of commercial layer breeds for future research.

Lactobacillus kefiranofaciens M1 (M1) has been shown to possess many different beneficial health effects including anti-colitis activity. The purpose of this study was to develop a novel and easily scaled-up encapsulating technique that would improve the temperature tolerance of the bacterium and reduce the sensitivity of the organism to gastrointestinal fluid. A mixture of sodium alginate, gellan gum and skim milk powder was used as a coating material to entrap M1. The M1 gel was then directly freeze dried in order to dehydrate the covering and form microcapsules. The viable cell numbers of M1 present only dropped ten folds after the freeze-drying encapsulation process. The viable cell counts remained constant at 5 × 10(7) CFU/g after heating from 25 °C to 75 °C and holding at 75 °C for 1 min. The viable cell counts were reduced to 10(6) CFU/g and 10(5) CFU/g after 8-week storage at 4 °C and subsequent heat treatment with simulated gastrointestinal fluid test (SGFT) and bile salts, respectively. The effect of encapsulated M1 on the organism's anti-colitis activity was evaluated using the dextran sodium sulfate (DSS) induced colitis mouse model. An in vivo study indicated that administration of heat treated encapsulated M1 was able to ameliorate DSS-induced colitis producing a significant reduction in the bleeding score and an attenuation of inflammatory score. These findings clearly demonstrate that encapsulation of M1 using this novel technique is able to provide good protection from temperature changes and SGFT treatment and also does not affect the organism's anti-colitis activity.

The purpose of this study was to understand the significance of each microorganism in grain formation by evaluating their microbial aggregation and cell surface properties during co-aggregation of LAB and yeasts together with an investigation of biofilm formation. Non-grain forming strains from viili were also evaluated as a comparison. Results indicated that the kefir grain strains, Lactobacillus kefiranofaciens and Saccharomyces turicensis possess strong auto-aggregation ability and that Lactobacillus kefiri shows significant biofilm formation properties. Significant co-aggregation was noted when S. turicensis and kefir LAB strains (Lb. kefiranofaciens and Lb. kefiri) were co-cultured. Most of the tested LAB strains are hydrophilic and had a negative charge on their cell surface. Only the kefir LAB strains, Lb. kefiranofaciens HL1 and Lb. kefiri HL2, possessed very high hydrophobicity and had a positive cell surface charge at pH 4.2. In contrast, the LAB and yeasts in viili did not show any significant self-aggregation or biofilm formation. Based on the above results, we propose that grain formation begins with the self-aggregation of Lb. kefiranofaciens and S. turicensis to form small granules. At this point, the biofilm producer, Lb. kefiri, then begins to attach to the surface of granules and co-aggregates with other organisms and components in the milk to form the grains. On sub-culturing, more organisms attach to the grains resulting in grain growth. When investigated by scanning electron microscopy, it was found that short-chain lactobacilli such as Lb. kefiri occupy the surface, while long-chain lactobacilli such as Lb. kefiranofaciens have aggregated towards the center of the kefir grains. These findings agree with the above hypothesis on the formation of grains. Taken together, this study demonstrates the importance of cell surface properties together with fermentation conditions to the formation of grains in kefir.

The purpose of this study was to identify species of lactic acid bacteria in Taiwanese ropy fermented milk and to study their microbial dynamics during the fermentation process through conventional microbiological cultivation and PCR-denaturing gradient gel electrophoresis. Identification results indicated that Lactococcus lactis ssp. cremoris and Leuconostoc mesenteroides ssp. mesenteroides were the major lactic acid bacteria in Taiwanese ropy fermented milk. Interestingly, 3 groups were identified as Lc. lactis ssp. cremoris using 16S rDNA sequencing, but they showed different denaturing gradient gel electrophoresis patterns and assimilation of carbohydrates. In addition, the microbial dynamics study in different fermentation stages demonstrated that Lc. lactis ssp. cremoris was the most dominant bacterial species in the samples, followed by Leu. mesenteroides ssp. mesenteroides with no differences among the fermentation stages. Finally, the microbial distribution profiles showed that the microbial ecology was different in bovine, caprine, and reconstituted milk, which might further affect the characteristics of the product.

The objective of the present study was to investigate yeast communities in kefir grains and viili starters in Taiwan through conventional microbiological cultivation and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). The DNA sequencing was used as a validity technique to ensure that all isolates within each group belonged to just one species, and to confirm the identified results of PCR-DGGE. Results indicated that a combination of conventional microbiological cultivation with PCR-DGGE and sequencing could successfully identify 4 yeast species from both types of cultures in Taiwan. Kluyveromyces marxianus, Saccharomyces turicensis, and Pichia fermentans were found in Taiwanese kefir grains with a distribution of 76, 22, and 2%, respectively, whereas Klu. marxianus, Saccharomyces unisporus and P. fermentans were identified in viili starters corresponding to 58, 11, and 31% of the total cell counts, respectively. Furthermore, the culture-independent method was applied to identify the yeast species using DGGE. Only 2 yeast species, Klu. marxianus and S. turicensis, were found in kefir grains and 2, Klu. marxianus and P. fermentans, in viili starters. These results suggest that in samples containing multiple species, PCR-DGGE may fail to detect some species. Sequences of yeast isolates reported in this study have been deposited in the GenBank database under accession nos. DQ139802, AF398485, DQ377652, and AY007920.

Lactic acid bacteria (LAB) in different original kefir grains were first assessed using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) by a culture-dependent way, and were further confirmed by DNA sequencing techniques. Results indicated that a combined method of cultivation with PCR-DGGE and subsequent DNA sequencing could successfully identify four LAB strains from three kefir grains from Taiwan (named Hsinchu, Mongolia and Ilan). Lactobacillus kefiri accounted, in the three kefir grains, for at least half of the isolated colonies while Lb. kefiranofaciens was the second most frequently isolated species. Leuconostoc mesenteroides was less frequently found but still in the three kefir grains conversely to Lactococcus lactis which based on culture-dependent isolation was only found in two of the kefir grains. It was interesting to find that all three kefir grains contain similar LAB species. Furthermore, the DGGE as a culture-independent method was also applied to detect the LAB strains. Results indicated that Lb. kefiranofaciens was found in all three kefir grains, whereas Lb. kefiri was only observed in Hsinchu kefir grain and Lc. lactis was found in both Mongolia and Ilan samples. Two additional strains, Pseudomonas spp. and E. coli, were also detected in kefir grains.

UNLABELLED The purpose of this study was to manufacture new functional low-fat cheeses using Taiwanese ropy fermented milk (TRFM) and Lactococcus lactis subsp. cremoris strains isolated from TRFM. After 28 d of ripening and storage, the viable populations of lactic acid bacteria (LAB) in the low-fat cheeses made with L. lactis subsp. cremoris TL1 (TL1), L. lactis subsp. cremoris TL4 (TL4), and TRFM still maintained above 10(8) CFU/g. The low-fat cheeses made with TL1 and TRFM showed higher moisture contents than the cheeses made with TL4, full-fat, and low-fat cheese controls. The low-fat cheeses made with TL1 and TL4 had higher customer preferential scores similar to full-fat cheese control in the sensory evaluation. Additionally, the low-fat cheeses fermented with TL1, TL4, and TRFM for 4 h had higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging and ferrous ion-chelating abilities than the cheeses fermented with the starters for 8 h, full-fat, and low-fat cheese controls. A better angiotensin-converting enzyme (ACE) inhibition activity was also observed in the low-fat cheeses made with TL1, TL4, and TRFM than that in the full-fat and low-fat cheese controls during ripening and storage period. PRACTICAL APPLICATION As health-conscious consumers continue to seek low-fat alternatives in their diets, there remain strong interests for the dairy industry to develop low-fat cheeses to meet the demands. This study clearly demonstrated that the low-fat cheeses fermented with TL1 for 4 h showed a better overall acceptability and possessed antioxidative abilities and ACE inhibitory activities than other cheeses tested in this study. By improving its flavor and investigating the possible mechanisms of its functionalities in the future, this low-fat cheese might possibly be commercialized and give a positive impact on cheese consumption in the future.

In the present study, we have investigated the importance of fermentation media on grain formation and the microbial characteristics of sugary kefir. The sugary kefir grains were fermented in brown sugar, cow's milk or goat's milk. Using culture-dependent and culture-independent methods, we identified the microorganisms present in both the grains and filtrate and then evaluated their distribution. The structure of the grains was also observed by scanning electronic microscopy (SEM). The identification results indicated that there were remarkable changes in microbial ecological profiles of the sugary kefir grains and their filtrates when brown sugar and milk were compared as fermentation media. Three lactic acid bacteria (LAB) species (Leuconostoc mesenteroides, Lactobacillus mali and Lactobacillus hordei) were found in the grains fermented using brown sugar. However, four species, named Leu. mesenteroides, Lactococcus lactis, Bifidobacterium psychraerophilum and Enterococcus faecalis, were identified in the grains fermented using either cow's or goat's milk. The size and structure of the kefir grains were also significantly influenced by the culture medium. We hypothesize that the grains originally may contain many different microorganisms and the identified changes are an adaption to each specific medium during grain formation and growth. The distribution of strains thus may vary depending on the carbon and energy sources available for grain fermentation and these microbial changes will further affect the granulation and growth of the grains. This study is important to our understanding of the mechanism of kefir grain formation and growth because it explores the relationship between fermentation media and kefir microorganisms.

We assayed the effects of velvet antler (VA) of Formosan sambar deer (Cervus unicolor swinhoei) and its extracts on the anti-infective activity against pathogenicStaphylococcus aureus in vitroandin vivoin this study.In vitrodata indicated that the VA extracts stimulated the proliferation of resting splenocytes and macrophages in a dose-dependent manner up to the highest concentration used (150 μg mL−1). The production of proinflammatory cytokines (TNF-α, IL-6, IL-12) by lipoteichoic acid was significantly suppressed after being cocultured with the VA extracts in a dose-dependent manner. Animal test inS. aureus-infected mice demonstrated that the numbers of bacteria determined in the kidneys and peritoneal lavage fluid ofS. aureus-infected mice were significantly higher than those found in the same organs of mice pretreated with the VA samples. Moreover, the highly enhanced phagocytic activity of macrophages was further verified afterin vitrotreatment with the VA samples. The protective mechanisms of the VA samples might include an immune enhancer and an inflammatory cytokine suppressor.