Traditional Fermented Milk Research Articles

Technological Characterization of Lactic Acid Bacteria Protease Isolated from Traditional Chinese Fermented Milk

AbstractThe proteolysis activity, texture, viscosity, particle size and sensory evaluation of 12 isolates identified by 16S rDNA sequence analysis, which were screened from 123 lactic acid bacteria (LAB) isolated from Chinese traditional fermented milk, were evaluated. Proteolytic activity of these selected strains ranged from 2.43 to 11.60 mmol Leu/L of milk. Texture analysis indicated that yogurts of Streptococcus thermophilus were of higher value than those of Lactobacillus delbrueckii at all levels of measurement. Apparent viscosity of yogurt varied considerably among the strains, with values ranging from 4790 to 9870 mPa·s. All the strains showed excellence in firmness, consistency, cohesiveness, viscosity and little difference in the particle size. L. delbrueckii CH9‐3 4.0, SB3 and SB25 provided excellent protease activity and could be used as yogurt culture to improve the curd quality. S. thermophilus LBH, Q10 and L. delbrueckii SP1.1 showed high viscosity, and could be mixed with other LAB strains to obtain thick yogurts.Practical ApplicationsThe different technological characterizations of lactic acid bacteria could contribute to the different physicochemical and sensorial properties of the fermented dairy products. The studied strains with different properties would provide a well‐adapted tool for producing new dairy products or possibly assign to the same traditional products with different physicochemical and sensorial properties through the new specified proteolytic activity, viscosity and flavor.

A one-step PCR-based method for specific identification of 10 common lactic acid bacteria and Bifidobacterium in fermented milk

A one-step PCR-based method was constructed for the rapid detection of 10 common lactic acid bacteria (LAB) and Bifidobacterium. Ten primer pairs were designed based on the sequences that specify the 16S rRNA genes of Lactococcus lactis subsp. lactis, Lactococcus lactis subsp. cremoris, Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus fermentum, Lactobacillus helveticus, Bifidobacterium and Leuconostoc. The primers showed high specificity for target species. The detection limit was 104–105 cfu mL−1 for Lb. delbrueckii and 103–104 cfu mL−1 for the others. This method was applied to identify the species mentioned above, in situ, from 8 samples of traditional fermented milk, and monitor the constitution of the species in commercial dairy yoghurt. The results were consistent with the results of 16S rRNA sequencing, suggesting that the method was reliable for the rapid identification of LAB and Bifidobacterium used in fermented milk.

Identification of Angiotensin I-converting enzyme Inhibitory Activities from traditional Mongolian fermented milk products

Several angiotensen-converting enzyme (ACE) inhibitory peptites have been detected in milk products. There are many traditional milk products in Mongolia. For this study, some Mongolian milk products were collected, and the ACE inhibitory activities of these samples were tested; an active fraction was found in aaruul made from mare’s milk. After purification by dialysis and HPLC, the active fractions were isolated. The molecular weight of the active component was 362.05 M, as determined by mass spectrometry. An authentic standard was used to determine the IC50 value of the inhibitory activity. From 5’-GMP is not much higher than that of the active peptide in sour milk and some flavonoids. However, this is the first report that shows that 5’ –GMP inhibits ACE activity. These results will provide useful information for the development of hypertension therapy agents.DOI: http://dx.doi.org/10.5564/mjc.v12i0.175 Mongolian Journal of Chemistry Vol.12 2011: 65-68

New lactic acid bacterial strains from traditional Mongolian fermented milk products have altered adhesion to porcine gastric mucin depending on the carbon source.

Attachment of lactic acid bacteria to the mucosal surface of the gastrointestinal tract is a major property of probiotics. Here, we examined the ability of 21 lactic acid bacterial strains isolated from traditional fermented milk products in Mongolia to adhere to porcine gastric mucin in vitro. Higher attachment was observed with Lactobacillus delbrueckii subsp. bulgaricus strains 6-8 and 8-1 than with Lactobacillus rhamnosus GG (positive control). Lactococcus lactis subsp. cremoris strain 7-1 adhered to mucin as effectively as did strain GG. Heat inactivation decreased the adhesive ability of strains 6-8 and 8-1 but did not affect strain 7-1. The adhesion of strains 6-8, 7-1 and 8-1 was significantly inhibited when the cells were pretreated with periodate and trypsin, indicating that proteinaceous and carbohydrate-like cell surface compounds are involved in the adhesion of these strains. The adhesion of strain 7-1 was affected by the type of carbohydrate present in the growth medium, being higher with fructose than with lactose, galactose or xylose as the carbon source. The sugar content of 7-1 cells grown on various carbohydrates was negatively correlated with its adhesive ability. We provide new probiotic candidate strains and new information regarding carbohydrate preference that influences lactic acid bacterial adhesion to mucin.

Historical and Cultural Study on Korean Traditional Fermented Milk, Tarak

Historical and Cultural Study on Korean Traditional Fermented Milk, Tarak

Quality Characteristics of Pudding Using Tarak, Traditional Fermented Milk

Quality Characteristics of Pudding Using Tarak, Traditional Fermented Milk

Quality Characteristics of Pudding Using Tarak, Traditional Fermented Milk

Quality Characteristics of Pudding Using Tarak, Traditional Fermented Milk

A Survey of the Processing and Chemical Composition of Gariss Produced by Nomadic Camel Women Herders in Al Gaderif State , Sudan

Gariss is the most popular stable food for the camel herders who depend on Gariss for the sustainability of their livestock. The objective of the current study is to assess the traditional fermented camel milk (Gariss) prepared by nomadic camel woman herders in AlGadarif State in Butana. It is also meant to improve the quality of camel milk products through sharing knowledge. The samples (n= 19) were collected during rainy and dry seasons. The nomad’s housekeepers were interviewed in the study area. The effect of different types of containers and the additives used during Gariss preparation and the compositional quality were all estimated. The survey reported the different types of spoilage and the variations in the shelf life of Gariss. When compared with the mean values of the Gariss samples collected during dry season, the result indicated that the values of the total solids and the pH of the samples collected during the rainy season were significantly higher (p<0.05), whereas the values of the fat, protein and ash were significantly lower (p<0.05). The container types had a significant (p<0.05) effect on the total solids, fat and ash content only. The Gariss prepared in Bukhsa showed the highest total solids content (13.15±0.54%) and that prepared in stainless steel showed the highest fat (4.65± 0.34%) content. However, when Gariss was prepared in plastic containers it showed the lowest pH value (3.59±0.16%), whereas samples from ‘‘Siin’’ (goat leather) was significantly lower (p<0.05) in the ash content (0.35± 0.09%). The present study concludes that the chemical composition of Gariss from the nomadic camel women herders is affected by seasons, types of additives and containers used. Hence more studies are needed to be done on the effect of the additive and containers on Gariss quality.

Isolation and molecular characterization of lactobacilli from traditional fermented Dahi produced at different altitudes in Nepal

Dairy products are an important part of daily food in the Himalayan country of Nepal. A wide variety of traditional fermented milk products are obtained in relation to different geo-climatic conditions of the country and different ethnic groups. Locally called Dahi is the most popular product, but little data are available on the autochthonous lactic acid bacteria (LAB) characterizing this yogurt-like product. Thirty-two replicate samples of indigenous Dahi were collected from four districts of Nepal at different altitude. In total of 193 isolates were obtained. Of these, the 120 rod-shaped isolates representing the dominant LAB population (62%) were further identified at the species level by using internal transcribed spacers (ITS) amplification, 16S rRNA gene sequence determination, and species-specific PCR. A further characterization at the strain level was carried out by combining analysis of repetitive elements and randomly amplified polymorphic DNA (RAPD) typing. Based on these analyses, the isolates were grouped in ten different species, among which Lactobacillus delbrueckii subsp. bulgaricus, L. paracasei, and L. rhamnosus represented the dominant species. A high degree of intraspecies diversity was also observed for all Lactobacillus species, except for L. rhamnosus isolates, which proved to give a single typing profile. Bacterial isolates represent a source of novel potential probiotics and starter cultures. The strain collection obtained from this study is a first step in the preservation of the natural biodiversity of bacterial population of the traditional Nepalese fermented Dahi.

Influence of autochthonous lactic acid bacteria and enzymatic yeast extracts on the microbiological, biochemical and sensorial properties of Lben generic products

In this study we identified Lactococcus lactis subsp. lactis, Lc. lactis subsp. lactis biovar diacetylactis, Kluyveromices lactis and Saccharomyces cerevisiae as the dominant microorganisms of traditional Moroccan acid-alcoholic fermented milk named Lben. The low pH (3·8±0·3), lactose (16·8±3·4mg/l) and lactic acid (8·16±0·6mg/l) content indicated that a strong fermentation occurred in the traditional product which was also characterised by the substantial presence of ethanol and typical volatile carbonyl compounds (i.e., acetoin, diacetyl and acetaldehyde). Microbiological analyses of experimental Lben manufactured with selected strains (isolated from the traditional product) of Lc. lactis subsp. lactis and Lc. lactis subsp. lactis biovar. diacetylactis alone (batch A) and in combination with enzymatic extract of a K. lactis strain (batch B) indicated a good effectiveness of the starters employed (∼1010 CFU/g of lactococci after 8h of incubation) and a significant effect of the yeast enzyme extract on lactococci viability. Despite slight changes in the physicochemical characteristics of the two Lben during the 15d storage period, volatile compounds (i.e. ethanol, acetaldehyde, diacetyl and acetoin) were consistently higher in batch B. Moreover, sensorial analysis performed after 15d of storage, highlighted higher odour and flavour intensity, vegetable odour and viscosity in batch B while batch A displayed higher astringency.

バングラデシュの伝統的発酵乳"ダヒ"の品質評価

バングラデシュの伝統的発酵乳"ダヒ"の品質評価

Whole Genome Sequence of the Probiotic Strain Lactobacillus paracasei N1115, Isolated from Traditional Chinese Fermented Milk

Lactobacillus paracasei N1115 is a new strain with probiotic properties isolated from traditional homemade dairy products in Inner Mongolia, China. Here, we report the complete genome sequence of L. paracasei N1115, which shows high similarity to the well-studied probiotic Lactobacillus rhamnosus GG, and 3 structures turned out to be inversions, according to the colinearity analysis of the BLAST alignment.

Purification and characterization of bacteriocin F1, a novel bacteriocin produced by Lactobacillus paracasei subsp. tolerans FX-6 from Tibetan kefir, a traditional fermented milk from Tibet, China

A bacteriocin-producing lactic acid bacteria, FX-6, was isolated from Tibetan kefir using the agar well diffusion assay. Strain FX-6 was identified as Lactobacillus paracasei subsp. tolerans on the basis of 16S rDNA sequence analyses. This bacteriocin, which was designated bacteriocin F1, was purified by a three-step purification procedure. The molecular mass of bacteriocin F1 was 2113.842 Da by MALDI-TOF–MS analyses. It was also discovered to have blocked N-termini, hampering analysis by Edman degradation. Bacteriocin F1 exhibited a wide range of antimicrobial activity, strong heat stability (20 min at 121 °C, or 60 min at 100 °C) and pH stability (pH 3.0–9.0). Following treatment by pepsin and trypsin, the antibacterial activity was partly reduced. Bacteriocin F1 is the first reported bacteriocin produced by L. paracasei subsp. tolerans which can not only inhibit fungi but also bacteria. The characterization of bacteriocin F1 suggested that it was a novel bacteriocin with potential research and application value in food industry.

Screening Research Methods for ^|^alpha;-glucosidase Inhibitors and Angiotensin-converting Enzyme Inhibitors in Fermented Soybean Products and Fermented Milk Products

A simple and highly sensitive assay method for α-glucosidase inhibitory activity was devised and a microplate method using absorbance at 450 nm for angiotensin-converting enzyme activity was introduced. Successful examples using these methods are shown, in which active components from Chinese traditional fermented foods and Mongolian fermented milk products were identified. These traditional fermented foods are expected to elicit effective components against lifestyle-related diseases.

Dominant Lactic Acid Bacteria and Their Antimicrobial Profile from Three Fermented Milk Products from Northern Namibia

The present study focused on the isolation, identification and antimicrobial profile of the dominant lactic acid bacteria from three traditional fermented milk products namely: Omashikwa, Mabisi and Mashini Ghamushikwa from the north-central and north-eastern parts of Namibia. The microbiological and antimicrobial activities of these products fluctuate from one region to another depending on the local indigenous microflora. Omashikwa and Mashini Ghamushikwa fermentation processes involves the addition of Boscia albitrunca root (Omunkuzi) and butter churning. The root contributes to the flavor of the product, increasing the milk fermentation rate and churning. Mabisi is produced by letting the milk to ferment naturally until the water is separated from the whey. The water is then decanted, and the whey is shaken until it is smooth without removal of fat. A total of 180 isolates of Lactic acid bacteria (LAB) were obtained and identified based on their phenotypical characterization. Cell free supernatants (CFS) of the 180 LAB isolates were evaluated for antimicrobial activities against selected food borne pathogens; Escherichia coli ATCC 25,922, Staphylococcus aureus ATCC 25,923, Bacillus cereus ATTC 10,876, Candida famata and Geotrichum klebahnii using the well diffusion assay. Twenty LAB isolates having the highest inhibitory effects were selected for biochemical identification using API 50 kit and these were identified as being; Lactobacillus plantarum (53%), Lactobacillus rhamnosus (29%), Pediococcus pentosaceus (6%), Lactobacillus paracasei ssp. paracasei (6%) and Lactococcus lactic ssp. lactis (6%). Pediococcus pentosaceus showed the highest inhibitory effect on all the indicator strains. This study provides an insight into LAB diversity of unstudied Namibian fermented milk products and reports a potential production of antimicrobial compounds which is significant in the standardization of protective starter cultures which can be used to control fermentation process and shelf life extension of dairy products in Namibia.

전통발효유 타락을 이용한 젤리의 품질 특성

Tarak is our own traditional fermented milk made through lactic acid fermentation by using makgeolli as inoculum for milk or using already made tarak as inoculum but it is hardly known to people as its related studies are also insufficient. Accordingly, the purpose of this study was to manufacture jelly by using tarak and analyze its quality characteristics for the diversification of consumption promotion and demand of traditional fermented milk tarak. Tarak jelly that was made according to the percentage of adding tarak showed a tendency that the content of crue protein, crude fat and crude ash except for moisture water meaningfully increased as the amount of tarak added increased (P

A Screening of Class IIa Bacteriocins Produced by Lactic Acid Bacteria Isolated from Fermented Mare Milk

AbstractTwelve fermented mare milk samples were screened for class IIa bacteriocins based on a polymerase chain reaction (PCR) method. The positive PCR products were cloned and sequenced. The sequences shared 99% identity to enterocin A‐coding gene. The lactic acid bacteria, which showed positive PCR results, were detected with antimicrobial activity by means of traditional well‐diffusion method. The strains C71 and C102 showed antimicrobial activity to Listeria sp. These strains showed a potential application in food preservation. The results also indicated the PCR screening method proposed in this study can be used for the screening of antimicrobial peptides of class IIa.Practical ApplicationsIn the present study, 44 class IIa bacteriocins from a wide range of lactic acid bacteria were included in a cluster analysis, and primers were designed on basis of the cluster analysis. We screened class IIa bacteriocin‐producing lactic acid bacteria that were isolated from traditional fermented mare milk by means of a PCR‐based assay. Two strains showed potential application in food preservation. The results indicated the PCR screening method proposed in this study can be used for the screening of antimicrobial peptides of class IIa. This method is still in an exploratory stage. It needs to be improved in the future.

Microbiological, physico-chemical, nutritional and sensory characterization of traditional Matsoni: Selection and use of autochthonous multiple strain cultures to extend its shelf-life

Matsoni, a traditional Georgian fermented milk, has variable quality and stability besides a short shelf-life (72–120 h at 6 °C) due to inadequate production and storage conditions. To individuate its typical traits as well as select and exploit autochthonous starter cultures to standardize its overall quality without altering its typicality, we carried out a thorough physico-chemical, sensorial and microbial characterization of traditional Matsoni. A polyphasic approach, including a culture-independent (PCR-DGGE) and two PCR culture-dependent methods, was employed to study the ecology of Matsoni. Overall, the microbial ecosystem of Matsoni resulted largely dominated by Streptococcus (S.) thermophilus and Lactobacillus (Lb.) delbrueckii subsp. bulgaricus. High loads of other lactic acid bacteria species, including Lb. helveticus, Lb. paracasei and Leuconostoc (Leuc.) lactis were found to occur as well. A selected autochthonous multiple strain culture (AMSC) composed of one Lb. bulgaricus, one Lb. paracasei and one S. thermophilus strain, applied for the pilot-scale production of traditional Matsoni, resulted the best in terms of enhanced shelf-life (one month), sensorial and nutritional quality without altering its overall typical quality. This AMSC is at disposal of SMEs who need to exploit and standardize the overall quality of this traditional fermented milk, preserving its typicality.

Effect of Boscia albitrunca (Omukunzi) root on the bacteriology and viscosity of Omashikwa, traditional fermented buttermilk from Namibia

The objective of this study was to determine the role of Omukunzi root ( Boscia albi trunca ) in the viscosity or consistency , sensory and bacteriological profile of Omashikwa , traditional fermented buttermilk from Namibia . Omashikwa is a popular traditional fermented butter milk product made with Omukunzi root among the Owambo and Herero tribes living in the North and Central Namibia. It is processed by fermenting raw milk in the presence of Omukunzi root in a calabash and agitated to obtain butter granules. Butter granules are then removed, washed, salted and made into butter or processed into ghee (butter oil). The remaining fermented milk is Omashikwa or traditional fermented buttermilk. The results of this study indicated that the root of Omukunzi tree had low pH (4.9) , exhibited bacterial inhibition properties and had high content of soluble carbohydrates (19.4%) . Omashikwa made with Omukunzi root (TO) was more viscous , 2.9 Pa.s compared to 2.5 Pa.s of laboratory Omashikwa made without the root (LO) . The total aerobic count s were 6.62 cfu/g for TO and 8.62 cfu/g for LO and lactic acid bacteria (LAB) was 6.58 cfu/g for TO and 7.87 cfu/g for LO and were lower in samples with the root . C oliforms , 2.68 cfu/g (TO) and 2.70 cfu/g (LO) and yeasts and moulds were not significantly different (p ≤ 0.05) and were 1.57 cfu/g for TO and 1.69 cfu/g for LO . Yeasts and mould counts from the gourd swabs were high , 4.78 cfu/g . T he LAB identified belonged to the genera Lactobacillus (Lb.) , Leuconostoc (Leuc.) , Lactoc occus (Lact.) and Streptococcus (Strep.). The LAB species identified were Lb. plantarum, Lb. lac tis subsp . lactis, Leuc. lactis, Leuc. citreum, Lact. lactis subsp. lactis, Lact. lactis subsp. diacetylactis and Strep. t hermophillus. The result s indicate d that Omukunzi root plays a positive role in the quality of value added Omashikwa in terms of improving consistency , sensory quality and controlling microbial profile which could finally help to increase income, create jobs and improve food security and nutrition to the rural communities.

Bacterial diversity of aMasi, a South African fermented milk product, determined by clone library and denaturing gradient gel electrophoresis analysis

In the present study, we investigated the bacterial diversity of aMasi, a traditional South African fermented milk product, by 16S rRNA clone library and Denaturing Gradient Gel Electrophoresis (DGGE) analysis. Two hundred and eighty two clones from clone library were isolated and identified from aMasi, prepared from the milk of four cows from one herd in the EkuPindiseni Community, North West of Hluhluwe-iMfolozi Park in KwaZulu-Natal Province. The majority of the identified sequences corresponded to lactic acid bacteria (LAB), with the genus Lactococcus as major representative. The speciesLactococcus lactis accounted for 179 of the identified clones. In addition, several species of Lactobacillus, Leuconostoc and Enterococcus were detected. Furthermore, several clones belonging to Acinetobacter, Aeromonas and genera within the Enterobacteriaceaewere detected. It is important to note that human pathogens such as Klebsiella pneumoniae were identified in aMasi in the present study. Conversely, zoonotic bacteria such as Brucella abortus and Mycobacterium bovis were not detected in aMasi, although, they are present in the cattle population in the study area. Thirty (30) clones were identified as uncultured bacterial clones. Nine DGGE bands were successfully sequenced, of which four were classified as L. lactis with other bands belonging to lactobacilli, Clostridium acidurici, Enterobacter sp., Acinetobacter baumannii and an un-culturable bacterium. Even though there was some discrepancy between the two culture independent methods used to study the bacteriological community in aMasi, a general conclusion can be drawn,L. lactis may be considered as the dominant bacterium within a diverse bacterial community in this locally-produced dairy product. Key words: South Africa, aMasi, fermented milk, microbial diversity, clone library, denaturing gradient gel electrophoresis (DGGE).