scholarly journals The Functionality of African Streptococcus Thermophillus and Streptococcus Infantarius Sub Sp. Infantarius in Milk Fermentation

2021 ◽  
Vol 9 (1) ◽  
pp. 111-121
Author(s):  
Isaac M. Maitha ◽  
Dasel W. M. Kaindi ◽  
Cherotich Cheruiyot

Fermentation serves a key role in inhibiting spoilage microorganism through acidification and production of antimicrobial compounds. The technological information on properties of Streptococcus infantarius sub sp. infantarius which is predominant in most African fermented is dairy products very little. This study was therefore carried out to determine the functionality of selected African Streptococci strains in fermented dairy products. Pasteurized milk samples from camels and cows were inoculated with different strains and a selected combination at a rate of 3% v/v and incubated at different temperatures of 25 oC, 30 oC, 37 oC, and 45 oC for 9 hours. Analysis was done after every 3 hours for pH and titratable acidity while viscosity was done after incubation and cooling of the product. The different fermented milk samples were subsequently evaluated for consumer acceptability. Milk inoculated with both African type Streptococcus thermophillus (146A8.2) and Streptococcus infantarius sub sp. infantarius CJ 18 (9377), and incubated for nine hours recorded the highest amount of titratable acidity of 0.97 for the camel milk and had the least pH value of 4.12 for cow milk compared to the other strains. The cow milk had the highest viscosity level of 59.64 cPs compared to camel milk which was 29.44 cPs. The levels of titratable acidity and viscosity depended on the strain and incubation temperature. The African type Streptococcus thermophillus (146A8.2) and Streptococcus infantarius sub sp. infantarius CJ 18 (9377), isolated from fermented camel milk had good technological properties that are useful as starter culture for development of fermented milk products.

2019 ◽  
Vol 15 (1) ◽  
pp. 40-47
Author(s):  
Elaheh Ahmadi ◽  
Reza Mohammadi ◽  
Sara Hasanvand ◽  
Milad Rouhi ◽  
Amir Mohammad Mortazavian ◽  
...  

Background: Doogh is a traditional Iranian fermented milk drink that is currently a very popular product in Iran. In the present study, the combined effects of incubation temperature, type of starter culture, and final pH of fermentation on the viability of two probiotic strains (Lactobacillus acidophilus La-5 (A) and Bifidobacterium lactis Bb-12 (B)) and biochemical and sensory characteristics of probiotic Doogh were investigated. </P><P> Method: Different treatments were prepared with yoghurt starter culture containing probiotics, using reconstituted skimmed milk with 6% of solid nonfat. They were incubated at 38°C or 44°C until pH 4.0 or pH 4.5 and were kept for 21 days at 4&#176;C or 8&#176;C storage temperature. The biochemical properties of treatments were evaluated during fermentation and refrigerated storage. The viable count and sensory attributes of treatments were studied at the end of fermentation and at the end of storage. </P><P> Results: Results showed that the greatest mean pH drop rate, mean acidity increase rate and mean redox potential increase rate and the shortest incubation time were observed in treatments incubated at 44&#176;C with final pH of 4.5. The highest survival of both probiotic strains during storage was related to treatments with fermentation temperature of 38&#176;C and final pH of 4.5. Treatments ABY1-38&#176;C-4.0 had the highest sensorial total acceptance at the end of refrigerated storage. </P><P> Conclusion: It would be concluded that the best treatment was ABY3-38&#176;C-4 stored at 8°C in regards of probiotics’ viability and sensory characteristics of Doogh. Thus, controlling the temperature of refrigerated storage is the most importance factor during storage and distribution.


Author(s):  
C. U. Obiora ◽  
E. C. Igwe ◽  
E. C. Udeagha ◽  
S. N. Orjiakor ◽  
C. S. Anarado

This research was carried out to evaluate the appropriate levels of substitution of powdered cow milk with soy milk and cornstarch needed to produce yoghurt, evaluating its quality and potential for acceptance. Powdered cow milk was substituted with soymilk and cornstarch up to 30% to produce yogurt and market sample yogurt was used as control. Each composite blend milk samples was homogenized, pasteurized at 75°C for 5 min, cooled and inoculated with a mixed freeze-dried starter culture containing strains of Streptococcus thermophilus and Lactobacillus bulgaricus at 45°C, fermented for 6 h and cooled to 4˚C. The proximate, chemical, microbial, functional and sensory evaluation of the composite yogurt samples was determined. The yogurt samples were coded ACS-1 to ACS-13 where ACS-13 represent control. The result of the proximate analysis showed that moisture content ranged from 82.04 – 88.71%, protein ranged 2.05 – 6.48%,  fat ranged from 2.14 – 3.62%,  carbohydrate ranged from 4.30 – 9.91% and ash content ranged from 0.53 – 1.48%. The pH ranged from 3.73 – 4.82. For microbial evaluation, the total viable bacteria count ranged from 1.90x107 – 11.60x107, total coliform count ranged from 0.50x107 – 3.90x107. For chemical and functional evaluation, the total solids ranged from 11.28 – 16.96%, titratable acidity ranged from 0.30 – 1.80%, syneresis ranged from 0.00 – 28.33%, water absorption capacity ranged from 0.00 – 75.53% and apparent viscosity ranged from 1337- 4863 cP. For sensory evaluation, yogurt produced with 100% powdered milk (ACS-1) was the most preferred while yogurt sample produced with 50% powdered milk, 30% cornstarch and 20% soy milk (ACS-10) was the least preferred among other yogurt samples. This study revealed the mix ratios of powdered cow milk, soy milk and cornstarch that were acceptable in accordance with yogurt standard and the extent the quality of yogurt was generally accepted with the use of processing adjuncts (soymilk and cornstarch).


2021 ◽  
Vol 9 (1) ◽  
pp. 329-337
Author(s):  
Zerihun Shambel ◽  
Ewonetu Kebede ◽  
Melese Mengistu ◽  
Tesfahun Lamboro

The majority of communities in different regions of Ethiopia are relying on a variety of plants to improve the quality of their dairy products. However, this cultural perception was scientifically not well strengthened. Therefore, the objectives of the study were to identify milk preservative plants and evaluate the effects of preservative plants on fermented milk redox potential, Potential hydrogen (pH), and sensory analysis. The survey study was conducted on purposefully selected 80 households in the Haramaya district. However, the laboratory study was conducted on four top-ranked plants for the preparation of fermented milk samples at ambient temperature following similar techniques and procedures observed at households. All the collected data were analysed by Statitsical Analysis software (SAS). In the study area, five plants in the families of Oleaceae, Celastraceae, Lamiaceae, and Rutaceae were identified and used by the majority of respondents with perceptions of enhancing the flavour of their products. The Analysis of variance (ANOVA) results of redox potential were proved the cultural perception of the majority of respondents that they were used both Olea Africana and Catha edulis in substitute to each other for the same purpose. The pH of all treatments was continuously decreased and the milk samples treated by Olea Africana and Catha edulis were recorded the lowest values at the end. The observed pH results have disproved the communities cultural perceptions that they believed smoking increased the shelf life and extended the fermentation time whereas the Hedonic scores of panelists proved the local perceptions of respondents that they were mainly intended to make their products much more acceptable and preferable by its flavour to the consumers.


2001 ◽  
Vol 68 (1) ◽  
pp. 63-70 ◽  
Author(s):  
PRIMO MARIANI ◽  
ANDREA SUMMER ◽  
PAOLA DI GREGORIO ◽  
ANDREA RANDO ◽  
ENRICO FOSSA ◽  
...  

The aim of this research was to study the effects of the CSN1AG allele on the main rennet coagulation properties of milk. The study was carried out on individual milk samples with low αs1-casein obtained from 19 Italian Brown cows heterozygous for the CSN1AG allele (seventeen CSN1A BG and two CSN1A CG) from four herds in the province of Parma (Italy). Control cows (sixteen CSN1A BB and three CSN1A BC) giving milk with normal αs1-casein levels were chosen from within the same herds in order to establish pairs of cows with identical environment and management conditions, and comparable lactation stages and numbers. Individual milk samples from single pairs of cows with somatic cell counts and lactose and chloride levels within the normal ranges were collected and analysed in parallel. Rennet coagulation properties of milk were analysed using Formagraph and Gel Tester. Milk from low αs1-casein cows was characterized by lower casein content, lower titratable acidity and a higher proportion of κ-casein in total casein. The clotting time of this milk was ∼ 23% lower than that obtained with milk from normal αs1-casein cows. Rennet curd from low αs1-casein milk was obtained more rapidly and had a higher final firmness: curd-firming time was ∼ 35% lower and curd firmness measured 30 min after rennet addition was ∼ 27 % higher compared with that for normal αs1-casein milk. In addition, curd from low αs1-casein milk had a higher resistance to compression. These results suggest that, although a role for the CSN2 locus cannot be definitely excluded, the CSN1AG allele can considerably affect the main rennet coagulation properties of milk.


1988 ◽  
Vol 51 (5) ◽  
pp. 386-390 ◽  
Author(s):  
Y. A. EL-SAMRAGY ◽  
E. O. FAYED ◽  
A. A. ALY ◽  
A. E. A. HAGRASS

The traditional yogurt starter, i.e. Staphylococcus thermophilus and Lactobacillus bulgaricus, has always been used to bring about the lactic acid fermentation during manufacture of concentrated yogurt known in Egypt as “Labneh”. Different combinations of some strains of Enterococcus faecalis, isolated from Laban Rayeb (a type of fermented milk), in combination with a certain strain of Lactobacillus bulgaricus were used to produce a Labneh-like product. Chemical, microbiological and organoleptic properties of the Labneh-like product were assessed and compared to the characteristics of Labneh processed traditionally by two different dairy plants in Egypt. All treatments showed similar changes during storage at 5 ± 1°C for 28 d. Total solids, fat, titratable acidity and pH values coincided with those of Labneh. Some components increased until the seventh day, i.e. acetaldehyde and diacetyl, while other features, such as the ratio of soluble nitrogen/total nitrogen and tyrosine, increased until the fourteenth day of storage. Thereafter, no marked variations occurred. However, a decrease in tryptophan content of all products occurred during the storage period. Total viable count and count of lactic acid bacteria of Labneh-like product as well as Labneh increased until the end of the second week of storage and then decreased. Coliforms, yeasts and molds and psychrotrophic bacteria were detected in some fresh and stored samples. The starter culture which consisted of 1.5% Enterococcus faecalis 19 and 1.5% Enterococcus faecalis 22 was used successfully to manufacture a Labneh-like product with high acceptability when fresh or refrigerated at 5 ± 1°C.


Author(s):  
Wanida Pan-utai ◽  
Jariya Atkonghan ◽  
Tipakorn Onsamark ◽  
Wachiraya Imthalay

Arthrospira (Spirulina) platensis, a blue-green microalga, is a rich source of organic nutrients. Microalgae are used as food supplements with enhanced nutritional and functional values. Consumption of fermented milk products such as yogurt has recently increased. Both oven-dried and fresh Arthrospira biomass supplemented into yogurt at different concentrations of 0.1, 0.3, and 0.5% (w/v) and 1, 5, and 10% (v/v), respectively improved physicochemical properties. Arthrospira supplemented in yogurt fermentation gave faster decrease in pH value with green color index of finished yogurt. Oven drying is a convenient method; however, fresh biomass gave similar nutritional value with higher C-phycocyanin content. During storage, pH, titratable acidity, and color of yogurt showed negligible variations. Results indicated that Arthrospira increased both nutritional composition and functional properties of yogurt as a natural food ingredient.


2018 ◽  
Vol 7 (2) ◽  
Author(s):  
Obakeng Galeboe ◽  
Eyassu Seifu ◽  
Bonno Sekwati-Monang

The objectives of this study were to make yoghurt from camel milk and determine its physicochemical, microbiological and sensory qualities. The quality of camel milk yoghurt was compared with cow milk yoghurt and all parameters were analyzed following standard procedures. Yoghurt of acceptable consistency was made from camel milk using 1.2% gelatin, 5% bovine skim milk powder, 1.5 ml/L of calcium chloride, 40 ml/L of maple strawberry syrup and 6% yoghurt culture (YF-L811) and by incubating the milk at 42°C for 18 h. The average values for moisture, ash, syneresis, pH, titratable acidity and total solids of camel milk yoghurt were 83.4%, 1.13%, 58%, 4.37, 1.255% lactic acid and 16.7%, respectively. The corresponding values for cow milk yoghurt were 80.6%, 0.71%, 56%, 4.67, 0.865% lactic acid and 19.5%, respectively. The titratable acidity of camel milk yoghurt was significantly higher (P<0.05) than cow milk yoghurt; however, no significant difference was observed between the two yoghurt types for the other parameters. Coliforms were not detected in both yoghurt types. The sensory analysis showed that cow milk yoghurt was more preferred by the panellists than camel milk yoghurt. Production of yoghurt from camel milk using the same procedure as for cow milk yoghurt proved to be difficult.  Further research is called for to improve the acceptability of camel milk yoghurt using locally available and acceptable flavouring agents. Research needs to be conducted to optimize the operating parameters and standardize the production procedures of camel milk yoghurt in the future.


Author(s):  
M. Samilyk ◽  
X. Qin ◽  
Y. Luo

Rice bran is an agro-industrial waste with excellent nutritional value and a considerable content of bioactive compounds. Biotransformation processes by fermented milk drink fermentation increase the interest in obtaining products from agro-industrial wastes with good biological properties. The viability of introducing rice bran (RB) into fermented milk drinks to improve the structural stability and sensory was studied. Fermented milk drink supplemented with 0, 0.1 %, 0.3 %, 0.5 %, 0.7 % amount of RB were studied. Samples were stored for 28 days at 4 ± 1 °C. Samples composition was studied, Physicochemical properties (total titratable acidity, apparent viscosity, and pH) and consumer’s acceptability of fermented milk drinks were determined at 0, 7th, 14th, 21th and 28th days of storage. Studies showed that rice bran wan rich in dietary fiber (28.57 %), fat (21.56 %), and protein (11.18 %). The introduction of RB showed a significant influence on these parameters (P < 0.05). The introduction of RB would significantly improve the value of titratable acidity and apparent viscosity and decrease pH value. The more rice bran was added, the higher the values of titratable acidity and apparent viscosity were. The lower the pH value was, which could shorten the fermentation time, improve the texture stability, save production cost. The storage period could significantly influence the value of titratable acidity, pH, and apparent viscosity. The longer the storage period was, the higher the titratable acidity values were, the lower the pH value was caused by the post-fermentation of fermented milk drink. The apparent viscosity showed a trend of rising first and falling then during the storage period. The introduction of RB could significantly influence the sensory characteristic (color, consistency, sour, and texture). The introduction of RB would lead to whey separation and rough structure. Fermented milk drink supplemented with 0.1 % RB showed higher sensory acceptance. The best shelf life of the sample is 14 days,during which time fermented milk drink was of the best quality. RB is a kind of raw material with bright application prospects in a fermented milk drink.


2019 ◽  
pp. 324-331
Author(s):  
Dajana Vukic ◽  
Snezana Kravic ◽  
Spasenija Milanovic ◽  
Mirela Ilicic ◽  
Katarina Kanuric ◽  
...  

In this study, the effects of kombucha inoculum as non-conventional starter culture on fatty acids composition of fermented milk, compared to a commercial probiotic (ABT-7) and yoghurt (YF-L812) starter cultures, during 21 days of storage was investigated. Fatty acids composition was determined by gas chromatography-mass spectrometry after the previous extraction of lipids and derivatization. The atherogenic (AI) and thrombogenic (TI) indices determined on the basis of fatty acids composition have been used for evaluation of the nutritive lipid quality of the fermented dairy products. The most significant levels of fatty acids in fermented milk products were palmitic, followed by oleic, stearic and myristic fatty acids. Fermented milk products were characterized by low atherogenic (2.14-2.39) and thrombogenic (2.91-3.18) indices, suggesting their consumption could have a favorable effect on human health. The AI and TI were comparable during the storage of fermented milk samples. Starter culture did not affect the health-related fatty acid composition of fermented milk products during storage.


Author(s):  
Prasad Patil ◽  
Akanksha Wadehra ◽  
Kanchan Munjal ◽  
Pradip Behare

Currently, much attention is being paid for improving the texture of food by screening the new exopolysaccharides (EPS) producing strains. The aim of the present work was to isolate EPS producing Lactic acid bacteria (LAB) strains from raw milk and milk products samples. Total of thirty eight dahi, lassi and raw milk samples were collected from different villages and towns of Karnal and Delhi District. The samples were plated on milk agar and colonies showing ropy polysaccharides production were subjected to biochemical test. After molecular identification 2 were found as <italic>S. thermophilus</italic>, 2 were <italic>Lb. rhamnosus</italic> and 2 were confirmed as <italic>Lb. fermentum</italic>. Two <italic>S. thermophilus</italic> strains (PD7 and PD11) and <italic>Lb. fermentum</italic> strains (AL6 and AD3) showed better curdling pattern, acidity, exopolysaccharides production, and sensory properties. These cultures can be used for manufacture of indigenous fermented milk products.


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