scholarly journals Detoxification of Aflatoxin M1 in Milk by Lactic Acid Bacteria

2021 ◽  
Author(s):  
Sanaz Seyedjafarri
Keyword(s):  
Animal Feed ◽  
Starter Culture ◽  
Streptococcus Thermophilus ◽  
The Body ◽  
Lactobacillus Delbrueckii ◽  
Aflatoxin M1 ◽  
Milk Products ◽  
University Department ◽  
Dairy Animal ◽  
Positive Effect

Background: Aflatoxin M1 is a highly toxic and carcinogenic compound which is found in milk and milk products and it is a hydorxylated metabolite of Aflatoxin B1. When the dairy animal digested AFB1 contaminated feed, it is changed to aflatoxin M1 and transferred to tissues and milk. Aflatoxin M1 is less carcinogenic than AFB1, but it is acutely hepatotoxic as AFB1. Liver is their main target organ in the body. It has been calculated approximately that 0.3- 6.2% of presented AFB1 in animal feed transferred as aflatoxin M1 in milk. Occurrence of AFM1 in milk and milk products is a big concern. Therefore, several countries have standardized the maximum levels of AFM1 in milk and milk products. Methods: In this experiment, the ability of yoghurt bacteria to degrade AFM1 levels in milk and yoghurt were analysed. The starter culture of yoghurt contains Streptococcus thermophilus and Lactobacillus delbrueckii subsp. Bulgaricus (1:1). The experiment is carried out in Glasgow Caledonian University, department of life science in 2010. Result: These bacteria showed the higher binding ability between 90- 100% in milk samples whereas no considerable reduction was observed in yoghurt samples. In some yoghurt samples, an increase of AFM1 level was detected but in overall, concentration of AFM1 was stable in yoghurt. Also, the fat content of milk and yoghurt did not have any negative or positive effect on the concentration of AFM1 in milk and yoghurt.

Aflatoxin M1 in milk and milk products: a short review

2016 ◽  
Vol 9 (2) ◽  
pp. 305-315 ◽  
Author(s):  
E.D. Womack ◽  
D.L. Sparks ◽  
A.E. Brown
Keyword(s):  
High Performance ◽  
Animal Feed ◽  
Short Review ◽  
Aflatoxin M1 ◽  
Official Method ◽  
The European Union ◽  
Fluorescence Detector ◽  
Analytical Methodology ◽  
Milk Products ◽  
Analytical Technique

Aflatoxin M1 (AFM1) is associated with carcinogenicity, genotoxicity, mutagenicity, and teratogenicity and as a result, represents a human health problem worldwide. This review will detail the toxicity, analytical methodology, occurrence, and prevention and control of AFM1 in milk and milk products. The probable daily intakes (PDI) per bodyweight (bw) worldwide ranged from 0.002 to 0.26 ng/kg bw/day for AFM1. Nevertheless, the high occurrence of AFM1 demonstrated in this review establishes the need for monitoring to reduce the risk of toxicity to humans. The recommended extraction method of AFM1 from milk is liquid-liquid with acetonitrile because of the acceptable recoveries (85-97%), compatibility with the environment, and cleanest extracts. The recommended analytical technique for the determination of AFM1 in milk is the high performance-liquid chromatography-fluorescence detector (HPLC-FLD), achieving a 0.001 µg/kg detection limit. The HPLC-FLD is the most common internationally recognised official method for the analysis of AFM1 in milk. The suggested extraction and analytical method for cheese is dichloromethane (81-108% recoveries) and ELISA, respectively. This review reports the projected worldwide occurrence of AFM1 in milk of 2010-2015. Of the 7,841 samples, 5,873 (75%) were positive for AFM1, 26% (2,042) exceeded the maximum residue levels (MRL) of 0.05 µg/kg defined by the European Union and 1.53% (120) exceeded the MRL of 0.5 µg/kg defined by the US Food and Drug Administration. The most effective way of preventing AFM1 occurrences is to reduce contamination of AFB1 in animal feed using biological control with atoxigenic strains of Aspergillus flavus, proper storage of crops, and the addition of binders to AFB1-contaminated feed. Controllable measures include the addition of binders and use of biological transforming agents such as lactic acid bacteria applied directly to milk. Though the one accepted method for the control of AFM1 in milk and milk products is the enforcement of governmental MRL.

scholarly journals Functional strain redundancy and persistent phage infection in Swiss hard cheese starter cultures

2021 ◽  
Author(s):  
Vincent Somerville ◽  
Hélène Berthoud ◽  
Remo S. Schmidt ◽  
Hans-Peter Bachmann ◽  
Yi Hélène Meng ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Evolutionary Dynamics ◽  
Temporal Dynamics ◽  
Negative Impact ◽  
Bacterial Species ◽  
Starter Culture ◽  
Streptococcus Thermophilus ◽  
Starter Cultures ◽  
Lactobacillus Delbrueckii ◽  
Shotgun Metagenomics

AbstractUndefined starter cultures are poorly characterized bacterial communities from environmental origin used in cheese making. They are phenotypically stable and have evolved through domestication by repeated propagation in closed and highly controlled environments over centuries. This makes them interesting for understanding eco-evolutionary dynamics governing microbial communities. While cheese starter cultures are known to be dominated by a few bacterial species, little is known about the composition, functional relevance, and temporal dynamics of strain-level diversity. Here, we applied shotgun metagenomics to an important Swiss cheese starter culture and analyzed historical and experimental samples reflecting 82 years of starter culture propagation. We found that the bacterial community is highly stable and dominated by only a few coexisting strains of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. lactis. Genome sequencing, metabolomics analysis, and co-culturing experiments of 43 isolates show that these strains are functionally redundant, but differ tremendously in their phage resistance potential. Moreover, we identified two highly abundant Streptococcus phages that seem to stably coexist in the community without any negative impact on bacterial growth or strain persistence, and despite the presence of a large and diverse repertoire of matching CRISPR spacers. Our findings show that functionally equivalent strains can coexist in domesticated microbial communities and highlight an important role of bacteria-phage interactions that are different from kill-the-winner dynamics.

scholarly journals Improvement of the Texture of Yogurt by Use of Exopolysaccharide Producing Lactic Acid Bacteria

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Xue Han ◽  
Zhe Yang ◽  
Xueping Jing ◽  
Peng Yu ◽  
Yingchun Zhang ◽  
...  
Keyword(s):  
Dairy Products ◽  
Starter Culture ◽  
Streptococcus Thermophilus ◽  
Fermented Milk ◽  
Starter Cultures ◽  
Lactobacillus Delbrueckii ◽  
Exopolysaccharide Production ◽  
Fermented Dairy Products ◽  
Fermented Dairy

19Streptococcus thermophiluswith high exopolysaccharide production were isolated from traditional Chinese fermented dairy products. The exopolysaccharide and viscosity of milk fermented by these 19 isolates were assayed. The strains ofStreptococcus thermophiluszlw TM11 were selected because its fermented milk had the highest exopolysaccharide content (380 mg/L) and viscosity (7716 mpa/s). ThenStreptococcus thermophiluszlw TM11 was combined withLactobacillus delbrueckiisubsp.bulgaricus3 4.5 and the combination was named SH-1. The quality of the yogurt fermented by SH-1 and two commercial starter cultures (YO-MIX 465, YF-L711) were compared. It was shown that the exopolysaccharide content of yogurt fermented by SH-1 was similar to that of yogurt fermented by YF-L711 and significantly higher than YO-MIX 465 (p<0.05). In addition, the yogurt fermented by SH-1 had the lowest syneresis (8.5%) and better texture and sensory than the samples fermented by YO-MIX 465 and YF-L711. It manifested that the selected higher exopolysaccharide production starter SH-1 could be used as yogurt starter and reduce the amount of adding stabilizer, which can compare with the imported commercial starter culture.

Isolation of Streptococcus thermophilus and Lactobacillus delbrueckii as Starter Culture Candidate Originated from Indonesian Cow��s Milk

2018 ◽  
Vol 46 (3) ◽  
pp. 201-209
Author(s):  
Denny Rizkinata ◽  
Danish Andrian ◽  
Steven Ryan Susanto Tan ◽  
Lucy Jap ◽  
Tjie Jan Tan
Keyword(s):  
Starter Culture ◽  
Streptococcus Thermophilus ◽  
Lactobacillus Delbrueckii

scholarly journals BIOTECHNOLOGY OF PRODUCTION OF YEAST-FREE BREAD USING THE LOCAL STREPTOCOCCUS THERMOPHILUS STRAIN BREEDED BY GORSK GAU AND WILD HOP IN RNO-ALANIA

2021 ◽  
pp. 28-34
Author(s):  
S. A. Grevtsova ◽  
E. I. Rekhviashvili ◽  
M. K. Ailyarova ◽  
M. Yu. Kabulova ◽  
I. E. Soldatova
Keyword(s):  
Lactic Acid ◽  
Starter Culture ◽  
Local Strain ◽  
Streptococcus Thermophilus ◽  
Botanical Garden ◽  
The Body ◽  
Biologically Active ◽  
Active Components ◽  
Local Strains ◽  
Local Selection

The modern food industry offers the consumer bread baked with sourdough using various biologically active components of plant origin. In the production of yeast-free bread, it is advisable to use a sourdough from biologically active strains of Streptococcus thermophilus selected by the Gorsk State Agricultural University. The authors have compiled a starter culture from local strains of lactic acid microorganisms selected by the Research Institute of Biotechnology of the Gorsky State Agrarian University. Research was carried out at the Department of Biological and Chemical Technology of the Gorsky State Agrarian University. We also used cones of wild-growing hops from the botanical garden of the Gorsky State Agrarian University in order that the bitter acids present in the hops suppress the putrefactive microflora, do not have a detrimental effect on local strains of lactic acid microorganisms and allow increasing the productivity of the hop starter culture. Yeast-free bread is easily absorbed by the body, does not harm the intestinal microflora, retains useful properties during storage. The flour used in the experiment met the requirements of GOST 26574–85. When using wild-growing hops in the production of bread, useful substances included in its composition were determined that could increase the quality and safety of bread. The content of alpha acids was 6.0%, and that of essential oils was 0.7%, which corresponds to GOST 32912–2014. We used two strains of a lactic acid microorganism of local selection – Streptococcus thermophilus. Hops were extracted for 30 min at a temperature of 96 °C. Laboratory baking of bread was carried out in accordance with GOST 27669–88. Studies have shown that bread prepared using a local strain of Streptococcus thermophilus selected by the Gorsky State Agricultural University and wild-growing hops is of high quality.

scholarly journals Development of Freeze-Dried Red Dragon Fruit Yoghurt Containing Probiotics

2021 ◽  
Vol 31 (4) ◽  
pp. 14-18
Keyword(s):  
Starter Culture ◽  
Food Product ◽  
Streptococcus Thermophilus ◽  
Bioactive Compound ◽  
Lactobacillus Delbrueckii ◽  
Bioactive Component ◽  
Freeze Dried ◽  
Dragon Fruit ◽  
Long Time ◽  
Viable Bacteria

Yoghurt, a product prepared by fermentation of milk with bacterial cultures consisting of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus, has been popular for a long time, however, dehydrated yogurt is still uncommon. Freeze drying is well-known as an effective method to preserve the nutritional and sensory characteristics of the food product compared to other dehydration ways. This study developed a protocol to produce freeze-dried yoghurt fermented by commercial probiotic starter culture containing betacyanin – a bioactive component from red dragon fruit on laboratory scale. The freeze-dried red dragon yoghurt was produced by the following steps: (1) plain yoghurt preparation: Milk with 12% milk dry matte was heated at 95oC for 5 min, cooled down to 42oC, followed by the addition of commercial probiotic bacteria starter, then fermented for 3 hours until the pH reached to 4.6 and the milk coagulated (2) obtained yoghurt was mixed with 30 % red dragon fruit, molding in the tray (3) Freeze at -20oC and freeze-dried (4) packaging to obtain the final product. Betacyanin – well-known as a bioactive compound from red dragon fruit of the obtained products and viable bacteria remained during 30 days storage at room temperature.

scholarly journals Research of rheological properties of fermented milk ice cream with high content of exopolysaccharides

2021 ◽  
Vol 30 ◽  
pp. 01015
Author(s):  
Ekaterina Pozhidaeva ◽  
Lyubov Golubeva ◽  
Anton Sadchenko ◽  
Yana Dymovskih
Keyword(s):  
Starter Culture ◽  
Control Sample ◽  
Ice Cream ◽  
Streptococcus Thermophilus ◽  
Fermented Milk ◽  
Starter Cultures ◽  
Lactobacillus Delbrueckii ◽  
Lactobacillus Bulgaricus ◽  
Thawing Rate ◽  
Milk Mixture

As a result of scientific and technological research, the ingredient composition and the feasibility of using complex bacterial starter cultures as part of fermented milk ice cream have been substantiated. The objects of the study were samples of mixtures for the production of fermented milk ice cream were considered, which included dairy and non-dairy components, including complex bacterial starter cultures: YF-L812 (Streptococcus thermophilus, Lactobacillus bulgaricus) - control sample and YO-PROX 777 (Streptococcus thermophilus, Lactobacillus delbrueckii ssp.bulgaricus), as well as pectin stabilizers “Grindsted Pektin LC 710” and “Cremodan SE 334” with a concentration of 0.1-0.7%. It was found that a prototype sample with starter culture YO-PROX 777 has increased values of dynamic viscosity compared with the control sample with similar stabilizers and their identical concentrations, which is evidence of the accumulation of exopolysaccharides in the fermented fermented milk mixture. A prototype of fermented milk ice cream has better shape stability during temperature control, the thawing rate is reduced by 1.6 times compared to the control. The degree of overrun of the prototype fermented milk ice cream is 37.6%, which is 1.2 times higher compared to the control.

Role of Streptococcus thermophilus MR-1C Capsular Exopolysaccharide in Cheese Moisture Retention

1998 ◽  
Vol 64 (6) ◽  
pp. 2147-2151 ◽  
Author(s):  
Deborah Low ◽  
Jeffrey A. Ahlgren ◽  
Diane Horne ◽  
Donald J. McMahon ◽  
Craig J. Oberg ◽  
...  
Keyword(s):  
Starter Culture ◽  
Streptococcus Thermophilus ◽  
Gene Replacement ◽  
Lactobacillus Helveticus ◽  
Lactobacillus Delbrueckii ◽  
Low Fat ◽  
Moisture Retention ◽  
Binding Properties ◽  
Water Binding

ABSTRACT Recent work by our group has shown that an exopolysaccharide (EPS)-producing starter pair, Streptococcus thermophilusMR-1C and Lactobacillus delbrueckii subsp.bulgaricus MR-1R, can significantly increase moisture retention in low-fat mozzarella (D. B. Perry, D. J. McMahon, and C. J. Oberg, J. Dairy Sci. 80:799–805, 1997). The objectives of this study were to determine whether MR-1C, MR-1R, or both of these strains are required for enhanced moisture retention and to establish the role of EPS in this phenomenon. Analysis of low-fat mozzarella made with different combinations of MR-1C, MR-1R, and the non-EPS-producing starter culture strains S. thermophilus TA061 andLactobacillus helveticus LH100 showed that S. thermophilus MR-1C was responsible for the increased cheese moisture level. To investigate the role of the S. thermophilus MR-1C EPS in cheese moisture retention, theepsE gene in this bacterium was inactivated by gene replacement. Low-fat mozzarella made with L. helveticusLH100 plus the non-EPS-producing mutant S. thermophilusDM10 had a significantly lower moisture content than did cheese made with strains LH100 and MR-1C, which confirmed that the MR-1C capsular EPS was responsible for the water-binding properties of this bacterium in cheese. Chemical analysis of the S. thermophilus MR-1C EPS indicated that the polymer has a novel basic repeating unit composed of d-galactose, l-rhamnose, andl-fucose in a ratio of 5:2:1.

Effect of incorporation of cottage cheese whey solids andBifidobacterium bifidumin freshly made yogurt

1996 ◽  
Vol 63 (3) ◽  
pp. 467-473 ◽  
Author(s):  
Mirza I. Baig ◽  
Velore Prasad
Keyword(s):  
Whey Protein ◽  
Cheese Whey ◽  
Starter Culture ◽  
Textural Properties ◽  
Streptococcus Thermophilus ◽  
Lactobacillus Delbrueckii ◽  
Cottage Cheese ◽  
Whey Protein Concentrate ◽  
Marginal Effect ◽  
Protein Concentrate

SummaryFresh rennet-coagulated cottage cheese whey was vacuum concentrated to 400 g total solids kg−1, and part of this evaporated whey was acidified to pH 4·6 to prepare whey protein concentrate. Both products were used separately to replace non-fat dried milk in yogurt. Diacetyl concentration increased on fortification with whey protein concentrate, and acetaldehyde increased with evaporated whey. However, the use ofBifidobacterium bifidumas a supplementary starter culture in addition toStreptococcus thermophilusandLactobacillus delbrueckiisubsp.bulgaricusreduced the concentration of diacetyl and acetaldehyde. Incorporation of whey solids stimulated the growth ofStr.thermophilusandBifid. bifidumin yogurt but the count ofLb. bulgaricuswas reduced whenBifid. bifidumwas incorporated. Examination of the organoleptic properties of the yogurts showed that both forms of whey solids were satisfactory replacements for non-fat dried milk. Fortification by whey protein concentrate improved the textural properties. Supplementation byBifid. bifidumhad only a marginal effect on the flavour of the product.

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