SELECTION OF A MEDIUM FOR THE ISOLATION AND ENUMERATION OF ENTEROCOCCI IN DAIRY PRODUCTS1

1963 ◽  
Vol 26 (4) ◽  
pp. 114-118 ◽  
Author(s):  
Devi S. Saraswat ◽  
Warren S. Clark ◽  
George W. Reinbold
Keyword(s):  
Dairy Products ◽  
High Selectivity ◽  
Agar Plate ◽  
Food Products ◽  
Raw Milk ◽  
Inhibitory Effects ◽  
High Recovery ◽  
Plate Method ◽  
Raw Milk Cheese ◽  
Selection Of

Ten media, commonly used for the detection and isolation of streptococci of sanitary significance in water, dairy and other food products, were compared to establish a plating medium for the enumeration of enterococci in dairy products. To make all media suitable for comparison by the agar plate method, agar was added to those media which initially were recommended for use as broths. Criteria used in selecting the medium were high recovery, selectivity but not undue inhibition of enterococci and ease in obtaining and interpreting results. The recovery data of three different platings of enterococcus cultures were statistically analyzed. In this manner, one medium was eliminated on the basis of low recovery. Six of the remaining nine media were eliminated because they permitted the growth of non-enterococcus cultures. Two of the three media then remaining were eliminated because they allowed one S. bovis culture to grow. In addition, these media showed considerable variation in size and color of enterococcus colonies. The medium selected, the Citrate azide medium of Reinbold, Swern and Hussong (13), was modified by increasing the azide concentration. This did not result in undue inhibitory effects. It was further tested by obtaining recovery data for 158 known enterococcus cultures. High selectivity was demonstrated by showing that 408 colonial isolates from plates of raw milk, cheese and butter could be identified as enterococci.

scholarly journals Antilisterial Activity of Bacteriocins Produced by Lactic Bacteria Isolated from Dairy Products

Foods ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1757
Author(s):  
Simona de Niederhäusern ◽  
Stefania Camellini ◽  
Carla Sabia ◽  
Ramona Iseppi ◽  
Moreno Bondi ◽  
...  
Keyword(s):  
Dairy Products ◽  
Raw Milk ◽  
Lactobacillus Bulgaricus ◽  
Molecular Characteristics ◽  
Soft Cheese ◽  
Wide Range ◽  
Agar Well Diffusion Assay ◽  
Diffusion Assay ◽  
Lactic Bacteria ◽  
Selection Of

Sixty-nine Lactic Acid Bacteria (LAB) and bifidobacteria were isolated and identified from Italian dairy products (raw milk, cream, butter, soft cheese and yoghurt) to find new antimicrobial compounds to use as food bio-preservatives. All the isolates were preliminarily screened by the deferred antagonism method for bacteriocin production. Afterwards, to evaluate the release of bacteriocin in liquid medium, the Cell-Free Supernatant Fluid (CFSF) of the best producers was tested by agar well diffusion assay. The study allowed the selection of three bacteriocin producing strains (Enterococcus faecium E23, Bifidobacterium thermophilum B23 and Lactobacillus bulgaricus L21), endowed with the strongest and broadest inhibitory capability against the pathogen Listeria monocytogenes. The molecular characteristics and the chemical–physical properties of both producers and the respective bacteriocins were studied and compared. The results showed that E. faecium E23 was the best producer strain and its class IIa bacteriocins, called enterocin E23, exhibited a good spectrum of activity towards L. monocytogenes. Enterocin E23 was stable over a wide range of pH and at low temperatures for at least four months and, for this reason, it can be employed in refrigerated foods for the control of L. monocytogenes, the major concern in dairy products.

scholarly journals Molecular genetic methods of analysis to identify the species affiliation of the raw material composition in food products

Vestnik MGTU ◽  
2020 ◽  
Vol 23 (3) ◽  
pp. 214-223
Author(s):  
E. A. Yurova ◽  
N. A. Zhizhin ◽  
S. A. Filchakova
Keyword(s):  
Dairy Products ◽  
Diagnostic Method ◽  
Molecular Genetic ◽  
Food Products ◽  
Raw Milk ◽  
Biological Tissues ◽  
Raw Material ◽  
Dna Molecules ◽  
Milk Samples ◽  
Sheep Milk

Received in revised 08.08.2020 Methods based on the analysis of proteins and DNA molecules are more and more used to assess the composition of food products. Proteins research methods include immunological, electrophoretic and chromatographic ones. The analysis of DNA molecules is most often used to identify the species affiliation of food components. This is due to the stability of their structure compared to proteins, as well as their presence in most biological tissues. The results of studies evaluating methodological approaches for the application of the PCR diagnostic method to identify the composition of food products and the possibility of their use for monitoring dairy products have been shown. The objects of research were samples of cow, goat, sheep milk, as well as milk samples of different animal species mixed in various ratios. DNA was extracted from milk samples according to a unified technique for the separation of DNA molecules in milk and dairy products. The work also considers the possibility of using the PCR diagnostic method to identify the raw material origin of the product. To evaluate the measurement methods, artificially created samples of raw milk were used, which were cow, goat and sheep milk, a mix of three types of milk in different ratios. As a result of the research, the main method has been chosen as the real time PCR method, which has reliability, high sensitivity, sufficient rapidity, with the possibility of using it for dairy multicomponent products with a complex structural matrix, as well as products that have undergone deep technological processing.

scholarly journals Characterization and nutritional assessment of traditional dairy products from the Zlatibor region, Republic of Serbia

2021 ◽  
Vol 53 (1) ◽  
Author(s):  
Dragan Milićević ◽  
Greta Krešić ◽  
Danijela Vranić ◽  
Tina Lešić ◽  
Jelana Nedeljković-Trailović ◽  
...  
Keyword(s):  
Dairy Products ◽  
Nutritional Assessment ◽  
Saturated Fatty Acids ◽  
Dairy Product ◽  
Raw Milk ◽  
Quality Indices ◽  
Mean Values ◽  
High Sodium ◽  
Lipid Quality ◽  
Raw Milk Cheese

The aim of this study was to determine the nutritional properties of raw milk, cheese and a traditional creamy dairy product called kajmak originating from the Zlatibor region in Serbia. Chemical composition, minerals, fatty acid (FA) profile, lipid quality indices, and the dietary intake of saturated fatty acids (SFA), cholesterol, salt and sodium were investigated in three sampling sessions during the period June–September 2019. All chemical properties of raw milk, cheese and kajmak differed significantly (P<0.05), except lactose, salt and total proteins. Palmitic acid (C16:0) was present in the highest share, followed by oleic (C18:1cis-9) and myrstic (C14:0) acids, with no significant differences (P>0.05) between products. Among the FAs, conjugated linoleic acids (CLA) were determined, and mean values of total FAs ranged from 0.16% in raw milk and kajmak to 0.31% in cheese. The recommended values for the lipid quality indices were not obtained for the analysed products. Despite a high sodium content, the tested dairy products can be considered valuable sources of calcium, chromium, zinc and selenium. In the future, additional efforts should be employed in product modification with the aim of optimising nutritional value and to obtain the protect designation of origin.

scholarly journals FORMATION OF THE DOMESTIC MARKET OF LACTOSE-FREE AND LOW-LACTOSE DAIRY PRODUCTS

2021 ◽  
Vol 38 (2) ◽  
pp. 33-43
Author(s):  
YUDINA Tetiana ◽  
SERENKO Anton
Keyword(s):  
Dairy Products ◽  
New Technologies ◽  
Raw Materials ◽  
Food Products ◽  
Raw Milk ◽  
World Market ◽  
Domestic Market ◽  
Natural Food ◽  
Resource Saving ◽  
Complete Collection

Background. The problem of lactose intolerance is becoming widespread, especially in Ukraine it affects 15–35 % of the population. Dairy products are a valuable source of essential nutrients, that’s why it is impossible to completely rule out them from the diet. To solve this problem, it is important to develop technology for dairy products that are free of lactose or with reduced content. The aim of thework is to analyze the world market of low-lactose dairy products and to identify the factors which influence on the formation of such a market in Ukraine. Materials and methods. The subject of the study is the market segment of lactose-free and low-lactose dairy products. Methods of analysis and synthesis, statistical methods of evaluation, scientific generalization and comparison of data are used. Results. The formation of a healthy food market is characterized by gro­wing demand for special food products with regulated nutrient composition, in particular for dairy products, lactose-free or with its reduced content. However, in Ukraine, this market is still in its infancy. Today in country there are 160 units of lactose-free and low-lactose dairy pro­ducts. The volume of imported products in the general range is 68.13%. Kefir and sour cream have the largest share in the formation of the domestic market of low- and lactose-free dairy products, and domestic yogurts have the smallest part. Therefore, the saturation of the market with domestic yogurt, free of lactose, or with its reduced content, is an important area of the development of the Ukraine’s dairy industry. The restriction of natural food resources negatively affects the formation of the domestic market of low-lactose dairy products. In 2020, milk production decreased by about 7 %, due to the unstable economic situation caused by quarantine restrictions in the context of the COVID-19 pandemic. That’s why today the problem of complete collection and rational use of secondary raw milk in the production of food products dominates., especially dairy products of the "free-from" category. Conclusion. The need to create new technologies for low-lactose dairy products using local bioavailable raw materials is essentially due to their high demand and a narrow range of domestic products. The priority directions of development of the domestic market of low-lactose and lac­tose-free dairy products are offered in the context of the state policy of introduction of resource-saving and increase of volumes of high-quality production of domestic production.

Iodine Content of Milk and Other Foods

1984 ◽  
Vol 47 (9) ◽  
pp. 678-684 ◽  
Author(s):  
M. E. DELLAVALLE ◽  
D. M. BARBANO
Keyword(s):  
Drug Administration ◽  
Dairy Products ◽  
New York State ◽  
Iodine Content ◽  
Food Products ◽  
Raw Milk ◽  
Iodine Intake ◽  
Health Concern ◽  
Breakfast Cereal ◽  
Total Iodine

Excess dietary iodine intake has been identified as an issue of public health concern. The recommended dietary allowance for iodine is 100–150 (μg for adults and 70–120 (μg per day for children. A 1978 Food & Drug Administration survey found that milk and dairy products contributed more than 50% of the total food iodine intake for most age groups. A wide variety of dairy and food products were analyzed for iodine content. Red breakfast cereals and red candy (that contain FD&C Red No. 3), dairy products, eggs, milk, marine fish, and iodized salt contained the most significant quantities of iodine. Iodide content of individual raw milk samples from approximately 2500 farms in New York State was measured. Approximately 62% of all farms had milk iodide levels less than 200 μg/L, 28% between 200 and 499 μg/L, 7% between 500 and 1000 μg/L and 3% had greater than 1000 μg/L. The iodine content of all types of retail milk averaged 394.1 μg/L, cheese and cheese products averaged 15.2 μg/100 g. Most of the iodine partitions into the whey during cheese processing. For dairy powders (including whey), the average iodine content was 471.8 μg/100 g. Use of these powders as ingredients in other dairy and non-dairy products can contribute to high iodine content of other food products. In particular, the iodine content of ice cream was extremely variable, ranging from 18 to 359 μg/100 g. Generally, ice creams and ice milks that contained high proportions of whey and non-fat milk powders had higher levels of iodine in the finished product. Addition of FD&C Red No. 3 to foods substantially increases their total iodine content. However, the measured free iodide content of four brands of red breakfast cereal was higher than would be expected. Food and Drug Administration specifications for certified lots of FD&C Red No. 3 allows up to 0.4% sodium iodide as a contaminant from manufacture. The four brands of red breakfast cereal averaged 6% of their total iodine as free iodide (366 μg/30 g serving). This may indicate that free iodide may be released from FD&C Red No. 3 during processing.

THE BUYER’S GENDER AND THE EFFECT OF PROMOTION ACTIVITIES ON THE PROCESS OF SELECTION OF FOOD PRODUCTS

2018 ◽  
Vol XIX (6) ◽  
pp. 11-18
Author(s):  
Marek Angowski
Keyword(s):  
Dairy Products ◽  
Meat Products ◽  
Food Products ◽  
Decision Making Process ◽  
Product Selection ◽  
Main Research ◽  
Research Goal ◽  
The Impact ◽  
Selection Of ◽  
Purchasing Process

The aim of the considerations and analyzes presented in the publication is to approximate the importance of gender in shaping the behavior of buyers in the decision-making process. The main research goal was to assess the impact of promotional activities on the consumer purchasing process on the market for selected food products. The research part was based on the results of surveys that were conducted in 2016 on a group of 486 food consumers using the targeted selection method. The research has shown that the importance of particular promotional activities in the purchasing process of the surveyed consumers was different depending on the gender. Statistical analyzes show that these differences were not large. Based on the respondents’ answers, it can be noticed that men were much more sensitive to promotional activities in their decisions related to product selection. The respondents in the group of purchasers of fruit and vegetables and dairy products were the most diversified in the assessment of the impact of advertising on the basis of gender, and the least diversified were the purchaser of meat products.

Enterococci from Appenzeller and Schabziger Raw Milk Cheese: Antibiotic Resistance, Virulence Factors, and Persistence of Particular Strains in the Products

2007 ◽  
Vol 70 (2) ◽  
pp. 450-455 ◽  
Author(s):  
S. P. TEMPLER ◽  
A. BAUMGARTNER
Keyword(s):  
Virulence Factors ◽  
Gel Electrophoresis ◽  
Raw Milk ◽  
Pulsed Field Gel Electrophoresis ◽  
Pulsed Field ◽  
Phenotypic Resistance ◽  
Genes Encoding ◽  
Resistance Patterns ◽  
Raw Milk Cheese ◽  
Selection Of

Enterococci are natural residents of human and animal intestinal tracts, and grow to high numbers in a variety of cheeses. The aim of this study was to determine the diversity of enterococci in two types of artisanal raw milk cheese (Schabziger and Appenzeller) and to investigate whether particular strains with triple resistance against chloramphenicol (Chl), tetracycline (Tet), and erythromycin (Ery) persist in the production system. Of 46 cheese samples, a total of 312 Enterococcus strains were isolated over a 5-month period on selective agar plates containing Chl, Tet, or, Ery. Enterococcus faecalis was the predominant species (80.7%), followed by Enterococcus faecium (5.1%), and Enterococcus durans (11.7%). According to the phenotypic resistance patterns, a selection of 150 strains was analyzed with PCR for the presence of genes encoding resistance to Ery (ereA, ereB, mphA, ermA, ermB, ermC, mrsA/mrsB, mefA/mefE), and Tet (tetM, tetL). Because virulence factors have been linked to the pathogenicity of enterococci, the strain selection was also tested for the presence of the following virulence factors: Agg, GelE, Cyl, Esp, EfaAfs, EfaAfm, Cpd, Cob, and Ccf. All tested strains contained at least two of the nine virulence genes taken into analysis. Pulsed-field gel electrophoresis patterns of the isolates showed a limited persistence of several strains over a period of 1 to 2 months in Schabziger, and more than 2 months in Appenzeller. Finally, the enterococcal flora in the two types of cheeses seems to be rather unrelated. Within 150 strains from 25 different cheese samples (11 Appenzeller and 14 Schabziger), 41 pulsed-field gel electrophoresis patterns could be identified, and only 1 of these was found in enterococci from both types of cheese.

scholarly journals Actual problems of quality and safety of food products in the context of providing food security in the Zhytomyr region

2019 ◽  
Vol 21 (93) ◽  
pp. 155-159
Author(s):  
V. A. Kotelevych
Keyword(s):  
Dairy Products ◽  
Specific Activity ◽  
Food Products ◽  
Raw Milk ◽  
The State ◽  
Toxic Substances ◽  
Beta Lactam ◽  
Regulatory Requirements ◽  
137Cs Content ◽  
Economic Markets

The results of the veterinary and sanitary examination of food products are based on data from Zhytomyr Regional State Laboratory of the State Service for Safety of Food and Consumer Protection and State Laboratories of Veterinary and Sanitary Expertise of Economic Markets in Zhytomyr and Zhytomyr Oblast for 2018. The main cause of detoxification of offal was invasive disease. Total sales: 80.26325 tons of products and 10397 positive results were obtained, out of which 92 carcasses, 4074 cases of invasive and non-communicable diseases – 10.262 tons, 6231 cases of other food products with a total weight of 70.00125. The analysis of the reporting documentation of the ZHDLDPPS and the state laboratories of all economic markets in Zhytomyr and Zhytomyr region showed that the main causes of milk and dairy products were: mechanical and bacterial contamination, falsification, subclinical mastics, inconsistency of organoleptic parameters with regulatory requirements, fat content and acidity, violation of terms of implementation. Screening test systems (Charm test Chloramphenicol, 4 sensors (antibiotics of Beta-lactam groups, Tetracyclines, Streptomycins, Chloramphenicol) 247 samples of raw milk were checked, of which 2.4% were positive. Security guarantor  dairy products in Ukraine remains a system for monitoring sanitary-dangerous pathogens and residual amounts of toxic substances. The pollution of forest fungi and game in the victims of the Chernobyl accident in the Zhytomyr region remains at a rather high level and they are the main source of danger to consumers. The most contaminated samples of fresh mushrooms, whose specific activity exceeded the regulatory requirements of DR-2006 for 137Cs content in 2018, were from Ovruch (5 samples 509.1 – 3375 Bq/kg), Native (1 sample – 1956 Bq/kg) and Zhitnaya Market of Zhytomyr (3 samples 2328–2345 bq/kg at a rate of 500 Bq/kg). Accordingly, samples of dry mushrooms at a norm of 2500 Bq/kg did not meet the normative requirements of Ovruch 1 (6329 Bq/kg), of the Nurses 2 samples (4330 Bq/kg and 4987 Bq/kg) and Olevsk 1 sample (2814Bk/kg. DLVSE the study of 28 samples of dry fungi showed that the specific activity of 50% of samples from the Ovruch region was 2520–5000 Bq/kg, 5.8% of samples from the Emilchinsky district – 2544–2923 Bq/kg, 7.2% of the samples from the Native -397– 29022 Bq/kg and 4.3% of samples from the Olevsk rayon – 2739–2892 Bq/kg. Of the LRDLDPPS examined, 3 samples of game – 1 sample from Ovruch exceeded the permissible levels by 2.3 times (464 Bq/kg), with Lugin in 3.3 times (634 Bq/kg), from the Native – 7.6 times (1531 Bq/kg) .And according to the DLVSE, the level of contamination of the game with 6 samples in the Germans – 4 samples (2000-12124 Bq/kg) In Samara, 1 sample in Korosten amounted to 1,500 Bq kg, of which 48 samples of milk tested by the DLVSE in the Germans all showed an excess of 137Cs (101-172 Bq/kg ), fish-2 samples – 203 and 590 Bq/kg.

Raw milk cheese as a potential infection source of pathogenic and toxigenic food born pathogens

2020 ◽  
Author(s):  
Marita Vedovelli CARDOZO ◽  
Natalia NESPOLO ◽  
Tammy Chioda DELFINO ◽  
Camila Chioda de ALMEIDA ◽  
Lucas José Luduverio PIZAURO ◽  
...  
Keyword(s):  
Raw Milk ◽  
Infection Source ◽  
Raw Milk Cheese

Estimation of Aflatoxin M1 Levels in Some Dairy Products Manufactured from Raw Milk Experimentally Inoculated with Toxin

2019 ◽  
Vol 43 (1) ◽  
pp. 50-58
Author(s):  
H. S. Alnaemi
Keyword(s):  
Dairy Products ◽  
Raw Milk ◽  
Aflatoxin M1 ◽  
Consumer Health ◽  
Goat’S Milk ◽  
White Cheese ◽  
Elisa Technique ◽  
Permissible Levels ◽  
Goat's Milk

     Fate of AflatoxinM1 in soft white cheese and its by-product (whey) and in yogurt locally made from raw sheep's and goat's milk experimentally inoculated with 0.05 and 0.5 µg/l AflatoxinM1 were investigated using ELISA technique. Results reported that AflatoxinM1 was concentrated in cheese at levels significantly higher than that recorded in the raw milk that used for its processing, with a significant decrease in AflatoxinM1 levels in its by-product (whey) comparable to the raw milk used in manufacturing at both inoculated levels. Yogurt produced from raw sheep's milk at second inoculated level exerted AflatoxinM1concentration significantly lower than that present in the milk. Significant differences in AflatoxinM1distribution in cheese and whey produced from sheep's milk comparable to their counterparts produced from goat's milk were recorded. Finally, results revealed the efficacious role of the various dairy manufacturing processes in AflatoxinM1 distribution and the necessity to issue of local legislations concerning the maximum permissible limits for AflatoxinM1 in milk in order to stay within the universal permissible levels for AflatoxinM1 in dairy products to provide greater protection for consumer health. 

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