Function of Preliminary Incubation of Raw Milk Samples for Quality Control

Clostridium tyrobutyricum represents the main spoiling agent responsible for late blowing defects (LBD) in hard and semi-hard cheeses. Its spores are resistant to manufacturing procedures and can germinate during the long ripening process, causing the burst of the cheese paste with a consequent undesirable taste. The lower quality of blown cheeses leads to considerable financial losses for the producers. The early identification of spore contaminations in raw milk samples thus assumes a pivotal role in industrial quality control. Herein, we developed a point of care (POC) testing method for the sensitive detection of C. tyrobutyricum in milk samples, combining fast DNA extraction (with no purification steps) with a robust colorimetric loop-mediated isothermal amplification (LAMP) technique. Our approach allows for the sensitive and specific detection of C. tyrobutyricum spores (limit of detection, LoD: ~2 spores/mL), with the advantage of a clear naked-eye visualization of the results and a potential semi-quantitative discrimination of the contamination level. In addition, we demonstrated the feasibility of this strategy using a portable battery-operated device that allowed both DNA extraction and amplification steps, proving its potential for on-site quality control applications without the requirement of sophisticated instrumentation and trained personnel.

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QUALITY CONTROL OF MILK PRODUCTION BY MEANS OF THE CYTOCHROME OXIDASE TEST

Journal of Milk and Food Technology ◽

10.4315/0022-2747-31.6.165 ◽

1968 ◽

Vol 31 (6) ◽

pp. 165-170 ◽

Cited By ~ 5

Author(s):

Lester Hankin ◽

Albert R. Pernice ◽

Walter F. Dillman

Keyword(s):

Heat Treatment ◽

Quality Control ◽

Milk Production ◽

Effective Means ◽

Raw Milk ◽

Case Histories ◽

Milk Samples ◽

Minimum Standards ◽

Oxidase Test

The test for determination of organisms which are oxidase-positive applied to raw milk samples is an effective means for indication of proper cleaning and sanitary procedures on the farm. The total and oxidase-positive counts of raw milk samples from many producers were determined over a 3 month period in order to obtain a basis for minimum standards. The ratio of the total count to the oxidase count, as well as the total numbers of oxidase-positive organisms in the sample, were used to decide if a potential bacterial problem on the farm would develop. Case histories of individual producers are cited to illustrate how to interpret data obtained with the test and to show how use of the data helps to produce milk of good quality. The number of oxidase-positive organisms in laboratory pasteurized samples was also determined and generally found to be low indicating that most, but not all, of such organisms are killed by proper heat treatment.

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The Physicochemical Quality of Traditional Burduf Cheese

Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca Food Science and Technology ◽

10.15835/buasvmcn-fst:9461 ◽

2013 ◽

Vol 70 (2) ◽

pp. 137

Author(s):

Carmen Pop ◽

Cristina Anamaria Semeniuc ◽

Sorin Apostu ◽

Ancuţa Mihaela Rotar

Keyword(s):

Quality Control ◽

Raw Milk ◽

Cow Milk ◽

Chemical Parameters ◽

Physicochemical Quality ◽

Milk Samples ◽

Sheep Milk ◽

Physico Chemical ◽

Different Types

The aim of this study is the assessmentof the quality control of raw milk and traditional burduf cheese obtained fromcow milk mixed with 10% sheep milk. Appreciation of the integrity and freshness assessmentof milk (cow and sheep) was tested by physico-chemical analysis.On theshelf-live were determined the physico-chemical parameters in cheese samples. Theantibiotics residues were tested of the milk samples with portable analyser,model Rosa Charm Reader. Theresults of physico-chemical determinations for the milk and cheese samples werewithin the maximum permissible by data legislation. Regardingthe content of antibiotics, the results were negative both for cow milk and forsheep milk. The sensorycharacteristics of burduf cheese are influenced by the different types of milk.

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Prevalence of Mastitis and Antibiotic Resistance of Bacterial Isolates from CMT Positive Milk Samples Obtained from Dairy Cows, Camels, and Goats in Two Pastoral Districts in Southern Ethiopia

Animals ◽

10.3390/ani11061530 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1530

Author(s):

Amanuel Balemi ◽

Balako Gumi ◽

Kebede Amenu ◽

Sisay Girma ◽

Muuz Gebru ◽

...

Keyword(s):

Antibiotic Resistance ◽

Dairy Cows ◽

Raw Milk ◽

Multidrug Resistant ◽

Southern Ethiopia ◽

Resistant Bacteria ◽

Coagulase Negative Staphylococcus ◽

Bacterial Isolates ◽

E Coli ◽

Milk Samples

A study was carried out from August 2017 to February 2018 on lactating dairy cows, one-humped dromedary camels, and goats to determine mastitis in the Bule Hora and Dugda Dawa districts of in Southern Ethiopia. Milk samples from 564 udder quarters and udder halves from 171 animals consisting of 60 dairy cows, 51 camels, and 60 goats were tested for mastitis. Sixty-four positive udder milk samples were cultured, and bacterial mastitis pathogens were isolated and identified. The antibiotic resistance of bacterial isolates from milk with mastitis was tested against nine antimicrobials commonly used in the study area. Cow- and quarter-level prevalence of mastitis in dairy cows, camels, and goats was 33.3%, 26.3%, and 25% and 17.6%, 14.5%, and 20%, respectively. In cattle, the prevalence was significantly higher in Dugda Dawa than in Bule Hora. Major bacterial isolates were coagulase-negative Staphylococcus species (39.1%), S. aureus (17.2%), S. hyicus (14.1%), and S. intermedius and Escherichia coli (9.4% each). In camels, udder abnormality and mastitis were significantly higher in late lactation than in early lactation. Mastitis tends to increase with parity in camels. E. coli isolates were highly resistant to spectinomycin, vancomycin, and doxycycline, whereas most S. aureus isolates were multidrug-resistant. Most of the rural and periurban communities in this area consume raw milk, which indicates a high risk of infection with multidrug-resistant bacteria. We recommend a community-focused training program to improve community awareness of the need to boil milk and the risk of raw milk consumption.

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MOLECULAR DETECTION AND CHARACTERIZATION OF STAPHYLOCOCCUS AUREUS ISOLATED FROM RAW MILK SOLD IN DIFFERENT MARKETS OF BANGLADESH

Bangladesh Journal of Veterinary Medicine ◽

10.3329/bjvm.v14i2.31409 ◽

2017 ◽

Vol 14 (2) ◽

pp. 277-282 ◽

Cited By ~ 1

Author(s):

M. A. Islam ◽

S. M. L. Kabir ◽

M. T. Rahman

Keyword(s):

Molecular Detection ◽

Culture Media ◽

Raw Milk ◽

Rrna Gene ◽

Biochemical Tests ◽

Selective Media ◽

Milk Samples ◽

Antimicrobial Sensitivity ◽

Antimicrobial Sensitivity Test

The study was intended for molecular detection of S. aureus isolated from raw cows milk. A total of 20 milk samples were collected from different upazila markets of Jamalpur, Tangail, Kishoreganj and Netrokona districts of Bangladesh. Milk samples were cultured onto various culture media for the isolation of bacteria. The isolated bacteria were identified by studying cultural properties on different selective media, biochemical tests, and finally by PCR. Out of 20 samples, 15 (75%) milk samples were found to be positive for S. aureus. S. aureus specific 16S rRNA gene was amplified from all isolates and identified as S. aureus. Antimicrobial sensitivity test was carried out to ascertain the susceptibility of the organism to various antibiotics. Its results showed that the S. aureus isolates were resistant to amoxicillin (100%), erythromycin (73.33%) and tetracycline (73.33%) but sensitive to azithromycin (93.33%), ciprofloxacin (93.33%), gentamicin (100%), norfloxacin (86.67%) and streptomycin (86.67%).

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Bulk tank somatic cell count and associated microbial quality of milk from selected dairy cattle herds in Oyo State, Nigeria

Italian Journal of Food Safety ◽

10.4081/ijfs.2018.7130 ◽

2018 ◽

Vol 7 (2) ◽

Cited By ~ 2

Author(s):

Olufemi Olatoye ◽

Adesola Amosun ◽

Uzo Ogbu ◽

Yemi Okunlade

Keyword(s):

Somatic Cell ◽

Cell Count ◽

Somatic Cell Count ◽

Health Management ◽

Development Program ◽

Raw Milk ◽

Human Consumption ◽

Quality And Safety ◽

Milk Samples ◽

California Mastitis Test

Improvement of traditional and nomadic milk production through dairy development program in Nigeria requires routine quality and safety monitoring of milk both at herd level and milk collection centers. A total of 411 bulk raw milk samples aseptically obtained from Ibarapa, Oyo and Oke-Ogun industrial milk collection centers were subjected to California Mastitis Test (CMT), Bulk Somatic Cell Count (BSCC) and bacteriological analysis for assessment of quality and safety of milk from the herds. One hundred and seven (26.0%) of the samples were CMT positive, while 74.0% were negative to CMT. The overall mean BSCC, TAC and TCC were 1.27×103 ± cells/mL, 1.12×103± 34 cfu/mL, 97.8±9.8 cfu/mL in the CMT negative milk samples while for the strong positive samples the mean BSCC, TAC and TCC were 4.33×106 ± cells/mL, 2.35×106 ± 453 cfu/mL, 189.3±41.1 cfu/mL respectively; these were higher than the Pasteurized Milk Ordinance acceptable limits. Positive correlation was found between CMT scores and bacterial contamination and between CMT scores and SCC was recorded. About 26.0% of the samples with positive CMT could be considered unsafe due to strong correlation with microbial contamination that could result in milk borne zoonoses and public health hazards. However, a greater proportion (76.9%) of the milk with negative CMT scores could be safe for human consumption after post-harvest pasteurization. Consequently, there is need to improve handling, environmental and milking hygiene; as well as proper herd and udder health management to improve quality and safety of Nigeria dairy products.

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Toxoplasma gondii and pre-treatment protocols for polymerase chain reaction analysis of milk samples: a field trial in sheep from Southern Italy

Italian Journal of Food Safety ◽

10.4081/ijfs.2017.6501 ◽

2017 ◽

Vol 6 (1) ◽

Cited By ~ 1

Author(s):

Alice Vismarra ◽

Elena Barilli ◽

Maura Miceli ◽

Carlo Mangia ◽

Cristina Bacci ◽

...

Keyword(s):

Toxoplasma Gondii ◽

Real Time ◽

Dna Extraction ◽

Real Time Pcr ◽

Southern Italy ◽

Raw Milk ◽

Type I ◽

Treatment Protocols ◽

Milk Samples ◽

Pre Treatment

Toxoplasmosis is a zoonotic disease caused by the protozoan Toxoplasma gondii. Ingestion of raw milk has been suggested as a risk for transmission to humans. Here the authors evaluated pre-treatment protocols for DNA extraction on T. gondii tachyzoite-spiked sheep milk with the aim of identifying the method that resulted in the most rapid and reliable PCR positivity. This protocol was then used to analyze milk samples form sheep from three different farms in southern Italy, including Real Time PCR for DNA quantification and PCR-RFLP for genotyping. The pre-treatment protocol using EDTA and Tris-HCl to remove casein gave the best results in the least amount of time compared to the others on spiked milk samples. One sample of 21 collected from sheep farms was positive on one-step PCR, Real Time PCR and resulted in a Type I genotype at one locus (SAG3). Milk usually contains a low number of tachyzoites and this could be a limiting factor for molecular identification. Our preliminary data has evaluated a rapid, cost-effective and sensitive protocol to treat milk before DNA extraction. The results of the present study also confirm the possibility of T. gondii transmission through consumption of raw milk and its unpasteurized derivatives.

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Isolation and molecular characterization of Mycobacterium tuberculosis complex isolated from raw milk in some dairy farms in Egypt

International Journal of Basic and Applied Sciences ◽

10.14419/ijbas.v5i2.5299 ◽

2016 ◽

Vol 5 (2) ◽

pp. 105

Author(s):

Heba Hussien ◽

Eman Mahrous

Keyword(s):

Mycobacterium Tuberculosis ◽

Real Time ◽

Real Time Pcr ◽

Culture Method ◽

Raw Milk ◽

Accurate Method ◽

Tuberculosis Complex ◽

Milk Samples ◽

Source Of Infection

This study was conducted to detect Mycobacterium tuberculosis complex in milk in three Egyptian Governorates; El-Sharkia, El-Menoufia and El-Behera Governorates. 300 milk samples were collected from tuberculin positive cases, 18 (6.0%) were shedding Mycobacterium tuberculosis complex in their milk which detected by real time PCR. On another hand, 170 milk samples were collected from tuberculin negative cases, 5 (2.9%) were shedding Mycobacterium tuberculosis complex in their milk which detected by real time PCR. All milk samples were examined by three techniques including Microscopic examination, culture and real time PCR. Real time PCR is more rapid and accurate method than microscopic and culture method. The isolated colonies from culture were examined by Multiplex PCR to demonstrate the source of infection either human or animal source.

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Composition of raw milk from conventional and organic dairy farming

Biotechnology in Animal Husbandry ◽

10.2298/bah1602133k ◽

2016 ◽

Vol 32 (2) ◽

pp. 133-143 ◽

Cited By ~ 2

Author(s):

Denis Kucevic ◽

Snezana Trivunovic ◽

Vladan Bogdanovic ◽

Ksenija Cobanovic ◽

Dobrila Jankovic ◽

...

Keyword(s):

Statistical Significance ◽

Raw Milk ◽

Farming System ◽

Dairy Farming ◽

Milk Samples ◽

High Statistical Significance ◽

Significant Difference ◽

Organic Dairy ◽

One Year ◽

The Impact

Possible differences between composition of raw milk due to dairy farming system (organic vs conventional) as well as seasonal variations were investigated. The samples were analysed during one year. A total of 6.782 samples of raw milk were collected (4.496 from organic farming). Dairy farms were located in the northern part of Republic of Serbia (Province of Vojvodina). The principle of analysis of raw milk samples was in accordance with the methodology by midinfrared spectrometry and flow cytometry. The fixed effect of system of farming and season (winter, spring, summer and fall) have shown a high statistical significance (P < 0.01) on all examined milk parameters except fat, total solids and somatic cell count, where the impact was slightly lower (P < 0.05). Significant difference wasn't found in number of bacterial colonies (P > 0.05). Composition of milk is also affected by a number of other factors, therefore it is recommended to involve factors such as nutrition of dairy cows, breed and farm management.

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Simultaneous Determination of C18 Fatty Acids in Milk by GC-MS

Separations ◽

10.3390/separations8080118 ◽

2021 ◽

Vol 8 (8) ◽

pp. 118

Author(s):

Meiqing Chen ◽

Yangdong Zhang ◽

Fengen Wang ◽

Nan Zheng ◽

Jiaqi Wang

Keyword(s):

Fatty Acids ◽

High Sensitivity ◽

Raw Milk ◽

Uht Milk ◽

Milk Samples ◽

Accuracy And Precision ◽

Different Temperatures ◽

Chromatographic Resolution ◽

Commercial Milk

The determination of C18 fatty acids (FAs) is a key and difficult aspect in FA profiling, and a qualified method with good chromatographic separation and high sensitivity, as well as easy methylation, is required. A GC-MS method was established to simultaneously determine C18 FAs in milk. To simplify the methylation protocol for milk samples, besides a base-catalyzation methylation (50 °C for 20 min), the necessity of an additional acid-catalyzation was also studied using different temperatures (60 °C, 70 °C, 80 °C, and 90 °C) and durations (90 min and 150 min). The results showed that the chromatographic resolution was improved, although three co-eluted peaks existed. The base-catalyzation was sufficient, and an additional acid-catalyzation was not necessary. The proposed method was validated with good sensitivity, linearity, accuracy, and precision, and then applied in determining C18 FAs in 20 raw milk and 30 commercial milk samples. UHT milk presented a different profile of C18 FAs from raw milk and PAS milk samples, which indicated that excessive heating could change the profile. Overall, the proposed method is a high-throughput and competent approach for the determination of C18 FAs in milk, and which presents an improvement in chromatographic resolution and sensitivity, as well as a simplification of methylation.

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