Qualitative Detection of Tetracycline Residues in Milk with a Luminescence-Based Microbial Method: The Effect of Milk Composition and Assay Performance in Relation to an Immunoassay and a Microbial Inhibition Assay

2000 ◽  
Vol 63 (7) ◽  
pp. 953-957 ◽  
Author(s):  
JUSSI KURITTU ◽  
STEFAN LÖNNBERG ◽  
MARKO VIRTA ◽  
MATTI KARP

Performance of Tet-Lux, a newly developed microbiological test for the detection of tetracycline residues in raw milk, based on tetracycline-controlled luminescence activation of the test bacteria, was evaluated in bovine milks with variable amounts of somatic cells, bacteria, fat, protein, and natural inhibitory compounds. The sensitivity of Tet-Lux was also compared to a commercially available tetracycline immunoassay (Snap, Idexx Laboratories Inc.) and to a microbial inhibition test (Delvotest SP, Gist-Brogades). There were slight differences in the luminescence signals between different milk samples, but no single factor could be pointed out to be responsible for them. There appeared to be a modest inverse relationship between luminescence and increasing fat and protein content. The amount of somatic cells, bacteria, and the natural inhibitors lysozyme and lactoferrin did not affect the luminescence response. The test fulfilled the sensitivity requirement specified by the European Union (maximum residue limit 100 ng/ml for tetracyclines). The Tet-Lux test was clearly more sensitive to all tetracyclines tested (oxytetracycline, tetracycline, chlortetracycline, doxycycline, demeclocycline, methacycline, minocycline) than Delvotest SP, and for five tetracyclines out of seven more sensitive than Snap. The test provides a fast, simple, and robust microbial method for the qualitative detection of tetracycline residues in milk.

2000 ◽  
Vol 48 (8) ◽  
pp. 3372-3377 ◽  
Author(s):  
Jussi Kurittu ◽  
Stefan Lönnberg ◽  
Marko Virta ◽  
Matti Karp

2021 ◽  
Vol 65 (4) ◽  
pp. 57-66
Author(s):  
S. Hriciková ◽  
I. Kožárová

Abstract Milk used for human consumption must comply with the European Union legislative requirements for residues of inhibitory substances in milk, the values of which must not exceed the established maximum residue limit. In order to ensure the quality and safety of milk and milk products placed on the market, the presence of residues of inhibitory substances should be monitored and verified. The aim of our study was to select the most reliable method for the analysis of residues of inhibitory substances in milk. In the search for the most reliable method, a total of 49 milk samples were tested in the form of raw milk, skimmed milk and skimmed-milk powder throughout the agri-food chain. For comparison, the microbial inhibition tests Eclipse 50, Eclipse Farm, Explorer 2.0, Delvotest®, Premi®Test and the fast receptor screening test TwinSensor were used. The most relevant results were obtained by the Eclipse 50 and Eclipse Farm tests, the reliability of which were also confirmed by the Explorer 2.0 and Premi®Test tests. Moreover, according to the State Veterinary and Food Administration of the Slovak Republic, Eclipse 50 is an official reference method for the determination of residues of inhibitory substances in milk. Therefore, we can only state that of all the methods used, the Eclipse 50 seems to be the most reliable for routine control analysis of residues of inhibitory substances in all types of milk.


2017 ◽  
Vol 3 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Mukta Talukder ◽  
HM Manir Ahmed

Somatic cells are the most essential factors naturally present in milk, and somatic cell count (SCC) is used as an indicator of monitoring mastitis incidence in the herd and also to assess the quality of milk. In addition, SCC is frequently used to determine quality payments to dairy producers. The SCC is directly related to get maximum milk production from individual cow and a lower SCC indicates better animal health, as somatic cells originate only from inside the animal's udder. SCC monitoring is important because as the number of somatic cells increases, milk yield is likely to fall, primarily due to the damage to milk-producing tissue in the udder caused by mastitis pathogens and the toxins they produce, particularly when epithelial cells are lost. Keeping low SSC will allow good quality more raw milk and provide a better product to milk processors whether used as fluid milk or converted to milk based products. Somatic cells containing lipolytic and proteolytic enzymes lead to degrade major nutrients fats and proteins, respectively. Elevated SCC is related to udder inflammation, which leads to alter the normal microbial count and physicochemical parameters of milk, as well as the quality of heat treated fluid milk and milk based product. The objective of this review is to discuss on the SSC and endogenous enzymes released from somatic cells in raw milk as well as effect of somatic cells count and their endogenous enzymes in processed milk and milk based products.Asian J. Med. Biol. Res. March 2017, 3(1): 1-9


Author(s):  
Renata Kučerová

The paper deals with the analysis of changes in the development of basic characteristics of the dairy industry in the Czech Republic, which cohere with the integration of the Czech Republic into the European Union. The attention is paid on size of the market, growth rate, life cycle, development of prices and development of foreign trade. The total domestic consumption reached 2111.1 million litres in 2004. The industry is in the maturity. The excess of supply exists in the industry; the growth rate is low, under 5% per year. The integration of the Czech Republic into the EU didn’t bring about changes in the development of basic characteristics – size of the market, growth rate, and life cycle. The volume of production changed. The total volume of purchase of raw milk for production went down by 1.4% to the value in 2000. And all prices in the product vertical – milk and milk products (prices of agricultural producers, production prices and consumer’s prices) rose.The paper is a part of solution of the research plan of the FBE MUAF in Brno, No. MSM 6215648904.


1996 ◽  
Vol 79 (3) ◽  
pp. 711-717 ◽  
Author(s):  
Dominique Lefier ◽  
Remy Grappin ◽  
Sylvie Pochet

Abstract The accuracy of fat, crude protein (CP), true protein (TP), and lactose determinations of raw milk by Fourier transform infrared (FTIR) spectroscopy and by analysis with a conventional filter-based milk analyzer was assessed in 6 trials performed over a 10-month period. At each trial, 30 bulk milk samples collected from 15 European countries and 11 reconstituted milks made from raw milk components were analyzed. When calibrations were performed with reconstituted milks at each trial, accuracy standard deviations for fat, CP, TP, and lactose were, respectively, 0.050,0.048,0.035, and 0.076 g/100 g for the filter instrument and 0.047, 0.046,0.042, and 0.065 g/100 g for the FTIR instrument. When a single calibration was made instead of calibrations at each trial, accuracy standard deviations increased for the filter instrument to 0.130, 0.119,0.121, and 0.083 for fat, CP, TP, and lactose, respectively, and for the FTIR instrument to 0.082, 0.053,0.044, and 0.084 g/100 g. Because the FTIR instrument provides more spectral information related to milk composition than does the filter instrument, single-calibration FTIR analysis of milk samples collected in different seasons is more accurate. Using reconstituted milks, prepared such that there is no correlation between fat, CP, and lactose, provides a more robust calibration than using genuine bulk milk, especially when milks with unusual composition are analyzed.


1974 ◽  
Vol 37 (6) ◽  
pp. 346-349 ◽  
Author(s):  
Sidney E. Barnard

Today's consumer determines the acceptance of milk by flavor and shelf life. Rancid, oxidized, and strong feed tastes of raw milk need to be eliminated. To prevent rancid and psychrotrophic flavor development, milk should be processed within 24 h of collection. Hot water sterilization of processing and filling equipment is essential. Product temperatures below 40 F at the filler extend shelf life. Proper handling during delivery and in stores is necessary to maintain good taste and keeping quality. Temperatures below 40 F, minimal fluorescent light and daylight exposure, and proper rotation are the key factors. Containers vary in their ability to protect the flavor and change in milk composition. Holding quality programs of 14 days at 45 F should be adopted by industry. Ten-day coding or open dating should be practiced by all processors. Regulatory agencies need to permit tests which will indicate shelf life. More emphasis must be placed on factors which determine consumer acceptability. These are flavor and shelf life.


2002 ◽  
Vol 56 (5) ◽  
pp. 599-604 ◽  
Author(s):  
Young-Ah Woo ◽  
Yoko Terazawa ◽  
Jie Yu Chen ◽  
Chie Iyo ◽  
Fuminori Terada ◽  
...  

A new measurement unit, the MilkSpec-1, has been developed to determine rapidly and nondestructively the content of fat, lactose, and protein in raw milk using near-infrared transmittance spectroscopy. The spectral range over 700 to 1100 nm was used. This unit was designed for general glass test tubes, 12 mm in diameter and 10 mL in volume. Al2O3 with a thickness of 2.5 mm was found to be optimum as a reference for acquiring the milk spectrum for this measurement. The NIR transmittance spectra of milk were acquired from raw milk samples without homogenization. The calibration model was developed and predicted by using a partial least-squares (PLS) algorithm. In order to reduce the scattering effect due to fat globules and casein micelles in NIR transmittance spectra, multiplicative scatter correction (MSC) and/or second derivative treatment were performed. MSC treatment proved to be useful for the development of calibration models for fat and protein. This study resulted in low standard errors of prediction (SEP), with 0.06, 0.10, and 0.10% for fat, lactose, and protein, respectively. It is shown that accurate, rapid, and nondestructive determination of milk composition could be successfully performed by using the MilkSpec-1, presenting the potential use of this method for real-time on-line monitoring in a milking process.


Author(s):  
P. V. Jadhav ◽  
S. B. Tarate ◽  
M. Bhuvana ◽  
D. N. Das ◽  
B. R. Shome

The major alteration in the milk composition due to mastitis includes presence of somatic cells (neutrophills, monocytes, macrophages and mammary epithelial cells), bactericidal and bacteriostatic compounds and certain enzymes. Antibiotic residue violation and presence of foodborn pathogens with/without their toxins is another threat of immense importance. These changes in the milk account for the deterioration of the milk quality, risk of health hazards and also its acceptance in the international market. Of all these components, milk somatic cells are the single most widely used indicator of the udder health and mastitis. Somatic cell count (SCC) is used as a system for measurement of milk quality internationally. Strict legislation for monitoring the minimum SCC level is followed to ensure healthy milk in most of the developed countries. This paper introduces the concept of ‘Clean White Revolution’ and reviews the importance of SCC as a measure to ensure hygienic milk production in India. It also emphasizes upon a need to strengthen the existing legislations concerned.


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