scholarly journals Determination of insecticide Deltamethrin residues in local and imported raw milk samples collected from different animal's species and the effect of processing heat treatment on its content in milk

2017 ◽  
Vol 41 (1) ◽  
pp. 49-54
Author(s):  
Sara Ahmed Abd Al-Zahra
Keyword(s):  
Animal Species ◽  
Heat Exposure ◽  
Winter Season ◽  
Raw Milk ◽  
Summer Season ◽  
Fat Percentage ◽  
Milk Samples ◽  
Bulk Milk ◽  
C 30

      A total of 163 milk samples (500 ml each) of cows, ewe, goats, buffaloes, camels were collected randomly at weekly intervals (10 samples/ week) from both Abu-Ghraib and Al-Fudhailiya villages and also for different local retail markets inside the Baghdad province and these samples were including milk of different animal species, milk cans, bulk milk tanks and imported Ultra-high temperature processing milk. Among the total milk samples only 138 milk samples were examined during two climatic periods where the first period was in summer that extended from the beginning of September to the end of October 2015 while the second period was in winter that extended from the beginning of January to the end of February 2016. Besides that, some of the selected positive samples for Deltametrin residues were subjected to one of the commercial heat treatments such as 63°C/30 min., 80°C/5 min. and 100°C/5 min. to evaluate the efficiency of heat exposure on the degradation of Deltametrin residues in milk. The results pointed out that milk samples containing the higher fat percentage exhibited significantly (P<0.05) the highest concentration of Deltametrin in summer (0.08ppm) than in winter (0.008 ppm) seasons. It was clearly obvious that the detectable concentrations of the Deltametrin were higher in buffalo's and ewe milk samples than those found in cows, goats and camels and such results could be attributed to the higher fat content of buffalos and ewes milk than the other animals as well as the lipophilic nature of the Deltamethrin. In other word, increased the fat percentages of milk was being associated with an increased level of Deltametrin residues due to the lipophilic nature of the Deltametrin pesticide. The current results revealed that milk samples that were collected from buffaloes, ewes and cows recorded significantly (P<0.05) the highest Deltametrin residues in summer season where their mean levels that exceeded the accepted MRLs of 0.05 ppm to milk samples of goats and camels that had significantly (P<0.05) the lowest mean levels of Deltametrin residues where their means levels were 0.038 and 0.032 ppm respectively. There was a significant (P<0.05) seasonal variation of the Deltametrin concentrations in milk samples for each animal species where all the milk samples that were collected from buffaloes, ewe, cows, goats and camels had significantly (P<0.05) higher mean levels of Deltametrin residues in summer season than in winter season, milk samples that were collected from milk cans (5, 25 and 50 kg) recorded significantly (P<0.05). The highest Deltametrin residues during the summer season in comparison to 10 tons bulk milk tank samples.

The use of single or composite milk samples for the determination of fat

1968 ◽  
Vol 35 (2) ◽  
pp. 291-294 ◽  
Author(s):  
M. G. O'Keeffe
Keyword(s):  
Analysis Of Variance ◽  
Fat Percentage ◽  
Milk Samples ◽  
Bulk Milk ◽  
Testing Accuracy ◽  
The Mean ◽  
Composite Samples

SummarySamples were tested for fat percentage from every consignment of herd bulk milk from 10 herds over a period of 12 months. The mean monthly within-herd variance was 0·043. Also, triplicate samples were taken from 8 herd bulk supplies for 8 days and tested in duplicate and an analysis of variance was applied to the within-herd fat percentage in order to find the contribution sampling, testing and biological variances. It is shown that when dealing with tanker-collected milk where composite samples are not used the testing accuracy is secondary to frequency of sampling. By combining the variances in the formulae given, the accuracy of different systems may be obtained and compared using either single tested or composite samples.

scholarly journals Evaluation of development in indirect determination of milk fat free fatty acids in Czech Republic

2013 ◽  
Vol 61 (6) ◽  
pp. 1669-1679 ◽  
Author(s):  
Oto Hanuš ◽  
Eva Samková ◽  
Jan Říha ◽  
Marcela Vyletělová Klimešová ◽  
Petr Roubal
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Milk Fat ◽  
Raw Milk ◽  
Important Indicator ◽  
Indirect Determination ◽  
Milk Samples ◽  
Bulk Milk ◽  
Instrumental Values

Free fatty acids (FFAs) in fat are important indicator of raw milk quality. Result reliability of FFAs is important. Aim was to verify MIR–FT (mid infrared spectroscopy with Fourier’s transformations) method for its calibration to determine FFAs, time stability of MIR–FT FFA calibration and calibration levelling in laboratory networks. Reference (RE) milk samples (1 set = 8) were prepared according to CSN 57 0533 (FFAs in mmol.100g−1 of fat). MIR–FT instruments were: 1 LactoScope FTIR (DE); 2 Bentley FTS (BE); 2 MilkoScan FT 6000 (FO). 3 calibrations of MIR–FT (5) in 3 laboratories were performed. Bulk milk samples came from 4 herds and 2 breeds. These 4 samples were used for calibration in native and modified form. Modification increased FFAs by cca 100%. Calibration set had 8 samples. 1 between calibration interval was checked monthly by proficiency testing (PT). PT set had 10 samples. 5 samples were with native milk and 5 had modified fat content, lower and higher. Maximal value of difference variability for calibration quality validation is x (sd of difference MIR–FT and RE) plus 1.64 multiple of sd (on 95% level), 1.0613 mmol.100g−1. Mean validation correlation coefficient (r) between MIR–FT and RE results was 0.802 ± 0.082 (P < 0.001), from 0.666 to 0.945. Minimal value at calibration is x minus 1.64 multiple of sd (0.668). Correlations between MIR–FT results were higher by 8.4% (0.869 (P < 0.001) > 0.802). Example PT with 10 and 5 milk samples had similar results of r 0.887 and 0.953 (P < 0.001 and P < 0.05). There is possibility to construct a levelling programme for calibrated instruments. Some equation between PT reference and instrumental values could correct MIR–FT results for their better comparability.

Addition to Thermized Milk of Lactococcus lactis subsp. cremoris M104, a Wild, Novel Nisin A–Producing Strain, Replaces the Natural Antilisterial Activity of the Autochthonous Raw Milk Microbiota Reduced by Thermization

2014 ◽  
Vol 77 (8) ◽  
pp. 1289-1297 ◽  
Author(s):  
ALEXANDRA LIANOU ◽  
JOHN SAMELIS
Keyword(s):  
Lactococcus Lactis ◽  
Great Part ◽  
Raw Milk ◽  
Control Treatment ◽  
Lactococcus Lactis Subsp ◽  
Milk Samples ◽  
Bulk Milk ◽  
C 30 ◽  
Sterilized Milk ◽  
Cheese Production

Recent research has shown that mild milk thermization treatments routinely used in traditional Greek cheese production are efficient to inactivate Listeria monocytogenes and other pathogenic or undesirable bacteria, but they also inactivate a great part of the autochthonous antagonistic microbiota of raw milk. Therefore, in this study, the antilisterial activity of raw or thermized (63°C, 30 s) milk in the presence or absence of Lactococcus lactis subsp. cremoris M104, a wild, novel, nisin A–producing (Nis-A+) raw milk isolate, was assessed. Bulk milk samples were taken from a local cheese plant before or after thermization and were inoculated with a five-strain cocktail of L. monocytogenes (approximately 4 log CFU/ml) or with the cocktail, as above, plus the Nis-A+ strain (approximately 6 log CFU/ml) as a bioprotective culture. Heat-sterilized (121°C, 5 min) raw milk inoculated with L. monocytogenes was used as a control treatment. All milk samples were incubated at 37°C for 6 h and then at 18°C for an additional 66 h. L. monocytogenes grew abundantly (&gt;8 log CFU/ml) in heat-sterilized milk, whereas its growth was completely inhibited in all raw milk samples. Conversely, in thermized milk, L. monocytogenes increased by 2 log CFU/ml in the absence of strain M104, whereas its growth was completely inhibited in the presence of strain M104. Furthermore, nisin activity was detected only in milk samples inoculated with strain M104. Thus, postthermal supplementation of thermized bulk milk with bioprotective L. lactis subsp. cremoris cultures replaces the natural antilisterial activity of raw milk reduced by thermization.

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

Separations ◽  
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.

scholarly journals Determination of Fat, Protein, and Lactose in Raw Milk by Fourier Transform Infrared Spectroscopy and by Analysis with a Conventional Filter-Based Milk Analyzer

1996 ◽  
Vol 79 (3) ◽  
pp. 711-717 ◽  
Author(s):  
Dominique Lefier ◽  
Remy Grappin ◽  
Sylvie Pochet
Keyword(s):  
Fourier Transform ◽  
Fourier Transform Infrared ◽  
Raw Milk ◽  
Milk Composition ◽  
Milk Samples ◽  
Bulk Milk ◽  
Different Seasons ◽  
Standard Deviations ◽  
True Protein ◽  
Single Calibration

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.

Determination of Viable Bacterial Populations in Raw Milk within 20 Minutes by Using a Direct Epifluorescent Filter Technique

1997 ◽  
Vol 60 (7) ◽  
pp. 874-876 ◽  
Author(s):  
CLAUDE P. CHAMPAGNE ◽  
NANCY J. GARDNER ◽  
JULIE FONTAINE ◽  
JACQUES RICHARD
Keyword(s):  
Raw Milk ◽  
Plate Count ◽  
Bacterial Populations ◽  
Filter Technique ◽  
Milk Samples ◽  
Standard Plate ◽  
Plate Counts ◽  
Direct Epifluorescent Filter Technique ◽  
Triton X

The results from a shortened procedure for the direct epifluorescent filter technique (DEFT) determination of viable bacterial populations in raw milk were compared to standard plate counts. Shortening the prefiltration trypsin-Triton X-100 incubation period from 10 to 3 min enabled the completion of the analysis within 20 min. The short DEFT method results had a correlation coefficient (r) of 0.81 with plate counts. With respect to precision, the average difference between values of duplicate plate count analyses was 0.16 log units; that of the short DEFT was 0.14 log units. The slopes of the regressions equations were less than 1, indicating that a direct correlation is not achieved. Short DEFT values were 0.17 log units higher than those of plate counts on milk samples containing less than 10,000 CFU/ml. For milk samples containing counts over 10,000 CFU/ml, short DEFT values averaged only 0.05 log units above plate count readings. Daily preparation of the stain appears unnecessary since acridine orange solutions stored for up to 2 days at 4°C did not produce results significantly (P &gt; 0.05) different from those obtained with fresh solutions. The short DEFT method has potential for the assessment of the bacteriological quality of raw milk in tanker deliveries.

scholarly journals Determination of Four Fluoroquinolones in Milk by Liquid Chromatography

1997 ◽  
Vol 80 (5) ◽  
pp. 982-987 ◽  
Author(s):  
José E Roybal ◽  
Allen P Pfenning ◽  
Sherri B Turnipseed ◽  
Calvin C Walker ◽  
Jeffrey A Hurlbut
Keyword(s):  
Fluorescence Detection ◽  
Solid Phase ◽  
Raw Milk ◽  
Extraction Column ◽  
Isocratic Elution ◽  
Standard Curve ◽  
Milk Samples ◽  
Relative Standard ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method with fluorescence detection is presented for the analysis of 4 fluoroquinolones; enrofloxacin (ENRO), ciprofloxacin (CIPRO), sarafloxacin (SARA), and difloxacin (DIFLX) in milk. The procedure consists of extraction of milk with acidified ethanol, isolation and retention on a cation exchange solid-phase extraction column, elution with basic methanol, and LC analysis with fluorescence detection. LC analysis is performed by isocratic elution using an acetonitrile-2% acetic acid (15 + 85) mobile phase and an Inertsil phenyl column with fluorescence detection at excitation and emission wavelengths of 278 and 450 nm, respectively. A target level of 10 ppb for each of the 4 fluoroquinolones has been established for this method. Average recovery from fortified raw milk samples (5-100 ppb each) based on a 5-point standard curve calculation was 70-90%, with relative standard deviations of &lt;15%.

scholarly journals Physical and microbial qualities of raw milk collected from Bangladesh Agricultural University dairy farm and the surrounding villages

1970 ◽  
Vol 6 (2) ◽  
pp. 217-221 ◽  
Author(s):  
MTG Khan ◽  
MA Zinnah ◽  
MP Siddique ◽  
MHA Rashid ◽  
MA Islam ◽  
...  
Keyword(s):  
Microbiological Quality ◽  
Dairy Farm ◽  
Raw Milk ◽  
Viable Count ◽  
Physical Parameters ◽  
Total Viable Count ◽  
Coliform Count ◽  
Milk Samples

The present study was undertaken with the aim of investigating the physical parameters (e.g. organoleptic and specific gravity of raw milk) and also to study the microbiological quality of raw milk (total viable count, Coliform count and Staphylococcal count) from different villages and Bangladesh Agricultural University (BAU) Dairy Farm of Mymensingh District of Bangladesh, during the period from July to November 2007. A total number of 100 raw milk samples were collected at morning and evening from BAU dairy farm and surrounding four villages of BAU campus. The organoleptic and bacteriological qualities of each sample were analyzed. The organoleptic examination included taste panel score to assess consumer's acceptance and the bacteriological analysis comprised enumeration of total viable count (TVC), total colifrom count (TCC) and total staphylococcal count (TSC) for the determination of sanitary quality. The organoleptic quality of the milk samples is more or less same except the Churkhai milk samples which had flat taste (in 16% milk sample). The average values of TVC/ml were log 5.920, 5.934, 6.007, 6.075 and 6.127 for BAU Dairy Farm, Boira, Shutiakhali, Churkahai and Paglabazar respectively; coliform count were log 2.501, 2.522, 2.550, 2.620 and 2.619 respectively; staphylococcal count were log 2.832, 2.812, 2.866, 2.931 and 2.988 respectively. So, it may be concluded that the raw milk samples of BAU Dairy Farm were superior to others collected from the selected villages which may be due to maintaining better hygienic condition. Key words: Raw milk, physical and microbial quality   doi: 10.3329/bjvm.v6i2.2339 Bangl. J. Vet. Med. (2008). 6 (2): 217-221

Application of a microbial sensor for determination of short-chain fatty acids in raw milk samples

1992 ◽  
Vol 195 (1) ◽  
pp. 1-2 ◽  
Author(s):  
Hiroyuki Ukeda ◽  
Gotthold Wagner ◽  
G�nther Weis ◽  
Manfred Miller ◽  
Henning Klostermeyer ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Raw Milk ◽  
Short Chain Fatty Acids ◽  
Short Chain ◽  
Milk Samples ◽  
Microbial Sensor ◽  
Chain Fatty Acids

Assessment of milk quality based on bovine BAF60c gene mutation

2018 ◽  
Vol 156 (4) ◽  
pp. 570-574
Author(s):  
J. Liao ◽  
T. Ku ◽  
Y. F. Liu ◽  
J. Zhao
Keyword(s):  
Milk Fat ◽  
Fragment Length Polymorphism ◽  
Raw Milk ◽  
Milk Quality ◽  
Quality Traits ◽  
Fat Percentage ◽  
Milk Samples ◽  
Polymerase Chain ◽  
Solids Content

AbstractMonitoring milk quality traits and the classification of raw milk are important steps for generating high-quality dairy products. Given the important roles of the BRG1/BRM-associated factor 60c (BAF60c) gene in the regulation of physiological growth and production, the objective of the current study was to analyse the association between the BAF60c gene and milk quality and establish a gene-based method for pre-evaluating raw milk quality. For this purpose, DNA was isolated from 507 milk samples and genotyped using the polymerase chain reaction-restricted fragment length polymorphism method. Milk quality traits including milk protein percentage (MPP), milk fat percentage (MFP), lactose percentage (LP) and total solids content (TSC) were also evaluated from the same 507 milk samples. The newly found 6060 T > C mutation of the BAF60c gene was associated significantly with MPP and LP, but not with MFP and TSC. The results demonstrated that this mutation could be used for the pre-evaluation of MPP and LP; therefore, raw milk could be graded according to different genotypes.

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