scholarly journals Appraisal of the influence of the temperature at the composition of cow's milk by FT NIR spectroscopy

Author(s):  
Květoslava Šustová

NIR spectroscopy making use of a near infrared spectrum offers wide using in a food quality control. This quick method allows the measuring of numerous samples with minimal usage of chemicals. Due this fact it is also used in quantitative analyses of milk composition. In this study we observed an impact of different temperatures of cow’s milk samples on measuring exactness. The milk samples were taken from separate dairy cows and immediately refrigerated to 6–8 °C. Until the analysis the samples were deposited in the refrigerator. Just before the analysis on FT NIR spectrometer they were warmed to 40 °C and then cooled down in water bath to the temperatures 20 °C, 21 °C, 23 °C and 25 °C. Afterwards the samples were measured on Petri dish in reflectance mode with resolution 8 and number of scans 100. The spectres of samples were evaluated using calibration models for determination of solids and contents of proteins, fat and lactose. Observed measures were statistically compared within separate temperatures in relation to standard temperature 20 °C.

2019 ◽  
Vol 49 (6) ◽  
Author(s):  
Carlos Bondan ◽  
Jéssica Aneris Folchini ◽  
Mirela Noro ◽  
Karine Martini Machado ◽  
Eduardo Muhls ◽  
...  

ABSTRACT: This study vised to detect possible changes in chemical and cellular composition of cow’s milk at different milking sessions and to test if proportional or composite milk sampling can be used instead of separate milk analysis. Two experiments were conducted: one in cows milked thrice daily and the other one in cows milked twice daily. In both experiments, three milk samples were collected from each cow in each milking session in order to determine milk composition at each milking; to have a composite sample, i.e., a single sample from the same aliquots of milk from each milking session; and to have a proportional sample, i.e., a single sample from each milking session in a volume proportional to milk volume yielded. Fat content and fat to protein ratio were higher in the afternoon on both experiments. Protein content was larger in the afternoon on cows milked twice daily, but not on cows milked thrice daily. Lactose level was not different across the milking sessions in any of the experiments. The urea level was higher in the afternoon and evening milking on cows milked thrice daily, and in the morning milking on cows milked twice daily. Somatic cell count did not differ between milking in any experiment. No difference in milk composition was noted between proportional and composite samples on cows milked thrice or twice daily. The collection of proportional and composite samples is recommended in twice or thrice daily milking sessions so that the analysis of milk components becomes more easy and cheap.


PEDIATRICS ◽  
1991 ◽  
Vol 87 (4) ◽  
pp. 439-444
Author(s):  
Patrick S. Clyne ◽  
Anthony Kulczycki

Previous studies have suggested that an unidentified cow's milk protein, other than β-lactoglobulin and casein, might play a pathogenetic role in infant colic. Therefore, a radioimmunoassay was used to analyze human breast milk and infant formula samples for the presence of bovine IgG. Milk samples from 88 of the 97 mothers tested contained greater than 0.1 µg/mL of bovine IgG. In a study group of 59 mothers with infants in the colic-prone 2- to 17-week age group, the 29 mothers of colicky infants had higher levels of bovine IgG in their breast milk (median 0.42 µg/mL) than the 30 mothers of noncolicky infants (median 0.32 µg/mL) (P < .02). The highest concentrations of bovine IgG observed in human milk were 8.5 and 8.2 µg/mL. Most cow's milk-based infant formulas contained 0.6 to 6.4 µg/mL of bovine IgG, a concentration comparable with levels found in many human milk samples. The results suggest that appreciable quantities of bovine IgG are commonly present in human milk, that significantly higher levels are present in milk from mothers of colicky infants, and that bovine IgG may possibly be involved in the pathogenesis of infant colic.


2019 ◽  
Vol 63 (1) ◽  
pp. 93-97 ◽  
Author(s):  
Hanna Różańska ◽  
Aleksandra Lewtak-Piłat ◽  
Maria Kubajka ◽  
Marcin Weiner

Abstract Introduction: The aim of the study was to evaluate the occurrence of enterococci in inflammatory secretions from mastitic bovine udders and to assess their antimicrobial resistance. Material and Methods: A total of 2,000 mastitic milk samples from cows were tested in 2014–2017. The isolation of enterococci was performed by precultivation in buffered peptone water, selective multiplication in a broth with sodium azide and cristal violet, and cultivation on Slanetz and Bartley agar. The identification of enterococci was carried out using Api rapid ID 32 strep kits. The antimicrobial susceptibility was evaluated using the MIC technique. Results: Enterococci were isolated from 426 samples (21.3%). Enterococcus faecalis was the predominant species (360 strains), followed by E. faecium (35 isolates), and small numbers of others. The highest level of resistance was observed to lincomycin, tetracycline, quinupristin/dalfopristin (Synercid), erythromycin, kanamycin, streptomycin, chloramphenicol, and tylosin. Single strains were resistant to vancomycin and ciprofloxacin. All isolates were sensitive to daptomycin. E. faecalis presented a higher level of resistance in comparison to E. faecium, except to nitrofurantoin. Conclusion: The results showed frequent occurrence of enterococci in mastitic cow’s milk and confirmed the high rate of their antimicrobial resistance.


2008 ◽  
Vol 18 (3) ◽  
pp. 410-416 ◽  
Author(s):  
Stephen R. Delwiche ◽  
Weena Mekwatanakarn ◽  
Chien Y. Wang

A rapid, reliable, and nondestructive method for quality evaluation of mango (Magnifera indica) fruit is important to the mango industry for international trade. The objective of this study was to determine the potential of near-infrared (NIR) spectroscopy to predict soluble solids content (SSC) and individual and combined concentrations of sucrose, glucose, and fructose nondestructively in mango. Mature mangoes at two different temperatures (15 °C and 20 °C) were measured by NIR interactance (750–1088 nm wavelength region analyzed) over an 11-day period, starting when the fruit were underripe and extending to a few days past optimal ripeness. Partial least squares regression was used to develop models for SSC, individual sugar concentration, and the sum of the concentrations of the three sugars. Such analyses yielded calibration equations with R2 = 0.77 to 0.88 (SSC), 0.75 (sucrose), 0.67 (glucose), 0.70 (fructose), and 0.82 (sum); standard error of calibration = 0.56 to 0.90 (SSC), 10.0 (sucrose), 0.9 (glucose), 4.5 (fructose), and 10.4 (sum); and standard error of cross-validation = 0.93 to 1.10 (SSC), 15.6 (sucrose), 1.4 (glucose), 6.9 (fructose), and 16.8 (sum). When the SSC calibration was applied to a separate validation set, the standard error of performance ranged from 0.94% to 1.72%. These results suggest that for assessment of mango ripeness, NIR SSC calibrations are superior to the NIR calibrations for any of the individual sugars. This nondestructive technology can be used in the screening and grading of mangoes and in quality evaluation at wholesale and retail levels.


2020 ◽  
Vol 52 (3) ◽  
Author(s):  
Blerta Mehmedi ◽  
Rreze M. Gecaj ◽  
Taulant Kastrati ◽  
Miklós Heltai ◽  
Luigj Turmalaj

Pregnancy diagnosis is an essential part of fertility management in cattle. Early detection of pregnancy 21 days after artificial insemination (AI) allows for early recognition and rebreeding of non-pregnant animals with a minimum delay, which benefits the economic interest for farmers. Rapid progesterone P4 tests are widely used in fertility management strategies, yet there is limited data about the efficiency of tests for P4 measurements in cow’s milk. By measuring P4 concentrations in the milk of different breeds: Red Holstein, Black-Holstein, Simmental, and local crossbreeds, this study aimed to assess the practical application and efficiency of an early and rapid pregnancy detection test from cow’s milk. The study was conducted in 2017–2018 and milk samples were taken from animals at day 21 after artificial insemination (AI) to diagnose pregnancy. The test indicated that of the total cows (n=400) included in this study, 69% were pregnant and 31% were not pregnant, as interpreted based on the P4 Rapid (Ridgeway Science UK) test results. Accuracy of the early diagnosis was verified 60 days after AI (without further AI of cows) by rectal palpation. Based on this examination, 263 (66%) cows were diagnosed as pregnant, while 14 (34%) were diagnosed as non-pregnant. The highest accuracy in pregnancy detection was found in the local crossbreeds and the Simmental breed, with 97% correct diagnosis of cows, followed by Red Holstein with 94% and Black Holstein with an accuracy of 90%. This study showed that the use of progesterone P4 rapid tests in milk samples is an effective, fast and accurate method for the early detection of pregnancy in cows, with an accuracy rate of 90 to 97% based on cattle breed.


2019 ◽  
Vol 82 (12) ◽  
pp. 2194-2200 ◽  
Author(s):  
DIANA RIOS-MUÑIZ ◽  
JORGE F. CERNA-CORTES ◽  
CATALINA LOPEZ-SAUCEDO ◽  
ERIKA ANGELES-MORALES ◽  
MIRIAM BOBADILLA-del VALLE ◽  
...  

ABSTRACT In Mexico, the total milk production that family dairy farms (FDF) contribute is ca. 35%, but this milk is not evaluated for microbiological quality. Forty percent of the milk and dairy products consumed by Mexicans is unpasteurized. In total, 24 raw cow's milk samples from three FDF (one sample per each season from each FDF for two sequent years) were characterized for the presence of food quality indicator organisms, Staphylococcus aureus, Salmonella enterica, Listeria monocytogenes, and Mycobacterium spp., by standard procedures. Escherichia coli presence was also evaluated by a direct count method and diarrheagenic E. coli (DEC) by molecular methods. On the basis of Mexican guidelines for raw milk entering production, 42% of samples exceeded the aerobic mesophilic bacteria limits. A total of 83% raw milk samples were positive for total coliforms, 54% for fecal coliforms, and 46% for E. coli. Forty-three E. coli isolates were selected and characterized for the presence of 11 DEC loci; of theses, 40 isolates were negative for all DEC loci, and 3 isolates, all collected from the same sample, were Shiga toxin 2 (stx2) positive and O157 antigen negative, and one stx2 isolate was resistant to 6 of the 16 antibiotics tested. None of the 24 raw milk samples were positive for Salmonella enterica, L. monocytogenes, or staphylococcal enterotoxin. S. aureus was isolated from nine samples, of which only three samples harbored resistant isolates. From three samples, four nontuberculous mycobacterial isolates were recovered (Mycobacteroides chelonae, Mycobacteroides porcinum, and two Mycobacteroides abscessus). All four isolates produced biofilm and had sliding motility, and three isolates (M. porcinum and two M. abscessus) were resistant to the two antibiotics tested (clarithromycin and linezolid). FDF provide raw milk to a large proportion of the Mexican population, but its consumption could be harmful to health, emphasizing the need to implement national microbiological quality guidelines for raw milk intended for direct human consumption. HIGHLIGHTS


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