1,685 research outputs found

    Fluorescence-based analyser as a rapid tool for determining soluble protein content in dairy ingredients and infant milk formula

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    peer-reviewedAbstract: Milk protein, in particular native whey protein, is of interest to dairy manufacturers as a measure of functional and nutritional quality. However, quantification of soluble whey protein (SP) is time consuming; giving rise to the need to develop rapid, accurate, and portable at-line process analytical technology. In this study, the performance of a fluorescence-based analyser(F) (Amaltheys II, Spectralys Innovations, France) was evaluated for quantification of SPF and whey protein nitrogen index (WPNI)F in skim milk, whey protein concentrate and infant formula powders. Rehydration of powders prior to analysis was a key factor for ensuring repeatability and reproducibility. A comparison of the analyser with reference methods for SPF and WPNIF resulted in coefficient of determination (R2)ā€Æ>ā€Æ0.993 for both SPKjeldahl method and WPNIGEA. The results show the fluorescence-based analyser to be rapid, compact, and accurate device, suited for providing reliable support to dairy ingredient and infant formula manufacturers. Industrial relevance: The fluorescence based analysis investigated in this article is suitable for application in the dairy industry where it can be used as a rapid, at-line PAT tool for both liquid and powder samples. The technology has the potential to replace well-established methods for measurement of soluble protein. The main benefit to industry is the ability to respond more rapidly to variations in soluble protein without compromising on the accuracy associated with more time consuming methods

    Evaluation of Milking Systems in Terms of Mastitis Risk, Teat Tissue Reactions & Milking Performance.

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    End of Project ReportsMeasurements of milking vacuum recorded on a flow simulator can provide guidelines for optimum design of milking units. ā€¢ Increasing the bore of the short milk tube above the recommended diameter or claw volume above 150ml does not improve milking efficiency. ā€¢ Increasing the long milk-tube bore from 13.5mm to 16mm increased the level of milking vacuum. ā€¢ The milking vacuum was highest with wide-bore tapered liners and simultaneous pulsation. ā€¢ The minimum vacuum was increased with narrow-bore liners and alternate pulsation. ā€¢ The milk yield with wide-bore tapered liners in heavy 3-kg clusters and using simultaneous pulsation was 5% higher than with light clusters (1.65 kg) with alternate pulsation. ā€¢ The milk yield depressions obtained with light clusters were similar in short and long term experiments and increased with the magnitude of the milk yield per milking. ā€¢ The teat condition scores were not affected by the magnitude of vacuum fluctuations

    A serological survey of ruminant livestock in Kazakhstan during post-Soviet transitions in farming and disease control

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    The results of a serological survey of livestock in Kazakhstan, carried out in 1997ā€“1998, are reported. Serum samples from 958 animals (cattle, sheep and goats) were tested for antibodies to foot and mouth disease (FMD), bluetongue (BT), epizootic haemorrhagic disease (EHD), rinderpest (RP) and peste des petits ruminants (PPR) viruses, and to Brucella spp. We also investigated the vaccination status of livestock and related this to changes in veterinary provision since independence in 1991. For the 2 diseases under official surveillance (FMD and brucellosis) our results were similar to official data, although we found significantly higher brucellosis levels in 2 districts and widespread ignorance about FMD vaccination status. The seroprevalence for BT virus was 23%, and seropositive animals were widespread suggesting endemicity, despite the disease not having being previously reported. We found a few seropositives for EHDV and PPRV, which may suggest that these diseases are also present in Kazakhstan. An hierarchical model showed that seroprevalence to FMD and BT viruses were clustered at the farm/village level, rather than at a larger spatial scale. This was unexpected for FMD, which is subject to vaccination policies which vary at the raion (county) level

    A study of factors affecting the efficiency of milking operations.

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    End of Project ReportWith a mid-level milking system the milking time was reduced significantly when the teat end vacuum was increased ā€¢ Vacuum losses were lower and milking time was shorter with simultaneous pulsation than with alternate pulsation ā€¢ Milk yield was not affected by the magnitude of teat end vacuum. ā€¢ Both the mean flowrate and peak flowrate increased when the teat end vacuum was increased. ā€¢ New milking plants and conversions should have 16 mm bore long milk tubes (LMT) and 16 mm bore entries in the milk pipeline ā€¢ The omission of udder washing as a pre-milking preparation procedure did not influence milking characteristics. ā€¢ TBC and E. coli were significantly reduced with full pre-milking preparation compared to no pre-milking preparation when milk was produced from cows on pasture ā€¢ Counts for individual bacterial species were well below maximum numbers permitted in EU Council Directive (Anon. 1992) when no pre-milking preparation was carried out

    The Application of On-line Sensors and Novel Control Technologies for Food Processing

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    End of Project ReportThe objective of this research was to apply on-line continuous sensors in food processing, in particular in cheese and milk powder manufacture, in order to improve process control, for example, by achieving higher quality, increased yields, reduced losses and less downgrading of product. This project focused on technologies for monitoring rheologyrelated parameters. The main conclusions were as follows: * Seven systems for monitoring curd formation in cheesemaking were evaluated in the laboratory. * Two on-line systems for monitoring curd firmness (hot-wire and NIR reflectance) have been deployed in a commercial cheese plant with promising results. * Experimental results demonstrated that NIR reflectance / transmission probes have a potential for on-line application in cheesemaking. Despite the difference in scale, the commercial sensors compared well with the cheesemaker s observation of curd firming and look promising as an objective means of predicting curd cut time in an industrial cheese plan. * A detailed knowledge of the rheological variation in cheese curd has been developed and a means of investigating factors which influence the rheology of cheese curd (e.g. effect of heat treatment or fortification of cheesemilk) has been determined. * Technologies available for monitoring concentrate viscosity changes in the production of milk powder have been assembled at pilot scale, and initial trials have been encouraging. Further evaluation of the MTL plant to assess on-line performance, ruggedness and cleanability are planned.Department of Agriculture, Food and the Marin

    Effect of liner design, pulsator setting, and vacuum level on bovine teat tissue changes and milking characteristics as measured by ultrasonography

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    peer-reviewedFriesian-type dairy cows were milked with different machine settings to determine the effect of these settings on teat tissue reaction and on milking characteristics. Three teat-cup liner designs were used with varying upper barrel dimensions (wide-bore WB = 31.6 mm; narrow-bore NB = 21.0 mm; narrow-bore NB1 = 25.0 mm). These liners were tested with alternate and simultaneous pulsation patterns, pulsator ratios (60:40 and 67:33) and three system vacuum levels (40, 44 and 50 kPa). Teat tissue was measured using ultrasonography, before milking and directly after milking. The measurements recorded were teat canal length (TCL), teat diameter (TD), cistern diameter (CD) and teat wall thickness (TWT). Teat tissue changes were similar with a system vacuum level of either 50 kPa (mid-level) or 40 kPa (low-level). Widening the liner upper barrel bore dimension from 21.0 mm (P < 0.01) or 25.0 mm (P < 0.001) to 31.6 mm increased the magnitude of changes in TD and TWT after machine milking. Milk yield per cow was significantly (P < 0.05) higher and cluster-on time was reduced (P < 0.01) with the WB cluster as compared to the NB1 cluster. Minimum changes in teat tissue parameters were achieved with system vacuum level of 40 kPa and 50 kPa using NB and WB clusters, respectively. Similar changes in teat tissue and milk yield per cow were observed with alternate and simultaneous pulsation patterns. Widening pulsator ratio from 60:40 to 67:33 did not have negative effects on changes in teat tissue and had a positive effect on milk yield and milking time. Milk liner design had a bigger effect on teat tissue changes and milking characteristics than pulsation settings

    Effects of anisotropic dynamics on cosmic strings

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    The dynamics of cosmic strings is considered in anisotropic backgrounds. In particular, the behaviour of infinitely long straight cosmic strings and of cosmic string loops is determined. Small perturbations of a straight cosmic string are calculated. The relevance of these results is discussed with respect to the possible observational imprints of an anisotropic phase on the behaviour of a cosmic string network.Comment: 16 pages, 9 figures; matches version published in JCA
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