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Hillerød, Denmark

Baum A.,Technical University of Denmark | Hansen P.W.,Foss Analytical | Norgaard L.,Foss Analytical | Sorensen J.,Arla Foods | Mikkelsen J.D.,Technical University of Denmark
Journal of Dairy Science | Year: 2016

In this study, we introduce enzymatic perturbation combined with Fourier transform infrared (FTIR) spectroscopy as a concept for quantifying casein in subcritical heated skim milk using chemometric multiway analysis. Chymosin is a protease that cleaves specifically caseins. As a result of hydrolysis, all casein proteins clot to form a creamy precipitate, and whey proteins remain in the supernatant. We monitored the cheese-clotting reaction in real time using FTIR and analyzed the resulting evolution profiles to establish calibration models using parallel factor analysis and multiway partial least squares regression. Because we observed casein-specific kinetic changes, the retrieved models were independent of the chemical background matrix and were therefore robust against possible covariance effects. We tested the robustness of the models by spiking the milk solutions with whey, calcium, and cream. This method can be used at different stages in the dairy production chain to ensure the quality of the delivered milk. In particular, the cheese-making industry can benefit from such methods to optimize production control. © 2016 American Dairy Science Association. Source


Baum A.,Technical University of Denmark | Agger J.,Norwegian University of Life Sciences | Meyer A.S.,Technical University of Denmark | Egebo M.,Foss Analytical | Mikkelsen J.D.,Technical University of Denmark
New Biotechnology | Year: 2012

Efficient generation of a fermentable hydrolysate is a primary requirement in the utilization of fibrous plant biomass as feedstocks in bioethanol processes. The first biomass conversion step usually involves a hydrothermal pretreatment before enzymatic hydrolysis. The purpose of the pretreatment step is to increase the responsivity of the substrate to enzymatic attack and the type of pretreatment affects the enzymatic conversion efficiency. Destarched corn bran is a fibrous, heteroxylan-rich side-stream from the starch industry which may be used as a feedstock for bioethanol production or as a source of xylose for other purposes. In the present study we demonstrate the use of diffuse reflectance near infrared spectroscopy (NIR) as a rapid and non-destructive analytical tool for evaluation of pretreatment effects on destarched corn bran. NIR was used to achieve classification between 43 differently pretreated corn bran samples using principal component analysis (PCA) and hierarchal clustering algorithms. Quantification of the enzymatically released monosaccharides by HPLC was used to design multivariate calibration models (biPLS) on the NIR spectra. The models could predict the enzymatic release of different levels of arabinose, xylose and glucose from all the differently pretreated destarched corn bran samples. The present study also demonstrates a generic, non-destructive solution to determine the enzymatic monosaccharide release from polymers in biomass side-streams, thereby potentially replacing the cumbersome HPLC analysis. © 2011 Elsevier B.V. Source


Tahir M.,Khyber Pakhtunkhwa Agricultural University | Tahir M.,University of Georgia | Shim M.Y.,University of Georgia | Ward N.E.,DSM Nutritional Products Inc. | And 2 more authors.
Poultry Science | Year: 2012

The purpose of this study was to determine the feasibility of estimating the total and phytate P content of common poultry feed ingredients by near-infrared reflectance spectroscopy (NIRS). Samples of 8 plant-origin feedstuffs were collected from poultry producers in the USA and Canada during the summer of 2009: corn (133), soybean meal (114), corn distillers dried grains with solubles (DDGS; 89), bakery byproduct meal (95), wheat (22), wheat middlings (31), canola meal (21), and wheat shorts (15). The samples were assayed by standard wet chemical techniques for total and phytate P contents. There was considerable variation found in most of the ingredient components. The average values for the laboratory determinations versus NIRS predictions were all within 0.030 for total phosphorus and 0.012 for phytate P. For phytate P, the magnitude of the standard errors of the predictions ranged from 0.009% for soybean meal to 0.012% for canola meal. These values may be sufficiently precise for nutritionists to use the NIRS predictions to estimate how much of the P in their ingredients is not available to the birds. For total P, the magnitude of the standard errors of the predictions ranged from 0.027% for corn DDGS to 0.142% for wheat middlings. In general, total P predictions by NIRS were not generally sufficiently precise for most nutritionists to use in feed formulation. Decision making may be quite easy in using NIRS estimates for the phytate P content of bakery by-product meal [R2 = 0.89 for predicted = f (determined)] but not for the total P content of soybean meal (R2 = 0.03). It is concluded that precise estimates of phytate P through NIRS should allow nutritionists for more efficient formulate and mix feed, lowering feed costs and reducing the amount of residual polluting phosphorus in poultry excreta. © 2012 Poultry Science Association Inc. Source


Baum A.,Technical University of Denmark | Meyer A.S.,Technical University of Denmark | Garcia J.L.,Technical University of Denmark | Egebo M.,Foss Analytical | And 2 more authors.
Analytica Chimica Acta | Year: 2013

The recent advances in multi-way analysis provide new solutions to traditional enzyme activity assessment. In the present study enzyme activity has been determined by monitoring spectral changes of substrates and products in real time. The method relies on measurement of distinct spectral fingerprints of the reaction mixture at specific time points during the course of the whole enzyme catalyzed reaction and employs multi-way analysis to detect the spectral changes. The methodology is demonstrated by spectral evolution profiling of Fourier Transform Infrared (FTIR) spectral fingerprints using parallel factor analysis (PARAFAC) for pectin lyase, glucose oxidase, and a cellulase preparation. © 2013 Elsevier B.V. Source

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