14 research outputs found
Calanus finmarchicus as a novel source of health-promoting bioactive peptides: Enzymatic protein hydrolysis, characterization, and in vitro bioactivity
Calanus finmarchicus is a crustacean currently used as a source of marine lipid. The lipids are extracted by enzymatic protein hydrolysis, while the remaining peptide fraction is regarded as a byproduct. In the present work, ten different commercial proteases and endogenous C. finmarchicus proteases were used to produce a set of 63 protein hydrolysates. Protease concentration and hydrolysis time were varied. Hydrolysates were characterized using size-exclusion chromatography and 1H nuclear magnetic resonance spectroscopy. Addition of commercial proteases had unremarkable effect on the yield and molecular weight distribution. This was attributed to the strong impact of endogenous enzymes dominating the hydrolysis process. However, multivariate classification based on 1H NMR spectra revealed subtle variations in composition of hydrolysates produced using different enzymes. The hydrolysates were further evaluated for DPP-IV inhibition and antioxidant activity. The hydrolysates showed significantly higher bioactivity than the unhydrolyzed control. A representative hydrolysate (CaFi55) was fractionated using semipreparative size-exclusion chromatography. A fraction consisting of short peptides with an average chain length of five amino acids (F2), was identified as a major contributor to the DPP-IV inhibitory activity (IC50 = 0.70 ± 0.07 mg/mL)
Raman and near Infrared Spectroscopy for Quantification of Fatty Acids in Muscle Tissue—A Salmon Case Study
The aim of the present study was to critically evaluate the potential of using NIR and Raman spectroscopy for prediction of fatty acid features and single fatty acids in salmon muscle. The study was based on 618 homogenized salmon muscle samples acquired from Atlantic salmon representing a one year-class nucleus, fed the same high fish oil feed. NIR and Raman spectra were used to make regression models for fatty acid features and single fatty acids measured by gas chromatography. The predictive performance of both NIR and Raman was good for most fatty acids, with R2 above 0.6. Overall, Raman performed marginally better than NIR, and since the Raman models generally required fewer components than respective NIR models to reach high and optimal performance, Raman is likely more robust for measuring fatty acids compared to NIR. The fatty acids of the salmon samples co-varied to a large extent, a feature that was exacerbated by the overlapping peaks in NIR and Raman spectra. Thus, the fatty acid related variation of the spectroscopic data of the present study can be explained by only a few independent principal components. For the Raman spectra, this variation was dominated by functional groups originating from long-chain polyunsaturated FAs like EPA and DHA. By exploring the independent EPA and DHA Raman models, spectral signatures similar to the respective pure fatty acids could be seen. This proves the potential of Raman spectroscopy for single fatty acid prediction in muscle tissue.Raman and near Infrared Spectroscopy for Quantification of Fatty Acids in Muscle Tissue—A Salmon Case StudypublishedVersio
A concept study on non-targeted screening for chemical contaminants in food using liquid chromatography–mass spectrometry in combination with a metabolomics approach
Data analysis of non-targeted mass spectrometry experiments
Data processing tools are valuable to the analytical chemist as they can speed up the analysis, and sometimes solve problems that are not feasible to solve in a traditional manner. However, the complexity of many data processing tools can make their use daunting for the inexperienced user. This thesis includes two applications and two tools for data processing. The first application focuses on minimizing the manual input, reducing the time required for a simple task. The second application required more manual input, in the form of parameter selection, but process far more data. The data processing tools both include features that simplify the manual work required. The first by including visual diagnostics tools that helps in setting the parameters. The second via internal validation that makes the tool’s process more robust and reliable, and thereby less sensitive to small changes in the parameters. No matter how good or precise a data processing tool is, if it is so cumbersome that it is not used by the analytical chemists that need it, it is useless. Therefore, the main focus of this thesis is to make data processing easier.At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 4: Submitted.</p
Data analysis of non-targeted mass spectrometry experiments
Data processing tools are valuable to the analytical chemist as they can speed up the analysis, and sometimes solve problems that are not feasible to solve in a traditional manner. However, the complexity of many data processing tools can make their use daunting for the inexperienced user. This thesis includes two applications and two tools for data processing. The first application focuses on minimizing the manual input, reducing the time required for a simple task. The second application required more manual input, in the form of parameter selection, but process far more data. The data processing tools both include features that simplify the manual work required. The first by including visual diagnostics tools that helps in setting the parameters. The second via internal validation that makes the tool’s process more robust and reliable, and thereby less sensitive to small changes in the parameters. No matter how good or precise a data processing tool is, if it is so cumbersome that it is not used by the analytical chemists that need it, it is useless. Therefore, the main focus of this thesis is to make data processing easier.At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 4: Submitted.</p
Klippt och skuret för ett digitalt samhälle : Användaracceptans av en digital servicetjänst under covid-19 med utgångspunkt i UTAUT
User acceptance measures the willingness to use an information system. The user acceptance has been challenged by covid-19 as customers demand more from companies. Cutters is a new type of digital service and is a hair salon that offers drop in via bookings through its app. To investigate Cutters, this study applies the Unified Theory of Acceptance and Use of Technology (UTAUT) to Cutter's systems for providing haircutting. A survey was conducted in order to find what factors contribute to people wanting to get a haircut at Cutters. The aim was also to clarify user acceptance during the covid-19 pandemic. The quantitative survey study showed that expected performance, expected usability, social factors and facilitating conditions all had a positive impact on respondents' attitudes towards using Cutters. The most important characteristics of a positive user image of a hairdresser during covid-19 are that it is time efficient, that it saves money, that you have the resources required to use the service and that the service suits your lifestyle. The intentions to use Cutters were higher after covid-19, which means that the pandemic has an effect on Cutter's user acceptance.Användaracceptans är det som mäter hur villiga användare är att använda ett informationssystem. Denna användaracceptans har utmanats i och med covid-19 då nya förväntningar har ställts på företagen av kunderna. Cutters är en frisörsalong som använder en ny typ av digital servicetjänst som erbjuder drop in via bokningar i mobilen. För att undersöka Cutters system applicerar denna studie Unified Theory of Acceptance and Use of Technology (UTAUT) på Cutters system för att tillhandahålla klippning. En enkätundersökning utfördes i syfte att hitta vilka faktorer som bidrar till att människor vill klippa sig hos Cutters. Syftet var även att klargöra användaracceptans under covid-19-pandemin. Den kvantitativa enkätstudien påvisade att förväntad prestanda, förväntad användbarhet, sociala faktorer och underlättande av förhållanden alla hade en positiv påverkan på respondenternas inställning till att använda Cutters. De viktigaste faktorerna för att en person ska ha viljan att använda Cutters under covid-19 är att de sparar personen tid och pengar, att den har tekniska resurserna som krävs för att använda tjänsten och att tjänsten passar deras livsstil. Intentionerna att använda Cutters var högre efter covid-19 vilket innebär att pandemin har en påverkan på Cutters användaracceptans
Klippt och skuret för ett digitalt samhälle : Användaracceptans av en digital servicetjänst under covid-19 med utgångspunkt i UTAUT
User acceptance measures the willingness to use an information system. The user acceptance has been challenged by covid-19 as customers demand more from companies. Cutters is a new type of digital service and is a hair salon that offers drop in via bookings through its app. To investigate Cutters, this study applies the Unified Theory of Acceptance and Use of Technology (UTAUT) to Cutter's systems for providing haircutting. A survey was conducted in order to find what factors contribute to people wanting to get a haircut at Cutters. The aim was also to clarify user acceptance during the covid-19 pandemic. The quantitative survey study showed that expected performance, expected usability, social factors and facilitating conditions all had a positive impact on respondents' attitudes towards using Cutters. The most important characteristics of a positive user image of a hairdresser during covid-19 are that it is time efficient, that it saves money, that you have the resources required to use the service and that the service suits your lifestyle. The intentions to use Cutters were higher after covid-19, which means that the pandemic has an effect on Cutter's user acceptance.Användaracceptans är det som mäter hur villiga användare är att använda ett informationssystem. Denna användaracceptans har utmanats i och med covid-19 då nya förväntningar har ställts på företagen av kunderna. Cutters är en frisörsalong som använder en ny typ av digital servicetjänst som erbjuder drop in via bokningar i mobilen. För att undersöka Cutters system applicerar denna studie Unified Theory of Acceptance and Use of Technology (UTAUT) på Cutters system för att tillhandahålla klippning. En enkätundersökning utfördes i syfte att hitta vilka faktorer som bidrar till att människor vill klippa sig hos Cutters. Syftet var även att klargöra användaracceptans under covid-19-pandemin. Den kvantitativa enkätstudien påvisade att förväntad prestanda, förväntad användbarhet, sociala faktorer och underlättande av förhållanden alla hade en positiv påverkan på respondenternas inställning till att använda Cutters. De viktigaste faktorerna för att en person ska ha viljan att använda Cutters under covid-19 är att de sparar personen tid och pengar, att den har tekniska resurserna som krävs för att använda tjänsten och att tjänsten passar deras livsstil. Intentionerna att använda Cutters var högre efter covid-19 vilket innebär att pandemin har en påverkan på Cutters användaracceptans
N-Glycan profile analysis of transferrin using a microfluidic compact disc and MALDI-MS
TracMass 2A Modular Suite of Tools for Processing Chromatography-Full Scan Mass Spectrometry Data
In untargeted proteomics and metabolomics,
raw data obtained with
an LC/MS instrument are processed into a format that can be used for
statistical analysis. Full scan MS data from chromatographic separation
of biological samples are complex and analyte concentrations need
to be extracted and aligned so that they can be compared across the
samples. Several computer programs and methods have been developed
for this purpose. There is still a need to improve the ease of use
and feedback to the user because of the advanced multiparametric algorithms
used. Here, we present and make publicly available, TracMass 2, a
suite of computer programs that gives immediate graphical feedback
to the data analyst on parameter settings and processing results,
as well as producing state-of-the-art results. The main advantage
of TracMass 2 is that the feedback and transparency of the processing
steps generate confidence in the end result, which is a table of peak
intensities. The data analyst can easily validate every step of the
processing pipeline. Because the user receives feedback on how all
parameter values affect the result before starting a lengthy computation,
the user’s learning curve is enhanced and the total time used
for data processing can be reduced. TracMass 2 has been released as
open source and is included in the Supporting
Information. We anticipate that TracMass 2 will set a new standard
for how chemometrical algorithms are implemented in computer programs
Structural, mechanical and electrical-contact properties of nanocrystalline-NbC/amorphous-C coatings deposited by magnetron sputtering
Niobium-carbide nanocomposite coatings with a carbon content varying from 43 to 64 at.% were deposited by dual DC magnetron sputtering. X-ray diffraction, x-ray photoelectron spectroscopy and electron microscopy showed that all coatings consisted of nanometer sized NbC grains embedded in a matrix of amorphous carbon. Mechanical properties and electrical resistivity showed a strong dependency on the amount of amorphous carbon (a-C) and NbC grain size in the coating. The highest hardness (23 GPa), elastic modulus (295 GPa) and the lowest resistivity (260 mu Omega cm) were measured for the coating with about 15% of a-C phase. Contact resistance measurements using a crossed cylinder set-up showed lowest contact resistance for the coating containing 33% a-C (140 mu Omega at a contact force of 100 N), which is comparable to a Ag reference (45 mu Omega at a contact force of 100 N). Comparison with TiC-based nanocomposites studied under similar conditions showed that the Nb-C system has less tendency to form a-C and that lowest contact resistance is obtained at comparable amounts of a-C phase in both material systems (33% for Nb-C compared to 35% for Ti-C). With these good electrical contact properties, the Nb- C nanocomposites can be considered as a potential material for electrical contact applications.Funding Agencies|Vinnova (Swedish Governmental Agency for Innovation Systems) through the VINN Excellence Centre FunMat||Swedish Research Council (VR)||</p