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Preprocessing Strategies for Sparse Infrared Spectroscopy: A Case Study on Cartilage Diagnostics
Get PDFThe aim of the study was to optimize preprocessing of sparse infrared spectral data. The sparse data were obtained by reducing broadband Fourier transform infrared attenuated total reflectance spectra of bovine and human cartilage, as well as of simulated spectral data, comprising several thousand spectral variables into datasets comprising only seven spectral variables. Different preprocessing approaches were compared, including simple baseline correction and normalization procedures, and model-based preprocessing, such as multiplicative signal correction (MSC). The optimal preprocessing was selected based on the quality of classification models established by partial least squares discriminant analysis for discriminating healthy and damaged cartilage samples. The best results for the sparse data were obtained by preprocessing using a baseline offset correction at 1800 cm−1, followed by peak normalization at 850 cm−1 and preprocessing by MSC.publishedVersio
On the use of pulsed electric field technology as a pretreatment to reduce the content of potentially toxic elements in dried Saccharina latissima
Get PDFSeaweeds, like sugar kelp, are increasingly popular for food production, but their application is often limited by the content of iodine and other potentially toxic elements (PTEs). Boiling and blanching are efficient in reducing the iodine content (-38-94%), but are energy demanding processes and could therefore be too expensive for viable commercial applications. Pulsed electric field (PEF) processing is gaining interest for commercial processing of seaweeds, aiming to reduce the energy demand for the pre-treatment. In this work, two conditional settings (energy levels: 2.7 and 14.4 kJ/kg) of PEF were evaluated as pretreatments prior to drying of sugar kelp, and compared to no pretreatment and freezing/thawing at −20/4 °C. Both PEF treatments reduced the iodine content significantly, by approximately 40%, compared to no pretreatment. Similarly, the content of mercury was reduced by approximately 19%. Freezing prior to drying did not significantly alter the content of PTEs in dried kelp. The energy input associated with PEF processing was <10% of the calculated input for traditional processing. These findings are promising as the industry is looking into rapid, non-destructive processing methods for reducing the energy requirements associated with drying and preservation, while improving the safety of products.publishedVersio
Gut microbiota is associated with dietary intake and metabolic markers in healthy individuals
Get PDFBackground: Metabolic diseases have been related to gut microbiota, and new knowledge indicates that diet impacts host metabolism through the gut microbiota. Identifying specific gut bacteria associated with both diet and metabolic risk markers may be a potential strategy for future dietary disease prevention. However, studies investigating the association between the gut microbiota, diet, and metabolic markers in healthy indi-viduals are scarce.Objective: We explored the relationship between a panel of gut bacteria, dietary intake, and metabolic and anthropometric markers in healthy adults.Design: Forty-nine volunteers were included in this cross-sectional study. Measures of glucose, serum tri-glyceride, total cholesterol, hemoglobin A1c (HbA1c), blood pressure (BP), and body mass index (BMI) were collected after an overnight fast, in addition to fecal samples for gut microbiota analyzes using a targeted approach with a panel of 48 bacterial DNA probes and assessment of dietary intake by a Food Frequency Questionnaire (FFQ). Correlations between gut bacteria, dietary intake, and metabolic and anthropometric markers were assessed by Pearson’s correlation. Gut bacteria varying according to dietary intake and metabolic markers were assessed by a linear regression model and adjusted for age, sex, and BMI.Results: Of the 48 gut bacteria measured, 24 and 16 bacteria correlated significantly with dietary intake and metabolic and/or anthropometric markers, respectively. Gut bacteria including Alistipes, Lactobacillus spp., and Bacteroides stercoris differed according to the intake of the food components, fiber, sodium, saturated fatty acids, and dietary indices, and metabolic markers (BP and total cholesterol) after adjustments. Notably, Bacteroides stercoris correlated positively with the intake of fiber, grain products, and vegetables, and higher Bacteroides stercoris abundance was associated with higher adherence to Healthy Nordic Food Index (HNFI) and lower diastolic BP after adjustment.Conclusion: Our findings highlight the relationship between the gut microbiota, diet, and metabolic mark-ers in healthy individuals. Further investigations are needed to address whether these findings are causally linked and whether targeting these gut bacteria can prevent metabolic diseases.publishedVersio
Insects as food and feed in Portugal and Norway – Cross-cultural comparison of determinants of acceptance
Get PDFEntomophagy – intentional consumption of insects – is practiced in several regions of the world, particularly in Asia, Africa and Latin America. In the Western world, edible insects have been growing in popularity as novel food and feed. The main objective of this cross-cultural study, performed in Portugal and Norway, was to evaluate the determinants of consumers’ acceptance of insects as food and feed. An online-based survey (n = 666, LimeSurvey -Portugal- and EyeQuestion -Norway-) composed of nine different sections, assessing acceptance of insects as food and feed, sociodemographic characteristics, attitudes towards edible insects and food choice motives was applied. Results showed that Norwegian consumers had a higher acceptance of insects as food or feed than Portuguese consumers did. It was also possible to divide consumers into four segments according to their acceptance level: Disgusted, Rejecters, Feed Acceptors and Acceptors. Considering the determinants of acceptance/rejection, disgust towards insects was the variable with the largest negative impact on either forms of entomophagy for both countries. On the other hand, consumers who seek new food experiences tend to have a higher acceptance of insects as food. Sociodemographic characteristics also influenced the acceptance of insects as food and feed, although differently for Norway and Portugal, while food choice motivations (convenience, health and ecological welfare) had minimal impact. These results highlight the importance of diminishing disgust reactions towards edible insects and to successfully marketing entomophagy to more neophilic consumers. This can be potentially obtained by improving the sensory appeal and experiences associated with edible insects.Insects as food and feed in Portugal and Norway – Cross-cultural comparison of determinants of acceptancepublishedVersio
Magnetic resonance imaging for non-invasive measurement of plastic ingestion in marine wildlife
Get PDFMonitoring plastic ingestion by marine wildlife is important for both characterizing the extent of plastic pollution in the environment and understanding its effect on species and ecosystems. Current methods to detect plastic in the digestive system of animals are slow and invasive, such that the number of animals that can be screened is limited. In this article, magnetic resonance imaging (MRI) is investigated as a possible technology to perform rapid, non-invasive detection of plastic ingestion. Standard MRI methods were able to directly measure one type of plastic in a fulmar stomach and another type was able to be indirectly detected. In addition to MRI, other standard nuclear magnetic resonance (NMR) measurements were made. Different types of plastic were tested, and distinctive NMR signal characteristics were found in common for each type, allowing them to be distin- guished from one another. The NMR results indicate specialized MRI sequences could be used to directly image several types of plastic. Although current commercial MRI technology is not suitable for field use, existing single- sided MRI research systems could be adapted for use outside the laboratory and become an important tool for future monitoring of wild animals.publishedVersio
Mechanical, barrier, antioxidant and antimicrobial properties of alginate films: Effect of seaweed powder and plasma-activated water
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Discriminability and uncertainty in principal component analysis (PCA) of temporal check-all-that-apply (TCATA) data
Get PDFTemporal check-all-that-apply (TCATA) data can be summarized and explored using principal component analysis (PCA). Here we analyze TCATA data on Syrah wines obtained from a trained sensory panel. We evaluate new and existing methods to explore the uncertainty in the PCA scores. To do so, we use the bootstrap procedure to obtain many virtual panels from the real panel’s data. Virtual-panel PCA scores are obtained using two methods. The first method, called the partial bootstrap (PB), obtains virtual-panel scores from regression. The second method, called the truncated total bootstrap (TTB), applies PCA to the virtual-panel results to obtain scores, which are truncated and superimposed on the real-panel scores by Procrustes rotation. We use the virtual scores from each method to investigate uncertainty in the real-panel PCA scores visually and numerically. To understand the uncertainty of the scores, we obtain confidence ellipses (CEs) and their areas, as well as confidence intervals (CIs) and their widths. Next, to determine whether PCA scores for different samples are well separated, we propose a procedure for approximating the standard errors of sample differences and correcting for multiple comparisons. We propose a discriminability index, and show that it can enhance the interpretability of PCA results. We incorporate graphical features into our PCA biplots to visualize discriminability. We did not find a large difference between the PB and TTB methods for understanding the uncertainty and discriminability in PCA scores. Although the TCATA data that we analyzed have a special structure, the methodological approaches presented here can be readily adapted to other applications of PCA.submittedVersio
Applications of hyperspectral imaging for documenting smoltification and welfare in Atlantic salmon
No full textpublishedVersio
Perspective Chapter: Hyperspectral Imaging for the Analysis of Seafood
Get PDFHyperspectral imaging technology is able to provide useful information about the interaction between electromagnetic radiation and matter. This information makes possible chemical characterization of materials in a non-invasive manner. For this reason, the technology has been of great interest for the food industry in recent decades. In this book chapter, we provide a survey of the current status of the use of hyperspectral technology for seafood evaluation. First, we provide a brief description of the optical properties of tissue and an introduction to the instrumentation used to capture these images. Then, we survey the main applications of hyperspectral imaging in the seafood industry, including the quantification of different chemical components, the estimation of freshness, the quality assessment of seafood products, and the detection of nematodes, among others. Finally, we provide a discussion about the current state of the art and the upcoming challenges for the application of this technology in the seafood industry.Perspective Chapter: Hyperspectral Imaging for the Analysis of SeafoodpublishedVersio
Diffusion tensor imaging for spatially-resolved characterization of muscle fiber structure in seafood
Get PDFThe fiber structure of tissue in meat and seafood has a significant impact on their perceived quality. However, quantifiable description of muscle structure is challenging. We investigate diffusion tensor imaging (DTI) magnetic resonance imaging (MRI) as a method to quantitatively describe tissue structure. DTI measures the anisotropy of water molecule diffusion within muscle fibers. A pilot study evaluated three different cod loin samples: one of high-quality, one of medium-quality, and one of poor-quality. DTI parameters such as fractional anisotropy, axial diffusion and radial diffusion showed clear differences between the sample qualities. Changes in the DTI metrics consistent with freezing and thawing damage to the tissue were observed. The DTI maps were compared to T2-weighted images and DTI detected significant details that were not visible in T2-weighted images. Overall, these results indicate that DTI is a promising method for spatially-resolved characterization of tissue structure in seafood and meat.publishedVersio