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Valideringsrapport - Analyse av frie aminosyrer ved bruk av Waters ACQUITY UPLC og Waters MassTrak™/Waters AccQ•Tag™ Ultra
No full textDet ble validert en ny metode for analyse av frie aminosyrer hos Nofima Biolab (BIOLAB A133). Selektivitet, linearitet, presisjon, riktighet og robusthet ble validert. Måleområde ble vurdert, og måleusikkerhet ble beregnet. Valideringen viste at metodens ytelse er god, og at metoden er godt egnet for analyse av frie aminosyrer i fôr, fôringredienser, fisk og hydrolysater.Valideringsrapport - Analyse av frie aminosyrer ved bruk av Waters ACQUITY UPLC og Waters MassTrak™/Waters AccQ•Tag™ UltrapublishedVersio
Impact on lipid profile and influence on sensory, texture and structural properties when replacing saturated fats with rapeseed oil in Frankfurter-type sausages
Full text linkSausages are one of the most diverse and widely consumed meat-based products in the world. However, they are often deemed an unhealthy option, high in saturated fats and linked to negative health aspects. Therefore, in this study, the aim was to examine the impact of both partial and full replacement of backfat in sausages using rapeseed oil. The replacement of solid, saturated fat-rich ingredients with liquid, plant-based oils, such as rapeseed oil (RSO), can help to introduce products with healthier lipid profiles. Gas chromatography (GC) analysis of the prepared sausages confirmed a more preferable n-6/n-3 ratio, from 7:1 in the control to below 5:1 in all other recipes. An increase in polyunsaturated fatty acid (PUFA)/saturated fatty acid (SFA) distribution was also achieved, from 0.25 in the control to over 0.5 in 3 out of 4 rapeseed oil substituted recipes. Only minor, non-significant effects were observed in the physical characteristics, as analyzed by texture profile and pH, while microscopy revealed interesting differences in the structuring of the products. Sensory analysis, performed by a trained expert panel of assessors identified variations in the most diverse recipe, meanwhile, the remaining three (out of four) recipes were found to be not significantly different to the controls. The findings show it is possible to create a product with a more favorable and healthier lipid content, without negatively impacting the physical characteristics or significantly affecting the sensory properties of the samples produced.publishedVersio
Early detection and population dynamics of Listeria monocytogenes in naturally contaminated drains from a meat processing plant
Full text linkListeria monocytogenes, a significant foodborne pathogen, often contaminates ready-to-eat foods through cross-contamination in food processing environments, and floor drains represent one of the most common sites of persistence. Subtyping of L. monocytogenes from food processing plants for the purpose of source tracking is usually performed on a single colony obtained after selective enrichment. This study investigates the temporal variation and population dynamics of L. monocytogenes in drains, focusing on the diversity of L. monocytogenes and the impact of the resident microbiota. Six different drains in a meat processing plant were each sampled four times over a period of 8 weeks and subjected to two-step selective enrichment in Half Fraser and Full Fraser broths. The clonal complexes (CCs) of at least 20 individual L. monocytogenes isolates from each positive sample (460 isolates in total) were determined using either the GenoListeria Multiplex qPCR assay or whole genome sequencing (WGS). The microbiota in drains and enrichment cultures was analyzed by 16S rRNA gene amplicon sequencing and metagenomic or quasimetagenomic sequencing. L. monocytogenes was detected in the majority of samples and four different CCs were identified – CC9, CC11 (ST451), CC121 and CC8 – with up to three CCs in the same sample and with different CCs dominating in different drains. The same clones of CC9, CC11, and CC121 had persisted in the facility for 3–5 years. The composition of the drain microbiota remained relatively stable over time, with Pseudomonas, Acinetobacter, Janthinobacterium, Chryseobacterium, Staphylococcus, and Sphingomonas as the most commonly identified genera. There were no apparent differences in the microbial genera present in L. monocytogenes positive and negative drains or samples. The study highlights the use of techniques such as qPCR and quasimetagenomics for monitoring and controlling the risk of L. monocytogenes contamination in processing environments.publishedVersio
High throughput shelf life determination of Atlantic cod (Gadus morhua L.) by use of hyperspectral imaging
Full text linkFish quality and shelf life can be evaluated using various assessment methods, such as sensory analysis, biochemical tests, microbiological evaluations, and physicochemical analyses. However, these methods are invasive and time-consuming, driving interest in technologies capable of estimating shelf life through non-invasive procedures. This study investigates the potential of hyperspectral imaging as a non-invasive technology for predicting the shelf life of Atlantic cod. A storage experiment was conducted that included both gutted fish with heads (GFWH) and fillets, with sensory evaluation and biochemical measurements employed to determine shelf life. Subsequently, hyperspectral images of the fish samples were captured under industrial production conditions, and the spectral data were analyzed using different regression algorithms. The majority of the regression techniques utilized in this research successfully predicted shelf life for both fillets and GFWH, achieving a root mean square error (RMSE) lower than one day. While most regression models exhibited comparable performance in predicting the shelf life of fillets, deep learningbased models demonstrated superior performance for GFWH. These results suggest that hyperspectral imaging technology has significant potential as a non-invasive tool for estimating the shelf life of Atlantic cod, thereby enabling effective quality-based sorting, reducing food waste, and enhancing sustainability in the seafood supply chain.publishedVersio
From discovery to potential application: engineering a novel M23 peptidase to combat Listeria monocytogenes
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A CACTA-like transposon in the Anthocyanidin synthase 1 (Ans-1) gene is responsible for apricot fruit colour in the raspberry (Rubus idaeus) cultivar ‘Varnes’
Full text linkCultivated raspberries (Rubus idaeus L.) most commonly bear small, red, highly aromatic fruits. Their colour is derived predominantly from anthocyanins, water soluble polyphenolic pigments, but as well as red forms, there exist cultivars that display yellow- and apricot-coloured fruits. In this investigation, we used a multi-omics approach to elucidate the genetic basis of the apricot fruit colour in raspberry. Using metabolomics, we quantified anthocyanins in red and apricot raspberry fruits and demonstrated that, in contrast to red-fruited raspberries, fruits of the apricot cultivar ‘Varnes’ contain low concentrations of only a small number of anthocyanin compounds. By performing RNASeq, we revealed differential expression patterns in the apricot-fruited ‘Varnes’ for genes in the anthocyanin biosynthesis pathway and following whole genome sequencing using long-read Oxford Nanopore Technologies sequencing, we identified a CACTA-like transposable element (TE) in the second exon of the Anthocyanidin synthase (Ans) gene that caused a truncated predicted ANS protein. PCR confirmed the presence in heterozygous form of the transposon in an unrelated, red-fruited cultivar ‘Veten’, indicating apricot fruit colour is recessive to red and that it may be widespread in raspberry germplasm, potentially explaining why apricot forms appear at regular intervals in modern raspberry breeding populations.publishedVersio
Dietary starch, non-starch polysaccharides and their interactions affect nutrient digestibility, faecal waste production and characteristics differentially in three salmonids: Rainbow trout, Atlantic salmon and Arctic charr
Full text linkWaste management has emerged as a critical issue in aquaculture. In this study, we examined the impact of dietary starch and non-starch polysaccharides (NSP) content on nutrient digestibility, faecal waste production, faecal removal efficiency and the faecal characteristics in three salmonid species, namely rainbow trout (Oncorhynchus mykiss), Atlantic salmon (Salmo salar) and Arctic charr (Salvelinus alpinus). Four diets were formulated according to a 2 × 2 factorial design. The first factor, starch, was tested by including 0% gelatinised wheat flour (low starch) or 20% gelatinised wheat flour (high starch) in a plant-based basal diet. The second factor, NSP, was tested by adding 0% NSP source (low NSP) or 10% NSP source (high NSP). High NSP level was achieved by adding an equal mixture of soya hull (5%) and wheat bran (5%). Diets were tested in triplicates for each species and feeding was done restrictively. Experimental duration was 42 days for rainbow trout and Atlantic salmon and 49 days for Arctic charrDietary starch, non-starch polysaccharides and their interactions affect nutrient digestibility, faecal waste production and characteristics differentially in three salmonids: Rainbow trout, Atlantic salmon and Arctic charrpublishedVersio
Quality parameters and storage stability of the Norwegian red sea cucumber (Parastichopus tremulus)
Full text linkQuality parameters and storage stability were evaluated through biochemical, textural, and microbial analyses of the Norwegian red sea cucumber Parastichopus tremulus at two different storage temperatures (0 °C and 4 °C) over 17 days. During storage, the pH decreased from 7 to 6.3, the texture became softer decreasing from 47.3 to 0.3 N, while K-value increased from 4 to 52 %, microbial counts increased from 2 to 8 log cfu/g and formation of volatiles increased. After storage for 7 days at 0 °C and 5 days at 4 °C, the microbial counts exceeded the acceptability for consumption (7 log cfu/g). Microorganisms such as Flavobacterium and Psychrobacter were the main specific spoilage organisms contributing to the deterioration. Prolonged storage favored the Polaribacter and Marinomonas proliferation regardless of storage temperatures. The free amino acid concentration increased from 24 to 86 mg/100 g at both storage temperatures, probably resulting from the autolysis degradation. The pH decrease could be attributed to the production and dissolution of volatile compounds during storage. Odor-active compounds such as aldehydes (decanal, 2,4-decadienal, nonanal), ketones (1-octen-3-one, 1-penten-3-one), alcohols (1-octen-3-ol, 2-heptanol), aromatics (p-cresol and phenol), indoles (indole) and sulfides (dimethyl disulfide and trisulfide) showed increasing levels with storage time, with the highest levels found in the samples stored at 4 °C. This is the first study that demonstrate the quality changes on molecular and microbial level occurring during cold storage of sea cucumber P. tremulus. These results can be used for evaluating the shelf-life limiting factors of such species.publishedVersio
Regulated Power Supply with High Power Factor for Hyperspectral Imaging Applications
Full text linkIllumination is a crucial factor in hyperspectral imaging systems. In this respect, this work is focused on analyzing the influence of the light power source in acquiring hyperspectral images. To this end, a custom regulated power supply was designed and developed. This power supply was then integrated into a hyperspectral acquisition system, and several light stability measurements were conducted. Finally, several parameters related to the stability of the light produced by those systems were extracted using image analysis techniques, and a statistical comparison among the different power supplies was performed. Two commercial power supplies were also analyzed under the same experimental conditions and compared with the proposed power supply. The hyperspectral measurements were conducted using light transmission and reflectance. The results indicate that the proposed power supply performs better than or at least as well as commercial power supplies in terms of light stability. Additionally, this study shows the impact of power supply design on the stability and quality of hyperspectral illumination, especially concerning the signal-to-noise ratio (SNR) across different spectral bands. It is shopublishedVersio
Flour composition, dough, and bread properties of intermediate wheatgrass (Thinopyrum intermedium) compared to annual wheat species
Full text linkThe aim of this study was to gain more knowledge about the breadmaking performance of a novel perennial crop, intermediate wheatgrass (IWG). The main flour constituents of IWG, its rheological properties of dough, and breadmaking performance were compared with those of wheat, einkorn, and emmer. IWG had significantly more protein but less starch and lower arabinose:xylose ratios (indicating sparsely substituted arabinoxylans) than the other species. Rheological analyses showed certain similarities between IWG and emmer dough, as both had low dough stability, more viscous than elastic compliance, and were, therefore, weak. Simultaneously, some properties of IWG dough resembled wheat dough, such as the proportion of large polymeric proteins and strain-stiffening ratio. Although the specific loaf volume was lower in IWG than wheat bread, they had similar form ratios. The results from rheological analyses and small-scale baking trials suggest that IWG proteins form a gas-holding network crucial for breadmaking.publishedVersio