Sensory Properties of Frozen Herring (Clupea harengus) from Different Catch Seasons and Locations

Freezing of herring (Clupea harengus) for human consumption is increasing in the Nordic herring industry, either onboard the fishing vessels or right after landing. The quality of frozen herring as a raw material does not only depend on the frozen storage conditions applied, but also on compositional features, something which in turn can vary with season and catching ground. To unravel the link between biological variations, basic muscle composition, and sensory properties of frozen herring, a unique herring raw material was caught by commercial fishing vessels at three locations: around Iceland, outside the Norwegian coast, and in Kattegat/Skagerrak. The samplings were done according to a specific scheme and conducted over several seasons and 2 years. The herring was converted into butterfly fillets, packed in cardboard boxes, frozen, and then stored at -20 °C or -80 °C for up to 18 mo. The sensory quality was characterized by objective sensory profiling. It was shown that two generalized sensory variables could be defined from a principal component analysis of the sensory data. Except for the expected pronounced effect from storage time, the most distinct variation followed the lipid content, which in turn varied with season. An unexpected conclusion was that catching location only had a minor affect on the changes in sensory quality of herring during frozen storage. Knowledge about how season and catching location affect herring during frozen storage will be useful for optimizing the utilization of herring for frozen storage for human consumption. Practical Application: The results of this study constitute important information for the herring processing industry when handling raw materials with different geographical and seasonal history. The reported information on a highly equal sensory quality of geographically diverse raw materials will give consumers and retailers valuable knowledge on the changes in eating quality to expect after long-term frozen storage under conditions similar to household freezers or refrigerated counters in supermarkets.     

Leaching characterisation and geochemical modelling of minor and trace elements released from recycled concrete aggregates

The pH dependent release of Cd, Cr, Cu, Mn, Mo, Ni, Pb, V and Zn from different recycled concrete aggregate samples was determined. Geochemical speciation modelling was applied on the concentrations of Cu, Cr, Mo and Ni in the leachates in order to predict the measured concentrations and the specific release mechanisms. The model was able to reproduce the characteristic pH dependent release patterns for these elements and reasonable to sometimes excellent matches between the predicted and measured concentrations were achieved. Binding of Mo and Cr as oxyanions (MoO₄²⁻ and CrO₄²⁻) to ettringite was modelled with fair agreement for Cr only. For Cu and Ni, the predicted and measured concentrations agreed well for the partly carbonated sample at high alkaline pH (11–13). The importance of complexation to humic substances was also shown in samples derived from construction debris.     

Grain orientation, deformation microstructure and flow stress

Dislocation structures in deformed metals have been analyzed quantitatively by transmission electron microscopy, high-resolution electron microscopy and Kikuchi line analysis. A general pattern for the microstructural evolution with increasing strain has been established and structural parameters have been defined and quantified. It has been found that two dislocation patterns co-exist in all grains, however, with very different characteristics dependent on grain orientation. This correlation with the grain orientation has been applied in modeling of the tensile flow stress and the flow stress anisotropy of fcc polycrystals. In conclusion some future research areas are briefly outlined.     

Kinetic analysis of the mechanism and specificity of protein-disulfide isomerase using fluorescence-quenched peptides

Protein-disulfide isomerase (PDI) is an abundant folding catalyst in the endoplasmic reticulum of eukaryotic cells. PDI introduces disulfide bonds into newly synthesized proteins and catalyzes disulfide bond isomerizations. We have synthesized a library of disulfide-linked fluorescence-quenched peptides, individually linked to resin beads, for two purposes: 1) to probe PDI specificity, and 2) to identify simple, sensitive peptide substrates of PDI. Using this library, beads that became rapidly fluorescent by reduction by human PDI were selected. Amino acid sequencing of the bead-linked peptides revealed substantial similarities. Several of the peptides were synthesized in solution, and a quantitative characterization of pre-steady state kinetics was carried out. Interestingly, a greater than 10-fold difference in affinity toward PDI was seen for various substrates of identical length. As opposed to conventional PDI assays involving larger polypeptides, the starting material for this assay is homogenous. It is furthermore simple and highly sensitive (requires less than 0.5 microgram of PDI/assay) and thus opens the possibility for quantitative determination of PDI activity and specificity.     

A discrete de Rham complex with enhanced smoothness

Abstract Discrete de Rham complexes are fundamental tools in the construction of stable elements for some finite element methods. The purpose of this paper is to discuss a new discrete de Rham complex in three space dimensions, where the finite element spaces have extra smoothness compared to the standard requirements. The motivation for this construction is to produce discretizations which have uniform stability properties for certain families of singular perturbation problem. In particular, we show how the spaces constructed here lead to discretizations of Stokes type systems which have uniform convergence properties as the Stokes flow approaches a Darcy flow. Keywords: Discrete exact sequences, nonconforming finite elements, Darcy–Stokes flow, uniform error estimates. Mathematics Subject Classification (1991): Primary 65N12, 65N15, 65N30     

The structure of 12-(tetrathiafulvenyl)-11-dodecenoic acid at 120 K

The structure of C₁₈H₂₄O₂S₄ (TTF---C₁₁H₂₀COOH) has been determined at 120 K. TTF---C₁₁H₂₀COOH, M_r = 400.65, crystallizes in the monoclinic space group P2₁/c with a = 18.117(5), b = 9.152(4), c = 12.100(3) Å, ß = 102.68(2)°, V = 1957(1) ų, Z = 4 andD_c = 1.361 g cm⁻³. Least-squares refinement gave R = 0.0898 for 788 observed unique reflections. The TTF parts of the molecules are not stacked, but are coupled into pairs with the usual overlap, double bond over ring. The high R-value reflects the disorder around the double bond in the aliphatic chain.     

Inhomogeneity Effects in Vapor Phase Polymerized PEDOT: A Tool to Influence Conductivity

Low‐MW urethanes were investigated to control domain formation as well as inhibiting cleavage reactions during vapor phase polymerization of PEDOT. A diurethanediol (DUDO) was identified as a highly efficient mediator for the process, resulting in PEDOT films exceeding conductivities of 1 000 S · cm^?1. All the urethanes investigated had the desired inhibiting effect on the polymerization, but all apart from DUDO also introduced unwanted domain formation on the micrometer scale. The addition of PEG generally improved conductivity by suppressing the domain formation and, with an optimized combination of DUDO and PEG, conductivities over 1 200 S · cm^?1 were achieved.