Using electricity as a tool in quality studies of Atlantic salmon

In order to reveal what role anaerobe muscle activity has on the fillet quality in Atlantic salmon (Salmo salar), 18 rested fish were killed on site and immediately filleted. One fillet was used as control group while the other was electrically exercised using 10 V, 5 Hz pDC for 3 min. Fillet weight and muscle pH was measured before the fillets were wrapped in aluminum foil and stored on ice. After 7 days muscle pH, color, and weight was measured. Texture profile analysis (TPA) was estimated using a 20 mm cylindrical probe compressing either at 40, 60 or 80% into the fillet and the shear force was estimated by slicing standardized muscles samples with a blade. Results show that electrical stimulation forces the muscle to contract and the muscle pH to drop by 0.5 units, leading to higher drip loss and loss of color. Comparing the fillets in pairs (paired t test) strengthens evidence on drip loss and color loss, but revealed also softer texture. Optimum compression rate for detecting differences in salmon muscle is at 60% compression. We conclude that electrical stimulation is a powerful tool for simulating anaerobe muscle activity enabling comparative studies within the same individual, hence isolating the variation amongst individuals and the location of sampling. Furthermore electrical stimulation reduces the need for live animal experimentation in quality studies.     

Procurement Routes in Public Building and Construction Projects

This paper deals with procurement routes in public building and construction projects in Norway. Seen from a practical point of view, as well as from a theoretical one, it is important to improve methods for selection of procurement procedure, contract model, and compensation formats. The paper objective is to find out if public owners select a procurement route according to recommended practice. The sources are literature, support material for two software tools for selection of the procurement route, and documentation from 22 public building and construction projects in Norway. According to the literature and the support material for the two software tools, the answer to what is the proper procurement route will depend on the characteristics of each project. The documentation study implies that public owners continue to select the same procurement route as they are in the habit of. They do not consider what procurement route suits each single project, and therefore they do not select the route according to recommended practice. The paper calls for innovation and better supported selection of the procurement route in public building and construction projects.     

The effect of bark content on quality parameters of Scots pine (Pinus sylvestris L.) pellets

Increased use of pellets has resulted in a shortage of the traditional raw materials required for pellet making, including saw dust, shavings and cuttings from saw mills. Therefore, the pellets industry has started to look for alternative raw materials. Limited consumption of pulpwood from Scots pine (Pinus sylvestris L.) in Norway has made it a potential raw material for the pellets industry.A study on how bark content affects the quality of pellets is reported in this paper. Pellets from pinewood containing zero, five, 10, 30 and 100 percent bark were produced, and their quality parameters were evaluated. Combustion tests were also performed on the produced pellets.Pellets made from pure bark had the best mechanical properties compared with pellets made of wood containing various concentrations of bark. The differences were not substantial and the durability for all chosen assortments was in the same quality class in the CEN standard. A positive effect off the amount of steam added was found. The bulk densities of the blend pellets were higher than those of pure wood and bark. The ash content increased with the amount of bark in the pellets. There were no problems with sintering when the bark content was low (five and 10 percent). For pure bark pellets some sintering was registered.     

Characterisation of the bacterial flora of modified atmosphere packaged farmed Atlantic cod (Gadus morhua) by PCR-DGGE of conserved 16S rRNA gene regions

The present article describes the use of broad-range molecular analyses to characterise the microbial population of farmed Atlantic cod (Gadus morhua) packaged for the retail market. Cod was filleted post rigor, packaged in air or in modified atmosphere (MA) (50% CO(2):50% N(2) or 50% CO(2):50% O(2)) and stored at 0 degrees C for 11 days. To determine the community profiles of the samples the variable V3-region of the bacterial 16S rRNA gene were amplified by PCR, before the PCR products were separated by denaturing gradient gel electrophoresis (DGGE). From sequence analyses Pseudomonas spp. were found to be the predominant bacteria in oxygen enriched atmospheres, whereas the spoilage bacteria Photobacterium sp., Shewanella putrefaciens and Pseudomonas spp. dominated in CO(2):N(2) and air packaged samples. Additional microbial analyses by cultivation methods observed highest bacterial numbers in air stored samples, and both MA mixtures gave growth inhibition when measuring aerobic plate count, psychrotrophic bacteria and H(2)S-producing bacteria. The results show that PCR-DGGE can be applied to examine bacterial diversity and population shifts among different MA-packaged products.