Improvement of nutritional properties of Chorizo de Pamplona by replacement of pork backfat with soy oil.

Dry fermented sausages with a partial substitution of 15, 20 and 25% of pork backfat by pre-emulsified soy oil were prepared. No differences were detected in the water, protein and fat content between control and modified sausages. Cholesterol amount scarcely decreased in the modified sausages (92.96 mg/100 g product in control sausages, 87.71 mg/100 g in sausages prepared with 25% of substitution). No increase in oxidation was detected through chemical or sensory analysis in modified sausages. Saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) in control products were 37.83 and 45.78 g/100 g of total fatty acid, respectively, decreasing in the modified formulations, to 32.81 and 42.09 g/100 g of total fatty acid in the 25% replacement products, respectively. Polyunsaturated fatty acids (PUFA) increased from 15.22 (control) to 23.96 g/100 g of total fatty acid (25% product) due to the significant increase in linoleic and α-linolenic acids when soy oil was added. In relation to texture profile analysis (TPA), hardness and springiness did not show significant differences among products. The instrumental measured colours were comparable with that of commercial products. Sensory evaluation of most of the modified sausages did not show significant differences with regard to the control

Functional dry fermented sausages manufactured with high levels of n-3 fatty acids: nutritional benefits and evaluation of oxidation

Dry fermented sausages including fish oil extracts rich in n-3 fatty acids were manufactured in order to obtain functional products, and their nutritional advantages and effects on oxidation process were compared with traditional ones. Modified products were manufactured with 5.3 g kg−1 and 10.7 g kg−1 of fish oil extract. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) contents per 100 g of dry fermented sausages were 0.15 g and 0.13 g for the lower rate of addition and 0.33 g and 0.26 g, respectively, for the higher rate, compared with only 0.01 g EPA and 0.03 g DHA in the control products. No significant differences were found in the other fatty acids. A decrease in the n-6/n-3 ratios from 16.14 in the control to 7.78 in batch A and 5.32 in batch B was achieved. Thiobarbituric acid reactive substances values were similar in control (0.31 ppm) and in batch A products (0.34 ppm) but increased significantly in batch B products (1.22 ppm). No statistical differences were observed among batches for the content of cholesterol oxidation products (2.36–2.43 µg g−1 fat) leading to similar percentages of oxidation. 7-Ketocholesterol, considered an indicator of oxidation, was not present in any sample. Values obtained for L* and hue (arctg b*/a*) were comparable with those of meat products. Although no effect was observed in cholesterol oxidation product formation and instrumental measurements of colour, the highest level of n-3 fatty acid seemed to accelerate the oxidation process significantly. Copyright © 2004 Society of Chemical Industr

Pressure pulsation in Kaplan turbines: Prototype-CFD comparison

Pressure pulsation phenomena in a large Kaplan turbine are investigated by means of numerical simulations (CFD) and prototype measurements in order to study the dynamic behavior of flow due to the blade passage and its interaction with other components of the turbine. Numerical simulations are performed with the commercial software Ansys CFX code, solving the incompressible Unsteady Reynolds-Averaged-Navier Stokes equations under a finite volume scheme. The computational domain involves the entire machine at prototype scale. Special care is taken in the discretization of the wicket gate overhang and runner blade gap. Prototype measurements are performed using pressure transducers at different locations among the wicket gate outlet and the draft tube inlet. Then, CFD results are compared with temporary signals of prototype measurements at identical locations to validate the numerical model. A detailed analysis was focused on the tip gap flow and the pressure field at the discharge ring. From a rotating reference frame perspective, it is found that the mean pressure fluctuates accordingly the wicket gate passage. Moreover, in prototype measurements the pressure frequency that reveals the presence of modulated cavitation at the discharge ring is distinguished, as also verified from the shape of erosion patches in concordance with the number of wicket gates.Facultad de Ingenierí

Pressure pulsation in Kaplan turbines: Prototype-CFD comparison

Pressure pulsation phenomena in a large Kaplan turbine are investigated by means of numerical simulations (CFD) and prototype measurements in order to study the dynamic behavior of flow due to the blade passage and its interaction with other components of the turbine. Numerical simulations are performed with the commercial software Ansys CFX code, solving the incompressible Unsteady Reynolds-Averaged-Navier Stokes equations under a finite volume scheme. The computational domain involves the entire machine at prototype scale. Special care is taken in the discretization of the wicket gate overhang and runner blade gap. Prototype measurements are performed using pressure transducers at different locations among the wicket gate outlet and the draft tube inlet. Then, CFD results are compared with temporary signals of prototype measurements at identical locations to validate the numerical model. A detailed analysis was focused on the tip gap flow and the pressure field at the discharge ring. From a rotating reference frame perspective, it is found that the mean pressure fluctuates accordingly the wicket gate passage. Moreover, in prototype measurements the pressure frequency that reveals the presence of modulated cavitation at the discharge ring is distinguished, as also verified from the shape of erosion patches in concordance with the number of wicket gates.Facultad de Ingenierí

New formulations for healthier dry fermented sausages: a review.

An excessive intake of meat products, particularly dryfermented sausages, is not recommended from a health point of view, at least for some population groups, due to their high level of sodium and animal fat. Many efforts of the meat industry are focused on the development of new products with better nutritional properties than traditional ones. KCl, CaCl2, and/or calcium ascorbate, among others, have been assessed as partial substitutes of NaCl, giving products with acceptable sensory quality, smaller amounts of sodium and being sometimes a significant source of potassium or calcium. In relation to fat, recent research has focused on the use of different types of fibres and vegetable oils as partial substitutes of pork backfat. The use of fibres results in low-fat and low-energy products. The use of vegetable oils results in products with healthier fatty acid profiles. Aspects related to improving sensory properties and control of oxidation should be taken into account in future research

Effect of fat level and partial replacement of pork backfat with olive oil on processing and quality characteristics of fermented sausages

Six formulations of dry fermented sausages were produced in three replications with three initial fat levels (30, 20 and 10%) and two levels (0 and 20%) of pork backfat replacing olive oil. After 4 weeks of fermentation and ripening the fat content of the treatments with 30, 20 and 10% fat level ranged from 38.86 to 43.60%, 25.56 to 26.86% and 19.01 to 20.14%, respectively. Fat level affected (P<0.05) the weight losses, the chemical composition, the Gram -ve bacterial count, the lightness, the texture and the appearance of fermented sausages. Replacing 20% of pork backfat by olive oil affected (P<0.05) the lightness and yellowness of sausages. Fat-reduced sausages without olive oil and low-fat sausages with olive oil had the highest score for odour and taste. However, the appearance of fat-reduced sausages was just acceptable while that of low-fat sausages was unacceptable, because the surface was intensively wrinkled and case hardening had developed. Further research is needed to improve the appearance of these sausages

Pressure pulsation in Kaplan turbines: Prototype-CFD comparison

Pressure pulsation phenomena in a large Kaplan turbine are investigated by means of numerical simulations (CFD) and prototype measurements in order to study the dynamic behavior of flow due to the blade passage and its interaction with other components of the turbine. Numerical simulations are performed with the commercial software Ansys CFX code, solving the incompressible Unsteady Reynolds-Averaged-Navier Stokes equations under a finite volume scheme. The computational domain involves the entire machine at prototype scale. Special care is taken in the discretization of the wicket gate overhang and runner blade gap. Prototype measurements are performed using pressure transducers at different locations among the wicket gate outlet and the draft tube inlet. Then, CFD results are compared with temporary signals of prototype measurements at identical locations to validate the numerical model. A detailed analysis was focused on the tip gap flow and the pressure field at the discharge ring. From a rotating reference frame perspective, it is found that the mean pressure fluctuates accordingly the wicket gate passage. Moreover, in prototype measurements the pressure frequency that reveals the presence of modulated cavitation at the discharge ring is distinguished, as also verified from the shape of erosion patches in concordance with the number of wicket gates

Pressure pulsation in Kaplan turbines: Prototype-CFD comparison

Abstract. Pressure pulsation phenomena in a large Kaplan turbine are investigated by means of numerical simulations (CFD) and prototype measurements in order to study the dynamic behavior of flow due to the blade passage and its interaction with other components of the turbine. Numerical simulations are performed with the commercial software Ansys CFX code, solving the incompressible Unsteady Reynolds-Averaged-Navier Stokes equations under a finite volume scheme. The computational domain involves the entire machine at prototype scale. Special care is taken in the discretization of the wicket gate overhang and runner blade gap. Prototype measurements are performed using pressure transducers at different locations among the wicket gate outlet and the draft tube inlet. Then, CFD results are compared with temporary signals of prototype measurements at identical locations to validate the numerical model. A detailed analysis was focused on the tip gap flow and the pressure field at the discharge ring. From a rotating reference frame perspective, it is found that the mean pressure fluctuates accordingly the wicket gate passage. Moreover, in prototype measurements the pressure frequency that reveals the presence of modulated cavitation at the discharge ring is distinguished, as also verified from the shape of erosion patches in concordance with the number of wicket gates

The consolidated tree construction algorithm in imbalanced defect prediction datasets

In this short paper, we compare well-known rule/tree classifiers in software defect prediction with the CTC decision tree classifier designed to deal with class imbalance. It is well-known that most software defect prediction datasets are highly imbalance (non-defective instances outnumber defective ones). In this work, we focused only on tree/rule classifiers as these are capable of explaining the decision, i.e., describing the metrics and thresholds that make a module error prone. Furthermore, rules/decision trees provide the advantage that they are easily understood and applied by project managers and quality assurance personnel. The CTC algorithm was designed to cope with class imbalance and noise datasets instead of using preprocessing techniques (oversampling or undersampling), ensembles or cost weights of misclassification. The experimental work was carried out using the NASA datasets and results showed that induced CTC decision trees performed better or similar to the rest of the rule/tree classifiers