Kind Of Heat Treatment Research Articles

Comparative study on the effects of sous-vide, microwave cooking, and stewing on functional properties and sensory quality of goose meat

The effect of sous-vide (SV), microwave (M) cooking, and stewing (S) on selected functional properties of goose meat were investigated in this study. It was measured cooking loss (CL), texture and color parameters, and sensory evaluation was carried out. The material were 96 breast muscles (BM, n=48 with skin and subcutaneous fat and n=48 without skin) from 17-wk-old "Polish oat geese." The kind of heat treatment and the type of goose meat and interaction the type of meat×heat treatment affected the amount of CL. The lowest value of CL was stated for SV samples. The meat with skin was characterized by a lower shear force value (SF), hardness, gumminess, and chewiness than samples without skin for all cooking methods. There were no differences in SF value for M and S samples with skin. The S samples characterized by the highest value of SF, hardness and the SV meat by the lowest for both kind of meat. The M samples characterized by the higher value of cohesiveness, gumminess and chewiness compare to SV and S meat. All instrumental color parameters were significantly affected by cooking technology (P=0.001). There were differences in color lightness (L*) of investigated cooked samples. The SV meat had the highest value of L* parameter and was characterized by a lighter color among others. The highest decrease in a* value was stated for S and lowest for SV meat. The SV showed more intense red color than remaining samples. The a* value decreased and b* parameter increases with an increase the heat treatment temperature. The value of b* was higher in S (about 100°C) samples than in raw meat and processed by SV (70°C). From consumer point of view the best color had goose breast muscles subjected to SV process. Considering all tested sensory features, the overall palatability of SV goose samples was rated as excellent, S as very good and M as good.

The Effects of Sous Vide, Microwave Cooking, and Stewing on Some Quality Criteria of Goose Meat.

Background: Heat treatment methods including frying (with and without fat or oil), deep frying, oven roasting, grilling, charcoal roasting, broiling, steaming, and microwave cooking promote a cascade of adverse changes in the functional properties of meat, including protein fraction, lipid oxidation, and loss of some vitamins and mineral compounds. The aim of this study was to evaluate the influence of three cooking methods (sous vide (SV), microwave (M) cooking, and stewing (S)) on the basic chemical composition, cholesterol content, energy value, mineral concentration, and retention coefficients in goose meat. Methods: Basic chemical composition and mineral analysis were determined using AOAC methods. Total cholesterol content was established using the HPLC method. Results: Both types of goose meat (without and with skin) and heat treatment had a significant effect on nutrient values, mineral concentration, and retention coefficients. The S meat was characterized by a higher protein content than M and SV meat, and had the lowest fat, protein, and cholesterol retention, among other methods. The M meat had lower total cholesterol content than SV and S meat. There were significant differences in energy value for SV, M, and S meats. The SV meat contained less P, Mg, Fe, Zn, and more Na and K than the M and S samples. The highest values of Zn, Mg, and Fe content and the lowest of K and Ca were recorded in S meat compared with the SV and M samples. The retention coefficients of P, Mg, Na, Ca, and K in S meat were lower than in the SV and M samples. The meat without skin was characterized by a lower energy value, fat content, retention of proteins, and cholesterol, but higher fat retention than skin samples. This meat contained more minerals such as P, Mg, Fe, K, Na, and less Ca than skin meat. Higher retention coefficients were observed for Zn, P, Mg, Ca, and lower were observed for Na, Fe, and K in meat without skin than in samples with skin. Conclusions: From a dietary point of view, the most beneficial were SV muscles without skin. Whereas, taking into account the protein, fat content, and retention coefficients of fat, cholesterol, Zn, and Na, the most optimal form of cooking for meat with skin seems to be stewing. These results may be used by consumers in making dietary choices by taking into account the type of goose meat and kind of heat treatment.

The effects of sous-vide, microwave cooking and stewing of goose meat on fatty acid profile and lipid indices

The effect of sous-vide (S-V), microwave cooking (M) and stewing (S) on the fatty acid profile and lipid indices of goose meat was investigated. The research material involved breast muscles (24 with skin and 24 without skin) cut from carcasses of 17-week-old females "Polish oat geese." Gas chromatography was used to establish the fatty acid profile and lipid indices were calculated. The kind of heat treatment and the type of goose meat (muscles with- and without skin) affected the fatty acid profile and lipid indices. The sum of SFA was higher in S-V, M, and S samples for both kinds of meat than in raw ones. The cooked samples with skin had a lower percentage of Ʃ SFA than the skinless meat. S-V and M cooking (for meat with skin) caused an increase, while in the case of S heating (for both kinds of meat) there were no significant differences in Ʃ MUFA compared to raw samples. The S-V, M, and S meat with skin was characterized by a higher value of Ʃ MUFA than skinless ones. The Ʃ PUFA was lower in S-V and M than in raw meat, wherein this decline was higher for M ones (for both kinds of meat). The M meat with skin had the lowest and S without skin the highest share of Σ PUFA. Heat treatment caused an increase in Σ PUFA n-6/n-3 ratio, the lowest value was shown by the S-V muscles. Sous-vide cooking was more beneficial for consumers than the remaining methods in terms of Σ DFA/Σ OFA, Σ UFA/Σ SFA, NVI, health-promoting index (HPI), inflammatory biomarker indexes, and Σ SFA, Σ OFA, Σ UFA, Σ DFA values for meat with skin (but not all of these were significant). In turn, stewing of meat without skin was more favorable than S-V and microwave cooking in relation to indexes such as: Σ DFA/Σ OFA, Σ UFA/Σ SFA, Σ PUFA/Σ SFA, PI, UI, AI, TI, HPI.

Fatty acid profile and health lipid indicies of goose meat in relation to various types of heat treatment

The effect of water bath cooking (WBC), oven convection roasting (OCR), grilling (G), pan-frying (PF) on the fatty acid profile and health lipid indices of goose meat was investigated in this study. The experimental material covered 80 breast muscles (40 with skin and subcutaneous fat and 40 without skin) cut from carcasses of 17-week-old “Polish oat geese”. The fatty acid profile of meat was determined by gas chromatography and health lipid indices were calculated. It was stated that the kind of heat treatment as well as the type of goose meat (muscles with and without skin) affected the fatty acid profile and health lipid indices. The sum of SFA was significantly higher in cooked samples for both kinds of meat than in raw ones. The cooked samples with skin had a lower increase in Ʃ SFA than the skinless meat. Boiling (meat without skin) and pan-frying (both kinds of meat) caused a slight decrease, while grilling and oven convection roasting (both kinds of meat) caused an increase of Ʃ MUFA in comparison to raw samples. Moreover, meat with skin is characterized by a higher value of Ʃ MUFA than meat without skin for all cooking methods. The Ʃ PUFA was lower in all cooked samples than in raw meat, wherein this decline was usually higher for skinned meat. The G meat was the lowest and PF the highest in Σ PUFA for both kinds of meat after heat treatment. The highest loss showed C20:4 n-6 in OCR samples and the lowest C18:2 n-6 in PF (both kinds of meat). Heat treatment caused an increase in the Σ PUFA n-6/n-3 ratio, wherein the lowest value was shown by the WBC samples without skin, and the highest by OCR with skin. Water bath cooking of meat was more beneficial for consumers in terms of AI, TI, Σ DFA/Σ OFA, Σ PUFA/Σ SFA, Σ UFA/Σ SFA indexes and Σ SFA, Σ OFA values than the remaining methods.

Thermal Annealing on the Thermal Performance of XLPE from Retired Cables

In the present paper, different annealing methods were performed on cross-linked polyethylene (XLPE) from three retired cables, the effects on thermal performance were discussed. The cables with length of 15 cm were prepared and the insulation layers were peeled, and the peels near the inner semi-conductive layer were used as the test samples. Isothermal treatment and heat recycling treatment were performed on the samples at temperatures of 85, 90, 95, and 100°C, and the temperature holding hour Th in the heat recycling treatment were 8, 16, and 24 h. Each kind of heat treatment was repeated 20 times, and the duration of the isothermal treatment was the same as that for the heat recycling treatment with 24 h temperature holding hour. Then, differential scanning calorimetry (DSC) were performed. The results show that the melting point, crystallinity, lamellar thickness increase and melting range decreases as the annealing temperature increases; the optimal values appear as the samples were annealed at 95°C. With longer Th, the cables annealed at 95°C exhibit decreased melting range and increased crystallinity, melting point, lamellar thickness.

Effect of Sub-Zero Treatment on the Wear Resistance of P/M Tool Steels

Sub-zero treatment of tool steels is included within the cycle of conventional heat treatment. This kind of heat treatment has been reported to improve wear resistance of tools. The improvement is attributed to precipitation of fine carbide particles, but is depending on a number of the other factors as well. This paper follows the previous works, in which the effect of sub-zero treatment on the mechanical and structural properties of P/M tool steels was evaluated. Two types of P/M cold work tool steels were used in the research: Vanadis 6 and high speed steel Vanadis 30. They were austenitized, nitrogen gas quenched and tempered. The 4 hours long sub-zero period of dwell at -196°C was also incorporated between quenching and tempering. Wear evaluation was carried out using a pin-on-disk method. The observed values of wear resistance have been collated with the values of hardness and the bending strength. The results of the work are supplemented by a detailed analysis of the carbide particles of both monitored conditions.

Microwave milk pasteurization without food safety risk

According to nutrition science, milk and milk products are essential food for humans. The primary processing of milk includes its storage, separation, homogenization and the pasteurization process as well. The latter is a kind of heat treatment, which has been used to extend the storage life of food since the late 18th century. Although heat treatment of milk can be achieved through the use of microwave technology, the inhomogeneity of electromagnetic fields leads to an uneven distribution of temperature in the food products, therefore precluding their use in industry. The pasteurization operation is very often Critical Controll Point (CCP) according of food safety systems. In recent years our research team has developed continuously operating heat treatment pilot-plant equipment, capable of measuring and contrasting the effects of different heat treatment methods, such as thermostat-controlled water baths and microwave energy, on liquid food products. We examined and compared protein, fat and bacterial content in samples of fresh cow milk with heat-treated cow milk samples. In addition, storage experiments were carried out under a microscope and recordings made of fat globules. Our results so far show that the microwave heat treatment is equivalent to the convection manner pasteurization technology, as we found no difference between the heat-treated products.

Alumina scale growth and degradation modes of a TBC system

The evolution of a thermal barrier coating system was followed during exposures at high temperature (1100°C) and under various thermal and mechanical loading conditions. The TBC system is composed of an EB-PVD yttria partially stabilised zirconia topcoat (TC) and a platinum nickel aluminide bondcoat (BC) deposited on a single crystal nickel based superalloy. Depending on the kind of heat treatment (isothermal or thermo-mechanically cycled), different types of defects (pores, cracks, re-oxidation), were observed at the BC/TGO interface, the TGO/TC interface or in the alumina scale. Damage processes were identified and discussed according to the type of imposed heat treatment.

Alumina scale growth and degradation modes of a TBC system

The evolution of a thermal barrier coating system was followed during exposures at high temperature (1100°C) and under various thermal and mechanical loading conditions. The TBC system is composed of an EB-PVD yttria partially stabilised zirconia topcoat (TC) and a platinum nickel aluminide bondcoat (BC) deposited on a single crystal nickel based superalloy. Depending on the kind of heat treatment (isothermal or thermo-mechanically cycled), different types of defects (pores, cracks, re-oxidation), were observed at the BC/TGO interface, the TGO/TC interface or in the alumina scale. Damage processes were identified and discussed according to the type of imposed heat treatment.

Relation Between the Microstructure and Properties of High-Chromium Cast Iron

The effects of carbon and chromium and of the kind of heat treatment on the structure and properties of high-chromium cast iron (HCCI) is investigated. The methods of x-ray spectral and metallographic analysis are used to determine the mechanical properties and wear resistance of HCCI. It is shown that it is necessary to provide an austenitic structure of the metallic matrix by hardening from 1150°C in still air in order to obtain maximum strength, impact toughness, and wear resistance of the metal. A high-temperature hold (1150°C) provides rounding of the sharp edges of the segregating carbides, which promotes additional enhancement of the combination of the properties.

The transformation behavior and the shape memory effect due to cyclic stress/strain for Ti–49.6Ni alloy

The transformation behavior for Ti–49.6 at.%Ni shape memory alloy was investigated under cyclic stress/strain by electrical resistance method and differential scanning calorimetry (DSC) method. After solution no R transformation occurred during the martensite transformation in the R– T curve, and the reverse martensite transformation temperature points A s as well as A f could be discerned clearly in the heating process. With the same kind of heat treatment, R transformation occurred after the specimen underwent cyclic stress or strain; in the meantime, the reverse transformation temperature points A s and A f were illegible during the reverse martensite transformation. The characteristics of resistance–temperature curve ( R– T curve) of Ti–49.6Ni shape memory alloy changed apparently and regularly. The results also showed that after cyclic strain, the transformation temperatures M s and A s were stable while the cyclic stress is not. That implied that the low-strain cycling itself could be used as a better method for mechanical training. For both stress and train cycling, the martensite transformation temperature M s was lower than that of the raw material. It indicated that stress/strain cycling would inhibit the martensite transformation and directly result in the R transformation occurring. The shape memory effect after cyclic stress/strain were also studied, respectively.

The origin of the red luminescence in incipient ferroelectric KTaO 3

The red luminescence at 686 nm in KTaO 3 has been investigated in pure as-grown, ultra-high purity and doped (Al, Ba, Cr, Fe, Er, Li, Mg, Ni, Rh, V, Cr, Zr) crystals from different growth laboratories. In contrast to earlier results [P. Grenier, G. Bernier, S. Jandl, B. Salce, L.A. Boatner, J. Phys.: Cond. Matt 1 (1989) 2515; P. Grenier, S. Jandl, M. Blouin, L.A. Boatner, Ferroel. 137 (1992) 105] which led to the conclusion that the main center should be an intrinsic defect Ta 3++O 2− vacancy, we found a strong dependence on any kind of heat treatment (oxidation or reduction) leading to a decreasing or vanishing of the red luminescence after these treatments. The red luminescence was found to be sample dependent, together with a dependence on growth procedure. Therefore, excited metastable defect states which can be quenched in the same manner by reduction or oxidation treatments, have to be discussed as the origin of the red luminescence. The (i) two hole polarons localised near a Ta 3+, (ii) Ta 3+–O 0-center (a vibronic exciton with double charge transfer) and at last (iii) a pair of Ta 3+, one in a Ta 5+ site and the other in a K + site are discussed as possible centers connected with the red luminescence.

Possible nature of the red luminescence in incipient ferroelectric KTaO3

The red luminescence at 686 nm in KTaO3 is investigated in pure as-grown and doped (Al, Ba, Cr, Fe, Er, Li, Mg, Ni, Rh, V, Zr) crystals from different growth laboratories. In contrast to earlier results [1,2] which led to the conclusion that the main center should be an intrinsic defect Ta3+ + O2- vacancy, we found that the red luminescence to be sample dependent, together with a dependence on growth procedure. Moreover a strong dependence on any kind of heat treatment (oxidation or reduction) leading to a decreasing or vanishing of the red luminescence after above treatments, was found. Therefore excited metastable defect states have to be discussed for the origin of the red luminescence. The (i) two hole polarons localized near a Ta3+, (ii) Ta3+-O0-center (a vibronic exciton with double charge transfer) and at last (iii) a pair of Ta3+, one in a Ta5+ site and the other in a K+ site are discussed as possible centers connected with the red luminescence.

Tool Life in Solid Forward Extrusion

Summary Tool life in bulk metal forming is limited both by wear and fracture. Due to the variation of life of Individual tools, the reliability of operation is low. For reducing tool costs a reduction of the absolute costs of tools as well as an increase of tool life should be achieved. Tool failure should either be avoided or it should be made predictable for reducing costs by Interrupted production. In cold extrusion, tool failure is often caused by fracture, especially in cases of complicated shapes of the workpieces. Until now, crack initiation and crack propagation (depending on the kind of heat treatment of the tool steel) systematically have not been studied. In the present work tool fracture in solid forward extrusion has been investigated. For this purpose mechanical properties of specimens of the tool steel were related to the tool life in extrusion tests under simulated production conditions. To understand the fracture behaviour due to fatigue, a fracture mechanics calculation was carried out using the weight-function method. The results of the investigation enable an estimation of tool life depending on the kind of heat treatment and hence, an optimized heat treatment for the special case of application.