Effect of prolonged heat treatment from 48 °C to 63 °C on toughness, cooking loss and color of pork

The effect of low temperature long time (LTLT) heat treatment at 48 °C, 53 °C, 58 °C, and 63 °C for T(c) (time to reach a core temperature equal to the water bath), T(c)+5h holding time, and T(c)+17h holding time was studied in Longissimus dorsi and Semitendinosus muscles from slaughter pigs and sows. Meat toughness (Warner-Bratzler Shear Force), cooking loss and color (Minolta L*a*b*-values) was measured and in the cooking loss the amount of heat-soluble collagen and activity of cathepsin B+L was determined. Decreasing shear force and increasing cooking loss during LTLT treatment was observed between 53 °C and 58 °C. Furthermore, increasing temperature from 53 °C to 58 °C and increasing time from T(c) to T(c)+17h increased the solubility of collagen. Residual activity of cathepsin B+L in LTLT treated pork was mainly affected by temperature, showing the highest activity at 58 °C and 63 °C.     

Serological methods and selective agars to enumerate Campylobacter from broiler carcasses: data from inter- and intralaboratory analyses

Routine analytical means to estimate Campylobacter numbers per milliliter of carcass rinses are needed in high-sample-throughput poultry laboratories. We compared three serological confirmatory tests that were amenable to such a setting when used in conjunction with Campy-Line and Campy-Cefex Campylobacter selective agars. Pre- and post-chlorinated chiller carcass rinse samples were obtained and held on ice, then analyzed 24 h later in two separate laboratories. Presumptive counts on both pre- and postchiller samples from between laboratories on individual agars and between both agars were highly correlated. Agreement among the three serological tests was nearly complete. The use of a premeasured and dried latex anti-Campylobacter antibody agglutination test format was superior to that of either a liquid latex agglutination format or a direct phosphate-buffer microscopic technique in terms of practicality as was the inclusion of an unarmed latex control to detect auto agglutination. A routine procedure for Campylobacter level estimation was suggested. This procedure, when used in conjunction with a serological confirmatory step, should provide processors with a means to assess reductions in numbers per milliliter of carcass rinses versus strictly presence-absence testing.     

Influence of chromium diboride on the oxidation resistance of ZrB2-MoSi2 and ZrB2-SiC ceramics

The effect of chromium diboride addition on the densification process and oxidation behavior of two ZrB₂-MoSi₂ and ZrB₂-SiC baseline systems was studied. CrB₂ was beneficial in lowering the sintering temperature owing to the tendency of its oxide to react with MoSi₂ and SiC forming low-melting phases that helped the powder consolidation. Oxidation at 1500 °C induced the formation of further boron oxide as first consequence. In one case, when CrB₂ was combined with MoSi₂, an improved oxidation resistance was observed due to the stabilization of Cr-borides in the subscales saturated with B₂O₃. In the other case, when it was combined with SiC, the excessive low viscosity of the borosilicate glass facilitated the consumption of a thicker portion of materials as compared to the ZrB₂-SiC reference.     

The Interaction of Titanium Diboride with Chromium

Powder Metallurgy and Metal Ceramics - The interaction of titanium diboride with chromium was studied in the temperature range 1200– 1950°C in vacuum. A solid-phase reaction was...     

Investigations on the Kinetic Energy of Trapped Ions by Consideration of Ion/Molecule Collisions

Abstract

To utilize the capabilities of the r.f. ion trap for high-precision spectroscopy and for the study of ion/molecule collisions, the kinetic energy of the ion cloud must be known as precisely as possible. One method for the determination of ion cloud kinetic energy is to measure the rate constant of a given reaction. We have investigated this method under ultra-high vacuum conditions which are those used in spectroscopic experiments and studies of ions in dilute media.     

Ecohydrological Landscape Management for Human Well-Being

Abstract

This paper introduces a new perspective on water resources emphasizing the role of water vapor flows for human well-being. The connections between freshwater and ecosystem services in terrestrial environments are addressed, particularly the role of freshwater for the biota that sustains the flow of ecosystem services and the role of the biota that modifies freshwater flows. First, the water dependence of terrestrial ecosystem services and food production are analyzed. Secondly, two examples of unintentional, large-scale, water-mediated cascading effects related to ecosystem services that result from local, uncoordinated decisions in Australia and South Africa are discussed. These two countries are taking the lead in the management of freshwater flows and terrestrial ecosystem services. Issues including potential conflicts of interest and trade-offs between food (or timber) production and ecosystem services at the catchment scale are taken into account. A world-wide, intentional ecohydrological landscape approach to handle these issues is suggested. One important step towards a more integrated approach to freshwater is the development of flexible institutional structures.     

Relationship between meat toughness and properties of connective tissue from cows and young bulls heat treated at low temperatures for prolonged times

The aim of the current study was to elucidate whether cows and young bulls require different combinations of heating temperature and heating time to reduce toughness of the meat. The combined effect of heating temperature and time on toughness of semitendinosus muscle from the two categories of beef was investigated and the relationship to properties of connective tissue was examined. Measurements of toughness, collagen solubility, cathepsin activity and protein denaturation of beef semitendinosus heated at temperatures between 53 °C and 63 °C for up to 19 1/2 h were conducted. The results revealed that slightly higher temperatures and prolonged heating times were required to reduce toughness of semitendinosus from cows to the same level as in young bulls. Reduced toughness of semitendinosus as a result of low temperature for prolonged time is suggested to result from weakening of the connective tissue, caused partly by denaturation or conformational changes of the proteins and/or by solubilization of collagen.     

基于SolidWorks和Adams的翻料机冲击研究

利用ADAMS软件建立半自动液压式翻料机的数字化虚拟平台,对翻料机的落料口进行柔性化建模,按ADAMS中冲击函数模型进行虚拟冲击,得出建模的抗冲击极限.此方法可以简化机械产品的设计开发过程,缩短产品开发周期,减少费用和成本,获得最优的创新设计产品.