Effect of Pre-Slaughter Practises and Early Post-Mortem Interventions on Sheep Meat Tenderness and Its Impact on Microbial Status

Tenderness, together with flavour, is the main quality trait that defines consumer acceptance of sheep meat. The factors affecting tenderness can be grouped as those influenced before slaughter, in the early post-mortem intervention and, finally, during the aging period. These factors have been extensively studied with respect to tenderness, but the impact of early post-mortem interventions and subsequent aging on the microbial quality of the final products has not been broadly reviewed to date. In this review, the authors summarize the most recent knowledge on lamb meat tenderness management and how such practices may impact the final meat quality, especially its microbial status. The impacts of pre-slaughter factors (age, sex, diet, genotype and transport) and post-mortem interventions (chilling regime, electrical stimulation, or hanging method), are described and comprehensively discussed.

Improvement of Pitting-Corrosion Resistance of Ultrafine-Grained 7475 Al Alloy by Aging

The effect of aging on the resistance to pitting corrosion of ultrafine-grained 7475 aluminium (Al) alloy processed by hydrostatic extrusion (HE) is studied. Differences in the microstructure were investigated using secondary electron (SEM) and transmission electron microscopy (TEM). Corrosion tests were performed in 0.1 M NaCl, and characterization of corroded surface was performed. The results of this work show that the pitting susceptibility of ultra-fine grained 7475Al is related to the distribution of MgZn2 precipitates. After HE, the formation of An ultrafine-grained microstructure at the grain boundaries of ultrafine grains is observed, while subsequent aging results in the formation of MgZn2 precipitates in the grain interior. Grain refinement increases susceptibility to localized attack, while the subsequent aging improves the overall corrosion resistance and limits the propagation of corrosion attack.

Effects of beef carcass size, and subsequent aging time, on yield and color characteristics of top round steaks

Variation in cut size and weight of fabricated subprimals is a challengeof increased beef carcass weights. Subsequently, variation in carcass size hasresulted in consistency challenges during retail display. Theobjective of this study was to assess the retail shelf-life of commerciallyavailable top rounds from varying carcass weights. In the current study, 21industry average weight (AW, 340-409 kg; no industry discount) beef carcassesand 21 oversized (OS, exceeding 454 kg; receive a discount) beef carcasses wereevaluated. Carcasses were selected at a commercial beef packing plant, wherethe left and right (paired) top round subprimals of each carcass were procured.Paired top rounds were assigned to a short (8d), average (23d), or extended(42d) postmortem aging period. After wet-aging, subprimals were fabricated intosteaks for additional analysis. Steaks were evaluated as whole top round steaksor further fabricated into “superficial” and “deep” portions at 5.08 cm fromthe superficial edge of the Semimembranosus and the Adductor muscle.Top rounds and steaks from OS carcasses were larger (P < 0.01) thanthose from AW carcasses. Quantitative color of the anatomically deep locationsof the OS steaks had the greatest mean L* (lightness; P < 0.01), a*(redness; P < 0.01) and b* (yellowness; P < 0.01) values. Extendingthe aging timeline increased L* (lightness; P < 0.01), decreased a*(redness; P < 0.01), and decreased b* (yellowness; P <0.01). Alternative top round steak fabrication which separates the deep andsuperficial anatomical locations could be an effective means of providing moreuniform steaks. 

Reducing the flaws of 08Yu steel sheet blanks, designed for cold stamping products

The aim of the work is to develop a method of increasing the technological plasticity while maintaining the strength and preventing aging of blanks of cold-rolled sheet steel 08Yu. The task of this work is research and determination of optimal temperature-time parameters of high-speed contact recrystallization annealing and subsequent aging of 08Yu steel sheet blanks to obtain the required level of mechanical properties that would improve their deformability and ability of very deep drawing during cold stamping of products. The optimal parameters of the speed mode are set recrystallization annealing of cold-rolled 08Yu sheet steel, which provides the best structure and properties for further cold pressure treatment. The temperature-time modes of further aging and possibilities to prevent the processes of its natural aging during prolonged operation or transportation have been studied. The method and modes of heat treatment of blanks from finished 08Yu sheet steel to facilitate their deformability and improve stamping in order to reduce waste in the manufacture of products by cold deformatiion with deep and complex drawing were suggested.

Assessment of the health status of middle-aged and elderly men with head scale, SF-36, IIEF5, AMS, and IPSS

Background Identifying practical and distinguished indicators and influencing factors of male aging may be useful in predicting subsequent aging trends, designing personalized prevention, and improving lifestyle and health. Methods A cross-sectional, population-based study was performed in Jiashan County, China in 2016. A total of 690 local male residents, aged 40 to 80 years, were eligible for recruitment. Demographic and lifestyle information was collected through structured interviews. A self-designed head scale, the Medical Outcomes Study 36-item Short Form (SF-36), International Index of Erectile Function (IIEF5), Aging Males’ Symptoms (AMS), and International Prostate Symptom Score (IPSS) were used. Analysis of variance, local polynomial regression smoothing curves, multiple linear regression, and partial correlation analyses were performed. Results All the scales deteriorated with increasing age (P < 0.01), especially from the age of 60. The most significant changes between adjacent age groups were found in IIEF5 scores (16.7, 43.5 and 39.4%). Income, nutrition, personality and neighborhood relationship had an effect on SF-36 and AMS after adjusting for age (P < 0.01). Furthermore, neighborhood relationship modified the age effect on the head scale score and IIEF5 (P = 0.03); nutrition modified the relationship between age and SF-36 (P < 0.01). Conclusions Recession of reproductive health may be a distinct predictor of male aging. The associations of social inequalities or personality and health offer potential interventions for men’s health in aging. Self-reported scales may limit the precision and more physical fitness tests could be combined for a more precise assessment.

Microstructure and Mechanical Properties of Al-Mg-Si Similar Alloy Laminates Produced by Accumulative Roll Bonding

As the applications of heterogeneous materials expand, aluminum laminates of similar materials have attracted much attention due to their greater bonding strength and easier recycling. In this work, an alloy design strategy was developed based on accumulative roll bonding (ARB) to produce laminates from similar materials. Twin roll casting (TRC) sheets of the same composition but different cooling rates were used as the starting materials, and they were roll bonded up to three cycles at varying temperatures. EBSD showed that the two TRC sheets deformed in distinct ways during ARB processes at 300°C. Major recrystallizations were significant after the first cycle on the thin sheet and after the third cycle on the thick sheet. The sheets were subject to subsequent aging for better mechanical properties. TEM observations showed that the size and distribution of nano-precipitations were different between the two sheet sides. These nano-precipitations were found to significantly promote precipitation strengthening, and such a promotive effect was referred to as hetero-deformation induced (HDI) strengthening. Our work provides a new promising method to prepare laminated heterogeneous materials with similar alloy TRC sheets.

Micro-Shear Bands and Their Enhancement on High Temperature Strength of Mg-Gd-Y-Zr Alloy

When Mg-Gd-Y-Zr alloy is cold forged, a large number of nano-micro shear bands are formed inside the grains. It is observed that micro-shear bands hinder the sliding of dislocations, resulting in an increase in tensile strength at elevated temperatures. The subsequent aging treatment further strengthens the alloy. Compared with unforged aged alloys, aged samples with pre-generated micro-shear bands exhibit higher strength at room temperature to 250 °C, but exhibit similar properties at higher temperatures. Microstructure characterization and fracture behavior analysis indicate that the transformation of deformation mode from dislocation sliding to grain boundary activity is mainly due to the change of mechanical properties with temperature. In addition, the alloy precipitates with the aid of dislocations during tension, and exhibits higher strength at 200 °C than that at room temperature.