A novel method for monitoring troponin T fragment from rabbit skeletal muscle during aging using quartz crystal microbalance

The novel sandwich composite structure: a new detection strategy for the ultra-sensitive detection of cyclotrimethylenetrinitramine (RDX)

This study presents a novel sandwich composite structure that was designed for the ultra-sensitive detection of cyclotrimethylenetrinitramine (RDX). Au nanorod arrays (Au NRAs) were prepared and bound to 10^-7M 6-MNA as adsorption sites for RDX, while Au nanorods (Au NRs) were modified using 10^-5M 6-MNA as SERS probes. During detection, RDX molecules connect the SERS probe to the surface of the Au NRAs, forming a novel type of Au NRAs-RDX-Au NRs 'sandwich' composite structure. The electromagnetic coupling effect between Au NRs and Au NRAs is enhanced due to the molecular level of the connection spacing, resulting in new 'hot spots'. Meanwhile, Au NRAs and Au NRs have an auto-enhancement effect on 6-MNA. In addition, the presence of charge transfer in the formed 6-MNA-RDX complex induced chemical enhancement. The limits of detection of RDX evaluated by Raman spectroscopy using 6-MNA were as low as 10^-12mg ml^-1(4.5 × 10^-15M) with good linear correlation between 10^-12and 10^-8mg ml^-1(correlation coefficientR² = 0.9985). This novel sandwich composite structure accurately detected RDX contamination in drinking water and on plant surfaces in an environment with detection limits as low as 10^-12mg ml^-1and 10^-8mg ml^-1.

Effect of wooden breast on postmortem changes in chicken meat

Wooden breast is a common problem in the poultry industry, occurring when broiler breast meat becomes rubber-like and extremely hard. Unclear points remain regarding the mechanical strength changes caused by post-mortem biochemical changes in wooden breasts. This study aimed to investigate this knowledge gap. We found endogenous protease activity to be high in wooden breasts and observed a 30 kDa fragment of troponin T (an indicator of postmortem tenderness) from day 1 postmortem. The amount of intramuscular connective tissue in wooden breasts was greater than that of normal breast meat, particularly in the perimysium. The intramuscular connective tissue structure and quantity significantly affect the mechanical strength of meat. It became clear that the wooden breasts are much more mechanically stronger than normal breasts at postmortem day 5 because the large amount of intramuscular connective tissue in the wooden breasts has hardly changed even 5 days postmortem.

Cold shortening decreases the tenderization of Biceps femoris muscle from lambs

SUMMARY This study evaluates the effects of Normal Shortening (NS) and Cold Shortening (CS) in sarcomere length, Warner-Bratzler shear force (WBS) and tenderization process examined by Myofibrillar Fragmentation Index (MFI). The Biceps femoris muscle from ten Dorper x Santa Inês lambs was randomly assigned to 1) NS = cooling of the muscle in the carcass for 24 hours in a cold room at 4°C; or 2) CS = rapid cooling, in ice bath, of the muscle removed from the carcass immediately after slaughter. Sarcomere Length (SL) was determined in the collected samples 24 hours after slaughter and WBS and MFI in the aging periods (1 or 10 days post-mortem). The WBS value of the meat for 1 and 10 days were greater (P<0.05) for CS (4.90 ± 0.42 and 3.73 ± 0.42 kgf, respectively) than NS (4.07 ± 0.36 and 2.98 ± 0.38 kgf, respectively). There were negative correlations between WBS and SL (r= −0.59 and r=−0.69, P< 0.05) at 1 and 10 postmortem, respectively. Furthermore, there were positive correlations for MFI and SL (r= 0.46 and r=0.48, P< 0.05) at days 1 and 10, respectively. These results point to a negative impact of sarcomere cold shortening in the sheep meat tenderization process in the hindlimb muscle.