Enhanced Characterization of the Smell of Death by Comprehensive Two-Dimensional Gas Chromatography-Time-of-Flight Mass Spectrometry (GCxGC-TOFMS)

Soon after death, the decay process of mammalian soft tissues begins and leads to the release of cadaveric volatile compounds in the surrounding environment. The study of postmortem decomposition products is an emerging field of study in forensic science. However, a better knowledge of the smell of death and its volatile constituents may have many applications in forensic sciences. Domestic pigs are the most widely used human body analogues in forensic experiments, mainly due to ethical restrictions. Indeed, decomposition trials on human corpses are restricted in many countries worldwide. This article reports on the use of comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GCxGC-TOFMS) for thanatochemistry applications. A total of 832 VOCs released by a decaying pig carcass in terrestrial ecosystem, i.e. a forest biotope, were identified by GCxGC-TOFMS. These postmortem compounds belong to many kinds of chemical class, mainly oxygen compounds (alcohols, acids, ketones, aldehydes, esters), sulfur and nitrogen compounds, aromatic compounds such as phenolic molecules and hydrocarbons. The use of GCxGC-TOFMS in study of postmortem volatile compounds instead of conventional GC-MS was successful

Effect of harvest and delaying controlled atmosphere storage conditions on core breakdown incidence in 'conference' pears

A logistic regression model was built to describe the effect of picking time and the most relevant commercially applied storage factors on the incidence of core breakdown in pears (Pyrus communis L. cv. Conference). The statistical analysis showed that the probability of core breakdown depended on several variables in a more complicated way than assumed before. In general, more mature fruit, stored at lower O-2 and higher CO2 concentrations, at a higher temperature and for longer times are more susceptible to core breakdown. However, delaying the controlled atmosphere (CA) conditions for 21 days decreased the core breakdown incidence efficiently even for late-picked fruit. Together with a proper delay of CA, a sufficiently high O-2 concentration during CA was most important. The model was validated with data of 16 orchards gathered over five harvest seasons in two countries which gives it a wide validity range and a high practical relevance. (C) 2002 Silsoc Research Institute. Published by Elsevier Science Ltd. All rights reserved

Utilizzo dell'1-metilciclopropene (1-MCP) per lo studio della fisiologia post-raccolta e della maturazione dei frutti

The discovery of 1-methylcyclopropene (1-MCP) as an inhibitor of ethylene action has provided an important tool in understanding fruit ripening physiology as shown by the huge amount of 1-MCPtargeted research carried out particularly, although not exclusively, in postharvest science. It has been clearly demonstrated that 1-MCP is able to improve the handling procedures and storage life of a number of commodities. In fact, 1-MCP can reduce ethylene biosynthesis, respiration, softening color changes, aroma production, and the occurrence of physiological disorders and stress responses. These effects are related to the interference of 1-MCP on the ethylene receptor functioning (1-MCP-receptor binding is irreversible) and for some of them in their transcription rate and protein stability. However, the efficacy of this olefin strongly depends upon the concentration used, the species and variety, storage condition and duration, and maturity of the fruit before the 1-MCP application. A marked effect of 1-MCP occurs in climacteric fruit, although studies carried out in nonclimacteric fruit demonstrates that this olefin can also alter specific ripening processes in these fruit types. The research results obtained by applying 1-MCP confirms the very well-known ethylene-dependent ripening processes as well as allowed tthe identification of previously unrecognized responses to ethylene. Molecular studies performed on 1-MCP-treated fruit have provided new insights into the role of ethylene in the regulation (mainly at the transcriptional and, to a lesser extent, at the translational level) of genes involved in ripening processes such as cell wall metabolism, and pigment and aromatic compound biosynthesis, as well as the signal transduction pathway of the gaseous hormone. Postharvest use of 1-MCP has improved our understanding of ethylene effects on the development of physiological disorders (e.g. superficial scald, internal breakdown) and stress responses (e.g. chilling injury and pathogen attack). This extensive information base will be extremely useful in the future development of innovative and more efficient postharvest strategies where the effect of 1-MCP could be enhanced by the concomitant applications of other storage technologies

Histology and Raman spectroscopy of limed human remains from the Rwandan Genocide

The Murambi Genocide Memorial Centre is one of the major centres in Rwanda that commemorate the 1994 Rwandan genocide. Seventeen months after the genocide, about 1000 excavated human remains were put on display in Murambi Technical School. Repeated efforts were made to desiccate the human remains with lime for educational reasons. The aim of this study was to assess their state of preservation and understand the extent of degradation of the tissue. Limed soft tissue samples from four individuals were examined with light and electron microscopy, and subjected to histological analysis. Raman spectroscopy at 785 nm and 1064 nm provided information about the impact of environmental conditions on the extent of deterioration to these samples, the presence of organics and the conversion of the associated lime from calcium hydroxide to calcium carbonate. While visual degradation of the bodies in Murambi has been reported, this study confirms deterioration at a microscopic and molecular level. Both histology and Raman spectroscopic analysis revealed that the limed bodies in Murambi were deteriorating at the time the samples were collected. The results of this study will inform future decisions regarding the long-term conservation of those human remains