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A B S T R A C TThe aim of this work was to determine the effect of temperature on the formation of acrylamide in cocoa beans during drying treatment by an experimental and computational study, in order to assess the presence of this neoformed compound from postharvest stage. The computational study was conducted on the reaction between fructose, glyoxal from glucose, and on asparagine at the M06-2X/6-31þG(d,p) level, under cocoa bean drying conditions at 323.15 to 343.15 K. The proposed reaction for acrylamide formation consisted of seven steps, which required to progress a via cyclic transition state of the four members. In addition, step III (decarboxylation) was considered to be the rate-determining step. Glucose followed an E1-like elimination and fructose exhibited an E1cb-like elimination. Computational model showed that the reaction of acrylamide formation was favored by fructose rather than glucose.The content of reducing sugars, asparagine and acrylamide in fermented and dried cocoa from two subregions of Antioquia-Colombia, as well as roasted cocoa, were evaluated by UHPLC-C-CAD and UHPLC-QqQ. The concentrations of monosaccharides measured at the end of the fermentation and drying process of cocoa nibs showed greater decreases in the levels of fructose as compared to glucose, supporting the main model hypothesis. Acrylamide formation only occurred in Bajo Cauca due to the presence of both precursors and fast drying time (72 h). Finally, it was possible to find the conditions to which acrylamide can be formed from the drying process and not only from roasting, information that can be used for future control strategies.

The nature of bonding along the gas-phase thermal decomposition of 1-chlorohexane to produce 1-hexene and hydrogen chloride has been examined at the DFT M05-2X/6-311+G(d,p) level of theory. Based on results both from energetical and topological analysis of the electron localization function (ELF), we propose to rationalize the experimental available results not in terms of a decomposition via a four-membered cyclic transition structure (TS), but properly as a two stage one step reaction mechanism featuring a slightly asynchronous process associated to the catalytic planar reaction center at the TS. In this context, the first electronic stage corresponds to the ‫ܥ‬ ఋା ••• ‫݈ܥ‬ ఋି bond cleavage, which take place on the activation path earlier the transition structure be reached. There is no evidence of a Cl-C bond at the TS configuration. The second stage, associated to the top of the energy barrier, includes the TS and extends beyond on the deactivation pathway towards the products. The existence of both bonding and nonbonding non covalent interactions (NCI) are also revealed for the first time for the TS configuration. 17 47 to point -9 along the IRC reaction pathway. Arbitrarily the second stage concerning main electronic changes will be associated to points -9 to +9. Both stages refer to regions where key electronic changes driving the transformation take place. Note that from point -34 to point -5, the population associated to the disynaptic basin V(C α ,C β ) increases from 1.99e to 2.20e, whereas the population integrated in the disynaptic protonated basin V(H β ,C β ) decreases from 1.98e to 1.72e. The attractor corresponding to the forming double bond localizes out of the line connecting the carbon center cores. This topology for the C  -C  region remains unchanged until point 12 in region g. At the top of the energy barrier, within the entire interval IRC=(-0.97962,+0.97971), i.e., point -9 to point 9, we observe an isolated electron localization region integrating to 7.64e which is associated to the migrating chlorine center. This picture, on the top of the barrier, corresponds to a lonely chlorine atom bearing an electronic charge of -0.64 while evolving to the encounter of the H β center.Thereafter, within the tiny region d four valence monosynaptic basins V(Cl) associated to the negatively charged chlorine center adopt a tetrahedral conformation, with an increasing in the population from 7.64e to 7.70e. In this region the valence basins populations for V(C α ,C β ) and V(H β ,C β ) varies from 2.41e to 2.34e, and from 1.81e to 1.51e, respectively. The migrating chlorine center develops thus a maximum charge of -0.71 at the transition structure (point 0). ELF picture of bonding reveals that activation events are mainly associated to conformational changes in preparation of the reaction center (region a), followed by the breaking of the Cl-C α bond (regions b and c), and the start of the migration of H  atom with the associated bonding changes at C α -C β -H β moiety (regions c and d). Regarding t...