Use of gas chromatography-olfactometry to identify key odorant compounds in dark chocolate. Comparison of samples before and after conching

After vacuum distillation and liquid-liquid extraction, the volatile fractions of dark chocolates were analyzed by gas chromatography-olfactometry and gas chromatography-mass spectrometry. Aroma extract dilution analysis revealed the presence of 33 potent odorants in the neutral/basic fraction. Three of these had a strong chocolate flavor: 2-methylpropanal, 2-methylbutanal, and 3-methylbutanal. Many others were characterized by cocoa/praline-flavored/nutty/coffee notes: 2,3-dimethylpyrazine, trimethylpyrazine, tetramethylpyrazine, 3(or 2),5-dimethyl-2(or 3)-ethylpyrazine, 3,5(or 6)-diethyl-2-methylpyrazine, and furfurylpyrrole. Comparisons carried out before and after conching indicate that although no new key odorant is synthesized during the heating process, levels of 2-phenyl-5-methyl-2-hexenal, Furaneol, and branched pyrazines are significantly increased while most Strecker aldehydes are lost by evaporation.     

The newly proposed EU risk assessment concept for the sediment compartment

Within the frame of the EU Existing Chemicals Regulation (793/93/EEC), a new concept for the assessment of the sediment compartment has been developed. During the assessment process it has become clear that for substances that strongly adsorb or bind to sediment the equilibrium partitioning method (EPM) presently employed is not sufficient. The new approach is therefore based on long-term sediment tests with benthic organisms. A testing strategy has been developed which considers species which represent different habitats and feeding strategies in order to adequately address all possible routes of exposure. The new concept has proven to be valuable in risk assessments, two examples (3,4-DCA, DODMAC) of which are shown in more detail.     

Linking the B ring hydroxylation pattern of condensed tannins to C, N and P mineralization. A case study using four tannins

Condensed tannins (CTs) are a major component of litter inputs, but little is known about the effects of tannin structural variations on soil biological processes and organic matter development. Four different CTs extracted from balsam fir, western red cedar, kalmia and black spruce were added to Corsican pine litter and subsequently incubated for 16 weeks in order to investigate the effect of the B ring hydroxylation pattern on C, N and P transformations. While for C mineralization the chain length and stereochemistry of the CTs seemed to be a more important parameter, net N and P mineralization rates were clearly reduced compared with non-amended litter. With regard to the B ring hydroxylation, the prodelphinidin (PD) CTs having predominantly three hydroxy groups at the B ring (balsam fir and western red cedar) exhibited significantly lower mineralization rates than the procyanidin (PC) CTs having two OH groups (kalmia and black spruce). The same was true for net nitrification, but this process was only slightly affected by the CTs. Although based on only four CTs, this study indicates that B ring hydroxylation is an important variable determining net N and P mineralization rates. Our results support previous suggestions that PD tannins bind to or react more strongly with soil organic matter. Therefore, more than PC tannins, they reduce the availability of organic N for mineralization as well as their own detectability by standard methods for soil CT.     

Host immune responses after administration of inactivated Venezuelan equine encephalomyelitis virus vaccines—III. Kinetics for neutralizing antibody immunoglobulin class responses in donors and adoptively-immunized recipients

C57B16 mice were immunized with either live, attenuated TC-83 strain VEE virus vaccine or formalin-inactivated VEE vaccine combined with Bordetella pertussis. The kinetics of specific donor and adoptively-immunized recipient anti-VEE neutralizing antibody responses were studied. Donor mice immunized with either live or inactivated VEE virus vaccine combined with potent adjuvants develop specific anti-VEE IgM and IgG responses as early as 7 days post-immunization. Anti-VEE IgM antibody responses comprise the majority of anti-VEE neutralizing antibody at this early time period. By 14 to 21 days post-immunization, anti-VEE IgG responses predominated. When adoptively-immunized recipients were studied, the anti-VEE IgM to IgG predominance seen in donors early after administration was reversed, and for each time-period studied, recipients' serum anti-VEE antibody class responses consisted principally of IgG rather than IgM antibody. Since T-cells cooperation with B-cells is critical in the IgM-IgG antibody shift, these studies support the critical role T-cells exert in adoptive transfer in a murine model of experimental VEE infection. Furthermore, immunization with either live or inactivated VEE vaccine coupled to a potent adjuvant induce comparable donor and adoptively-immunized recipient anti-VEE antibody class responses.     

A preliminary equine abuse policy with potential application to veterinary practice

An equine abuse policy was developed as an adjunct to an equine management survey. If at least 3 of 5 categories caused concern, a report to the authorities was indicated. The policy was not used but, in the absence of other guidelines, it might assist veterinarians considering potential abuse cases.     

Acral mutilation and analgesia in 13 French spaniels

Acral mutilation and analgesia (AMA) is reported in 13 French spaniels in Canada. This newly recognized disorder shares striking similarities in clinical features and biopsy findings to the other acral mutilation syndromes or hereditary sensory neuropathies reported in German short-haired pointer dogs, English pointer dogs and English springer spaniels. Clinical signs are first noted between 3.5 and 12 months of age. Affected dogs lick, bite and severely self-mutilate their distal extremities resulting in ulcers with secondary bacterial infection. Auto-amputation of claws, digits and footpads occurs in severe cases. Single or multiple feet can be affected. Affected dogs walked on their severely mutilated feet without evidence of pain, lameness, or ataxia. The majority of the dogs were euthanized within days to months of diagnosis.     

Oesophageal strictures in cats associated with doxycycline therapy

Four cases of oesophageal stricture subsequent to doxycycline administration are reported. All cases were young to middle age (median age 3 years; range 1-7 years), and either domestic shorthair or domestic longhair breed. In all cases the predominant clinical sign was regurgitation, which developed at variable times after doxycycline administration. In all cases the reason for doxycycline use was treatment or prophylaxis of suspected infections (Mycoplasma haemofelis, Chlamydophila felis or Bordetella bronchiseptica), and the duration of therapy was variable. In one case the stricture was definitively diagnosed at post mortem examination, in the three other cases, definitive diagnosis was by endoscopy. Balloon dilation was successful in the three cases that were treated. This is the largest case series, to date, of oesophageal disease in cats associated with doxycycline administration. Caution should be exercised when administering oral medication to cats, especially doxycycline, and should be accompanied either by a water or food swallow.