Difference in leaf herbivory between two plant-ant taxa associating with a myrmecophytic species, Macaranga lamellata

Macaranga lamellata (Euphorbiaceae) is a myrmecophytic species that is protected against herbivorous insects by two plant-ant taxa, Colobopsis macarangae (Formicinae) and Crematogaster spp. (Myrmicinae). Although a single M. lamellata tree houses one plant-ant colony of either of the two taxa, both coexist in a population of M. lamellata in a Bornean rainforest. To elucidate the extent of herbivory damage upon M. lamellata trees associated with Colobopsis relative to trees associated with Crematogaster, we counted the number of leaf galls and measured the leaf loss area chewed by leaf-chewing insects on M. lamellata in the forest. The occurrence of gall midges was not significantly different between the trees associated with the two plant-ants, while the degree of leaf-chewing herbivory was significantly higher on Crematogaster-associated trees than Colobopsis-associated trees. The data gathered on chewing traces observed on Crematogaster-associated trees indicated that most herbivory damage was caused by a phasmid species. These results suggest that the herbivory pressures and occurrences of different herbivore species differ between Crematogaster-associated and Colobopsis-associated trees within a population of M. lamellata

A sensory 3-D map of the odor description space derived from a comparison of numeric odor profile databases

Many authors have proposed different schemes of odor classification, which are useful to aid the complex task of describing smells. However, reaching a consensus on a particular classification seems difficult because our psychophysical space of odor description is a continuum and is not clustered into well-defined categories. An alternative approach is to describe the perceptual space of odors as a low-dimensional coordinate system. This idea was first proposed by Crocker and Henderson in 1927, who suggested using numeric profiles based on 4 dimensions: fragrant, acid, burnt, and caprylic. In the present work, the odor profiles of 144 aroma chemicals were compared by means of statistical regression with comparable numeric odor profiles obtained from 2 databases, enabling a plausible interpretation of the 4 dimensions. Based on the results and taking into account comparable 2D sensory maps of odor descriptors from the literature, a 3D sensory map (odor cube) has been drawn up to improve understanding of the similarities and dissimilarities of the odor descriptors most frequently used in fragrance chemistry.Zarzo Castelló, M. (2015). A sensory 3-D map of the odor description space derived from a comparison of numeric odor profile databases. Chemical Senses. 40(5):305-313. doi:10.1093/chemse/bjv012S30531340

Medicinal Plants in Traditional Herbal Wines and Liquors in the East of Spain and the Balearic Islands

Homemade herbal preparations from the East of Spain are the witness of traditional medicine inherited from the ancient complex formulas of herbal teas and medicinal wines. In this study, we document the use of traditional alcoholic beverages, identify their ingredients, almost exclusively botanical, record the local medicinal uses of these mixtures, and discuss patterns of distribution of this knowledge in regions of eastern Spain, the Balearic Islands and Andorra. We determine marker species and relevant patterns of herbal formulas in the different regions of the territory. Homemade liquors and liqueurs are consumed for their digestive and tonic-restorative properties but they also play in some cases an important social role. The elderly remember other medicinal uses such as aperitif, emmenagogue, or antidiarrheal, for some of the most popular preparations. The herbal liqueur formulas include predominantly Lamiaceae, Asteraceae, Rosaceae, Rutaceae, and Apiaceae species. Herbs (58%), fruits (28%), and mixtures of both (12%) are ingredients of liquors and wines, being the aerial parts the most frequent in terms of species (30%) and records (49%). Dictamnus hispanicus, Santolina villosa, Salvia blancoana subsp. mariolensis, Rosmarinus officinalis, Thymus vulgaris, and Clinopodium serpyllifolium subsp. fruticosum are the species most frequently used. Others species used to a lesser extent as Polygonatum odoratum, Thymus moroderi, and Saxifraga longifolia are restricted to locally homemade preparations because their collection and uses require special knowledge of the rare or endemic flora. Sustainability of these practices is strongly limited by the overall loss of local traditional knowledge and by the limited availability of most of the wild species; some of them are endangered or threatened mainly by the loss of their natural habitats. Cultivation and domestication are a promising alternative to collecting from wild populations. The cultivation of Thymus moroderi in the province of Alicante and Polygonatum odoratum in the province of Teruel are good examples. There is a notable decrease in the complexity of the formulas registered throughout the nearly 15 years of the study. This is interpreted as a consequence of a loss of knowledge, less accessibility to wild resources, and changes in traditions and preferences

Selected markets for the essential oils of lemongrass, citronella and eucalyptus

The essential oils of lemongrass, citronella and eucalyptus have traditionally been regarded as large-volume oils used in a very wide range of perfumery products and, to a much smaller extent, in flavours. They are used either as perfumery oils in their own right or, particularly in the case of lemongrass oil and citronella oil, as sources of individual chemical constituents or their derivatives which are themselves important materials in the perfumery or flavouring industries. As oils in their own right they tend to be used in relatively low-priced products, although some of their derivatives have applications in high-class perfumery. This report contains a review of recent market trends and their implications for the future of these essential oils and for both existing and potential producers

The Discovery of Citral-Like Thiophenes in Fried Chicken

The isomers of 3,7-dimethyl-2,6-octadienal, more commonly known together as citral, are two of the most notable natural compounds in the flavor and fragrance industry. However, both isomers are inherently unstable, limiting their potential use in various applications. To identify molecules in nature that can impart the fresh lemon character of citral while demonstrating stability under acidic and thermal conditions has been a major challenge and goal for the flavor and fragrance industry. In the study of fried chicken, several alkyl thiophenecarbaldehydes were identified by gas chromatography–mass spectrometry and gas chromatography–olfactometry that provided a similar citral-like aroma. The potential mechanism of formation in fried chicken is discussed. Furthermore, in order to explore the organoleptic properties of this structural backbone, a total of 35 thiophenecarbaldehyde derivatives were synthesized or purchased for evaluation by odor and taste. Certain organoleptic trends were observed as the length of the alkyl or alkenyl chain increased or when the chain was moved to different positions on the thiophene backbone. The 3-substituted alkyl thiophenecarbaldehydes, specifically 3-butyl-2-thiophenecarbaldehyde and 3-(3-methylbut-2-en-1-yl)-2-thiophenecarbaldehyde, exhibited strong citrus and citral-like notes. Several alkyl thiophenecarbaldehydes were tested in high acid stability trials (4 °C vs 38 °C) and outperformed citral both in terms of maintaining freshness over time and minimizing off-notes. Additional measurements were completed to calculate the odor thresholds for a select group of thiophenecarbaldehydes, which were found to be between 4.7–215.0 ng/L in air