Fatty Acid Composition, Tocopherols, Volatile Compounds, and Sensory Evaluation of Low Morphine Yielding Varieties of Poppy (Papaver somniferum L.) Seeds and Oils.

Low morphine yielding winter ('Zeno Morphex') and summer ('Viola', 'Mieszko', 'Borowski') poppy varieties were investigated for their chemical composition and sensory properties. The oil content of the 13 seed samples as well as that of fatty acids, tocopherols, and volatile compounds in the respective oils were determined, and the sensory profiles of the seeds and oils were established. Linoleic acid made up 70.7-75.2% of the fatty acids. High amounts of γ-tocopherol were detected, especially in variety 'Viola' (287 ± 34 mg kg-1), while δ-tocopherol was only present in 'Zeno Morphex' (3.9 ± 0.6 mg kg-1). The most abundant volatiles were caproic acid (1.4-148 µg g-1), hexanal (0.9-15.2 µg g-1), 1-hexanol (0.3-20.1 µg g-1), limonene (1.3-9.4 µg g-1), and 2-pentylfuran (1.0-7.8 µg g-1). The sensory panel distinguished samples in particular by fatty/oily, rancid, sweet, and green attributes, the green aroma being correlated to three methoxypyrazines only present in summer poppies.

The Plant Sesquiterpene Nootkatone Efficiently Reduces Heterodera schachtii Parasitism by Activating Plant Defense.

Plant parasitic nematodes, including the beet cyst nematode Heterodera schachtii, constitute a devastating problem for crops worldwide. The limited availability of sustainable management options illustrates the need for new eco-friendly control means. Plant metabolites represent an invaluable source of active compounds for the discovery of such novel antagonistic agents. Here, we evaluated the impact of eight plant terpenoids on the H. schachtii parasitism of Arabidopsis thaliana. None of the metabolites affected the plant development (5 or 10 ppm). Nootkatone decreased the number of adult nematodes on A. thaliana to 50%, with the female nematodes being smaller compared to the control. In contrast, three other terpenoids increased the parasitism and/or female size. We discovered that nootkatone considerably decreased the number of nematodes that penetrated A. thaliana roots, but neither affected the nematode viability or attraction to plant roots, nor triggered the production of plant reactive oxygen species or changed the plant's sesquiterpene profile. However, we demonstrated that nootkatone led to a significant upregulation of defense-related genes involved in salicylic and jasmonic acid pathways. Our results indicate that nootkatone is a promising candidate to be developed into a novel plant protection agent acting as a stimulator of plant immunity against parasitic nematodes.

Biosynthesis of 2-acetyl-1-pyrroline in rice calli cultures: Demonstration of 1-pyrroline as a limiting substrate.

The role of 1-pyrroline was studied via feeding experiments using rice calli cultures to gain further insight into the key steps of 2-acetyl-1-pyrroline (2AP) biosynthesis in rice. The origin of the acetyl donor was also studied through stable isotope labelled substrates. Incubation of fresh calli from a fragrant rice variety (Aychade) and a non-fragrant variety (Gladio×Fidji K2) with 1-pyrroline led to a significant increase in 2AP in both varieties. Importantly, the amount of 2AP in the non-fragrant variety could be greatly enhanced by this supplementation. When rice calli were fed with increasing levels of 1-pyrroline, 2AP levels increased accordingly. Our data show that 1-pyrroline is a limiting factor for 2AP synthesis in rice. Heat treatment of calli suggested that 1-pyrroline might be enzymatically acetylated. The presence of labelled 2AP in calli supplemented with [U-(13)C]glucose, sodium acetate (1,2-(13)C2) and sodium octanoate (1,2,3,4-(13)C4) suggested that these compounds are possible candidates for acetyl group-donors of 2AP, predominately in the form of intact labelled (13)C2-units.

Accurate mass-time tag library for LC/MS-based metabolite profiling of medicinal plants.

We report the development and testing of an accurate mass-time (AMT) tag approach for the LC/MS-based identification of plant natural products (PNPs) in complex extracts. An AMT tag library was developed for approximately 500 PNPs with diverse chemical structures, detected in electrospray and atmospheric pressure chemical ionization modes (both positive and negative polarities). In addition, to enable peak annotations with high confidence, MS/MS spectra were acquired with three different fragmentation energies. The LC/MS and MS/MS data sets were integrated into online spectral search tools and repositories (Spektraris and MassBank), thus allowing users to interrogate their own data sets for the potential presence of PNPs. The utility of the AMT tag library approach is demonstrated by the detection and annotation of active principles in 27 different medicinal plant species with diverse chemical constituents.

Expression of multidisciplinary flavor science: research highlights from the 12th Weurman Symposium.

The 12th Weurman Flavour Research Symposium contributed 177 lectures and posters to the wealth of flavor knowledge; these were presented in eight sessions: biology, retention and release, psychophysics, quality, thermal generation, bioflavors, impact molecules, and analytics. Emerging topics were discussed in three workshops dealing with flavor and health, in vivo flavor research, and flavor metabolomics. It has been an excellent forum for passionate exchange of recent results obtained in traditional and emerging fields of flavor research. The symposium allowed coverage of the broad diversity of flavor-related topics: comprising odor and taste; applying targeted and holistic approaches; using sensorial, chemical, biological, physical, and chemometric techniques; as well as considering nutrition and health aspects.