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31.
Identification and aroma impact of norisoprenoids in orange juice   总被引:1,自引:0,他引:1  
Four norisoprenoids, alpha-ionone, beta-ionone, beta-cyclocitral, and beta-damascenone, along with their putative carotenoid precursors, were identified in Valencia orange juice using time-intensity GC-O, GC-MS, and photodiode array HPLC. alpha-Ionone and beta-cyclocitral are reported in orange juice for the first time. GC-O aroma peaks were categorized into seven groups with similar sensory qualities: citrus/minty, metallic/mushroom/geranium, roasted/cooked/meaty/spice, fatty/soapy/green, sulfury/solventy/medicine, floral, and sweet fruity. The four norisoprenoids contributed approximately 8% of the total aroma intensity and 78% of the total floral aroma category. The putative carotenoid norisoprenoid precursors, alpha- and beta-carotene, alpha- and beta-cryptoxanthin, and neoxanthin, were identified in the same orange juice using photodiode array HPLC retention times and spectral characteristics.  相似文献   
32.
The presence of the psyllid Calophya schini infesting the Peruvian pepper tree, Schinus molle, was detected in several localities in the region of Lisbon, in Portugal. This is the first record of this jumping plant-louse in Europe and the Palaearctic region.  相似文献   
33.
Two Gram-negative bacterial strains capable of using lupanine, the predominant quinolizidine alkaloid in Lupinus albus, as a sole carbon source were isolated from soil in which L. albus and L. luteus had been grown [Santana, F. M. et al. J. Ind. Microbiol. 1996, 17, 110-115]. In the present study, we present results suggesting that these isolates are of potential interest for removing lupanine and other quinolizidine alkaloids (QA) from the effluent resulting from the wet processing of Lupinus seeds, at temperatures within the range 20-34 degrees C. Growth in L. albus aqueous extract was diauxic, with a first period of rapid growth leading to the simultaneous consumption of a significant part of the initial concentration of QA (3 g L(-1), being 2 g L(-1) lupanine) and amino acids (1.5 g L(-1)). This period was followed by a second period of slower growth corresponding to the subsequent partial utilization (25%) of the carbohydrates (initial concentration of 20 g L(-1)) together with further removal of QA and amino acids. Despite the differences detected in the susceptibility of the two strains to lupanine toxicity, in particular at supraoptimal temperatures, and in the efficiency of lupanine catabolism, their performance on L. albus extract did not vary significantly.  相似文献   
34.
Biscogniauxia mediterranea is one of the most frequent fungal pathogens involved in cork oak decline in the Mediterranean Basin, causing charcoal canker. In Portugal, this disease is widespread on adult declining trees but nowadays it increasingly affects young trees and exhibits atypical symptoms, leading to the hypothesis that some change in the fungus may have occurred. In order to evaluate the genetic diversity and phylogenetic relationship of B. mediterranea associated with cork oak, 102 isolates were obtained from young and adult trees of Quercus suber and other hosts species with different disease expression, from several Mediterranean countries. The collection of isolates was analyzed by individual and multigene phylogenies using Maximum-Likelihood approach based on nucleotide sequences of the internal transcribed spacers of ribosomal DNA, translation elongation factor 1-α and β-tubulin genes, and by microsatellite-primed PCR profiles. Sequence analyses separated the Mediterranean isolates from those from other regions, while MSP-PCR analysis revealed relevant but unstructured diversity among the Mediterranean isolates under study, making this a monophyletic but diverse population. Considering the adaptive capacity of the fungus in the Mediterranean-climate ecosystems and the present climatic change scenario, all conditions are gathered to favor aggravation of the disease in cork oak stands.  相似文献   
35.
The present study describes for the first time the in vitro properties of Iris pseudopumila flowers and rhizomes extracts and their constituents. The methanolic extract of rhizomes showed significant anti-inflammatory activity through inhibition of NO production in the murine monocytic macrophage cell line RAW 264.7. Among the isolated compounds, those which most effectively inhibited LPS-induced NO production were irisolidone and 7-methyl-tectorigenin-4′-O-[β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside], with IC50 values of 23.6 μM and 29.4 μM respectively. Isoorientin and isovitexin exhibited the most promising activity against AChE with IC50 of 26.8 μM and 36.4 μM, respectively. The same compounds exhibited also the higher activity against BChE.  相似文献   
36.
The only supernovae (SNe) to show gamma-ray bursts (GRBs) or early x-ray emission thus far are overenergetic, broad-lined type Ic SNe (hypernovae, HNe). Recently, SN 2008D has shown several unusual features: (i) weak x-ray flash (XRF), (ii) an early, narrow optical peak, (iii) disappearance of the broad lines typical of SN Ic HNe, and (iv) development of helium lines as in SNe Ib. Detailed analysis shows that SN 2008D was not a normal supernova: Its explosion energy (E approximately 6x10(51) erg) and ejected mass [ approximately 7 times the mass of the Sun (M(middle dot in circle))] are intermediate between normal SNe Ibc and HNe. We conclude that SN 2008D was originally a approximately 30 M(middle dot in circle) star. When it collapsed, a black hole formed and a weak, mildly relativistic jet was produced, which caused the XRF. SN 2008D is probably among the weakest explosions that produce relativistic jets. Inner engine activity appears to be present whenever massive stars collapse to black holes.  相似文献   
37.
Phytoparasitica - Since October 2019, chinch bugs have been detected in large sunken dead patches of St. Augustinegrass (Stenotaphrum secundatum) lawns in different locations of Lisbon and Setubal...  相似文献   
38.
Ambrosia beetles, including Platypus cylindrus, commonly act as vectors of Ophiostomatales. In an investigation of fungi associated with P. cylindrus, several species of Ophiostomatales were identified, including two species of Ophiostoma s. str. These two species were characterized based on comparisons of DNA sequences of the internal transcribed spacer regions including the 5.8S gene of rDNA and β‐tubulin gene. Two distinct clades were discernable in the phylogenetic trees, supported by high bootstrap values. One clade included the species Ophiostoma tsotsi, reported herein for the first time in Tunisia, and the species Ophiostoma quercus.  相似文献   
39.
An exhaustive exploration into the metabolic content of the Mediterranean sponge Axinella-polypoides resulted in the isolation of the new betaine 5 and the new cyclonucleoside 8. The structures of the new metabolites were elucidated by spectroscopic methods assisted by computational methods. The analysis also provided evidence that the sponge does not elaborate pyrrole-imidazole alkaloids (PIAs) but, interestingly, it was shown to contain two already known cyclodipeptides, compounds 9 (verpacamide A) and 10.  相似文献   
40.
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