Integrated production of aromatic amines,aromatic hydrocarbon and N-heterocyclic bio-char from catalytic pyrolysis of biomass impregnated with ammonia sources over Zn/HZSM-5 catalyst

By introducing exogenous nitrogen during biomass pyrolysis under nitrogen-rich conditions, high-value nitrogen-containing products, i.e., nitrogen-rich char and oil may be produced. Based on the cogeneration of high-value nitrogen products from biomass, biomass nitrogen-enriched pyrolysis was performed in a fixed bed with different sources and contents of ammonia. The yields, composition and characteristics of the products were investigated. Moreover, the formation mechanism of N-containing species was explored in depth for the pyrolysis and catalytic pyrolysis with HZSM-5 and Zn/HZSM-5 catalysts via elemental analysis, XPS, FTIR and BET. The results showed that ammonia impregnation could promote a Maillard reaction, reduce the content of small aldehydes and ketones, and produce a nitrogen-enriched bio-oil. The contents of N-containing species and phenolic substances in the pyrolysis oil of biomass impregnated with 10% urea reached 15.66% and 56.69%, respectively. Moreover, the nitrogen on the coke surface after pretreatment was mainly composed of CN, CN and NCOO functional groups. The bio-char generated abundant pyridinic-N, pyrrolic-N, quaternary-N, and pyridone-N oxides. The presence of urea introduced many alkaline N-containing functional groups on the surface of the bio-char and promoted the transformation of nitrogen from amides and imides to heterocyclic nitrogen with higher thermal stability. Furthermore, Zn was an excellent catalyst for the Maillard reaction, and the Zn/HZSM-5 catalyst had a higher selectivity for aromatic hydrocarbons (96.98% for biomass and 86.48% for urea/biomass) and N-containing heterocyclic compounds, such as indoles (6.16% for biomass and 13.51% for urea/biomass). Additionally, the coke content decreased, and the catalyst deactivation decreased.     

A comparative study of different DNA barcoding markers for the identification of some members of Lamiacaea

The objective of the present work is to evaluate the efficacy of a DNA barcoding approach as a tool for the recognition of commercial kitchen spices belonging to the Lamiaceae family that are usually sold as enhancers of food flavor. A total of 64 spices samples, encompassing six different genera (i.e. Mentha, Ocimum, Origanum, Salvia, Thymus and Rosmarinus) were processed with a classical DNA barcoding approach by amplifying and sequencing four candidate barcode regions (rpoB, rbcL, matK and trnH-psbA) with universal primers. Results suggest that the non-coding trnH-psbA intergenic spacer is the most suitable marker for molecular spices identification followed by matK, with interspecific genetic distance values ranging between about 0% to 7% and 0% to 5%, respectively. Both markers were almost invariably able to distinguish spices species from closest taxa with the exclusion of samples belonging to the genus Oregano. Moreover, in a context of food traceability the two markers are useful to identify commercial processed spice species (sold as dried plant material). We also evaluated the potential benefits of a multilocus barcode approach over a single-marker and although the most suitable combination was the matK + trhH-psbA, the observed genetic distances values were very similar to the discriminatory performance of the trnH-psbA. Finally, this preliminary work provide clear evidences that the efficacy of a DNA barcoding approach to the recognition of commercial spices is biased by the occurrence of taxonomic criticisms as well as traces of hybridization events within the family Lamiaceae. For this reason, to better define a more practical and standardized DNA barcoding tool for spices traceability, the building of a dedicated aromatic plants database in which all species and cultivars are described (both morphologically and molecularly) is strongly required.     

Retention and Distribution of 1-Naphthol and Naphthol Polymerization Products on Surface Soils

Sorption and extractability of naphthol and naphthol polymerization products (NPP) were evaluated in two surface soils. NPP were generated by the addition of horseradish peroxidase and H2O2 to naphthol solutions in contact with the surface soils. While NPP retention on the forest soil was lower compared to the parent naphthol, no difference in sorption of naphthol and NPP was observed in the agricultural soil. The agricultural soil retained more naphthol and NPP than the forest soil. The NPP sorption behavior noted in this study was in contrast to that of phenol polymerization products observed by other researchers. The presence of phenol and 2,4-dichlorophenol as cosolutes had no significant impact on naphthol or NPP retention on the two soils, and naphthol was more easily extracted from both soils whenever phenol was present as a cosolute. Characterization of the naphthol polymerization products using reverse-phase high-pressure liquid chromatography and octanol-water partitioning indicated that significant fractions of the water-soluble and insoluble NPP were comprised of oligomers that were more polar than the parent 1-naphthol. This decrease in polarity upon polymerization is believed to have been responsible for the NPP retention and binding behavior observed in this study.     

Determination of phenolic compounds in aromatic plants by RP-HPLC and GC-MS

It is well known that phenolic compounds are constituents of many plants and herbs, and they have attracted a great deal of public and scientific interest because of their health-promoting effects as antioxidants. Five plants, Vitex agnus-castus (Verbenaceae), Origanum dictamnus (Lamiaceae), Teucrium polium (Lamiaceae), Lavandula vera (Lamiaceae) and Lippia triphylla (Verbenaceae), were examined in order to determine their phenolic composition. Reversed phase high performance liquid chromatography was employed for the identification and quantification of phenolic compounds. Gas chromatography–mass spectometry(GC-MS) was also used for identification of phenolic compounds after silylation. Analysis of the non-volatile and thermolabile phenolic compounds by GC-MS presupposes their conversion into volatile and thermotolerant derivatives. The derivatization process was optimized against reagents, temperature and reaction time. A large excess of N,O-bis(trimethylsilyl)trifluoroacetamide containing trimethylchlorosilane proved to be the best derivatization reagent to convert analytes into volatile trimethylsilyl derivatives. The most abundant phenolic compounds detected were caffeic acid (0.12–0.93 mg 100 g⁻¹ dry sample), ferulic acid (0.34–1.52 mg 100 g⁻¹ dry sample), and (+)-catechin (0.22–0.43 mg 100 g⁻¹ dry sample).     

Use of Water as a Solvent in Directing Hydrogenation Reactions of Aromatic Acids over Pd/carbon Nanofibre Catalysts

By conducting the catalytic hydrogenation over water miscible Pd/carbon nanofibre catalysts, selective ring hydrogenation of aromatic acids can be performed in aqueous solution without the need to provide protection for the external acid function.     

草桥,单家寺原油的组分化学结构及有关热采的性质

使用RV20、RV100型流变仪研究了草桥、单家寺重油的流变性,用核磁共振氢谱等剖析对比了两种原油的组分化学结构,探讨了蒸汽吞吐开采工艺中的一些问题。     

Effect of P-K-fertilizer with a low Cl content on the yield and quality of aromatic and sun-cured tobacco

The effect of a phosphate rock—sulfuric acid—potassium chloride-complex fertilizer with a low chloride content (PKLCl) on the yield and quality of aromatic and sun-cured tobacco was studied. In areas where the soil is deficient in Cl and/or the rainfall is sufficient to leach the chloride below the plants' root zone, an application of PKLCl, together with a N fertilizer substitute for NPK complex fertilizer (K from K₂SO₄), can be administered to the tobacco. The PKLCl was able to increase the yield and improve the quality of cured-leaf tobacco, while the Cl content in the cured-leaf was still below 2% for sun-cured tobacco and below 1% for aromatic tobacco.     

Evaluation of soil biological activity after a diesel fuel spill

Diesel fuel contamination in soils may be toxic to soil microorganisms and plants and acts as a source of groundwater contamination. The objective of this study was to evaluate the soil biological activity and phytotoxicity to garden cress (Lepidium sativum L.) in a soil polluted with diesel fuel. For this, a diesel fuel spill was simulated on agricultural soil at dose 1 l m^− 2. During the experiment (400 days) the soil was not covered in vegetation and no agricultural tasks were carried out. A stress period of 18 days following the spill led to a decrease in soil biological activity, reflected by the soil microbial biomass and soil enzymatic activities, after which it increased again. The n-C₁₇/Pristine and n-C₁₈/Phytane ratios were correlated negatively and significantly with the dehydrogenase, arylsulphatase, protease, phosphatase and urease activities and with the soil microbial biomass during the course of the experiment. The β-glucosidase activity indicated no significant connection with the parameters related with the evolution of hydrocarbons in the soil. Finally, the germination activity of the soil was seen to recover 200 days after the spill.     

Unmasking Sensory Defects of Olive Oils Flavored with Basil and Oregano Using an Electronic Tongue-Chemometric Tool

Olive oil price and consumers’ preference depend on the commercial grade classification that can decrease if any sensory defect is perceived leading to an economic loss. Enriched oils, obtained by incorporating dried aromatic herbs, spices, or essential oils, which is a common practice in the Mediterranean region, are commercially available. This practice may conceal the fraudulent purpose of masking the perception of sensory defects. The detection of this type of fraud is a difficult task, requiring sensory analysis. Thus, in this study, extra-virgin and lampante olive oils, the latter classification being due to the perception of an intense winey-vinegary defect, were deliberately enriched with different amounts of basil-dried herbs and oregano-dried herbs. Sensory analysis showed that, depending on the aromatic herb and on the added amount (0.011–0.110 g herb per kg oil), the defect intensity could be masked leading to an erroneous classification of flavored lampante oils as flavored virgin oils. In contrast, the electronic tongue-chemometric approach could unmask the defect in flavored oils (predictive sensitivities: 70–78%) and semiquantitatively discriminate flavored oils according to the added levels of basil or oregano (predictive sensitivities: 93–100%). The electronic tongue approach showed satisfactory unmasking performance when compared with the sensory panel, and so, its future application as a quality control taste-sensor device for disclosing olive oil sensory defects masked by the incorporation of flavoring agents may be forseen.     

In vitro kinetic analysis of carbohydrate and aromatic amino acid metabolism of different members of the human colon

The carbohydrate and aromatic amino acid metabolism of several species related to the human colon was investigated into more detail. Therefore, in vitro fermentations were performed, with different carbohydrate sources, during which several aromatic amino acids were added to the fermentation medium. Shifts in end-product formation in response to the available nutrients were observed for all strains tested. The major part of amino acid degradation occurred after depletion of the carbohydrates. Moreover, it was shown that Bifidobacterium strains are capable of degrading aromatic amino acids in the absence of carbohydrates. The excretion of certain intermediates of the aromatic amino acid metabolism was observed for a strain of Clostridium clostridioforme, after which they were metabolized again during a later stage of fermentation. This implies that cross-feeding on degradation products of aromatic amino acids, albeit within the same species, can occur in the human colon.