Gas Chromatography Coupled To A Mass Spectrometer Research Articles

Gut Microbiota Ecological and Functional Modulation in Post-Stroke Recovery Patients: An Italian Study.

Ischemic stroke (IS) can be caused by perturbations of the gut-brain axis. An imbalance in the gut microbiota (GM), or dysbiosis, may be linked to several IS risk factors and can influence the brain through the production of different metabolites, such as short-chain fatty acids (SCFAs), indole and derivatives. This study examines ecological changes in the GM and its metabolic activities after stroke. Fecal samples of 10 IS patients were compared to 21 healthy controls (CTRLs). GM ecological profiles were generated via 16S rRNA taxonomy as functional profiles using metabolomics analysis performed with a gas chromatograph coupled to a mass spectrometer (GC-MS). Additionally fecal zonulin, a marker of gut permeability, was measured using an enzyme-linked immuno assay (ELISA). Data were analyzed using univariate and multivariate statistical analyses and correlated with clinical features and biochemical variables using correlation and nonparametric tests. Metabolomic analyses, carried out on a subject subgroup, revealed a high concentration of fecal metabolites, such as SCFAs, in the GM of IS patients, which was corroborated by the enrichment of SCFA-producing bacterial genera such as Bacteroides, Christensellaceae, Alistipes and Akkermansia. Conversely, indole and 3-methyl indole (skatole) decreased compared to a subset of six CTRLs. This study illustrates how IS might affect the gut microbial milieu and may suggest potential microbial and metabolic biomarkers of IS. Expanded populations of Akkermansia and enrichment of acetic acid could be considered potential disease phenotype signatures.

Unveiling the volatile compounds and antibacterial mechanisms of action of Cupressus sempervirens L., against Bacillus subtilis and Pseudomonas aeruginosa

Cupressus sempervirens is a known traditional plant used to manage various ailments, including cancer, inflammatory and infectious diseases. In this investigation, we aimed to explore the chemical profile of Cupressus sempervirens essential oil (CSEO) as well as their antibacterial mode of action. The volatile components were characterized using gas chromatography coupled to a mass spectrometer (GC-MS). The results revealed remarkable antibacterial properties of EO derived from C. sempervirens. GC-MS analysis indicated that C. sempervirens EO characterized by δ-3-carene (47.72%), D-limonene (5.44%), β-pinene (4.36%), β-myrcene (4.02%). The oil exhibited significant inhibitory effects against a range of bacteria, including Staphylococcus aureus ATCC 29213, Bacillus subtilis ATCC 13048, Bacillus cereus (Clinical isolate), Pseudomonas aeruginosa ATCC 27853, and Escherichia coli ATCC 25922. These inhibitory effects surpassed those of conventional antibiotics. Furthermore, the EO demonstrated low minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs), indicating its bactericidal nature (MBC/MIC < 4.0). Time-kill kinetics analysis showed that CSEO was particularly effective at 2 × MIC doses, rapidly reduced viable count of B. subtilis and P. aeruginosa within 8 h. This suggests that the oil acts quickly and efficiently. The cell membrane permeability test further demonstrated the impact of CSEO on the relative conductivity of B. subtilis and P. aeruginosa, both at 2 × MIC concentrations. These observations suggest that EO disrupts the bacterial membrane, thereby influencing their growth and viability. Additionally, the cell membrane integrity test indicated that the addition of CSEO to bacterial cultures resulted in the significant release of proteins from the bacterial cells. This suggests that EO affects the structural integrity of the bacterial cells. Furthermore, the anti-biofilm assay confirmed the efficacy of CSEO as a potent anti-biofilm agent. It demonstrated the oil's ability to inhibit quorum sensing, a crucial mechanism for biofilm formation, and its competitive performance compared to the tested antibiotics.

Exploring the antibacterial mechanisms of chemically characterized essential oils from leaves and buds of Syzygium aromaticum (L.) Merr. et Perry against Staphylococcus aureus and Pseudomonas aeruginosa

Syzygium aromaticum (L.) Merr. et Perry is a medicinal plant extensively used in international pharmacopeia to treat different ailments, including infectious diseases. In this study, we designed to determine the chemical constituents of S. aromaticum essential oils extracted from leaves (CEOL) and floral buds (CEOB) and their antibacterial mechanism of action against S. aureus and P. aeruginosa. The volatile components from CEOL and CEOB were detected using gas chromatography coupled to a mass spectrometer (GC/MS). The results indicated that eugenol was the major component for both CEOL (65.75%) and CEOB (74.03%). The antibacterial findings demonstrated the potent antibacterial activity of CEOL and CEOB. These oils exhibited significant zones of inhibition against all tested bacteria, including S. aureus ATCC 29213, K. aerogenes ATCC 13048, P. aeruginosa ATCC 27853, and E. coli ATCC 25922, surpassing the effects of antibiotics. Additionally, they displayed low minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs), indicating their bactericidal nature (MBC/MIC < 4.0). Time-kill kinetics revealed that CEOB was more effective than CEOL at sub-MIC doses, eradicating S. aureus within 12 h and P. aeruginosa within 12–24 h. The cell membrane permeability test demonstrated that CEOL and CEOB treatment affected the relative conductivity of S. aureus and P. aeruginosa at both MIC and sub-MIC concentrations, indicating disruption of the bacterial membrane and influencing their growth and viability. Furthermore, the cell membrane integrity test showed that the addition of CEOL and CEOB to S. aureus and P. aeruginosa cultures led to significant protein release from the bacterial cells. The results of the anti-biofilm activity test confirmed the efficacy of S. aromaticum EOs, particularly CEOB, as potent anti-biofilm agents, suggesting its potential effect on inhibiting quorum sensing. Scanning electron microscope (SEM) microscopy further revealed significant alterations in bacterial cells treated with CEOB essential oil, including damage to the cell wall and distorted cell morphology, highlighting its impact on bacterial cell structure. Presented information suggests the use of clove EOs as natural alternatives for sustainable application in food and pharmaceutical industries.

Human health risk assessment for consumption of microplastics and plasticizing substances through marine species

A special characteristic of MP (microplastics) in the ocean is they may act as carriers of additives specific to the plastic materials used in their manufacture, such as plasticizers, among which Bisphenol-A (BPA), bis (2-ethylhexyl) phthalate (DEHP), dybuthyl phthalate (DBP). Both MP as the plasticizers were searched in composite samples of mangrove cockle (Anadara tuberculosa), Stolzmann's weakfish (Cynoscion stolzmanni) and arched swimming crab (Callinectes arcuatus). Extraction of MP was done through physical-chemical techniques and identification was carried out employing the techniques of light microscopy, energy dispersive spectrometer (EDS), scanning electron microscope (SEM) and Raman spectroscopy; the sizes of MP obtained were between 0.5 μm and 106 μm, the following average results being obtained: for Arched swimming crab 4.0 ± 1.0 MP/g; mangrove cockle 3.3 ± 2.9 MP/g; and for Stolzmann's weakfish, the average was 2.4 ± 1.3 MP/g; the most observed shapes were fibers and irregular segments; the most identified MP was polyethylene terephthalate (PET). Regarding extraction and quantification of plasticizers, the extraction stage was carried out using QuEChERS tubes; and the identification and quantification with gas chromatography coupled to a mass spectrometer (GC-MS). Regarding the plasticizing substances, DEHP was found in detectable levels in all the samples; BPA was found in 84% of the composite samples analyzed; DBP was found in 50% of them, of the analyzed samples 34% were positive for the 3 analytes. The dietary exposure of people to plasticizers was calculated and for BPA the exposure obtained was compared with respect to the TDI (tolerable intake dose) for pregnant women and the new TDI proposed by EFSA in 2021 according to the estrogenic effect of this substance in the fetus. The objective of the work was to determine if a relationship could be established between both PM and plasticizers, which gave a positive relationship.

Effect of Rootstock on the Volatile Profile of Mandarins.

Mandarin production has increased in recent years, especially for fresh consumption, due to its ease of peeling, its aroma, and its content of bioactive compounds. In this sense, aromas play a fundamental role in the sensory quality of this fruit. The selection of the appropriate rootstock is crucial for the success of the crop and its quality. Therefore, the objective of this study was to identify the influence of 9 rootstocks ("Carrizo citrange", "Swingle citrumelo CPB 4475", "Macrophylla", "Volkameriana", "Forner-Alcaide 5", "Forner-Alcaide V17", "C-35", "Forner-Alcaide 418", and "Forner-Alcaide 517") on the volatile composition of "Clemenules" mandarin. For this, the volatile compounds of mandarin juice were measured using headspace solid-phase micro-extraction in a gas chromatograph coupled to a mass spectrometer (GC-MS). Seventy-one volatile compounds were identified in the analyzed samples, with limonene being the main compound. The results obtained showed that the rootstock used in the cultivation of mandarins affects the volatile content of the juice, with "Carrizo citrange", "Forner-Alcaide 5", "Forner-Alcaide 418", and "Forner-Alcaide 517" being those that presented the highest concentration.

Biogasoline Obtained Using Catalytic Pyrolysis of Desmodesmus sp. Microalgae: Comparison between Dry Biomass and n-Hexane Extract

The present work deals with the production of hydrocarbons in the C5–C12 range obtained from the fast micropyrolysis of a laboratory-grown Desmodesmus sp. microalgae. It compares the properties of this specific fraction of hydrocarbons using or not using transition alumina catalysts during pyrolysis in experiments with both pure dried microalgae and its n-hexane extract. The microalgae were characterised using thermogravimetry (TG) and CHN analysis; the n-hexane extract was analysed through Fourier transform infrared spectroscopy (FTIR). The pyrolysis experiments were performed in a multi-shot pyrolyser connected online with a gas chromatograph coupled to a mass spectrometer (GC/MS). The composition of the C5–C12 fraction was compared to that of an industrial pyrolysis gasoline. The results of pyrolysis at 600 °C show that the alumina catalyst increases the quantity of C5–C12 hydrocarbon families when compared to purely thermal pyrolysis, representing about 40% of all the dry microalgae pyrolysis products. In the case of n-hexane extract, the C5–C12 area fraction corresponds to 33.5% of the whole products’ area when pyrolysis is conducted with an alumina catalyst. A detailed analysis shows that linear molecules, mainly unsaturated, are predominant in the products. Dry biomass formed more aromatic but less cyclic and alkylated molecules in relation to the n-hexane extract. Nitrogen products, essentially alkylated pyrroles, were produced in large quantities when dry biomass was used but were below the detection limit when pyrolysing the extracts. Thus, the extraction with hexane proved to be an effective way to remove nitrogen compounds, which are undesirable in fuels. The estimated low heating values of the present C5–C12 pyrolysis hydrocarbon fractions (between 43 and 44 MJ/kg) are quite comparable to the reported values for reformulated and conventional industrial gasolines (42 and 43 MJ/kg, respectively).

In Vitro Antibacterial Activity of Some Plant Essential Oils against Four Different Microbial Strains

This study evaluates the antimicrobial and antioxidant activities of five essential oils (EO): pine oil, thyme oil, sage oil, fennel oil, and eucalyptus essential oils. To identify the chemical composition of the essential oils, we used gas chromatography coupled to a mass spectrometer (GC-MS). EO are predominantly characterized by the presence of monoterpene hydrocarbons and oxygenated monoterpenes, except in the case of fennel essential oil which contains phenylpropanoids as its main components. The antimicrobial activity of the EO was highlighted on four standard microbial strains (two Gram-negative strains-Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853; one Gram-positive strain Staphylococcus aureus ATCC 25923, and one yeast strain-Candida albicans ATCC 10231). Antimicrobial activity was assessed by measuring the diameter of the inhibition zone, and by determining the values of the minimum inhibitory concentration (MIC) and minimum concentration of biofilm eradication (MCBE). Analyzing the diameter values of the inhibition zones we observed increased efficiency of thyme essential oil, which showed the highest values for all tested microbial species. The results of tests performed in a liquid confirm the high sensitivity of the standard strain Escherichia coli ATCC 25922 to the action of all essential oils, the lowest values of MIC being recorded for sage and thyme essential oils. For the most essential oils tested in this study, the MCBE values are close to the MIC values, except for the pine EO which seems to have stimulated the adhesion of the yeast strain at concentrations lower than 5%. The study highlights the antimicrobial activity of the tested essential oils on Gram-positive and Gram-negative strains.

Characterization of natural extracts obtained by supercritical fluids (SCF) from Mashua tubers (Tropaeolum Tuberosum) grown in Ecuador

The mashua (Tropaeolum tuberosum) is a plant native to the central Andes whose cultivation is concentrated in Colombia, Bolivia, Ecuador and Peru between 3500 and 4100 meters of altitude, this tuber is rich in nutrients due to its bioactive properties, generally in Ecuador it is cultivated in association with the oca, and the melloco. Therefore, the purpose of this work was to characterize by chromatography two varieties of white and yellow Mashua. Therefore, the supercritical fluid extraction method (FSC) was applied in the two varieties, the volatile compounds of the obtained extracts were characterized by Gas Chromatography coupled to a Mass Spectrometer (GC-MS). After characterization, in general, 16 and 11 major volatile compounds considered to belong to the families or functional groups of ketones, fatty acids, furans, furfurals, alcohols, phyto esters, alkaloids and sterols were identified, some of these compounds considered useful for the prevention of diseases such as cancer, they also have antioxidant properties, hypoglycein agent and in the inhibition of the thyroid gland.

Characterization of natural extracts obtained by supercritical fluids (SCF) from Mashua tubers (Tropaeolum Tuberosum) grown in Ecuador

The mashua (Tropaeolum tuberosum) is a plant native to the central Andes whose cultivation is concentrated in Colombia, Bolivia, Ecuador and Peru between 3500 and 4100 meters of altitude, this tuber is rich in nutrients due to its bioactive properties, generally in Ecuador it is cultivated in association with the oca, and the melloco. Therefore, the purpose of this work was to characterize by chromatography two varieties of white and yellow Mashua. Therefore, the supercritical fluid extraction method (FSC) was applied in the two varieties, the volatile compounds of the obtained extracts were characterized by Gas Chromatography coupled to a Mass Spectrometer (GC-MS). After characterization, in general, 16 and 11 major volatile compounds considered to belong to the families or functional groups of ketones, fatty acids, furans, furfurals, alcohols, phyto esters, alkaloids and sterols were identified, some of these compounds considered useful for the prevention of diseases such as cancer, they also have antioxidant properties, hypoglycein agent and in the inhibition of the thyroid gland.

Evaluation of the effect of treated wastewater and well water irrigation on the quality, quantity and antibacterial/antifungal activities of Rosa × damascena Herrm. essential oil

Water is one of the important environmental factors affecting the quality and quantity of Rosa × damascena Herrm. essential oil. This study aimed to evaluate and compare the quality, quantity, and antibacterial/antifungal activity of R. × Damascena essential oil in fields under irrigation treatments such as treated wastewater and well water at the University of Kashan, Kashan, Iran. In each field, flowers (sepals and petals) were collected from different bushes in May 2019, coinciding with the beginning of buds opening. After extracting the essential oil by water distillation using the Clevenger apparatus, the analysis and identification of the compounds were performed by a gas chromatograph coupled to a mass spectrometer (GC/MS). The antibacterial/antifungal activity of the essential oils was evaluated by determining the diameter of the inhibition zone by the agar diffusion method and determining the minimum concentration of growth inhibitor and bactericidal/fungal lethality. The results of quantitative analysis of essential oil showed that the highest yield belonged to R. × damascena irrigated with treated wastewater with a value of 0.1527 ± 0.0045%. Based on the results of the analysis of chemical compounds, citronellol (32.38%), geraniol (12.86%), nonadecane (10.14%), and heneicosane (6.16%) were the predominant compounds of R. × damascena essential oil under irrigation with treated wastewater and geraniol (17.81%), citronellol (17.67%), nonadecane (12.87%), heptadecane (5.60%), and heneicosane (5.44%) were the predominant compounds of R. × damascena essential oil under irrigation with well water. The strongest inhibitory and lethal activity of R. × damascena essential oil under treated wastewater irrigation was against Gram-negatives Pseudomonas aeruginosa (MIC<15.63 μg/mL) and Candida albicans (MIC=62.50 μg/mL) which were twice as strong as control antibiotics such as rifampin and nystatin. Therefore, it can be found that irrigation with treated wastewater increases the quantity and quality, and antimicrobial activity of R. × damascena essential oil against many microbial strains, which can be a possible option to produce high-quality essential oil for treating infectious diseases.

Level of Contamination of Fishponds Water in Pesticide Residues and Metallic Trace Elements (Pb, Cd, As, Hg): Case of Fishponds of ZEPREGUHE (Daloa, C&amp;amp;ocirc;te d’Ivoire)

Fishponds waters intended to satisfy the nutritional needs of the populations in terms of supply of fish resources are strongly and unfortunately exposed to the mobility and dispersion of metallic trace elements (TMEs) or to the persistence in the environment and in the form of pesticide residues from human activities. The objective of this work is to evaluate, on the one hand, the levels of identified pesticide residues and, on the other hand, those of researched TMEs (lead, cadmium, mercury and arsenic) in the waters of ponds used for fish farming in Zépréguhé, a locality located 9 km from the town of Daloa in the centre-west of Côte d’Ivoire. The dosage of the samples carried out by means of a gas chromatograph coupled to a mass spectrometer (GC/MS) made it possible to detect nine (9) pesticide molecules, including eight (8) organochlorines and a single molecule from the pyrethroid family, obtained from the detection limit of 0.006 μg/L and the quantification limit of 0.018 μg/L. The maximum average concentration was obtained with α-endosulfan for a content reaching 0.8038 μg/L and well above the maximum admissible concentration of 0.1 μg/L. The TMEs were quantified using an atomic absorption spectrophotometer (AAS). Arsenic is the most abundant metal with an average concentration of 9.497 μg/L. With the exception of lead, these measured levels are above the acceptable limit values for freshwater. This study showed that human activities such as the use of fertilisers and plant protection products in plantations, sand extraction and road traffic have a negative impact on the quality of the water in ponds used for fish breeding.

Comparative Bioaccumulation of PAH and BTEX in Malapterurus electricus (Siluriformes: Malapteruridae) and its Enteric Parasite, Electrotaenia malopteruri Sampled from Lekki Lagoon, Lagos, Nigeria

Contamination of Lekki lagoon by petrogenic chemicals such as polycyclic aromatic hydrocarbons (PAH) and benzene, toluene, ethylbenzene, and xylene (BTEX) has been widely reported. The study was aimed at investigating the bioaccumulation of PAH and BTEX in Malapterurus electricus collected from Lekki lagoon in Lagos, Nigeria. BTEX was analyzed in the intestine, water, and sediment samples using 8260B Agilent 7890B gas chromatograph coupled to a mass spectrometer (GC-MS). While PAHs were tested in the same media using a gas chromatograph coupled to a flame ionization detector (GC-FID). Histopathological analysis of the fish intestine was conducted using haematoxylin and eosin (H&E) stains. Parasite intensity, antioxidant enzymes, and lipid peroxidation activities were investigated in the fish. The parasitic infection detected in Malapterurus electricus was Electrotaenia malopteruri. The parasite showed weak and no depurative capacities for BTEX and PAH respectively. The decrease in superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH) in conjunction with an increase in Malondialdehyde (MDA) characterized relatively higher susceptibility among the male fish. Varieties of tissue injuries increased with the standard length of the fish groups. Results suggest that lengthier and uninfected M. electricus were more susceptible to PAH in Lekki lagoon than the shorter and infected ones. The study demonstrated a promising tendency of the enteric parasite, E. malopteruri to depurate chlorobenzene, ethylbenzene, o-xylene, m+p-xylene, and 1,4-dichlorobenzene from the intestine of its host fish, M. electricus, while PAHs were poorly mediated by the parasite.

Identification of Possible Salivary Metabolic Biomarkers and Altered Metabolic Pathways in South American Patients Diagnosed with Oral Squamous Cell Carcinoma.

Oral squamous cell carcinoma (OSCC) represents 90% of oral malignant neoplasms. The search for specific biomarkers for OSCC is a very active field of research contributing to establishing early diagnostic methods and unraveling underlying pathogenic mechanisms. In this work we investigated the salivary metabolites and the metabolic pathways of OSCC aiming find possible biomarkers. Salivary metabolites samples from 27 OSCC patients and 41 control individuals were compared through a gas chromatography coupled to a mass spectrometer (GC-MS) technique. Our results allowed identification of pathways of the malate-aspartate shuttle, the beta-alanine metabolism, and the Warburg effect. The possible salivary biomarkers were identified using the area under receiver-operating curve (AUC) criterion. Twenty-four metabolites were identified with AUC > 0.8. Using the threshold of AUC = 0.9 we find malic acid, maltose, protocatechuic acid, lactose, 2-ketoadipic, and catechol metabolites expressed. We notice that this is the first report of salivary metabolome in South American oral cancer patients, to the best of our knowledge. Our findings regarding these metabolic changes are important in discovering salivary biomarkers of OSCC patients. However, additional work needs to be performed considering larger populations to validate our results.

Deoxygenation of pyrolysis vapor from palm fruit cake over NiMo/γ-Al2O3 catalyst: Effect of CeO2, TiO2, and ZrO2 additives

Deoxygenation of pyrolysis vapor from palm fruit cake by different catalysts was prior investigated by using Ni/γ-Al2O3, Mo/γ-Al2O3, and NiMo/γ-Al2O3 prepared by wet impregnation method. NiMo/γ-Al2O3 showing the highest degree of deoxygenation (%DOD) activity was subsequently mixed with metal oxides: CeO2, TiO2, and ZrO2. Effects of the catalysts on upgrading of pyrolysis vapor from palm fruit cake at 450°C under N2 atmosphere in a semi-batch process were investigated. The oil products were analyzed for CHNO elements by elemental analyzer, chemical compositions by a gas chromatograph coupled to a mass spectrometer (GC-MS), and higher heating values (HHV) by Dulong's equation. Catalysts have been characterized and discussed related to the product yields and properties. Acidity and acid strength of the catalyst mixture play an important role on the products. NiMo/γ-Al2O3 improved properties of the crude bio-oil by increasing organic phase yield, %DOD, and HHV. Addition of CeO2 to NiMo/γ-Al2O3 reduced phenol compound in the liquid products while addition of TiO2 to NiMo/γ-Al2O3 provided high aromatics and hydrocarbons comparable to those obtained from NiMo/γ-Al2O3/ZrO2. Addition of ZrO2 to NiMo/γ-Al2O3 exhibited the highest organic phase yield (%), %DOD (71%), and HHV (37 MJ/kg).

Chemical Composition and Antimicrobial Activity of Essential oil from Scales of Moroccan Juniperus phoenicea

Abstract-The essential oil of Juniperus phoenicea was obtained by hydrodistillation method using a Clevenger-type apparatus with a yield of 1.9 % and was analyzed by gas chromatography coupled to a mass spectrometer (GC-MS). Twelve volatile compounds were identified representing 99,85% of the total oil composition, while the α-pinene (78,31%), β-Myrcene (11,92%) and limonene (3,96%) were the major compounds. This essential oil was evaluated as an antibacterial and antifungal agent. The result showed that the oil presents a high biological activity as an antibacterial agent against the three tested strains Escherichia coli, Staphylococcus aureus and Pseudomonas aeroginos. It's also active as an antifungal agent against the Candida albicans with a zone inhibition of 28 mm. Keywords: Medicinal plant, Juniperus, phoenicea, Essential oil, Chemical composition, Antimicrobial activity.

Chemical Composition and Antimicrobial Activity of Essential oil from Scales of Moroccan Juniperus phoenicea

Abstract-The essential oil of Juniperus phoenicea was obtained by hydrodistillation method using Clevenger-type apparatus with a yield of 1.9 % and was analyzed by gas chromatography coupled to a mass spectrometer (GC-MS). Twelve volatile ompounds were identified representing 99,85% of the total oil composition, while the α-pinene (78,31%), β-Myrcene (11,92%) and limonene (3,96%) were the major compounds. This essential oil was evaluated as an antibacterial and antifungal agent. The result showed that the oil presents a high biological activity as an antibacterial agent against the three tested strains Escherichia coli, Staphylococcus aureus and Pseudomonas aeroginos. It's also active as an antifungal agent against the Candida albicans with a zone inhibition of 28 mm.

Morpho-Physiological Responses and Secondary Metabolites Modulation by Preharvest Factors of Three Hydroponically Grown Genovese Basil Cultivars.

Sweet basil (Ocimum basilicum L.) is an economically important leafy vegetable especially in Mediterranean countries. In Italian gastronomy, the large elliptical leaves of the Genovese type are mostly used for the well-known pesto sauce, and almost all (>90%) professional production is for the food industry. The growing demand for fresh leaves with standardized technological and sensory characteristics has prompted basil producers to adopt advanced cultivation methods such as the floating raft system (FRS). The aim of this study was to evaluate the productive, qualitative, and physiological performance of three Genovese basil cultivars (“Aroma 2,” “Eleonora,” and “Italiano Classico”) in two successive harvests and at two densities (159 and 317 plants m–2). Caffeic, chicoric, rosmarinic, and ferulic acid were determined through the high-performance liquid chromatography (HPLC) system, whereas the extraction and quantification of the volatile organic compounds (VOCs) were performed by solid-phase microextraction (SPME) and gas chromatography coupled to a mass spectrometer (GC/MS). “Aroma 2” showed the highest fresh yield and photosynthetic rate together with the lowest nitrate content. For all the tested cultivars, the higher density, while reducing the number of leaves per plant, resulted in higher fresh and dry production per unit area, without altering the aroma profile. Successive harvests resulted in a significant increase in both the yield (37.5%) and the total phenolic acids (75.1%) and favored Eucalyptol and 1-octen-3-ol accumulation (+25.9 and +15.1%, respectively). The here presented comprehensive and multifactorial assessment of the productive and qualitative response of basil provides evidence of the positive effects (from biomass to specialized metabolites) that can be obtained from the management of the pre-harvest factors in soilless cultivation. In addition, it also highlights the role and constraints of the genetic factor in the observed response. We also discuss the implications of our work considering the impact for the food processing industry. Future research may explore the phenolic acids accumulation as a possible fortification means to extend the pesto sauce shelf life, reducing the need of added antioxidants and thermal processing.

Chromatographic analysis of phytochemicals in the peel of Musa Paradisiaca to synthesize silver nanoparticles

This research work used Musa Paradisiaca (banana) peels as a natural solvent, assorted with the precursor AgNO3 (10 mM) to perform the green synthesis of silver nanoparticles. The phytochemical components present in the Musa Paradisiaca peel extracts were determined by gas chromatography coupled to a mass spectrometer (GC-MS), and it was possible to identify the compounds: 1.2 Ethanediol (60.0261 %) and 2.3 Butanediol (11.2 %); these -diols represent a highly reducing agent for metals, since they act as a solvent for the metal precursor behaving as a reducing agent, and facilitating the formation of nanoparticles. Likewise, the synthesized silver nanoparticles were subjected to a washing and drying treatment to be subsequently characterized by means of UV-Vis and XRD techniques, resulting in a wavelength of 411 nm, which is characteristic of these metallic nanoparticles, and achieving the identification of the face-centered cubic structure (fcc) of the metallic silver, with an average particle size of 21.8 nm according to the Debye-Scherrer equation.

Genotype and Successive Harvests Interaction Affects Phenolic Acids and Aroma Profile of Genovese Basil for Pesto Sauce Production.

Basil (Ocimum basilicum L.) is an essential ingredient of the Mediterranean cuisine due to its distinctive aroma. Genovese basil leaves are used to prepare “pesto”, a condiment that has always caught the interest of consumers and producers. Usually, basil for industrial processing is harvested more than once to extract a higher yield. However, successive cuts can affect quality traits that play a crucial role in defining the product’s final sensory profile. This research was aimed to evaluate the impact of cut on the quantitative and qualitative properties of three Genovese basil cultivars (Aroma 2, Eleonora and Italiano Classico) grown in an open field. Nitrate content, phenolic acids and aromatic profile were determined by ion chromatography (IC), high-performance liquid chromatography (HPLC), and gas chromatography coupled to a mass spectrometer (GC/MS) analysis, respectively. The second harvest increased fresh biomass and total phenolic acids content by 172% and 413%, respectively, with Italiano Classico recording the highest values. The combination of second-cut Aroma 2 yielded the lowest nitrate (473.8 mg kg−1 of fresh weight) and Eugenol (2.4%) levels. In the second harvest, Eleonora showed an increase in eugenol and trans-α-bergamotene of 75.3% and 48.2%, respectively; whereas, eucalyptol and β-cis-ocimene decreased by 34.4% and 51.6%, respectively. Although successive harvests may increase basil yield and quality overall, the cultivar-dependent response to successive cuts needs to be accounted for in order to accomplish standardization of industrial “pesto” sauce.

Synthesis of decyl methyl carbonate and a comparative assessment of its performance as the continuous phase of synthetic-based drilling fluids

Ester-based drilling fluids have been explored as an alternative to the mineral oil and diesel-based fluids for their low toxicity and high biodegradability. In this work, decyl methyl carbonate (DeMeC) was synthesized and assessed as a novel continuous phase for synthetic-based drilling fluids (SBF), since it is equally biodegradable, presents higher chemical stability and elastomer compatibility when compared to fatty ester bases. Babassu oil methyl esters (BME) were synthesized and tested for comparison. Fourier transform infrared spectroscopy (FTIR), gas chromatography coupled to a mass spectrometer (GC/MS) or a flame ionization (GC/FID) detector, thermogravimetry (TG/DTG/DSC) and proton nuclear magnetic resonance (1H NMR) techniques were applied for characterizing the obtained products and confirmed the synthesis of DeMeC and BME. The low pour point of DeMeC and BME may allow the application to approach the blowout preventer region in ultra-deepwater drilling, while the low viscosity of both compounds make them suitable for drilling operations. In addition, the high flash point value for both bases is considered safe for its use, transportation and storage. The drilling fluid produced with DeMeC (DeMeC-DF) presented high efficiency, with satisfactory results of plastic viscosity, initial and 10-min gel strengths, yield point and filtrate, thus standing out as a real alternative for application in synthetic-based drilling fluids.