Supercritical CO2 extraction of Eucalyptus leaves oil and comparison with Soxhlet extraction and hydro-distillation methods

Analysis of the Volatile Components in Different Parts of Three Species of the Genus Amomum via Combined HS-SPME-GC-TOF-MS and Multivariate Statistical Analysis

The study used headspace solid-phase microextraction coupled with gas chromatography-time-of-flight mass spectrometry (HS-SPME-GC-TOF-MS) to analyze volatile compounds in leaves and fruits of Amomum tsaoko, Amomum paratsaoko, and Amomum koenigii. The composition and aroma of distinct metabolites were analyzed using multivariate statistical methods. A total of 564 volatile compounds were identified from three species of the genus Amomum, which were further divided into nine categories: terpenoids, carboxylic acids, alcohols, hydrocarbons, aldehydes, ketones, phenols, ethers, and other compounds. Terpenoids and alcohols were the most abundant. The content and types of compounds vary in A. tsaoko, A. paratsaoko, and A. koenigii, so mixing or substituting them is not advisable. We selected 45 metabolites based on the criteria of the variable importance in projection values (VIP > 1.5) and one-way ANOVA (p < 0.05). The top 19 metabolites with the most significant VIP values were chosen. Interestingly, (Z)-2-decenal was only found in Amomum koenigii, while nitroethane and nonanal were only present in cultivated A. tsaoko. Additionally, linalool, cineole, and (D)-limonene were the main components affecting the aroma of three species of the genus Amomum. The volatile components identified in this study provide a theoretical basis for analyzing the unique flavor of A. tsaoko, A. paratsaoko, and A. koenigii.

Morphological 3D Analysis of PLGA/Chitosan Blend Polymer Scaffolds and Their Impregnation with Olive Pruning Residues via Supercritical CO2

Natural extracts, such as those from the residues of the Olea europaea industry, offer an opportunity for use due to their richness in antioxidant compounds. These compounds can be incorporated into porous polymeric devices with huge potential for tissue engineering such as bone, cardiovascular, osteogenesis, or neural applications using supercritical CO2. For this purpose, polymeric scaffolds of biodegradable poly(lactic-co-glycolic acid) (PLGA) and chitosan, generated in situ by foaming, were employed for the supercritical impregnation of ethanolic olive leaf extract (OLE). The influence of the presence of chitosan on porosity and interconnectivity in the scaffolds, both with and without impregnated extract, was studied. The scaffolds have been characterized by X-ray computed microtomography, scanning electron microscope, measurements of impregnated load, and antioxidant capacity. The expansion factor decreased as the chitosan content rose, which also occurred when OLE was used. Pore diameters varied, reducing from 0.19 mm in pure PLGA to 0.11 mm in the two experiments with the highest chitosan levels. The connectivity was analyzed, showing that in most instances, adding chitosan doubled the average number of connections, increasing it by a factor of 2.5. An experiment was also conducted to investigate the influence of key factors in the impregnation of the extract, such as pressure (10-30 MPa), temperature (308-328 K), and polymer ratio (1:1-9:1 PLGA/chitosan). Increased pressure facilitated increased OLE loading. The scaffolds were evaluated for antioxidant activity and demonstrated substantial oxidation inhibition (up to 82.5% under optimal conditions) and remarkable potential to combat oxidative stress-induced pathologies.

Antimicrobial, Herbicidal and pesticidal potential of Tunisian eucalyptus species: Chemoprofiling and biological evaluation

The Eucalyptus genus, characterized by its imposing stature and fragrant foliage, has been a source of fascination for humanity over the centuries. The focus of the present investigation was directed towards the essentials oils (EOs) of five Eucalyptus trees cultivated in Tunisia. The GC-MS analysis unveiled unique compositional profiles, a finding substantiated by both Hierarchical Clustering Analysis (HCA) and Principal Component Analysis (PCA) conducted on the leaves EOs. These analyses resulted in the formation of discrete HCA clades, delineating 23 significant components. Notably, the percentage of eucalyptol emerged as the pivotal factor demarcating the separation between three distinct groups. The statistical analysis revealed a dose-dependent relationship in both phytotoxicity evaluation and antibacterial activity. The EOs from Eucalyptus loxophleba and E. salubris exhibited the highest phytotoxicity, inhibiting radical elongation and germination of various seeds, especially Sinapis arvensis and Raphanus sativus. The antimicrobial assessment demonstrated significant inhibitory effects of the EOs on bacterial strains, with MIC values spanning from 14 to exceeding 50 mg/ml. The EOs also affected biofilm formation and cellular metabolism, displaying varied efficacy among different Eucalyptus species against some bacterial strains. The EOs exhibited selective inhibition against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), α-amylase, and α-glucosidase. E. campaspe EO showed the highest AChE activity, while E. loxophleba and E. salubris EOs were most potent toward α-amylase. E. loxophleba EO demonstrated notable activity against α-glucosidase. Overall, these findings provide important data about the diverse biological activities of Eucalyptus EOs, suggesting potential applications in agriculture, medicine, and pharmacy.

Carbon black preparation by partial oxidation of spent tyre pyrolysis oil - Influence of temperature, residence time and oxygen to feed ratio

Preparation of carbon black (CB) by partial oxidation of the spent tyre pyrolysis oil (STPO) and its heavy residue fraction (HRF) was systematically studied using a lab-scale drop tube furnace. The effect of furnace operating temperature (T: 1100 to 1400 °C), residence time (tr: 5 to 60 s) and oxygen to feed ratio (O/F: 174 to 732) on the yield and quality of CB was examined using the response surface methodology (RSM). T was shown to have the most significant influence on CB yield and properties. While the CB yield was also influenced by tr, the quality was more sensitively dependent on T and O/F. The predicted optimal tr and O/F were approximately the same for both feedstocks (60 s and 174, respectively). However, T was higher for the HRF feedstock (1368 °C) than the STPO feedstock (1331 °C) due to the abundance of more viscous heavy hydrocarbons in HRF. Validation experiments under the aforementioned conditions demonstrated the models' ability to predict responses accurately. The CB from both feedstocks had low contents of ash (<0.03%), volatiles (∼0.5%), sulphur (<0.7%), and high carbon (≥95%). The BET surface area and average primary particle size for CB from STPO and HRF were comparable to those of commercial CBs from fossil fuel feedstock. The CB from HRF had a higher carboxyl oxygen functional group (18%) compared to the CB from STPO (∼13%) and commercial CB (<5%).

Natural antimicrobials from plants: Recent advances and future prospects

Plant-based antimicrobial substances have emerged as promising alternatives to conventional antibiotics and preservatives. Although many review studies have been done in this field, many of these reviews solely focus on specific compounds from particular perspectives. This paper aims to provide a comprehensive review on the various types of plant-based antimicrobial substances, the extraction and purification processes, as well as the application and safety issues. Combining different natural plant-derived substances shows promise in enhancing antimicrobial activities. Moreover, despite the existence of various methods (e.g., microwave-assisted extraction, supercritical fluid extraction) to extract and purify antimicrobial substances, isolating pure compounds remains a laborious process. Sustainability issues should also be considered when developing extraction methods. Additionally, the extraction process generates a significant amount of plant waste, necessitating proper utilization to ensure economic viability. Lastly, not all plant-derived substances are safe, and further research is needed to investigate their toxicity before widespread application.

The essential oil of Kochia scoparia (L.) Schrad. as a potential repellent against stored-product insects

Chemical composition of the essential oil from Kochia scoparia (L.) Schrad. (syn. Bassia scoparia (L.) A. J. Scott) was analyzed in quality and quantity by GC-MS and GC-FID. Repellent activities of the essential oil from K. scoparia (KSEO) were evaluated against two common species of stored-product insects Tribolium castaneum Herbst and Liposcelis bostrychophila Badonnel. Results indicated that KSEO mainly consisted of eugenol, β-caryophyllene, and α-humulene, accounting for 75.6%, 8.2%, and 1.4% of the total oil, respectively. KSEO and the three major components were repellent to T. castaneum and L. bostrychophila adults. Notably, KSEO exerted significant effects, comparable to the positive control DEET at 2 and 4 h post-exposure. Eugenol at 63.17-2.53 nL/cm2 exhibited high percentage repellency ranging from 96 to 70% against L. bostrychophila during 4-h exposure. To gain further insights into the repellent activity, molecular docking simulation was performed with eugenol as the ligand and an odorant binding protein TcOBPC12 (gene: TcOBP10B) from the model insect T. castaneum as the receptor. Docking calculation results revealed that TcOBPC12 had binding affinity to eugenol (△G =  - 4.52 kcal/mol) along with a hydrogen bond of 0.18 nm (1.8 Å) long forming between them, which could be an important target protein associated with identifying volatile repellent molecules. This work highlights the promising potential of KSEO as a botanical repellent for controlling stored-product insects.

Development of an ultrasound-assisted pre-treatment strategy for the extraction of D-Limonene toward the production of bioethanol from citrus peel waste (CPW)

Citrus is one of the world's most abundant fruits containing vitamins, pigments, and fragrances, making it vital for several industries. However, these fruits contain about 45-50% residues (peels), which often end up as waste and can be harmful to the environment if not properly treated. Bioethanol production from citrus peel waste offers a potential solution to this problem. Hence, this study explores the potential of using ultrasound-assisted pre-treatment method as a novel strategy to extract D-Limonene (essential oil in the residue), and further demonstrates bioethanol production. This was done by investigating ultrasonication's optimal effect on pre-treatment of the citrus residue, followed by bioethanol production. The results show that, optimum values for D-Limonene extraction were obtained at a temperature of 14.6 °C and an ultrasound intensity of 25.81 W/cm2 with a validation yield of 134 ± 4.24 mg/100 g dry CPW. With optimal ultrasonic parameters, the study went further to demonstrate the effect of the essential oil on bioethanol production which is hindered by the oils present. Key findings show better bioethanol yield once the essential oil was extracted (treated) from the citrus waste as opposed to it not extracted (untreated), with a 66 and a 29% increase when comparing simultaneous saccharification and fermentation (SSF) and sequential hydrolysis and fermentation (SHF) respectively. Based on this result, ultrasound-assisted extraction as a pretreatment method was found suitable for bioethanol production from citrus residue and could be utilized as a biorefinery pre-treatment approach to scale bioethanol production.

Innovative Strategy for Aroma Stabilization Using Green Solvents: Supercritical CO2 Extracts of Satureja montana Dispersed in Deep Eutectic Solvents

The aim of this work was to establish the potential of natural deep eutectic solvents (NADES) for the stabilization of aroma volatile organic compounds from a natural source. Satureja montana was used as a source of volatile components, as it is rich in terpenes of great commercial and biological importance, such as carvacrol, thymol, and thymoquinone, among others. Supercritical CO₂ was used to extract the lipophilic fraction of S. montana, which was further directly dispersed in NADES. The stabilizing capacity of seven different NADES based on betaine and glycerol was analyzed. The stability of the components in NADES was monitored by analyzing the headspace profile during 6 months of storage at room temperature. The changes in the headspace profile over time were analyzed by using different statistical and chemometric tools and the Wilcoxon matched pair test. It was determined that alterations over time occurred such as degradation and oxidation, and they were the most prominent in the control. In addition, the indicator of decreased stability of the control was the formation of the new compounds that could compromise the quality of the product. In the stabilized NADES samples, the changes were significantly less prominent, indicating that the NADES had a stabilizing effect on the volatile compounds. According to Wilcoxon matched pair test, the most efficient stability was achieved by using betaine/ethylene glycol, glycerol/glucose, and betaine/sorbitol/water. Therefore, by applying two green solvents, a sustainable approach for obtaining pure and high-quality S. montana extracts with extended stability at room temperature was established.

Extraction of High-Value Chemicals from Plants for Technical and Medical Applications

Plants produce a variety of high-value chemicals (e.g., secondary metabolites) which have a plethora of biological activities, which may be utilised in many facets of industry (e.g., agrisciences, cosmetics, drugs, neutraceuticals, household products, etc.). Exposure to various different environments, as well as their treatment (e.g., exposure to chemicals), can influence the chemical makeup of these plants and, in turn, which chemicals will be prevalent within them. Essential oils (EOs) usually have complex compositions (>300 organic compounds, e.g., alkaloids, flavonoids, phenolic acids, saponins and terpenes) and are obtained from botanically defined plant raw materials by dry/steam distillation or a suitable mechanical process (without heating). In certain cases, an antioxidant may be added to the EO (EOs are produced by more than 17,500 species of plants, but only ca. 250 EOs are commercially available). The interesting bioactivity of the chemicals produced by plants renders them high in value, motivating investment in their production, extraction and analysis. Traditional methods for effectively extracting plant-derived biomolecules include cold pressing and hydro/steam distillation; newer methods include solvent/Soxhlet extractions and sustainable processes that reduce waste, decrease processing times and deliver competitive yields, examples of which include microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), subcritical water extraction (SWE) and supercritical CO2 extraction (scCO2). Once extracted, analytical techniques such as chromatography and mass spectrometry may be used to analyse the contents of the high-value extracts within a given feedstock. The bioactive components, which can be used in a variety of formulations and products (e.g., displaying anti-aging, antibacterial, anticancer, anti-depressive, antifungal, anti-inflammatory, antioxidant, antiparasitic, antiviral and anti-stress properties), are biorenewable high-value chemicals.

Organosilicone Compounds in Supercritical Carbon Dioxide

This review considers the key advantages of using supercritical carbon dioxide as a solvent for systems with organosilicon compounds. Organosilicon polymeric materials synthesis as well as the creation and modification of composites based on them are discussed. Polydimethylsiloxane and analogues used as polymerization stabilizers and nucleation promoters in pore formation processes are analyzed as well.

Process Optimization for Supercritical Carbon Dioxide Extraction of Origanum vulgare L. Essential Oil Based on the Yield, Carvacrol, and Thymol Contents

Background

Origanum vulgare L. essential oil (OEO) is widely known for its good biological activity, but different extraction methods with significant implications on the yield of OEO and the content of the thymol and carvacrol. As an efficient method for extracting essential oils (EO), the supercritical carbon dioxide extraction (SC-CO2) can improve the yield of EOs while protecting their main active components from loss.

Objective

In this study, the process optimization of SC-CO2 of OEO was carried out. The effects of extraction pressure, temperature, time, and modifier concentration on the composite score of OEO extraction process were investigated.

Method

Response surface analysis was performed using a Box-Behnken design with three levels and four independent variables. Steam distillation (SD) and lipophilic solvents (n-hexane) extraction (LSE) were compared with SC-CO2 for OEO yields. OEOs extracted by the three methods were qualitatively and semi-quantitatively analyzed by gas chromatography quadrupole-time-of-flight mass spectrometry and gas chromatography-flame ionization detector.

Results

The results showed that extraction pressure was the most significant factor affecting the OEO yield, thymol, and carvacrol content. In the optimal conditions (pressure: 217 bar, temperature: 54°C, time: 2 h, modifier concentration: 14%), the yield of OEO reached up to 1.136%, and the contents of thymol and carvacrol reached 53.172  and 41.785 mg/g, respectively.

Conclusions

SC-CO2 was the best extraction method compared to the other two methods. Under the optimal conditions, yield and the content of main components can be effectively improved. It can provide a theoretical basis for the industrial extraction of OEO.

Highlights

Taking the comprehensive score as the index, the interaction between the four independent variables in the supercritical fluid extraction process was evaluated by the response surface method. The effects of extraction parameters on the yield of EOs and the contents of thymol and carvacrol were comprehensively investigated.

Toward a Better Understanding of Metal Nanoparticles, a Novel Strategy from Eucalyptus Plants

Nanotechnology is a promising tool that has opened the doors of improvement to the quality of human's lives through its potential in numerous technological aspects. Green chemistry of nanoscale materials (1-100 nm) is as an effective and sustainable strategy to manufacture homogeneous nanoparticles (NPs) with unique properties, thus making the synthesis of green NPs, especially metal nanoparticles (MNPs), the scientist's core theme. Researchers have tested different organisms to manufacture MNPs and the results of experiments confirmed that plants tend to be the ideal candidate amongst all entities and are suitable to synthesize a wide variety of MNPs. Natural and cultivated Eucalyptus forests are among woody plants used for landscape beautification and as forest products. The present review has been written to reflect the efficacious role of Eucalyptus in the synthesis of MNPs. To better understand this, the route of extracting MNPs from plants, in general, and Eucalyptus, in particular, are discussed. Furthermore, the crucial factors influencing the process of MNP synthesis from Eucalyptus as well as their characterization and recent applications are highlighted. Information gathered in this review is useful to build a basis for new prospective research ideas on how to exploit this woody species in the production of MNPs. Nevertheless, there is a necessity to feed the scientific field with further investigations on wider applications of Eucalyptus-derived MNPs.

Green and Efficient Processing of Wood with Supercritical CO2: A Review

Wood processing is a crucial step of wood utilization, but the adding of environmentally hazardous feedstocks and the use of unreasonable technology allow it to harm the environment and human health. Supercritical CO2 (scCO2) is a non-toxic, odorless, and safe solvent, which is widely used in studies and industrial production, but there is no review summarizing wood processing with scCO2. The unique structure and chemical properties of wood combined with scCO2 technology produce positive results. In this paper, wood processing with scCO2 is summarized, including wood impregnation, wood drying, wood thermochemical conversion, and wood extraction. The green and efficient characteristics of wood processing with scCO2 are explained in detail for researchers, engineers, and investors to provide a clean wood processing method. Further study is needed to reduce its energy consumption and commercialize it eventually.

Antifungal Activity of Thai Cajuput Oil and Its Effect on Efflux-Pump Gene Expression in Fluconazole-Resistant Candida albicans Clinical Isolates

Candidiasis caused by the fluconazole-resistant opportunistic pathogen Candida albicans is an intractable clinical problem that threatens immunocompromised or normal individuals. The most common mechanism of fluconazole resistance in C. albicans is the failure of cells to accumulate the drug due to increased expression of the efflux proteins encoded by the CDR1, CDR2, and MDR1 genes. Because the number of current antifungal drugs is limited, it is necessary to develop new therapeutic strategies. This study aimed to evaluate the antifungal activity of Thai Cajuput oil, its synergism with fluconazole, and its effect on efflux-pump gene expression in fluconazole-resistant C. albicans clinical isolates. Thus, we first detected the efflux-pump genes in fourteen resistant strains by PCR. The frequencies of the CDR1, CDR2, and MDR1 genes were 68.75%, 62.5%, and 87.5%, respectively, and these efflux-pump genes were distributed in three distinct patterns. Subsequently, the antifungal activity of Thai Cajuput oil was assessed by broth macrodilution and its synergism with fluconazole was evaluated by the checkerboard assay. The changes in the expression levels of CDR1, CDR2, and MDR1 after treatment with Thai Cajuput oil were analyzed by qRT-PCR. The MICs and MFCs of Thai Cajuput oil ranged from 0.31 to 1.25 μl/ml and 0.63 to 1.25 μl/ml, respectively, and its activity was defined as fungicidal activity. The MICs of the combination of Thai Cajuput oil and fluconazole were much lower than the MICs of the individual drugs. Interestingly, sub-MICs of Thai Cajuput oil significantly reduced the MDR1 expression level in resistant strains (P < 0.05). Our study suggests that Thai Cajuput oil can be used to create new potential combination therapies to combat the antifungal resistance of C. albicans.

Extraction and Characterization of Flaxseed Oil Obtained with Subcritical n-Butane

In this study, subcritical n-butane was adopted to extract oil from flaxseed. The extraction conditions i.e. extraction temperature, extraction time, and liquid-solid ratio were investigated and optimized by response surface methodology. The flaxseed oil obtained by subcritical n-butane were characterized and compared with those prepared by n-hexane and cold pressing. Results indicated that the optimal combination of parameters was 53.93℃, 56.82 min, and 19.98:1 mL/g. Subcritical n-butane had higher yield (28.75%) than n-hexane and cold pressing. GC analysis indicated that subcritical n-butane extraction had no obvious influence on the fatty acid composition. Nevertheless, the oil obtained by subcritical n-butane with higher contents of phytosterols (2.93 mg/g) and carotenoids (46.56 mg/kg), and presented a higher oxidation stability (9.27 h). Thus, it was suggested that subcritical n-butane extraction is a promising alternative to extract high quality flaxseed oil.

Volatile Antimicrobial Agents and In Vitro Methods for Evaluating Their Activity in the Vapour Phase: A Review

This review summarizes data on the in vitro antimicrobial effectiveness of volatile agents of plant origin and in vitro methods for evaluating their activity in the vapour phase. As a result of literature analysis, the antimicrobial efficacy of vapours from 122 different plant species and 19 pure compounds examined in 61 studies using different in vitro tests against a broad spectrum of microorganisms was identified and summarized. In addition, 11 different techniques found in the literature are described in detail. An original classification of methods based on the solid and liquid matrix volatilization principle is proposed because carrier medium/matrix selection is crucial for the volatilization of any agents tested. This review should be useful for medicinal, pharmaceutical, food, and agricultural experts working in areas related to the management of infectious diseases (especially respiratory and skin infections), food preservation (active packaging), and protection of agriculture products (controlled atmosphere). It may also stimulate the interest of pharmaceutical, cosmetic, food, and agriculture industries in the research and development of new antimicrobial agents of natural origin. Since several original apparatuses previously developed for antimicrobial susceptibility testing in the vapour phase are described in this review, labware manufacturers may also be interested in this topic. The review also provides specific guidelines and recommendations for researchers studying the antimicrobial activity of volatile agents. The article will therefore appeal to communities of industrial stakeholders, pharmacists, physicians, food experts, agriculturists, and researchers in related areas such as pharmacology, medicinal chemistry, microbiology, natural product chemistry, food preservation and plant protection.

Extraction of corn germ oil with supercritical CO2 and cosolvents

The aim of this work was to investigate corn germ oil extraction using supercritical CO₂ and cosolvents addition (hexane, acetone and ethanol). The effects of temperature (45-85 °C) and pressure (15-25 MPa) on the extract yield were evaluated for the tests conducted only with supercritical CO₂. The addition of cosolvents to supercritical CO₂ was also examined at 25 MPa and 60 °C. The conventional Soxhlet extraction with different organic solvents was also performed for comparison purposes. The results of extraction with supercritical fluid showed that the yields increased with pressure at each temperature, but decreased with temperature increase. Mathematical modeling was applied to describe extraction curves, with very good fits. The addition of cosolvents led to higher yield, with a maximum yield of 13.81% using ethanol. The analysis of fatty acids profile did not present significant differences among the evaluated methods. On the other hand, the antioxidant activity of the extracts obtained by supercritical CO₂ extraction was higher than the ones verified for the extracts collected after conventional Soxhlet extraction. Therefore, the use of supercritical CO₂ extraction could be an interesting way to preserve antioxidant properties of this oil in order to use it for pharmaceutical purposes.

Sono hydrodistillation for isolation of citronella oil: A symbiotic effect of sonication and hydrodistillation towards energy efficiency and environment friendliness

Environmental benign approach for extraction of essential oil was made. An essential oil rich in citronellol, linalool and citronellal was extracted from the leaves of Cymbopogon winterianus using a clean hybrid extraction technique, sono hydrodistillation. Sono hydrodistillation combines ultrasonic waves along with conventional hydrodistillation process to have symbiotic outcomes in terms of process improvement. Significant process parameters such as size of the plant material, extraction time, power, ultrasound amplitude, pulse interval and solid loading were investigated independently to study the effect on yield of oil and composition of oil. The water residue remained after extraction of volatile oil was analyzed using Folin-Ciocalteu method to determine the total phenolic content (TPC) which would help in assessing the residue as a useful by-product. Substantial reduction in time was observed with the inclusion of ultrasound compared to conventional hydrodistillation. Further, to optimize the extraction conditions, observe interactive effects of various parameters and develop mathematical model, response surface methodology was employed. The maximum yield of oil was found to be 4.118% (w/w) at 21 min extraction time, 5 g solid loading, 250 mL water volume, 500 W heating mantle power, 70% ultrasonic amplitude and 10:50 pulse interval. Total phenolic content was 13.84 mg GAE/g DM. The citronella oil was found to be composed of 27.47% of linalool, 11.52% of citronellal, 34.25% citronellol and 11.15% of elemol. Extraction time, solid loading and pulse interval had the significant influence on the yield of oil and total phenolic contents. Microscopic analysis has assisted in envisaging the probable mechanism indicating the role of sonication for rapid extraction. This novel technique was compared with the conventional hydrodistillation to ascertain the impact towards process intensification. Sono hydrodistillation was found to be a greener and cleaner process as energy consumption has been reduced by 40% while carbon footprint has shrunken by 47%.

A novel, sensitive and non-destructive method for quantitative determination of lipid in live Eriocheir sinensis using low-field 1H Nuclear magnetic resonance

In this study, lipid content of live Eriocheir sinensis has been quickly and accurately determined by low-field 1H Nuclear magnetic resonance (LF-1H NMR). The experimental parameters of LF-1H NMR have been optimized and the validity of the established standard method has been confirmed with traditional Soxhlet extraction method. Results show that the lipid signal intensity is strongly correlated with its content and exhibits a good linear correlation (Y = 0.0376 + 4.899X, R 2 = 0.9999), thus demonstrating favorable accuracy and sensitivity for the quantitative determination of lipid content. In conclusion, the lipid content of live E. Sinensis can be directly obtained based on an established method, indicating a great application potential in food and other fields.

Nondestructive prediction and visualization of plumpness in live Eriocheir sinensis using low-field 1 H magnetic resonance imaging

BACKGROUND

The plumpness of hepatopancreas and gonad tissues in live Chinese mitten crabs (Eriocheir sinensis) depends on the grading scale and its commercial value. In this work, a low-field T₁ -weighted ¹ H magnetic resonance imaging (LF-¹ H MRI) technique was developed to nondestructively analyze the plumpness of hepatopancreas and gonad tissues in live E. sinensis. Both male and female E. sinensis were characterized by two-dimensional (2D) LF-¹ H MRI. Moreover, a three-dimensional (3D) LF-¹ H MRI model that quantitatively integrated the total volume of lipid tissues in live E. sinensis was used.

RESULTS

The results showed 2D LF-¹ H MRI could accurately discriminate the plumpness of hepatopancreas and gonad tissues in live E. sinensis. The results of the 3D LF-¹ H MRI model displayed that the lipid volume of E. sinensis could be used to quantify lipid accumulation in lipid tissues.

CONCLUSION

LF-¹ H MRI technology was successfully developed to accurately discriminate the development of E. sinensis hepatopancreas and gonad tissues in a nondestructive manner, indicating its application potential in grading commercial live crabs or advising crab farmers on breeding and fattening processes. © 2018 Society of Chemical Industry.

Optimization of Supercritical Carbon Dioxide Extraction of Eucommia ulmoides Seed Oil and Quality Evaluation of the Oil

Supercritical carbon dioxide extraction (SC-CO₂) technology was used to extract oil from Eucommia ulmoides seed. The optimum conditions and significant parameters in SC-CO₂ were obtained using response surface methodology (RSM). The qualities of the extracted oil were evaluated by physicochemical properties, fatty acid composition, vitamin E composition. It was found that the optimum extraction parameters were at pressure of 37 MPa, temperature of 40°C, extraction time of 125 min and CO₂ flow rate of 2.6 SL/min. Pressure, temperature and time were identified as significant parameter effecting on extraction yield. The importance of evaluated parameters decreased in the order of pressure > extraction time > temperature > CO₂ flow rate. GC analysis indicated that E. ulmoides seed oil contained about 61% of linolenic acid and its fatty acid composition was similar with that of flaxseed oil and perilla oil. The content and composition of vitamin E was determined using HPLC. The E. ulmoides seed oil was rich in vitamin E (190.72 mg/100 g), the predominant vitamin E isomers were γ- tocopherol and δ- tocopherol, which accounted for 70.87% and 24.81% of the total vitamin E, respectively. The high yield and good physicochemical properties of extracted oil support the notion that SC-CO₂ technology is an effective technique for extracting oil from E. ulmoides seed.

A novel non-destructive manner for quantitative determination of plumpness of live Eriocheir sinensis using low-field nuclear magnetic resonance

The present study investigated the quantitative and non-destructive determination of Eriocheir sinensis' plumpness during four mature stages using low field-nuclear magnetic resonance (LF-¹H NMR). Normalized lipid volume of live E. sinensis was calculated from Sept to Dec using 3D LF-¹H nuclear magnetic imaging (MRI) and the validity of proposed technique was compared and verified with traditional Soxhlet extraction and live dissection method, respectively. The results showed the plumpness of female E. sinensis was higher than that of male ones from Sept to Dec and the highest plumpness of male and female E. sinensis reached 99,436.44 and 109,207.15mm³ in Oct. The normalized lipid volume of live male and female E. sinensis had a positive correlation with lipid content. This proposed method with short assay time, favorable selectivity, and accuracy demonstrated its application potential in grading regulation and quality evaluation of live E. sinensis.

Antifungal Activity of Eucalyptus Oil against Rice Blast Fungi and the Possible Mechanism of Gene Expression Pattern

Eucalyptus oil possesses a wide spectrum of biological activity, including anti-microbial, fungicidal, herbicidal, acaricidal and nematicidal properties. We studied anti-fungal activities of the leaf oil extracted from Eucalyptus. grandis × E. urophylla. Eleven plant pathogenic fungi were tested based on the mycelium growth rates with negative control. The results showed that Eucalyptus oil has broad-spectrum inhibitory effects toward these fungi. Remarkable morphological and structural alterations of hypha have been observed for Magnaporthe grisea after the treatment. The mRNA genome array of M. grisea was used to detect genes that were differentially expressed in the test strains treated by the Eucalyptus oil than the normal strains. The results showed 1919 genes were significantly affected, among which 1109 were down-regulated and 810 were up-regulated (p < 0.05, absolute fold change >2). According to gene ontology annotation analysis, these differentially expressed genes may cause abnormal structures and physiological function disorders, which may reduce the fungus growth. These results show the oil has potential for use in the biological control of plant disease as a green biopesticide.

Optimizing Mass Spectrometry Analyses: A Tailored Review on the Utility of Design of Experiments

Mass spectrometry (MS) has emerged as a tool that can analyze nearly all classes of molecules, with its scope rapidly expanding in the areas of post-translational modifications, MS instrumentation, and many others. Yet integration of novel analyte preparatory and purification methods with existing or novel mass spectrometers can introduce new challenges for MS sensitivity. The mechanisms that govern detection by MS are particularly complex and interdependent, including ionization efficiency, ion suppression, and transmission. Performance of both off-line and MS methods can be optimized separately or, when appropriate, simultaneously through statistical designs, broadly referred to as "design of experiments" (DOE). The following review provides a tutorial-like guide into the selection of DOE for MS experiments, the practices for modeling and optimization of response variables, and the available software tools that support DOE implementation in any laboratory. This review comes 3 years after the latest DOE review (Hibbert DB, 2012), which provided a comprehensive overview on the types of designs available and their statistical construction. Since that time, new classes of DOE, such as the definitive screening design, have emerged and new calls have been made for mass spectrometrists to adopt the practice. Rather than exhaustively cover all possible designs, we have highlighted the three most practical DOE classes available to mass spectrometrists. This review further differentiates itself by providing expert recommendations for experimental setup and defining DOE entirely in the context of three case-studies that highlight the utility of different designs to achieve different goals. A step-by-step tutorial is also provided.