Composition Of Compounds Research Articles

Luminescent properties of Tm3+-activated phosphors with rosiaite structure

A series of solid solutions with compositions of La1-xTmxGa0.5Sb1.5O6 (x = 0.03, 0.05, 0.1) and La1-x-y-zTmxTbyDyzGa0.5Sb1.5O6 (x = 0.04, 0.07, 0.1; y = 0.04, 0.07, 0.1; z = 0.04, 0.04, 0.06) has been synthesized. It is shown that all the compounds have rosiaite structure (PbSb2O6, sp.gr. P-31m). Morphology, spectral-luminescent characteristics and color coordinates of the samples were studied. It was found that luminescence spectrum of thulium-activated samples recorded upon 351 nm excitation is typical for Tm3+ ions. At the same time, under excitation by radiation with λ = 457 nm and a power density of J = 4.7 kW/cm2, broadband thermal emission is observed, against which the bands corresponding to the 1G4→3H6, 1G4→3F4, 3F4→3H6 и 3H4→3H6 transitions of Tm3+ are detected. The luminescence spectra of the samples co-activated with Tm3+, Tb3+ and Dy3+are characterized by a relatively low intensity of the Tm3+ emission, which may be due to efficient energy transfer processes between Tb3+ and Dy3+ ions. A shift from the blue to the green color regions is observed in the color coordinates of the co-activated samples upon 351 nm excitation. Radiation with λ = 457 nm led to a shift in the emission colour to orange. Thus, it is shown that it is possible to create phosphors emitting in the blue, green and orange spectral regions by changing the wavelength of exciting radiation and activator composition for compounds with rosiaite structure.

Phenolic fingerprint of Macedonian propolis

Propolis is a chemically complex resinous material collected by honeybees (Apis mellifera) from tree buds and resins, comprising plant exudates, secreted substances from bee metabolism, pollen and waxes. Its chemical composition depends strongly on the plant sources available around the beehive, which have a direct impact оn the quality and bioactivity of the propolis. In this study, the composition of phenolic compounds in 13 Macedonian propolis extracts was investigated by HPLC-DAD-ESI-MS/MS. Overall, the UV spectra, the MS and MS/MS data allowed the identification of 36 compounds. The major constituents of propolis were phenolic acids (caffeic and coumaric) and their esters (methyl, (iso)prenyl, benzyl, phenylethyl, cinnamyl), flavonols (quercetin, kaemferol), flavones (chrysin, apigenin, acacetin), flavanonols (pinobanksin) flavanones (pinocembrin naringenin, hesperetin, pinostrobin) and their methylated/esterified derivatives. The results reveal that Macedonian propolis contains a diversity of phenolic compounds confirming that it is a poplar type of propolis with higher phenolic content (ranging from 43.75–637.94 mg/g) than reported in previous studies in the region and beyond in Europe (< 80 mg/g). This suggests the potential significance of Macedonian propolis as a valuable source of bioactive compounds with health benefits as well as for unlocking its economic potential for industry and beekeepers.

Enhancing Secondary Metabolite Production in Pelargonium graveolens Hort. Cell Cultures: Eliciting Effects of Chitosan and Jasmonic Acid on Bioactive Compound Production

This study explores the effects of chitosan (CHT) and jasmonic acid (JA) elicitors on rose-scented geranium (Pelargonium graveolens Hort.) cell suspension cultures, aiming to enhance the production of phenolics and flavonoids and antioxidant properties. Elicitation with CHT and JA resulted in varied biomass yields and callus characteristics, with higher concentrations generally leading to increased phenolic accumulation. Optimal biomass was achieved with CHT4 (75 mg/mL) and JA3 (50 µM) treatments. HPLC-DAD analysis revealed changes in phenolic compound composition and quantities, with specific compounds induced by either CHT4 or JA3. For instance, gallic acid content increased significantly in CHT4-treated cells, while catechin content increased notably in both CHT4 and JA3 treatments. Antioxidant enzyme activities like superoxide dismutase and peroxidase increased with elicitor concentration, particularly in CHT4 and JA3 treatments. Both treatments exhibited potent antioxidant activity, with JA3 exhibiting the lowest IC50 value in the DPPH assay and highest total antioxidant capacity (TAC) values. Surprisingly, both CHT4 and JA3 extracts effectively inhibited tyrosinase activity. These findings underscore the efficacy of CHT and JA elicitors in enhancing phenolic and flavonoid production, boosting antioxidant capacity, and inhibiting tyrosinase activity in P. graveolens cultures, offering promising implications for further research and industrial applications in pharmaceutical and cosmetic sectors.

Enhanced corrosion resistance of 9Cr alloy steel via Al alloying in simulated harsh marine atmosphere

The corrosion behaviors of Cr9Ni1 and Cr9Ni1Al in simulated harsh marine atmosphere were studied by dry-wet cyclic test (DWCT). Scanning electron microscopy (SEM), energy disperse spectroscopy (EDS) and electron probe microanalyzer (EPMA) were used to observe the cross-section morphology of rust layer. The composition of corrosion products were analyzed through X-ray diffractometer (XRD) and X-Photoelectron spectroscope (XPS). Electrochemical impedance spectroscopy (EIS) was used to determine the electrochemical properties of rusted samples. The results show that the corrosion rate of both 9Cr alloy steels increases continuously during the initial corrosion process of 576 h, which can be understood from α/γ*>1 of the rust layer and the acidification caused by increased CrO3. Interestingly, the addition of 0.7 % Al reduced the corrosion rate of 9Cr steel by more than 26 %. Al not only generates Al2O3 and Al(OH)3 enriched in the whole rust layer, but also optimizes the rust layer in terms of the Cr distribution, composition of Cr-containing compounds, and α-FeOOH content. Importantly, it is proposed that Al alloying weakens acidification through reducing CrO3 content and partial dissolution of the generated Al(OH)3.

Tritrophic Interactions Mediated by Zoophytophagous Predator-Induced Host Plant Volatiles.

The zoophytophagous mirid predator Nesidiocoris tenuis and the ectoparasitoid Stenomesius japonicus are important biological control agents for several agricultural pests including the invasive leafminer, Phthorimaea absoluta, a destructive pest of Solanaceous crops especially tomato in sub-Saharan Africa. However, little is known about how feeding by N. tenuis can influence the tritrophic interactions in the tomato plant. Here, we tested the hypothesis that N. tenuis phytophagy would influence the tritrophic olfactory interactions between the host plant tomato and pest, predator, and parasitoid. In olfactometer assays, P. absoluta females and N. tenuis adults were both attracted to constitutive volatiles released by the tomato plant. Whereas females of P. absoluta avoided volatiles released by N. tenuis-infested plants, S. japonicus females and N. tenuis adults were attracted to the induced volatiles. In coupled gas chromatography-electroantennographic detection (GC-EAD) recordings of intact and N. tenuis-infested plant volatiles, antennae of P. absoluta and S. japonicus females both detected eight components, whereas N. tenuis adults detected seven components which were identified by GC-mass spectrometry (GC-MS) as terpenes and green leaf volatiles (GLVs). Dose-response olfactometer bioassays revealed that the responses of P. absoluta, N. tenuis, and S. japonicus varied with the composition and concentration of blends and individual compounds tested from N tenuis-induced volatiles. Females of P. absoluta showed no preference for an eight-component blend formulated from the individual repellents including hexanal, (Z)-3-hexenyl butanoate, and δ-elemene identified in the volatiles. On the other hand, S. japonicus females were attracted to an eight-component blend including the attractants (E)-2-hexenal, (Z)-3-hexenol, methyl salicylate, β-phellandrene, and (E)-caryophyllene. Likewise, N. tenuis adults were attracted to a seven-component blend including the attractants β-phellandrene, δ-elemene, and (E)-caryophyllene identified in the volatiles. Our findings suggest that there is potential for the use of terpenes and GLVs to manage the insects in the tritrophic interaction.

Assessing the effect of COVID 19 lockdowns on the composition of organic compounds and potential source of PM2.5 in Hanoi, Vietnam.

The ambient air quality during COVID-19 lockdowns has been improved in many cities in the world. This study is to assess the changes in persistent organic pollutants in PM2.5 during the COVID-19 lockdown in Hanoi. Individual organic species in PM2.5 ((e.g., polycyclic aromatic hydrocarbons (PAHs), polychlorobiphenyls (PCBs), and organochlorine pesticides (OCPs)) were measured in an urban residential area in Hanoi from before the March 10th to April 22nd, 2020, including before the partial lockdown (BL) and the partial lockdown (PL) phases. During the PL phase, the concentration of Σ14PAHs and Σ28PCBs was reduced by 38 and 52% compared with the BL period, respectively. The diagnostic ratio method implied that the sources of PAHs within the PL phase had a less effect on traffic and industrial activities than in the BL phase. The characteristic ratio method indicated that PCBs were mixed by commercial product and combustion process in both the BL and the PL periods, however, the source of PCBs in the BL phase was influenced by municipal waste incineration more than those in the PL phase. The decreasing concentration of Σ20OCPs during the partial lockdown was attributed to the restriction of human activities during the quarantine period. The results suggested that the source of OCPs was probably derived from the usage of pesticides in current and, historical degradation or the transportation of pesticides from the soil to the atmosphere.

Tissue-Specific Distribution and Maternal Transfer of Persistent Organic Halogenated Pollutants in Frogs.

Persistent organic pollutants pose a great threat to amphibian populations, but information on the bioaccumulation of contaminants in amphibians remains scarce. To examine the tissue distribution and maternal transfer of organic halogenated pollutants (OHPs) in frogs, seven types of tissues from black-spotted frog (muscle, liver, kidney, stomach, intestine, heart, and egg) were collected from an e-waste-polluted area in South China. Among the seven frog tissues, median total OHP concentrations of 2.3 to 9.7 μg/g lipid weight were found (in 31 polychlorinated biphenyl [PCB] individuals and 15 polybrominated diphenyl ether [PBDE], dechlorane plus [syn-DP and anti-DP], bexabromobenzene [HBB], polybrominated biphenyl] PBB153 and -209], and decabromodiphenyl ethane [DBDPE] individuals). Sex-specific differences in contaminant concentration and compound compositions were observed among the frog tissues, and eggs had a significantly higher contaminant burden on the whole body of female frogs. In addition, a significant sex difference in the concentration ratios of other tissues to the liver was observed in most tissues except for muscle. These results suggest that egg production may involve the mobilization of other maternal tissues besides muscle, which resulted in the sex-specific distribution. Different parental tissues had similar maternal transfer mechanisms; factors other than lipophilicity (e.g., molecular size and proteinophilic characteristics) could influence the maternal transfer of OHPs in frogs. Environ Toxicol Chem 2024;00:1-12. © 2024 SETAC.

Volatile Organic Compound Composition and Emissions in a Residential Attic

Volatile Organic Compound Composition and Emissions in a Residential Attic

Transmission and nanohardness studies of ternary GaAs1-xPx layers grown from the vapor phase by heteroepitaxy

Transmission measurements in the 0.5–25-μm spectral range are performed on thin (<350 -μm) GaAsP layers grown by Hydride Vapor Phase Epitaxy (HVPE) on plain (100) GaAs substrates. Comparison with calculations taking into account multiple reflections reveals the role of the surface polishing quality on the clear transmission window and the wavelength dependent losses. A measurement of a 5-mm thick epitaxially grown GaP underlines more realistic spectral limitations on the application of orientation-patterned structures based on GaP and GaAsP for nonlinear optical frequency conversion. The mid-IR cut-off wavelength for the ternary GaAsP layers is almost independent of the composition and corresponds to the same two-phonon absorption limit observed in the binary GaP. Nanohardness and Young's modulus are measured for the same samples to evaluate their compositional dependence. The nanohardness dependence on the P-content obeys a second order polynomial law with a maximum around P = 0.8. Young's modulus depends linearly on the P-content, similar to the trend observed in other ternary systems, such as InxGa1−xAs and InxGa1-xP. The evolution of the band-gap, estimated from the transmission measurements, with the composition of the ternary compounds is linear in the range of 0–0.5 for the P content. In this same range the nanohardness can be considered to be linearly proportional to the band-gap.

High throughput identification of carbonyl compounds in natural organic matter by directional derivatization combined with ultra-high resolution mass spectrometry

Carbonyl compounds are important components of natural organic matter (NOM) with high reactivity, so that play a pivotal role in the dynamic transformation of NOM. However, due to the lack of effective analytical methods, our understanding on the molecular composition of these carbonyl compounds is still limited. Here, we developed a high-throughput screening method to detect carbonyl molecules in complex NOM samples by combining chemical derivatization with electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR-MS). In six different types of dissolved organic matter (DOM) samples tested in this study, 20%-30% of detected molecules contained at least one carbonyl group, with relative abundance accounted for 45% to 70%. These carbonyl molecules displayed lower unsaturation level, lower molecular weight, and higher oxidation degree compared to non-carbonyl molecules. More importantly, the measured abundances of carbonyl molecules were consistent with the results of 13C nuclear magnetic resonance (NMR) analysis. Based on this method, we found that carbonyl molecules can be produced at DOM-ferrihydrite interface, thus playing a role in shaping the molecular diversity of DOM. This method has broad application prospects in screening carbonyl compounds from complex mixtures, and the same strategy can be used to directional identification of molecules with other functional groups as well.

ML-Aided Computational Screening of 2D Materials for Photocatalytic Water Splitting.

The exploration of two-dimensional (2D) materials with exceptional physical and chemical properties is essential for the advancement of solar water splitting technologies. However, the discovery of 2D materials is currently heavily reliant on fragmented studies with limited opportunities for fine-tuning the chemical composition and electronic features of compounds. Starting from the V2DB digital library as a resource of 2D materials, we set up and execute a funnel approach that incorporates multiple screening steps to uncover potential candidates for photocatalytic water splitting. The initial screening step is based upon machine learning (ML) predicted properties, and subsequent steps involve first-principles modeling of increasing complexity, going from density functional theory (DFT) to hybrid-DFT to GW calculations. Ensuring that at each stage more complex calculations are only applied to the most promising candidates, our study introduces an effective screening methodology that may serve as a model for accelerating 2D materials discovery within a large chemical space. Our screening process yields a selection of 11 promising 2D photocatalysts.

Barley-derived beer brewing by-products contain a high diversity of hydroxycinnamoylagmatines and their dimers

To aid valorisation of beer brewing by-products, more insight into their composition is essential. We have analysed the phenolic compound composition of four brewing by-products, namely barley rootlets, spent grain, hot trub, and cold trub. The main phenolics detected were hydroxycinnamoylagmatines and dimers thereof. Barley rootlets contained the highest hydroxycinnamoylagmatine content and cold trub the highest dimer content. Additionally, variations in (dimeric) hydroxycinnamoylagmatine composition and content were observed in fourteen barley rootlet samples. The most abundant compound in all rootlets was the glycosylated 4-O-7′/3-8′-linked heterodimer of coumaroylagmatine and feruloylagmatine, i.e. CouAgm-4-O-7′/3-8′-(4′Hex)-DFerAgm. Structures of glycosylated and hydroxylated derivatives of coumaroylagmatine were elucidated by NMR spectroscopy after their purification from a rootlet extract. An MS-based decision tree was developed, which aids in identifying hydroxycinnamoylagmatine dimers in complex mixtures. In conclusion, this study shows that the diversity of phenolamides and (neo)lignanamides in barley-derived by-products is larger than previously reported.

Control of Fungal Pathogens Associated with Post-Harvest Rot Agents of Groundnut using Plant Extracts

Post-harvest losses due to fungal pathogens pose a significant threat to groundnut (Arachis hypogaea L.) production, affecting both food security and economic stability. In this study, we investigated the potential of plant extracts as eco-friendly alternatives for controlling fungal pathogens associated with post-harvest rot of groundnut. Four plant species, including neem (Azadirachta indica), garlic (Allium sativum), ginger (Zingiber officinale), and turmeric (Curcuma longa), were selected based on their known antimicrobial properties. Crude extracts were prepared from these plants and evaluated for their antifungal activity against common post-harvest rot agents, including Aspergillus spp., Fusarium spp., and Penicillium spp. The agar well diffusion method was employed to assess the inhibitory effects of the plant extracts against the fungal pathogens. Additionally, a control trial was conducted using leaf extracts of neem and drumstick (Moringa oleifera), with phytochemical analysis performed to determine the composition of bioactive compounds. The results revealed significant antifungal activity of all tested plant extracts, with neem extract exhibiting the highest efficacy against fungal pathogens. Phytochemical analysis indicated the presence of alkaloids, flavonoids, phenols, tannins, saponins, and terpenoids in the leaf extracts, highlighting their potential as sources of natural bioactive compounds. These findings suggest that plant extracts offer promising alternatives to synthetic fungicides for controlling post-harvest rot pathogens in groundnut. Further research is warranted to optimize the efficacy of plant extracts and elucidate their mechanisms of action for practical applications in groundnut storage and processing facilities.

Total Content and Composition of Phenolic Compounds from Filipendula Genus Plants and Their Potential Health-Promoting Properties.

This current article was dedicated to the determination of the composition of phenolic compounds in extracts of four species of the genus Filipendula in order to establish a connection between the composition of polyphenols and biological effects. A chemical analysis revealed that the composition of the extracts studied depended both on the plant species and its part (leaf or flower) and on the extractant used. All four species of Filipendula were rich sources of phenolic compounds and contained hydrolyzable tannins, condensed tannins, phenolic acids and their derivatives, and flavonoids. The activities included data on those that are most important for creating functional foods with Filipendula plant components: the influence on blood coagulation measured by prothrombin and activated partial thromboplastin time, and on the activity of the digestive enzymes (pancreatic amylase and lipase). It was established that plant species, their parts, and extraction methods contribute meaningfully to biological activity. The most prominent result is as follows: the plant organ determines the selective inhibition of either amylase or lipase; thus, the anticoagulant activities of F. camtschatica and F. stepposa hold promise for health-promoting food formulations associated with general metabolic disorders.

Synergistic enhancement of bio-oil production, quality, and optimization from co-pyrolysis purun tikus (Eleocharis dulcis) and plastic waste using response surface methodology

This study investigated the influence of varying pyrolysis temperatures (400–600°C) and biomass-to-plastic waste ratios (100:0, 70:30, 60:40, 50:50, and 40:60) on the product distribution during the co-pyrolysis of Purun tikus (PT) and Polyethylene Terephthalate (PET). The investigation revealed positive synergistic interactions. Notably, the bio-oil yield experienced a significant enhancement under optimal operational conditions (feedstock ratio of 40PT:60PET and a pyrolysis temperature of 600°C), with the yield doubling that of the feedstock ratio of 100PT. The composition of bio-oil compounds was analyzed using Gas Chromatography-Mass Spectrometry (GC-MS), revealing that the most abundant compounds were esters (ranging from 30.1 % to 37.2 % area), phenolics (ranging from 11.3 % to 32.2 % area), and furfural (ranging from 4.5 % to 18.5 % area). The study further explored the impact of different experimental conditions on the yields of bio-oil, bio-char, and syngas through the application of response surface methodology. It was determined that the optimal yield of bio-oil was attainable by adjusting the reaction temperature and the ratio of PT to PET. The identified optimum conditions, which resulted in the maximum bio-oil output of 40.46 %, were a PT to PET ratio of 40:60 and a temperature of 600°C.

Variation of volatile compounds and sensory profile for Protaetia brevitarsis larvae fermented with lactic acid bacteria and yeast

This study aimed to investigate the correlation between the composition of volatile compounds, consumer acceptance, and drivers of (dis)liking of Protaetia brevitarsis larvae fermented using lactic acid bacteria and yeast. Volatile compounds were analyzed using HS-SPME-Arrow-GC–MS, and a sensory evaluation was conducted with 72 consumers. A total of 113 volatile compounds were detected, and principal component analysis indicated that the samples could be divided into three groups. The calculated relative odor activity values (ROAV) revealed the presence of 27 compounds (ROAV >1). Volatile compounds with high ROAV were predominantly found during yeast fermentation. The sensory evaluation results indicated a strong correlation between low levels of off-odor intensity and high odor liking, emphasizing that odor profile had a more direct association with consumer acceptance than odor intensity. These findings suggest that yeast fermentation using volatile compounds, which positively influences consumer acceptance, is appropriate for Protaetia brevitarsis larvae.

Usefulness of Opuntia spp. on the Management of Obesity and Its Metabolic Co-Morbidities.

The plants of the Opuntia genus mainly grow in arid and semi-arid climates. Although the highest variety of wild species is found in Mexico, Opuntia spp. is widely distributed throughout the world. Extracts of these cacti have been described as important sources of bioactive substances that can have beneficial properties for the prevention and treatment of certain metabolic disorders. The objective of this review is to summarise the presently available knowledge regarding Opuntia ficus-indica (nopal or prickly pear), and some other species (O. streptacantha and O. robusta) on obesity and several metabolic complications. Current data show that Opuntia ficus-indica products used in preclinical studies have a significant capacity to prevent, at least partially, obesity and certain derived co-morbidities. On this subject, the potential beneficial effects of Opuntia are related to a reduction in oxidative stress and inflammation markers. Nevertheless, clinical studies have evidenced that the effects are highly contingent upon the experimental design. Moreover, the bioactive compound composition of nopal extracts has not been reported. As a result, there is a lack of information to elucidate the mechanisms of action responsible for the observed effects. Accordingly, further studies are needed to demonstrate whether Opuntia products can represent an effective tool to prevent and/or manage body weight and some metabolic disorders.

Leaching hazards of tire wear particles in hydrothermal treatment of sludge: Exploring molecular composition, transformation mechanism, and ecological effects of tire wear particle-derived compounds

Tire wear particles (TWPs) are considered a significant contributor of microplastics (MPs) in the sludge during heavy rainfall events. Numerous studies have shown that hydrothermal treatment (HT) of sludge can accelerate the leaching of MP-derived compound into hydrothermal liquid, thus impairing the performance of subsequent anaerobic digestion and the quality of the hydrothermal liquid fertilizer. However, the leaching behavior of TWPs in the HT of sludge remains inadequately explored. This study examined the molecular composition of TWP-derived compounds and transformation pathways of representative tire-related additives under different hydrothermal temperatures using liquid chromatography-tandem mass spectrometry (LC-MS/MS) combined with mass difference analysis. The acute toxicity and phytotoxicity of TWP leachates were assessed using Vibrio qinghaiensis Q67 and rice hydroponics experiments. The results indicated that elevating the hydrothermal temperature not only amplified the leaching behavior of TWPs but also enhanced the chemical complexity of the TWP leachate. Utilizing both suspect and non-target screenings, a total of 144 compounds were identified as additives, including N-(1,3-dimethylbutyl)-N’-phenyl-p-phenylenediamine (6-PPD), hexa(methoxymethyl)melamine (HMMM), dibutyl phthalate (DBP). These additives underwent various reactions, such as desaturation, acetylation, and other reactions, leading to the formation of different transformation products (TPs). Moreover, certain additives, including caprolactam and 2,2,6,6-tetramethyl-4-piperidinol, demonstrated the potential to form conjugate products with amino acids or Maillard products. Meanwhile, TWP-derived compounds showed significant acute toxicity and detrimental effects on plant growth. This study systematically investigated the environmental fate of TWPs and their derived compounds during the HT of sludge, offering novel insights into the intricate interactions between the micropollutants and dissolved organic matter (DOM) in sludge.

Characterization of Bioactive Metabolites and Antioxidant Activities in Solid and Liquid Fractions of Fresh Duckweed (Wolffia globosa) Subjected to Different Cell Wall Rupture Methods.

Fresh Wolffia globosa, the smallest flowering plant well-known for its favorable nutrient composition and rich content of bioactive compounds, was subjected to boiling, freeze-thawing, and mechanical crushing to reduce its excessive (95-96%) moisture level and consequent drying time. The resultant three wolffia matrixes were filtered through a plankton net to fractionate into the residue and the filtrate. The proximate composition, bioactive metabolites, antioxidant activity, and characterization of bioactive metabolites by LC-ESI-QTOF-MS/MS and Fourier transform infrared spectroscopy were made from oven-dried residues and filtrates. Among residues, crude protein (29.84%), crude lipid (5.77%), total carotenoids (TCC; 722.8 μg/g), and vitamin C (70.02 mg/100 g) were the highest (p < 0.05) for freeze-thawing against higher ash (7.99%), total phenolic content (TPC; 191.47 mg GAE g-1 dry weight), total flavonoid content (TFC; 91.54 mg QE g-1 dry weight), DPPH activity (47.46%), and ferric reducing antioxidant power (FRAP) activity (570.19 μmol FeSO4 equiv/mg) for the crushed counterpart and Chl-b in residues from boiling. No significant variation was evident in the total tannin content (TTC). Among filtrates, higher total phenolic content (773.29 mg GAE g-1 dry weight), TFC (392.77 mg QE g-1 dry weight), TTC (22.51 mg TAE g-1), and antioxidant activity as DPPH activity (66.46%) and FRAP (891.62 μmol FeSO4 equiv/mg) were evident for boiling, while that from crushing exhibited the highest TCC (1997.38 μg/g DM). LC-ESI-QTOF-MS/MS analysis identified 72 phenolic compounds with the maximum in residue (33) and filtrate (33) from freeze-thawing, followed by crushing (18 and 19) and boiling (14 and 13) in order, respectively. The results indicated that the predrying cell rupturing method significantly impacted quantitative, as well as qualitative compositions of residues and filtrates from fresh wolffia.

Characterization of odor-active compounds in Liuzhou River snail rice noodles soup by sensory-directed flavor analysis

Liuzhou River snails rice noodles, a special snack of Liuzhou City in the Guangxi Zhuang Autonomous Region, China, possess a unique flavor of spicy, refreshing, fresh, sour, and hot. The present study aimed to characterize the composition of volatile compounds and key odor-active compounds in river snails rice noodles soup (RSRNS) through aroma extract dilution analysis and odor activity value calculation using solid-phase microextraction (SPME) combined with comprehensive two-dimensional gas chromatography–olfactometry–mass spectrometry (GC×GC–O–MS) and gas chromatography–olfactometry–mass spectrometry (GC–O–MS). A total of 71 volatile compounds were identified by GC–O–MS, of which 49 were odor-active. Meanwhile, 125 volatile compounds were identified by GC×GC–O–MS, of which 68 were odor-active. These results indicated that 3-methylbutanal, linalool, 1,8-cineole, myrcene, 2-acetylpyrazine, 4-allylanisole, 2-acetylthiazole, 1-octen-3-ol, hexanal, and eugenol were the main odor-active compounds of RSRNS.