The effect of process and storage on the volatiles and odorant profi le of Chinese dry sausage was evaluated,as well as its physicochemical parameters.Microbial esterification and wine(27.54%–43.35%),and lipid oxidat...The effect of process and storage on the volatiles and odorant profi le of Chinese dry sausage was evaluated,as well as its physicochemical parameters.Microbial esterification and wine(27.54%–43.35%),and lipid oxidation(11.30%–34.92%)played a key role in flavor profile during process and storage.A significant increase of each volatile was detected during process except gradual decrease of volatiles from spices,while a gradual decrease of each volatile was detected during storage except signifi cant increase of volatiles from lipid oxidation and esterifi cation.15 and 6 odor-active compounds were respectively correlated(P<0.05)with the process and storage time.Level of heptanal,1-octen-3-ol,the ethyl of 2-methylbutanoic,3-methylbutanoic,butanoic,benzoic,hexanoic,heptanoic,octanoic and decanoic acid were best discriminators of process stage,while(E)-2-nonenal,ethyl hexanoate,ethyl heptanoate,and methyl decanoate,were marker compounds of storage time.An objective method was established to evaluate the stages of process and storage for samples.展开更多
Electrochemical nitrogen transformation techniques represent a burgeoning avenue for nitrogen pollutant remediation and synthesizing valuable nitrogenous products from atmospheric nitrogen.Intermetallic compounds(IMCs...Electrochemical nitrogen transformation techniques represent a burgeoning avenue for nitrogen pollutant remediation and synthesizing valuable nitrogenous products from atmospheric nitrogen.Intermetallic compounds(IMCs)nanocrystals,featured with unique geometric,electronic and functional properties,have emerged as promising candidates.The review discusses various synthesis approaches for IMCs,including thermal annealing,wet chemical synthesis,electrochemical synthesis,and other emerging methods,analyzing their advantages and limitations.Then we summarized the recent advances of IMCs in electrocatalytic nitrogen transformation reactions,such as nitrate reduction reaction,nitric oxide reduction reaction,nitrogen reduction reaction,and hydrazine oxidation reaction.Despite significant progress,challenges remain in the field,particularly in adopting more refined strategies to improve catalyst performance and stability.This review aims to comprehensively understand the structural properties of IMCs and their structure-performance relationship,guiding the development of more efficient and stable catalysts for future nitrogen electrochemistry.展开更多
Moringa oleifera Lam.is a Moringa genus in the Moringaceae family that is high in nutrients and has a wide range of applications.Phenolic compounds are widely found in plants and have various health benefits for the h...Moringa oleifera Lam.is a Moringa genus in the Moringaceae family that is high in nutrients and has a wide range of applications.Phenolic compounds are widely found in plants and have various health benefits for the human body.With its high content and wide variety of phenolic compounds,M.oleifera Lam.has been widely studied for its health benefits.The phenolic compounds in M.oleifera Lam.(MOPCs)can be a potential source of functional food ingredients in pharmaceutical and industrial applications.Numerous studies have shown that MOPCs have antioxidant,anti-obesity,anti-diabetic,and antibacterial effects.Although the research on MOPCs has been gradually increasing,the extraction,isolation,identification,biological activities,and comprehensive application of MOPCs need a more systematic summary and generalization.Therefore,this paper reviews the isolation and extraction methods,structure identification,biological activities,and comprehensive applications to provide a further reference for the research and application of MOPCs.展开更多
Lemon oils are broadly used as flavoring agents in beverages,foods,cosmetics and pharmaceuticals,yet the adulteration of natural,particularly cold pressed lemon oils is very common in the industry due to its unmet dem...Lemon oils are broadly used as flavoring agents in beverages,foods,cosmetics and pharmaceuticals,yet the adulteration of natural,particularly cold pressed lemon oils is very common in the industry due to its unmet demand and high cost.Nowadays,most quality control(QC)analysis of lemon oils is conducted by gas chromatography(GC)analysis,which is far from a reliable method.Oxygen heterocyclic compounds(OHCs)in non-volatile fraction are gaining increasing attention in authentication process because of the nearly finger-printing profiles of OHCs in cold pressed citrus essential oils.Our goal in this study was to identify OHCs using high performance liquid chromatography(HPLC)in lemon oils,establish OHC profiles,perform stepwise logistic regression analysis(SLRA)and build effective predicting model and further determine adulterated lemon oils by referencing the OHC profiles and established models.After HPLC analyses,profiling and SLRA modeling of 154 OHCs samples of industrial lemon oils,we found that the combination of isopimpinellin and total OHC concentration are essential and robust predictors to differentiate authentic samples from adulterated lemon oils with a success rate of 98%from the 5-fold cross validation.This study provided a reliable and efficient method in determining the authenticity of lemon oils.展开更多
To provide new insights into the development and utilization of Douchi artificial starters,three common strains(Aspergillus oryzae,Mucor racemosus,and Rhizopus oligosporus)were used to study their influence on the fer...To provide new insights into the development and utilization of Douchi artificial starters,three common strains(Aspergillus oryzae,Mucor racemosus,and Rhizopus oligosporus)were used to study their influence on the fermentation of Douchi.The results showed that the biogenic amine contents of the three types of Douchi were all within the safe range and far lower than those of traditional fermented Douchi.Aspergillus-type Douchi produced more free amino acids than the other two types of Douchi,and its umami taste was more prominent in sensory evaluation(P<0.01),while Mucor-type and Rhizopus-type Douchi produced more esters and pyrazines,making the aroma,sauce,and Douchi flavor more abundant.According to the Pearson and PLS analyses results,sweetness was significantly negatively correlated with phenylalanine,cysteine,and acetic acid(P<0.05),bitterness was significantly negatively correlated with malic acid(P<0.05),the sour taste was significantly positively correlated with citric acid and most free amino acids(P<0.05),while astringency was significantly negatively correlated with glucose(P<0.001).Thirteen volatile compounds such as furfuryl alcohol,phenethyl alcohol,and benzaldehyde caused the flavor difference of three types of Douchi.This study provides theoretical basis for the selection of starting strains for commercial Douchi production.展开更多
The significant demand for high quality food has motivated us to adopt appropriate processing methods to improve the food nutritional quality and flavors.In this study,the effects of five drying methods,namely,pulsed ...The significant demand for high quality food has motivated us to adopt appropriate processing methods to improve the food nutritional quality and flavors.In this study,the effects of five drying methods,namely,pulsed vacuum drying(PVD),freeze drying(FD),infrared drying(IRD),hot-air drying(HAD)and sun drying(SD)on free amino acids(FAAs),α-dicarbonyl compounds(α-DCs)and volatile compounds(VOCs)in rape bee pollen(RBP)were determined.The results showed that FD significantly released the essential amino acids(EAAs)compared with fresh samples while SD caused the highest loss.Glucosone was the dominantα-DCs in RBP and the highest loss was observed after PVD.Aldehydes were the dominant volatiles of RBP and SD samples contained more new volatile substances(especially aldehydes)than the other four drying methods.Comprehensively,FD and PVD would be potential methods to effectively reduce the quality deterioration of RBP in the drying process.展开更多
In order to better understand the specific substituent effects on the electrochemical oxidation process of β-O-4 bond, a series of methoxyphenyl type β-O-4 dimer model compounds with different localized methoxyl gro...In order to better understand the specific substituent effects on the electrochemical oxidation process of β-O-4 bond, a series of methoxyphenyl type β-O-4 dimer model compounds with different localized methoxyl groups, including 2-(2-methoxyphenoxy)-1-phenylethanone, 2-(2-methoxyphenoxy)-1-phenylethanol, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanol, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanol have been selected and their electrochemical properties have been studied experimentally by cyclic voltammetry, and FT-IR spectroelectrochemistry. Combining with electrolysis products distribution analysis and density functional theory calculations, oxidation mechanisms of all six model dimers have been explored. In particular, a total effect from substituents of both para-methoxy(on the aryl ring closing to Cα) and Cα-OH on the oxidation mechanisms has been clearly observed, showing a significant selectivity on the Cα-Cβbond cleavage induced by electrochemical oxidations.展开更多
Nitrogen-rich heterocyclic energetic compounds(NRHECs)and their salts have witnessed widespread synthesis in recent years.The substantial energy-density content within these compounds can lead to potentially dangerous...Nitrogen-rich heterocyclic energetic compounds(NRHECs)and their salts have witnessed widespread synthesis in recent years.The substantial energy-density content within these compounds can lead to potentially dangerous explosive reactions when subjected to external stimuli such as electrical discharge.Therefore,developing a reliable model for predicting their electrostatic discharge sensitivity(ESD)becomes imperative.This study proposes a novel and straightforward model based on the presence of specific groups(-NH_(2) or-NH-,-N=N^(+)-O^(-)and-NNO_(2),-ONO_(2) or-NO_(2))under certain conditions to assess the ESD of NRHECs and their salts,employing interpretable structural parameters.Utilizing a comprehensive dataset comprising 54 ESD measurements of NRHECs and their salts,divided into 49/5 training/test sets,the model achieves promising results.The Root Mean Square Error(RMSE),Mean Absolute Error(MAE),and Maximum Error for the training set are reported as 0.16 J,0.12 J,and 0.5 J,respectively.Notably,the ratios RMSE(training)/RMSE(test),MAE(training)/MAE(test),and Max Error(training)/Max Error(test)are all greater than 1.0,indicating the robust predictive capabilities of the model.The presented model demonstrates its efficacy in providing a reliable assessment of ESD for the targeted NRHECs and their salts,without the need for intricate computer codes or expert involvement.展开更多
Portulaca oleracea L.,commonly known as purslane,is a worldwide weed species belonging to the family Portulacaceae and has been known as“Global Panacea”.As one of the most widely consumed green vegetables and medici...Portulaca oleracea L.,commonly known as purslane,is a worldwide weed species belonging to the family Portulacaceae and has been known as“Global Panacea”.As one of the most widely consumed green vegetables and medicinal plants around the world,it has recently been re-evaluated as a potential“new crop”due to the properties that differentiate it as one of the best vegetable sources of omega-3 fatty acid(α-linolenic acid),as well as a variety of nutrients and phytochemicals.Accordingly,emerging research has found that purslane exhibits health-promoting properties like anti-inflammatory,anti-hyperglycemic,antioxidant,neuroprotective,and immunomodulatory.These findings suggest that this species possesses a potential using as a dietary supplement beyond potherb and traditional medicine.This review systematically summarizes the up-to-date research carried out on purslane,including the nutritional compositions,bioactive compounds,and health benefits it exerts as well as limitations,challenges,and future directions of research.Finally,we hope that this review would provide purslane with a comprehensive reference and future scope as functional and health-promoting food for disease prevention and treatment.展开更多
Hericium erinaceus is a nutritious edible and medicinal fungi,rich in a variety of functional active ingredients,with various physiological functions such as antioxidation,anticancer,and enhancing immunity.It is also ...Hericium erinaceus is a nutritious edible and medicinal fungi,rich in a variety of functional active ingredients,with various physiological functions such as antioxidation,anticancer,and enhancing immunity.It is also effective in protecting the digestive system and preventing neurodegenerative diseases.In this review paper,we summarize the sources,structures and efficacies of the main active components in H.erinaceus fruiting body,mycelium,and culture media,and update the latest research progress on their biological activities and the related molecular mechanisms.Based on this information,we provide detailed challenges in current research,industrialization and information on the active ingredients of H.erinaceus.Perspectives for future studies and new applications of H.erinaceus are proposed.展开更多
Quercetin compounds have antioxidant,anti-inflammatory and anticancer pharmacological functions.Longterm exposure to acrylamide(AA)can cause liver injury and endanger human health.However,whether quercetin compounds c...Quercetin compounds have antioxidant,anti-inflammatory and anticancer pharmacological functions.Longterm exposure to acrylamide(AA)can cause liver injury and endanger human health.However,whether quercetin compounds can attenuate AA-induced liver injury and the specific mechanism are not clear.Here,we studied the mechanism and structure-activity relationship of quercetin compounds in reducing AA-induced hepatotoxicity in vivo and in vitro.In vivo studies found that quercetin-like compounds protect against AAinduced liver injury by reducing oxidative stress levels,activating the Akt/m TOR signaling pathway to attenuate autophagy,and improving mitochondrial apoptosis and endoplasmic reticulum stress-mediated apoptosis.In vitro studies found that quercetin compounds protected Hep G2 cells from AA by attenuating the activation of AA-induced autophagy,lowering reactive oxygen species(ROS)levels by exerting antioxidant effects and thus attenuating oxidative stress,increasing mitochondrial membrane potential(MMP),and improving apoptosis-related proteins,thus attenuating AA-induced apoptosis.Furthermore,the conformational differences between quercetin compounds correlated with their protective capacity against AA-induced hepatotoxicity,with quercetin showing the best protective capacity due to its strongest antioxidant activity.In conclusion,quercetin compounds can protect against AA-induced liver injury through multiple pathways of oxidative stress,autophagy and apoptosis,and their protective capacity correlates with antioxidant activity.展开更多
Lactic acid bacteria and coagulase-negative staphylococci play an important role in the production of fermented sausages,such as inhibiting the growth of undesirable bacteria and antioxidant.In this study,the effects ...Lactic acid bacteria and coagulase-negative staphylococci play an important role in the production of fermented sausages,such as inhibiting the growth of undesirable bacteria and antioxidant.In this study,the effects of inoculation with different starter cultures(Lactiplantibacillus plantarum HN108 and Staphylococcus simulans NJ209)on the free amino acids(FAAs),biogenic amines(BAs)and volatile compounds of fermented sausages were investigated using an amino acid analyzer,ultra performance liquid chromatography and gas chromatography-ion mobility spectrometry,respectively.The pH and carbonyl content of the inoculated group was significantly lower than those in the control group(P<0.05).L.plantarum HN108 significantly reduced the content of FAAs and BAs in fermented sausage production(P<0.05),while S.simulans NJ209 promoted the formation of FAAs(especially bitter amino acids)and exhibited slight BAs-reducing activity.In addition,L.plantarum HN108 promoted the formation of volatile compounds such as ketones,alcohols and alkenes in sausages.In conclusion,L.plantarum HN108 could contribute to reducing the content of putrescine and tyramine and forming the desirable flavor compounds in fermented sausages.Thus,L.plantarum HN108 is expected to be a starter culture that can improve the safety and flavor of fermented sausages.展开更多
The aromatic compounds,including o-xylene,m-xylene,p-xylene,and ethylbenzene,primarily originate from the catalytic reforming of crude oil,and have a wide variety of applications.However,because of similar physical an...The aromatic compounds,including o-xylene,m-xylene,p-xylene,and ethylbenzene,primarily originate from the catalytic reforming of crude oil,and have a wide variety of applications.However,because of similar physical and chemical properties,these compounds are difficult to be identified by gas chromatography(GC)without standard samples.With the development of modern nuclear magnetic resonance(NMR)techniques,NMR has emerged as a powerful and efficient tool for the rapid analysis of complex and crude mixtures without purification.In this study,the parameters of one-dimensional(1D)total correlation spectroscopy(TOCSY)NMR techniques,including 1D selective gradient TOCSY and 1D chemicalshift-selective filtration(CSSF)with TOCSY,were optimized to obtain comprehensive molecular structure information.The results indicate that the overlapped signals in NMR spectra of nonpolar aromatic compounds(including o-xylene,m-xylene,p-xylene and ethylbenzene),polar aromatic compounds(benzyl alcohol,benzaldehyde,benzoic acid),and aromatic compounds with additional conjugated bonds(styrene)can be resolved in 1D TOCSY.More importantly,full molecular structures can be clearly distinguished by setting appropriate mixing time in 1D TOCSY.This approach simplifies the NMR spectra,provides structural information of entire molecules,and can be applied for the analysis of other structural isomers.展开更多
In this paper,the ultrasonic-assisted extraction process of flavonoid compounds from leaves of Amorpha fruticosa is optimized.In single factor experiments,solid/liquid ratios,ultrasonic power,ethanol concentrations an...In this paper,the ultrasonic-assisted extraction process of flavonoid compounds from leaves of Amorpha fruticosa is optimized.In single factor experiments,solid/liquid ratios,ultrasonic power,ethanol concentrations and extraction cycles were experimental factors.Box–Behnken central composite design and RSM analyzed the effects of the four factors on the yield of total flavonoids.The optimal extraction parameters were solid/liquid ratio 1:50 g/mL,ultrasonic power 316 W,ethanol concentration 50%,4 extraction cycles.In the optimized condition,the estimated value of the regression model was 66.6456 mg/g while the measured value was 66.4329 mg/g.展开更多
MgCoAl-hydrotalcite-like compounds （MgCoAI-HTLcs） were synthesized using the coprecipitation method of variable pH values. The effect of each factor on the preparation of HTLcs was discussed systematically, which in...MgCoAl-hydrotalcite-like compounds （MgCoAI-HTLcs） were synthesized using the coprecipitation method of variable pH values. The effect of each factor on the preparation of HTLcs was discussed systematically, which included pH values, mole ratios of Mg2＋ to Co2＋, the concentrations of the solution, and the temperature and time of the hydrothermal treatment. Besides, the thermal decomposition of MgCoAI-HTLcs was discussed. X-ray diffraction, thermogravimetric analysis, and FT-IR spectroscopy were performed to characterize the MgCoAI-HTLcs samples. The results showed that when the pH = 7.6-8.5 or 5.5-6.2, atomic ratios of （Mg^2＋＋Co2＋）/Al^3＋ 2 and Mg^2＋/Co^2＋ ranging from 1.00 to 2.00, temperature and time of hydrothermal treatment being 110℃ and 6 h, unique MgCoAI-HTLcs with high crystallinity could be obtained. When the calcination temperature was up to 250℃, the MgO phase was detected coexisting with Al2O3 and MgAl2O4 was highly spreaded on the derived mixed oxides. The synthesis reaction of benzoin methyl ether with methanol and benzaldehyde was chosen to study the catalytic activity of MgCoAI-HTLcs. The catalyst showed high activity and high stability in the synthesis of benzoin methyl ether in the feasible condition.展开更多
The magnetocaloric effect（MCE） of RT Si and RT Al systems with R = Gd–Tm, T = Fe–Cu and Pd, which have been widely investigated in recent years, is reviewed. It is found that these RT X compounds exhibit various c...The magnetocaloric effect（MCE） of RT Si and RT Al systems with R = Gd–Tm, T = Fe–Cu and Pd, which have been widely investigated in recent years, is reviewed. It is found that these RT X compounds exhibit various crystal structures and magnetic properties, which then result in different MCE. Large MCE has been observed not only in the typical ferromagnetic materials but also in the antiferromagnetic materials. The magnetic properties have been studied in detail to discuss the physical mechanism of large MCE in RT X compounds. Particularly, some RT X compounds such as Er Fe Si,Ho Cu Si, Ho Cu Al exhibit large reversible MCE under low magnetic field change, which suggests that these compounds could be promising materials for magnetic refrigeration in a low temperature range.展开更多
A study was conducted to explore the mechanism that emissions of volatile organic compounds（VOC） from heated needles and twigs（200°C,within 15 min） of Pinus pumila affect fire behaviours using the technology ...A study was conducted to explore the mechanism that emissions of volatile organic compounds（VOC） from heated needles and twigs（200°C,within 15 min） of Pinus pumila affect fire behaviours using the technology of Thermal Desorption-Gas Chromatography-Mass Spectrometry（TD-GC-MS）.The results indicated that the main components of VOC from heated needles and twigs are terpenoids.Most of these terpenoids are monoterpenes.Terpenoids account for 72.93% for the needles and 92.40% for the twigs of the total VOC,and their emission ratios are 61.200 μg·g-1 and 217.060 μg·g-1 respectively.Heated twigs can emit more terpenoids than heated needles because twigs had more volatile oils than needles.In actual fires,these large amounts of terpenoid emissions,especially the monoterpene emissions,have strong effects on fire behaviors that are not only in the initial stage but also in the fast propagation stage of fires.These flammable gases are capable of causing violent combustion and creating crown fires.In addition,if these gases accumulate in an uneven geographical area,there will be a possible for eruptive fires and/or fires flashover to occur.展开更多
The microwave assisted liquefaction process of wheat straw alkali lignin was investigated to obtain monophenolic compounds as the precursor of bio-fuel. It is found that the total yield of monophenolic compounds is si...The microwave assisted liquefaction process of wheat straw alkali lignin was investigated to obtain monophenolic compounds as the precursor of bio-fuel. It is found that the total yield of monophenolic compounds is significantly improved under microwave irradiation, reaching 15.77% under a relatively mild liquefaction condition of 10 wt% H2SO4 as the catalyst, 10 wt% phenol as the hydrogen-donor reagent at 120 ℃ for 40 rain. Compared with conventional thermal liquefaction process, microwave irradiation promotes the cleavage of C-C bonds, which gives an extra 29% of Caryl-Cα bond cleavage, and increases the yield of monophenolic compounds from 0.92% to 13.61% under the same conditions. The excessive temperature and prolonged time under microwave irradiation will promote the recondensation of degraded lignin fragments, so the key to obtain high yield of monophenolic compounds is to avoid the recondensation reaction. The selected solid catalyst promotes the dissociation of methoxy groups, and the addition of phenol into liquefaction can only slightly improve the yield of monophencolic compounds.展开更多
The steam reforming of four bio-oil model compounds（acetic acid,ethanol,acetone and phenol） was investigated over Ni-based catalysts supported on Al2O3 modified by Mg,Ce or Co in this paper.The activation process ca...The steam reforming of four bio-oil model compounds（acetic acid,ethanol,acetone and phenol） was investigated over Ni-based catalysts supported on Al2O3 modified by Mg,Ce or Co in this paper.The activation process can improve the catalytic activity with the change of high-valence Ni（Ni2O3,NiO） to low-valence Ni（Ni,NiO）.Among these catalysts after activation,the Ce-Ni/Co catalyst showed the best catalytic activity for the steam reforming of all the four model compounds.After long-term experiment at 700°C and the S/C ratio of 9,the Ce-Ni/Co catalyst still maintained excellent stability for the steam reforming of the simulated bio-oil（mixed by the four compounds with the equal masses）.With CaO calcinated from calcium acetate as CO2 sorbent,the catalytic steam reforming experiment combined with continuous in situ CO2 adsorption was performed.With the comparison of the case without the adding of CO2 sorbent,the hydrogen concentration was dramatically improved from 74.8% to 92.3%,with the CO2 concentration obviously decreased from 19.90% to 1.88%.展开更多
The adsorptive denitrogenation from fuels over three metal-organic frameworks(MIL-96(Al),MIL-53(Al)and MIL-101(Cr))was studied by batch adsorption experiments.Four nitrogen-containing compounds(NCCs)pyridine,pyrrole,q...The adsorptive denitrogenation from fuels over three metal-organic frameworks(MIL-96(Al),MIL-53(Al)and MIL-101(Cr))was studied by batch adsorption experiments.Four nitrogen-containing compounds(NCCs)pyridine,pyrrole,quinoline and indole were used as model NCCs in fuels to study the adsorption mechanism.The physicochemical properties of the adsorbents were characterized by XRD,N2physical adsorption,FT-IR spectrum and Hammett indicator method.The metal-organic frameworks(MOFs),especially the MIL-101(Cr)containing Lewis acid sites as well as high specific surface area,can adsorb large quantities of NCCs from fuels.In addition,the adsorptive capacity over MIL-101(Cr)will be different for NCCs with different basicity.The stronger basicity of the NCC is,the more it can be absorbed over MIL-101(Cr).Furthermore,pore size and shape also affect the adsorption capacity for a given adsorbate,which can be proved by the adsorption over MIL-53(Al)and MIL-96(Al).The pseudo-second-order kinetic model and Langmuir equation can be used to describe kinetics and thermodynamics of the adsorption process,respectively.Finally,the regeneration of the used adsorbent has been conducted successfully by just washing it with ethanol.展开更多
基金The authors were very grateful for the financial supports from national key research and development program of China(No.2017YFD0400105).
文摘The effect of process and storage on the volatiles and odorant profi le of Chinese dry sausage was evaluated,as well as its physicochemical parameters.Microbial esterification and wine(27.54%–43.35%),and lipid oxidation(11.30%–34.92%)played a key role in flavor profile during process and storage.A significant increase of each volatile was detected during process except gradual decrease of volatiles from spices,while a gradual decrease of each volatile was detected during storage except signifi cant increase of volatiles from lipid oxidation and esterifi cation.15 and 6 odor-active compounds were respectively correlated(P<0.05)with the process and storage time.Level of heptanal,1-octen-3-ol,the ethyl of 2-methylbutanoic,3-methylbutanoic,butanoic,benzoic,hexanoic,heptanoic,octanoic and decanoic acid were best discriminators of process stage,while(E)-2-nonenal,ethyl hexanoate,ethyl heptanoate,and methyl decanoate,were marker compounds of storage time.An objective method was established to evaluate the stages of process and storage for samples.
基金funded by the National Natural Science Foundation of China(No.22405173)the Shanghai Pujiang Program(No.23PJ1409100)the Project of Overseas Leading Talent of Shanghai.
文摘Electrochemical nitrogen transformation techniques represent a burgeoning avenue for nitrogen pollutant remediation and synthesizing valuable nitrogenous products from atmospheric nitrogen.Intermetallic compounds(IMCs)nanocrystals,featured with unique geometric,electronic and functional properties,have emerged as promising candidates.The review discusses various synthesis approaches for IMCs,including thermal annealing,wet chemical synthesis,electrochemical synthesis,and other emerging methods,analyzing their advantages and limitations.Then we summarized the recent advances of IMCs in electrocatalytic nitrogen transformation reactions,such as nitrate reduction reaction,nitric oxide reduction reaction,nitrogen reduction reaction,and hydrazine oxidation reaction.Despite significant progress,challenges remain in the field,particularly in adopting more refined strategies to improve catalyst performance and stability.This review aims to comprehensively understand the structural properties of IMCs and their structure-performance relationship,guiding the development of more efficient and stable catalysts for future nitrogen electrochemistry.
基金supported by Major Project of Science and Technology Department of Yunnan Province(202002AA100005,202102AE090027-2)National Natural Science Foundation of China(82260703)+1 种基金Cassava Industrial Technology System of China(CARS11-YNTY)Yunnan Province Ten Thousand Plan Industrial Technology Talents Project(YNWR-CYJS-2020-010)。
文摘Moringa oleifera Lam.is a Moringa genus in the Moringaceae family that is high in nutrients and has a wide range of applications.Phenolic compounds are widely found in plants and have various health benefits for the human body.With its high content and wide variety of phenolic compounds,M.oleifera Lam.has been widely studied for its health benefits.The phenolic compounds in M.oleifera Lam.(MOPCs)can be a potential source of functional food ingredients in pharmaceutical and industrial applications.Numerous studies have shown that MOPCs have antioxidant,anti-obesity,anti-diabetic,and antibacterial effects.Although the research on MOPCs has been gradually increasing,the extraction,isolation,identification,biological activities,and comprehensive application of MOPCs need a more systematic summary and generalization.Therefore,this paper reviews the isolation and extraction methods,structure identification,biological activities,and comprehensive applications to provide a further reference for the research and application of MOPCs.
文摘Lemon oils are broadly used as flavoring agents in beverages,foods,cosmetics and pharmaceuticals,yet the adulteration of natural,particularly cold pressed lemon oils is very common in the industry due to its unmet demand and high cost.Nowadays,most quality control(QC)analysis of lemon oils is conducted by gas chromatography(GC)analysis,which is far from a reliable method.Oxygen heterocyclic compounds(OHCs)in non-volatile fraction are gaining increasing attention in authentication process because of the nearly finger-printing profiles of OHCs in cold pressed citrus essential oils.Our goal in this study was to identify OHCs using high performance liquid chromatography(HPLC)in lemon oils,establish OHC profiles,perform stepwise logistic regression analysis(SLRA)and build effective predicting model and further determine adulterated lemon oils by referencing the OHC profiles and established models.After HPLC analyses,profiling and SLRA modeling of 154 OHCs samples of industrial lemon oils,we found that the combination of isopimpinellin and total OHC concentration are essential and robust predictors to differentiate authentic samples from adulterated lemon oils with a success rate of 98%from the 5-fold cross validation.This study provided a reliable and efficient method in determining the authenticity of lemon oils.
基金supported by Special key project of technological innovation and application development in Yongchuan District,Chongqing(2021yc-cxfz20002)the special funds of central government for guiding local science and technology developmentthe funds for the platform projects of professional technology innovation(CSTC2018ZYCXPT0006).
文摘To provide new insights into the development and utilization of Douchi artificial starters,three common strains(Aspergillus oryzae,Mucor racemosus,and Rhizopus oligosporus)were used to study their influence on the fermentation of Douchi.The results showed that the biogenic amine contents of the three types of Douchi were all within the safe range and far lower than those of traditional fermented Douchi.Aspergillus-type Douchi produced more free amino acids than the other two types of Douchi,and its umami taste was more prominent in sensory evaluation(P<0.01),while Mucor-type and Rhizopus-type Douchi produced more esters and pyrazines,making the aroma,sauce,and Douchi flavor more abundant.According to the Pearson and PLS analyses results,sweetness was significantly negatively correlated with phenylalanine,cysteine,and acetic acid(P<0.05),bitterness was significantly negatively correlated with malic acid(P<0.05),the sour taste was significantly positively correlated with citric acid and most free amino acids(P<0.05),while astringency was significantly negatively correlated with glucose(P<0.001).Thirteen volatile compounds such as furfuryl alcohol,phenethyl alcohol,and benzaldehyde caused the flavor difference of three types of Douchi.This study provides theoretical basis for the selection of starting strains for commercial Douchi production.
基金supported by National Natural Science Foundation of China(Nos.31871861 and 31501548)The Apicultural Industry Technology System(NCYTI-43-KXJ17)The Science and Technology Innovation Project of Chinese Academy of Agricultural Sciences(CAAS-ASTIP-2015-IAR)。
文摘The significant demand for high quality food has motivated us to adopt appropriate processing methods to improve the food nutritional quality and flavors.In this study,the effects of five drying methods,namely,pulsed vacuum drying(PVD),freeze drying(FD),infrared drying(IRD),hot-air drying(HAD)and sun drying(SD)on free amino acids(FAAs),α-dicarbonyl compounds(α-DCs)and volatile compounds(VOCs)in rape bee pollen(RBP)were determined.The results showed that FD significantly released the essential amino acids(EAAs)compared with fresh samples while SD caused the highest loss.Glucosone was the dominantα-DCs in RBP and the highest loss was observed after PVD.Aldehydes were the dominant volatiles of RBP and SD samples contained more new volatile substances(especially aldehydes)than the other four drying methods.Comprehensively,FD and PVD would be potential methods to effectively reduce the quality deterioration of RBP in the drying process.
基金The authors gratefully acknowledge the financial support of the Natural Science Foundation of China,China(Grant No.21975082 and 21736003)the Guangdong Basic and Applied Basic Research Foundation(Grant Number:2019A1515011472 and 2022A1515011341)the Science and Technology Program of Guangzhou(Grant Number:202102080479).
文摘In order to better understand the specific substituent effects on the electrochemical oxidation process of β-O-4 bond, a series of methoxyphenyl type β-O-4 dimer model compounds with different localized methoxyl groups, including 2-(2-methoxyphenoxy)-1-phenylethanone, 2-(2-methoxyphenoxy)-1-phenylethanol, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanol, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanol have been selected and their electrochemical properties have been studied experimentally by cyclic voltammetry, and FT-IR spectroelectrochemistry. Combining with electrolysis products distribution analysis and density functional theory calculations, oxidation mechanisms of all six model dimers have been explored. In particular, a total effect from substituents of both para-methoxy(on the aryl ring closing to Cα) and Cα-OH on the oxidation mechanisms has been clearly observed, showing a significant selectivity on the Cα-Cβbond cleavage induced by electrochemical oxidations.
文摘Nitrogen-rich heterocyclic energetic compounds(NRHECs)and their salts have witnessed widespread synthesis in recent years.The substantial energy-density content within these compounds can lead to potentially dangerous explosive reactions when subjected to external stimuli such as electrical discharge.Therefore,developing a reliable model for predicting their electrostatic discharge sensitivity(ESD)becomes imperative.This study proposes a novel and straightforward model based on the presence of specific groups(-NH_(2) or-NH-,-N=N^(+)-O^(-)and-NNO_(2),-ONO_(2) or-NO_(2))under certain conditions to assess the ESD of NRHECs and their salts,employing interpretable structural parameters.Utilizing a comprehensive dataset comprising 54 ESD measurements of NRHECs and their salts,divided into 49/5 training/test sets,the model achieves promising results.The Root Mean Square Error(RMSE),Mean Absolute Error(MAE),and Maximum Error for the training set are reported as 0.16 J,0.12 J,and 0.5 J,respectively.Notably,the ratios RMSE(training)/RMSE(test),MAE(training)/MAE(test),and Max Error(training)/Max Error(test)are all greater than 1.0,indicating the robust predictive capabilities of the model.The presented model demonstrates its efficacy in providing a reliable assessment of ESD for the targeted NRHECs and their salts,without the need for intricate computer codes or expert involvement.
基金supported by the National Natural Science Foundation of China(32170408,32000280,and U1802287)the Ten Thousand Talents Plan of Yunnan Province for Industrial Technology Leading Talents(YNWR-CYJS-2019-011)+2 种基金Yunnan Revitalization Talent Support Program“Top Team”Project(202305AT350001)the Training of Technological Innovation Talents of Yunnan Province(202305AD160009 for Huan Yan)the Project of Yunnan Characteristic Plant Screening and R&D Service CXO Platform(2022YKZY001).
文摘Portulaca oleracea L.,commonly known as purslane,is a worldwide weed species belonging to the family Portulacaceae and has been known as“Global Panacea”.As one of the most widely consumed green vegetables and medicinal plants around the world,it has recently been re-evaluated as a potential“new crop”due to the properties that differentiate it as one of the best vegetable sources of omega-3 fatty acid(α-linolenic acid),as well as a variety of nutrients and phytochemicals.Accordingly,emerging research has found that purslane exhibits health-promoting properties like anti-inflammatory,anti-hyperglycemic,antioxidant,neuroprotective,and immunomodulatory.These findings suggest that this species possesses a potential using as a dietary supplement beyond potherb and traditional medicine.This review systematically summarizes the up-to-date research carried out on purslane,including the nutritional compositions,bioactive compounds,and health benefits it exerts as well as limitations,challenges,and future directions of research.Finally,we hope that this review would provide purslane with a comprehensive reference and future scope as functional and health-promoting food for disease prevention and treatment.
基金supported by the fund from Natural Science Foundation of Zhejiang Province,China(LY17C200017)。
文摘Hericium erinaceus is a nutritious edible and medicinal fungi,rich in a variety of functional active ingredients,with various physiological functions such as antioxidation,anticancer,and enhancing immunity.It is also effective in protecting the digestive system and preventing neurodegenerative diseases.In this review paper,we summarize the sources,structures and efficacies of the main active components in H.erinaceus fruiting body,mycelium,and culture media,and update the latest research progress on their biological activities and the related molecular mechanisms.Based on this information,we provide detailed challenges in current research,industrialization and information on the active ingredients of H.erinaceus.Perspectives for future studies and new applications of H.erinaceus are proposed.
基金supported by the National Natural Science Foundation of China(32072142,31972099)Guangxi Science and Technology Base and Talent Special Projects(Guike AD21220004)。
文摘Quercetin compounds have antioxidant,anti-inflammatory and anticancer pharmacological functions.Longterm exposure to acrylamide(AA)can cause liver injury and endanger human health.However,whether quercetin compounds can attenuate AA-induced liver injury and the specific mechanism are not clear.Here,we studied the mechanism and structure-activity relationship of quercetin compounds in reducing AA-induced hepatotoxicity in vivo and in vitro.In vivo studies found that quercetin-like compounds protect against AAinduced liver injury by reducing oxidative stress levels,activating the Akt/m TOR signaling pathway to attenuate autophagy,and improving mitochondrial apoptosis and endoplasmic reticulum stress-mediated apoptosis.In vitro studies found that quercetin compounds protected Hep G2 cells from AA by attenuating the activation of AA-induced autophagy,lowering reactive oxygen species(ROS)levels by exerting antioxidant effects and thus attenuating oxidative stress,increasing mitochondrial membrane potential(MMP),and improving apoptosis-related proteins,thus attenuating AA-induced apoptosis.Furthermore,the conformational differences between quercetin compounds correlated with their protective capacity against AA-induced hepatotoxicity,with quercetin showing the best protective capacity due to its strongest antioxidant activity.In conclusion,quercetin compounds can protect against AA-induced liver injury through multiple pathways of oxidative stress,autophagy and apoptosis,and their protective capacity correlates with antioxidant activity.
基金supported by the Priority Academic Program Development of Jiangsu Higher Education Institution(PAPD).
文摘Lactic acid bacteria and coagulase-negative staphylococci play an important role in the production of fermented sausages,such as inhibiting the growth of undesirable bacteria and antioxidant.In this study,the effects of inoculation with different starter cultures(Lactiplantibacillus plantarum HN108 and Staphylococcus simulans NJ209)on the free amino acids(FAAs),biogenic amines(BAs)and volatile compounds of fermented sausages were investigated using an amino acid analyzer,ultra performance liquid chromatography and gas chromatography-ion mobility spectrometry,respectively.The pH and carbonyl content of the inoculated group was significantly lower than those in the control group(P<0.05).L.plantarum HN108 significantly reduced the content of FAAs and BAs in fermented sausage production(P<0.05),while S.simulans NJ209 promoted the formation of FAAs(especially bitter amino acids)and exhibited slight BAs-reducing activity.In addition,L.plantarum HN108 promoted the formation of volatile compounds such as ketones,alcohols and alkenes in sausages.In conclusion,L.plantarum HN108 could contribute to reducing the content of putrescine and tyramine and forming the desirable flavor compounds in fermented sausages.Thus,L.plantarum HN108 is expected to be a starter culture that can improve the safety and flavor of fermented sausages.
基金We thank the Natural Science Foundation of Shanxi Province(202103021224439)National Natural Science Foundation of China(22075308)for financial support.
文摘The aromatic compounds,including o-xylene,m-xylene,p-xylene,and ethylbenzene,primarily originate from the catalytic reforming of crude oil,and have a wide variety of applications.However,because of similar physical and chemical properties,these compounds are difficult to be identified by gas chromatography(GC)without standard samples.With the development of modern nuclear magnetic resonance(NMR)techniques,NMR has emerged as a powerful and efficient tool for the rapid analysis of complex and crude mixtures without purification.In this study,the parameters of one-dimensional(1D)total correlation spectroscopy(TOCSY)NMR techniques,including 1D selective gradient TOCSY and 1D chemicalshift-selective filtration(CSSF)with TOCSY,were optimized to obtain comprehensive molecular structure information.The results indicate that the overlapped signals in NMR spectra of nonpolar aromatic compounds(including o-xylene,m-xylene,p-xylene and ethylbenzene),polar aromatic compounds(benzyl alcohol,benzaldehyde,benzoic acid),and aromatic compounds with additional conjugated bonds(styrene)can be resolved in 1D TOCSY.More importantly,full molecular structures can be clearly distinguished by setting appropriate mixing time in 1D TOCSY.This approach simplifies the NMR spectra,provides structural information of entire molecules,and can be applied for the analysis of other structural isomers.
基金supported by Central University Basic Research Funds(2572014CA27),(2572018DB01)Heilongjiang Province Natural Fund(C200913)
文摘In this paper,the ultrasonic-assisted extraction process of flavonoid compounds from leaves of Amorpha fruticosa is optimized.In single factor experiments,solid/liquid ratios,ultrasonic power,ethanol concentrations and extraction cycles were experimental factors.Box–Behnken central composite design and RSM analyzed the effects of the four factors on the yield of total flavonoids.The optimal extraction parameters were solid/liquid ratio 1:50 g/mL,ultrasonic power 316 W,ethanol concentration 50%,4 extraction cycles.In the optimized condition,the estimated value of the regression model was 66.6456 mg/g while the measured value was 66.4329 mg/g.
基金Supported by the Natural Science Foundation of Shanxi Province(20001015).
文摘MgCoAl-hydrotalcite-like compounds （MgCoAI-HTLcs） were synthesized using the coprecipitation method of variable pH values. The effect of each factor on the preparation of HTLcs was discussed systematically, which included pH values, mole ratios of Mg2＋ to Co2＋, the concentrations of the solution, and the temperature and time of the hydrothermal treatment. Besides, the thermal decomposition of MgCoAI-HTLcs was discussed. X-ray diffraction, thermogravimetric analysis, and FT-IR spectroscopy were performed to characterize the MgCoAI-HTLcs samples. The results showed that when the pH = 7.6-8.5 or 5.5-6.2, atomic ratios of （Mg^2＋＋Co2＋）/Al^3＋ 2 and Mg^2＋/Co^2＋ ranging from 1.00 to 2.00, temperature and time of hydrothermal treatment being 110℃ and 6 h, unique MgCoAI-HTLcs with high crystallinity could be obtained. When the calcination temperature was up to 250℃, the MgO phase was detected coexisting with Al2O3 and MgAl2O4 was highly spreaded on the derived mixed oxides. The synthesis reaction of benzoin methyl ether with methanol and benzaldehyde was chosen to study the catalytic activity of MgCoAI-HTLcs. The catalyst showed high activity and high stability in the synthesis of benzoin methyl ether in the feasible condition.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.5137102611274357+1 种基金and 51327806)the Fundamental Research Funds for the Central Universities(Grant Nos.FRF-TP-14-011A2 and FRF-TP-15-002A3)
文摘The magnetocaloric effect（MCE） of RT Si and RT Al systems with R = Gd–Tm, T = Fe–Cu and Pd, which have been widely investigated in recent years, is reviewed. It is found that these RT X compounds exhibit various crystal structures and magnetic properties, which then result in different MCE. Large MCE has been observed not only in the typical ferromagnetic materials but also in the antiferromagnetic materials. The magnetic properties have been studied in detail to discuss the physical mechanism of large MCE in RT X compounds. Particularly, some RT X compounds such as Er Fe Si,Ho Cu Si, Ho Cu Al exhibit large reversible MCE under low magnetic field change, which suggests that these compounds could be promising materials for magnetic refrigeration in a low temperature range.
基金supported by National Natural Science Foundation of China (30872037, 31070587)Open Project Program of State Key Laboratory of Fire Science, University of Science and Technology of China (HZ2008-KF08)
文摘A study was conducted to explore the mechanism that emissions of volatile organic compounds（VOC） from heated needles and twigs（200°C,within 15 min） of Pinus pumila affect fire behaviours using the technology of Thermal Desorption-Gas Chromatography-Mass Spectrometry（TD-GC-MS）.The results indicated that the main components of VOC from heated needles and twigs are terpenoids.Most of these terpenoids are monoterpenes.Terpenoids account for 72.93% for the needles and 92.40% for the twigs of the total VOC,and their emission ratios are 61.200 μg·g-1 and 217.060 μg·g-1 respectively.Heated twigs can emit more terpenoids than heated needles because twigs had more volatile oils than needles.In actual fires,these large amounts of terpenoid emissions,especially the monoterpene emissions,have strong effects on fire behaviors that are not only in the initial stage but also in the fast propagation stage of fires.These flammable gases are capable of causing violent combustion and creating crown fires.In addition,if these gases accumulate in an uneven geographical area,there will be a possible for eruptive fires and/or fires flashover to occur.
基金supported by the National Basic Research Program of China(2012CB215302)Guangdong Provincial Natural Science Fund(9151064101000082)
文摘The microwave assisted liquefaction process of wheat straw alkali lignin was investigated to obtain monophenolic compounds as the precursor of bio-fuel. It is found that the total yield of monophenolic compounds is significantly improved under microwave irradiation, reaching 15.77% under a relatively mild liquefaction condition of 10 wt% H2SO4 as the catalyst, 10 wt% phenol as the hydrogen-donor reagent at 120 ℃ for 40 rain. Compared with conventional thermal liquefaction process, microwave irradiation promotes the cleavage of C-C bonds, which gives an extra 29% of Caryl-Cα bond cleavage, and increases the yield of monophenolic compounds from 0.92% to 13.61% under the same conditions. The excessive temperature and prolonged time under microwave irradiation will promote the recondensation of degraded lignin fragments, so the key to obtain high yield of monophenolic compounds is to avoid the recondensation reaction. The selected solid catalyst promotes the dissociation of methoxy groups, and the addition of phenol into liquefaction can only slightly improve the yield of monophencolic compounds.
基金supported by the National Natural Science Foundation of China(No.51274066,51304048)the National Key Technology R&D Program of China(No.2013BAA03B03)the National Science Foundation for Post-doctoral Scientists of China(No.2013M541240)
文摘The steam reforming of four bio-oil model compounds（acetic acid,ethanol,acetone and phenol） was investigated over Ni-based catalysts supported on Al2O3 modified by Mg,Ce or Co in this paper.The activation process can improve the catalytic activity with the change of high-valence Ni（Ni2O3,NiO） to low-valence Ni（Ni,NiO）.Among these catalysts after activation,the Ce-Ni/Co catalyst showed the best catalytic activity for the steam reforming of all the four model compounds.After long-term experiment at 700°C and the S/C ratio of 9,the Ce-Ni/Co catalyst still maintained excellent stability for the steam reforming of the simulated bio-oil（mixed by the four compounds with the equal masses）.With CaO calcinated from calcium acetate as CO2 sorbent,the catalytic steam reforming experiment combined with continuous in situ CO2 adsorption was performed.With the comparison of the case without the adding of CO2 sorbent,the hydrogen concentration was dramatically improved from 74.8% to 92.3%,with the CO2 concentration obviously decreased from 19.90% to 1.88%.
基金supported by the Program for New Century Excellent Talents in University (NCET-04-0270)National Basic Research Program of China (2011CB201301)
文摘The adsorptive denitrogenation from fuels over three metal-organic frameworks(MIL-96(Al),MIL-53(Al)and MIL-101(Cr))was studied by batch adsorption experiments.Four nitrogen-containing compounds(NCCs)pyridine,pyrrole,quinoline and indole were used as model NCCs in fuels to study the adsorption mechanism.The physicochemical properties of the adsorbents were characterized by XRD,N2physical adsorption,FT-IR spectrum and Hammett indicator method.The metal-organic frameworks(MOFs),especially the MIL-101(Cr)containing Lewis acid sites as well as high specific surface area,can adsorb large quantities of NCCs from fuels.In addition,the adsorptive capacity over MIL-101(Cr)will be different for NCCs with different basicity.The stronger basicity of the NCC is,the more it can be absorbed over MIL-101(Cr).Furthermore,pore size and shape also affect the adsorption capacity for a given adsorbate,which can be proved by the adsorption over MIL-53(Al)and MIL-96(Al).The pseudo-second-order kinetic model and Langmuir equation can be used to describe kinetics and thermodynamics of the adsorption process,respectively.Finally,the regeneration of the used adsorbent has been conducted successfully by just washing it with ethanol.
