To ensure the safety of the commercially available chenpi,a convenient and fast analytical method was developed for the determination of 133 pesticide residues in chenpi using gas chromatography-tandem mass spectromet...To ensure the safety of the commercially available chenpi,a convenient and fast analytical method was developed for the determination of 133 pesticide residues in chenpi using gas chromatography-tandem mass spectrometry(GC-MS/MS).In this study,different extraction solvents,redissolution solvents and adsorbents were tested according to the recovery and purification effect to obtain a modified QuEChERS method.The samples were extracted with acetonitrile.During the clean-up step,octadecyl-modified silica(C18)and graphitized carbon black(GCB)were selected,and aminopropyl(NH2)was used instead of primary secondary amine(PSA)because of its weaker ion exchange capacity which had little effect on the recovery of ditalimfos.Samples were quantified by matrix-matched calibration with internal standards.All pesticides showed good linearity in the respective range,both with values of r2>0.99.The average recoveries of the pesticides spiked samples ranged from 70.0% to 112.2% with the RSDs of 0.2%–14.4%.The modified QuEChERS method was validated and applied to twenty real samples.Five pesticides were found in eight batches,but no pesticide exceeded the maximum residue limits(MRL,MRL reference to European commission).展开更多
Hyperspectral data have important research and application value in the fields of meteorology and remote sensing.With the goal of improving retrievals of atmospheric temperature profiles,this paper outlines a novel te...Hyperspectral data have important research and application value in the fields of meteorology and remote sensing.With the goal of improving retrievals of atmospheric temperature profiles,this paper outlines a novel temperature channel selection method based on singular spectrum analysis(SSA)for the Geostationary Interferometric Infrared Sounder(GIIRS),which is the first infrared sounder operating in geostationary orbit.The method possesses not only the simplicity and rapidity of the principal component analysis method,but also the interpretability of the conventional channel selection method.The novel SSA method is used to decompose the GIIRS observed infrared brightness temperature spectrum(700-1130 cm-1),and the reconstructed grouped components can be obtained to reflect the energy variations in the temperature-sensitive waveband of the respective sequence.At 700-780 cm-1,the channels selected using our method perform better than IASI(Infrared Atmospheric Sounding Interferometer)and Cr IS(Cross-track Infrared Sounder)temperature channels when used as inputs to the neural network retrieval model.展开更多
The aim of the study was to develop protein enriched instant fish soup mix and analysis of the quality of various conditions. The study used a mechanical dryer for maintaining a constant air flow and temperature at it...The aim of the study was to develop protein enriched instant fish soup mix and analysis of the quality of various conditions. The study used a mechanical dryer for maintaining a constant air flow and temperature at its drying and dehydration stage. Powder was made after drying. An appropriate composition was used as an indicator. Various compositions like 75%, 65%, 55% and 45% fish powder were used as formulation 0, formulation 1, formulation 2, and formulation 3 respectively. Then these were reconstituted by boiled water for soup mix preparation. The result indicated that mixer 2 was the best composition. The finding suggested that 55% fish powder mix is the best composition for protein enriched instant soup mix. It will help to produce the instant soup mix and an alternative source of various costly animal and plant protein as a value-added material.展开更多
A new compound named DHDK was isolated from Viscum coloratum and identified as (1E,4E)-1,7-bis(4-hydroxyphenyl)hepta -1,4-dien-3-one. DHDK, a new potential anti-tumor drug, was synthesized and prepared poly(ethylene g...A new compound named DHDK was isolated from Viscum coloratum and identified as (1E,4E)-1,7-bis(4-hydroxyphenyl)hepta -1,4-dien-3-one. DHDK, a new potential anti-tumor drug, was synthesized and prepared poly(ethylene glycol)-poly(D.L-lactic acid)(mPEG-PLA) micelles due to cytotoxic effects on a range of cancer cells. A revered phase liquid chromatographyic method has been developed and validated for the determination of potential related impurities in DHDK-loaded mPEG-PLA micelles. The micelles was subjected to the stress conditions of acid, base, oxidation, thermal and photolysis. The determination was achieved on Phenomenex SynergiTM 4 μm Fusion-RP 80?(250 mm × 4.6 mm, 4 μm) with a gradient elution and the detection wavelength was set at 220 nm. Regression analysis shows as r value (correlation coefficient) of greater than 0.999 for DHDK and six potential impurities. Recoveries of impurities were found between 90.0% and 108.0%. The developed RP-LC method was validated with respect to linearity, accuracy, precision and robustness, which can be used for determination of related impurities in DHDK-loaded mPEG-PLA micelles.展开更多
With increasing adoption of intermittent renewable generation,challenges to maintain stable frequencies for power systems are increasing.Demand-side resources,such as thermostatically controlled loads(TCLs),have been ...With increasing adoption of intermittent renewable generation,challenges to maintain stable frequencies for power systems are increasing.Demand-side resources,such as thermostatically controlled loads(TCLs),have been proven capable of providing regulation services.The district cooling system(DCS),a type of centralized TCL that provides cooling services for a group of buildings,is an ideal resource for this purpose.A DCS usually has significant regulation flexibility because its rated power capacity is large(up to 100 MW)and it can utilize thermal inertia of an aggregation of buildings.However,as a large-scale system with complex thermal dynamics,its effective regulation is nontrivial,and its traditional demanddriven control scheme has difficulty considering regulation signals from power systems.To address these challenges,we propose a bidirectional-driven control scheme in a DCS for the first time.On this basis,we formulate the thermal and electricity model of a DCS in the frequency domain and derive an equivalent model to control it like a traditional generator.Furthermore,we propose a sensitivity-based control strategy for a DCS to allocate mass flow adjustments among buildings,which effectively considers heterogeneity of buildings to balance temperature impacts.Numerical studies illustrate effectiveness of the proposed model and control strategy.展开更多
The impact of high-temperature sterilization on the flavor of surimi gels were examined,alongside the utilization of tandem mass tag labeled quantitative proteomics to explore the correlations between flavor and prote...The impact of high-temperature sterilization on the flavor of surimi gels were examined,alongside the utilization of tandem mass tag labeled quantitative proteomics to explore the correlations between flavor and proteome profiles.Notable increase was observed in lipid oxidation,protein degradation,and the types and total content of volatile organic compounds(VOC),particularly aldehydes.A total of 67 shared differentially expressed proteins(DEP)were identified,confirming the aggregation and degradation of proteins.Gene Ontology functional analysis revealed that proteins possibly linked to flavor were primarily concentrated in the myosin complex,motor activity,and hydrolase activity categories.The Kyoto Encyclopedia of Genes and Genomes pathway analysis highlighted a focus on the motor protein pathway.Correlation analysis between DEP and key VOC revealed that most DEP exhibited significant correlations with aldehydes and ketones such as octanal,pentanal,and(Z)-4-heptenal,with flavor-associated proteins mainly concentrated in structural,antioxidant,and redox proteins.展开更多
This study was carried out to reveal the browning path of ready-to-eat(RTE)crayfish tails during thermal treatment and storage using path analysis.Maillard reactions,lipid oxidation,and phenol oxidation were evaluated...This study was carried out to reveal the browning path of ready-to-eat(RTE)crayfish tails during thermal treatment and storage using path analysis.Maillard reactions,lipid oxidation,and phenol oxidation were evaluated in combination with free radical content and FTIR analysis,and direct path coefficients as well as determination coefficients were obtained based on these parameters,such as the absorbance at 294 nm(A294),5-hydroxymethylfurfural(5-HMF),thiobarbituric acid-reactive substances(TBARS),and total phenols(TP).The result showed that the browning of seasoned RTE crayfish tails was ascribe to the synergistic effect of Maillard reaction and lipid oxidation by the order of determination coefficient.After the crayfish hepatopancreas were removed,the content of A294,5-HMF,TBARS,and TP declined more than 30%,specifically affecting the direct pathway from lipid oxidation to Maillard reaction and alleviating the browning.However,no significant change of color was observed in the group without thirteen-spices,while TBARS and free radical content increased by at least 16.7%.The removal of hepatopancreas and the control of Maillard reaction were deemed to be a good measure for inhibiting the non-enzymatic browning of RTE crayfish tails.展开更多
Fermentation has been found as an effective method to decrease the hypersensitive reactions of consumers by freshwater fish,but the reason is not clear.Therefore,the aim of this study was to investigate the impact of ...Fermentation has been found as an effective method to decrease the hypersensitive reactions of consumers by freshwater fish,but the reason is not clear.Therefore,the aim of this study was to investigate the impact of pH and acid-activated proteases on the decrease of immunological properties of parvalbumin from freshwater fish,by the indicators of SDS-polyacrylamide gel electrophoresis,western blotting,enzyme-linked immunosorbent assay,surface hydrophobicity and circular dichroism.The results showed that black carp(Mylopharyngodon piceus)had the highest level of immunological properties reflected by quantitation,the content of linear epitopes and conformational epitopes of parvalbumin,and IgE-binding rate.Afterwards,purified parvalbumin from black carp was obtained with purity higher than 95%.Then,for acidification and enzyme models,it indicated that acid-activated proteases were the reason for the decrease of immunological properties.Ulteriorly,the mechanism on the level of protein structure was provided,which showed the decrease ofα-helix and the increase ofβ-turn and random coil,as well as the decrease of surface hydrophobicity had joint contribution for the breaking of conformational epitopes.This study could provide a novel guidance for the decrease of immunological properties of fish and promote fish processing industry further.展开更多
Channel catfish is an important freshwater culture fish and occupies a large proportion in the field of freshwater aquatic product processing.In this study,changes in basic nutritional composition,texture characterist...Channel catfish is an important freshwater culture fish and occupies a large proportion in the field of freshwater aquatic product processing.In this study,changes in basic nutritional composition,texture characteristics and myofibrillar protein(MP)characteristics of the channel catfish(Ictalurus punctatus)were determined with respect to the seasons.Chromatography,TA-XTPlus physical property analyzer and Fourier transform infrared spectroscopy were used to analyze the samples for amino acid profile,fatty acid profile,textural properties and MP structure,respectively.The maximum moisture content of muscle was obtained in winter,and the fat content was highest in summer and lowest in winter.The highest levels of saturated fatty acids(SFA),eicosapentaenoic acid(EPA),docosahexaenoic acid(DHA),resilience and cohesion were found in summer.The hardness was 40%higher in winter than that in summer.The study of MP properties in different seasons revealed that MP had higher surface hydrophobicity but lowerα-helix content in autumn and winter(17.40%and 17.52%,respectively).There was no significant difference in the total sulfhydryl content between seasons(P>0.05),with the highest MP endogenous fluorescence intensity in spring.Seasonal variations in the nutritional quality and MP characteristics may be related to different water temperature environments,the duration of the overwintering period,and the different expression of genes.This study bridges the gap in the quality evaluation system of channel catfish and provides some useful information for its deep processing.展开更多
Consumers like dried meat slice,but the desired fiber-like chewiness may be affected by the addition of fish source.Therefore,this study was aimed to investigate the effect of component mixture(pork and fish);particle...Consumers like dried meat slice,but the desired fiber-like chewiness may be affected by the addition of fish source.Therefore,this study was aimed to investigate the effect of component mixture(pork and fish);particle size(fish mince or cube)and enzyme(transglutaminase and laccase)on dried slice texture.Furthermore,the reason was shown by water distribution,protein secondary structure,and microstructure.Results showed that hardness,chewiness,and tensile strength were the highest at the rate of pork and fish mince by 6:4;at the rate of fish cube and mince by 5:5;and at the addition of transglutaminase(TG)by 0.8%.To explore its reason,it showed the largest water peak area with 3983.8±45.9,4817.8±209.3 and 3642.5±18.1,the largest decrease of α-helix by 31.1%,1.8%,22.6%,and the most compact fiber-like morphology in the above three groups.This study indicated that a slight cross-linking between pork and fish proteins by TG was benefit for fiber-like chewiness,while over-cross-linking was detrimental with more elastic structure formed.In conclusion,percentage of pork to fish,fish cube to mince,and the addition amount of TG all contributed to the final fiber-like chewiness of dried slice significantly.展开更多
文摘To ensure the safety of the commercially available chenpi,a convenient and fast analytical method was developed for the determination of 133 pesticide residues in chenpi using gas chromatography-tandem mass spectrometry(GC-MS/MS).In this study,different extraction solvents,redissolution solvents and adsorbents were tested according to the recovery and purification effect to obtain a modified QuEChERS method.The samples were extracted with acetonitrile.During the clean-up step,octadecyl-modified silica(C18)and graphitized carbon black(GCB)were selected,and aminopropyl(NH2)was used instead of primary secondary amine(PSA)because of its weaker ion exchange capacity which had little effect on the recovery of ditalimfos.Samples were quantified by matrix-matched calibration with internal standards.All pesticides showed good linearity in the respective range,both with values of r2>0.99.The average recoveries of the pesticides spiked samples ranged from 70.0% to 112.2% with the RSDs of 0.2%–14.4%.The modified QuEChERS method was validated and applied to twenty real samples.Five pesticides were found in eight batches,but no pesticide exceeded the maximum residue limits(MRL,MRL reference to European commission).
文摘Hyperspectral data have important research and application value in the fields of meteorology and remote sensing.With the goal of improving retrievals of atmospheric temperature profiles,this paper outlines a novel temperature channel selection method based on singular spectrum analysis(SSA)for the Geostationary Interferometric Infrared Sounder(GIIRS),which is the first infrared sounder operating in geostationary orbit.The method possesses not only the simplicity and rapidity of the principal component analysis method,but also the interpretability of the conventional channel selection method.The novel SSA method is used to decompose the GIIRS observed infrared brightness temperature spectrum(700-1130 cm-1),and the reconstructed grouped components can be obtained to reflect the energy variations in the temperature-sensitive waveband of the respective sequence.At 700-780 cm-1,the channels selected using our method perform better than IASI(Infrared Atmospheric Sounding Interferometer)and Cr IS(Cross-track Infrared Sounder)temperature channels when used as inputs to the neural network retrieval model.
文摘The aim of the study was to develop protein enriched instant fish soup mix and analysis of the quality of various conditions. The study used a mechanical dryer for maintaining a constant air flow and temperature at its drying and dehydration stage. Powder was made after drying. An appropriate composition was used as an indicator. Various compositions like 75%, 65%, 55% and 45% fish powder were used as formulation 0, formulation 1, formulation 2, and formulation 3 respectively. Then these were reconstituted by boiled water for soup mix preparation. The result indicated that mixer 2 was the best composition. The finding suggested that 55% fish powder mix is the best composition for protein enriched instant soup mix. It will help to produce the instant soup mix and an alternative source of various costly animal and plant protein as a value-added material.
文摘A new compound named DHDK was isolated from Viscum coloratum and identified as (1E,4E)-1,7-bis(4-hydroxyphenyl)hepta -1,4-dien-3-one. DHDK, a new potential anti-tumor drug, was synthesized and prepared poly(ethylene glycol)-poly(D.L-lactic acid)(mPEG-PLA) micelles due to cytotoxic effects on a range of cancer cells. A revered phase liquid chromatographyic method has been developed and validated for the determination of potential related impurities in DHDK-loaded mPEG-PLA micelles. The micelles was subjected to the stress conditions of acid, base, oxidation, thermal and photolysis. The determination was achieved on Phenomenex SynergiTM 4 μm Fusion-RP 80?(250 mm × 4.6 mm, 4 μm) with a gradient elution and the detection wavelength was set at 220 nm. Regression analysis shows as r value (correlation coefficient) of greater than 0.999 for DHDK and six potential impurities. Recoveries of impurities were found between 90.0% and 108.0%. The developed RP-LC method was validated with respect to linearity, accuracy, precision and robustness, which can be used for determination of related impurities in DHDK-loaded mPEG-PLA micelles.
文摘With increasing adoption of intermittent renewable generation,challenges to maintain stable frequencies for power systems are increasing.Demand-side resources,such as thermostatically controlled loads(TCLs),have been proven capable of providing regulation services.The district cooling system(DCS),a type of centralized TCL that provides cooling services for a group of buildings,is an ideal resource for this purpose.A DCS usually has significant regulation flexibility because its rated power capacity is large(up to 100 MW)and it can utilize thermal inertia of an aggregation of buildings.However,as a large-scale system with complex thermal dynamics,its effective regulation is nontrivial,and its traditional demanddriven control scheme has difficulty considering regulation signals from power systems.To address these challenges,we propose a bidirectional-driven control scheme in a DCS for the first time.On this basis,we formulate the thermal and electricity model of a DCS in the frequency domain and derive an equivalent model to control it like a traditional generator.Furthermore,we propose a sensitivity-based control strategy for a DCS to allocate mass flow adjustments among buildings,which effectively considers heterogeneity of buildings to balance temperature impacts.Numerical studies illustrate effectiveness of the proposed model and control strategy.
基金financially supported by the earmarked fund for Jiangsu Agricultural Industry Technology System(JATS[2023]464)Jiangsu key R&D plan(BE2021319)China Agriculture Research System(CARS-45-28).
文摘The impact of high-temperature sterilization on the flavor of surimi gels were examined,alongside the utilization of tandem mass tag labeled quantitative proteomics to explore the correlations between flavor and proteome profiles.Notable increase was observed in lipid oxidation,protein degradation,and the types and total content of volatile organic compounds(VOC),particularly aldehydes.A total of 67 shared differentially expressed proteins(DEP)were identified,confirming the aggregation and degradation of proteins.Gene Ontology functional analysis revealed that proteins possibly linked to flavor were primarily concentrated in the myosin complex,motor activity,and hydrolase activity categories.The Kyoto Encyclopedia of Genes and Genomes pathway analysis highlighted a focus on the motor protein pathway.Correlation analysis between DEP and key VOC revealed that most DEP exhibited significant correlations with aldehydes and ketones such as octanal,pentanal,and(Z)-4-heptenal,with flavor-associated proteins mainly concentrated in structural,antioxidant,and redox proteins.
基金supported by the National Key R&D Program of China(2019YFC1606002).
文摘This study was carried out to reveal the browning path of ready-to-eat(RTE)crayfish tails during thermal treatment and storage using path analysis.Maillard reactions,lipid oxidation,and phenol oxidation were evaluated in combination with free radical content and FTIR analysis,and direct path coefficients as well as determination coefficients were obtained based on these parameters,such as the absorbance at 294 nm(A294),5-hydroxymethylfurfural(5-HMF),thiobarbituric acid-reactive substances(TBARS),and total phenols(TP).The result showed that the browning of seasoned RTE crayfish tails was ascribe to the synergistic effect of Maillard reaction and lipid oxidation by the order of determination coefficient.After the crayfish hepatopancreas were removed,the content of A294,5-HMF,TBARS,and TP declined more than 30%,specifically affecting the direct pathway from lipid oxidation to Maillard reaction and alleviating the browning.However,no significant change of color was observed in the group without thirteen-spices,while TBARS and free radical content increased by at least 16.7%.The removal of hepatopancreas and the control of Maillard reaction were deemed to be a good measure for inhibiting the non-enzymatic browning of RTE crayfish tails.
基金financially supported by the earmarked fund for Jiangsu Key R&D Project(BE2021319)Jiangsu Natural Science Fund(BK20170185)+1 种基金the earmarked fund for Jiangsu Agricultural Industry Technology System(JATS[2022]507)China Agricultures Research System(CARS-45).
文摘Fermentation has been found as an effective method to decrease the hypersensitive reactions of consumers by freshwater fish,but the reason is not clear.Therefore,the aim of this study was to investigate the impact of pH and acid-activated proteases on the decrease of immunological properties of parvalbumin from freshwater fish,by the indicators of SDS-polyacrylamide gel electrophoresis,western blotting,enzyme-linked immunosorbent assay,surface hydrophobicity and circular dichroism.The results showed that black carp(Mylopharyngodon piceus)had the highest level of immunological properties reflected by quantitation,the content of linear epitopes and conformational epitopes of parvalbumin,and IgE-binding rate.Afterwards,purified parvalbumin from black carp was obtained with purity higher than 95%.Then,for acidification and enzyme models,it indicated that acid-activated proteases were the reason for the decrease of immunological properties.Ulteriorly,the mechanism on the level of protein structure was provided,which showed the decrease ofα-helix and the increase ofβ-turn and random coil,as well as the decrease of surface hydrophobicity had joint contribution for the breaking of conformational epitopes.This study could provide a novel guidance for the decrease of immunological properties of fish and promote fish processing industry further.
基金funded by the earmarked fund for Jiangsu Agricultural Industry Technology System(JATS[2023]464)China Agriculture Research System(CARS-45-28).
文摘Channel catfish is an important freshwater culture fish and occupies a large proportion in the field of freshwater aquatic product processing.In this study,changes in basic nutritional composition,texture characteristics and myofibrillar protein(MP)characteristics of the channel catfish(Ictalurus punctatus)were determined with respect to the seasons.Chromatography,TA-XTPlus physical property analyzer and Fourier transform infrared spectroscopy were used to analyze the samples for amino acid profile,fatty acid profile,textural properties and MP structure,respectively.The maximum moisture content of muscle was obtained in winter,and the fat content was highest in summer and lowest in winter.The highest levels of saturated fatty acids(SFA),eicosapentaenoic acid(EPA),docosahexaenoic acid(DHA),resilience and cohesion were found in summer.The hardness was 40%higher in winter than that in summer.The study of MP properties in different seasons revealed that MP had higher surface hydrophobicity but lowerα-helix content in autumn and winter(17.40%and 17.52%,respectively).There was no significant difference in the total sulfhydryl content between seasons(P>0.05),with the highest MP endogenous fluorescence intensity in spring.Seasonal variations in the nutritional quality and MP characteristics may be related to different water temperature environments,the duration of the overwintering period,and the different expression of genes.This study bridges the gap in the quality evaluation system of channel catfish and provides some useful information for its deep processing.
基金financially supported by the earmarked fund for Jiangsu Key R&D Project(BE2021319)the earmarked fund for Jiangsu Agricultural Industry Technology System(JATS[2022]507)China Agricultures Research System(CASR-45).
文摘Consumers like dried meat slice,but the desired fiber-like chewiness may be affected by the addition of fish source.Therefore,this study was aimed to investigate the effect of component mixture(pork and fish);particle size(fish mince or cube)and enzyme(transglutaminase and laccase)on dried slice texture.Furthermore,the reason was shown by water distribution,protein secondary structure,and microstructure.Results showed that hardness,chewiness,and tensile strength were the highest at the rate of pork and fish mince by 6:4;at the rate of fish cube and mince by 5:5;and at the addition of transglutaminase(TG)by 0.8%.To explore its reason,it showed the largest water peak area with 3983.8±45.9,4817.8±209.3 and 3642.5±18.1,the largest decrease of α-helix by 31.1%,1.8%,22.6%,and the most compact fiber-like morphology in the above three groups.This study indicated that a slight cross-linking between pork and fish proteins by TG was benefit for fiber-like chewiness,while over-cross-linking was detrimental with more elastic structure formed.In conclusion,percentage of pork to fish,fish cube to mince,and the addition amount of TG all contributed to the final fiber-like chewiness of dried slice significantly.
