Shrimp sauce,one of the traditional salt-fermented food in China,has a unique flavor that is influenced by the resident microflora.The quality of salt-fermented shrimp sauce was evaluated in this work by determining t...Shrimp sauce,one of the traditional salt-fermented food in China,has a unique flavor that is influenced by the resident microflora.The quality of salt-fermented shrimp sauce was evaluated in this work by determining the total volatile basic nitrogen(TVB-N),the amino acid nitrogen(AAN),organic acid,5’-nucleotide and free amino acids(FAA).Moreover,the dynamics of microbial diversity during processing was investigated by using high-throughput sequencing technology.The results showed that the AAN,TVB-N,organic acid,5’-nucleotide and FAA content were in range of 0.93-1.42 g/100 mL,49.91-236.27 mg/100 mL,6.65-20.68 mg/mL,3.51-6.56 mg/mL and 81.27-102.90 mg/mL.Among the microbial diversity found in the shrimp sauce,Tetragenococcus,Flavobacterium,Polaribacter,Haematospirillum and Staphylococcus were the predominant genera.Correlation analysis indicated that the bacteria Tetragenococcus and Staphylococcus were important in the formation of non-volatile compounds.Tetragenococcus positively correlated with a variety of FAAs;Staphylococcus positively correlated with 5’-nucleotides.The analysis indicated that Tetragenococcus and Staphylococcus were the core genera affecting non-volatile components.These findings indicate the dynamics of the bacterial community and non-volatile components inter-relationships during shrimp sauce fermentation and provide a theoretical basis for improving the fermentation process of shrimp sauce.展开更多
The freshness and quality indices of whiting (Merlangius merlangus) influenced by a large number of chemical volatile compounds, are here analyzed in order to select the most relevant compounds as predictors for these...The freshness and quality indices of whiting (Merlangius merlangus) influenced by a large number of chemical volatile compounds, are here analyzed in order to select the most relevant compounds as predictors for these indices. The selection process was performed by means of recent statistical variable selection methods, namely robust model-free feature screening, based on quantile correlation and composite quantile correlation. On the one hand, compounds 2-Methyl-1-butanol, 3-Methyl-1-butanol, Ethanol, Trimethylamine, 3-Methyl butanal, 2-Methyl-1-propanol, Ethylacetate, 1-Butanol and 2,3-Butanedione were identified as major predictors for the freshness index and on the other hand, compounds 3-Methyl-1-butanol, 2-Methyl-1- butanol, Ethanol, 3-Methyl butanal, 3-Hydroxy-2-butanone, 1-Butanol, 2,3-Butane- dione, 3-Pentanol, 3-Pentanone and 2-Methyl-1-propanol were identified as major predictors for the quality index.展开更多
DHA-enriched eggs have gained popularity due to their unique nutritional value,but their flavor can be challenging for some consumers to accept.The study analyzed the correlation of lipids and flavors in DHA-enriched ...DHA-enriched eggs have gained popularity due to their unique nutritional value,but their flavor can be challenging for some consumers to accept.The study analyzed the correlation of lipids and flavors in DHA-enriched egg yolks using comprehensive lipidomics and volatile compound analysis.The results showed that 411 lipids were detected in two egg yolk samples.Among them,148 lipid species,including 48 DHA-containing lipids,were significantly higher in DHA-enriched egg yolks than in Common ones(P<0.05).Furthermore,of the 24 volatile compounds detected,the contents of benzaldehyde,heptanal,hexanal,decanal and 2-nonanone in DHA-enriched egg yolks were significantly higher than in Common egg yolks(P<0.05).The“fishy”smell characteristic of DHAenriched egg yolks was mainly caused by volatile aldehydes,which may be produced through the hydrolysis of lipids in the egg yolk to free fatty acids and further oxidation.Analysis of the correlation network diagram revealed that phospholipids containing docosahexaenoic acid(DHA),linoleic acid,or oleic acid chains were the main contributors to the characteristic flavor of DHA-enriched egg yolks.Overall,this study explored the effect of different lipids on the flavor of DHA-enriched egg yolks and provided a theoretical basis for the production and improvement of DHA-enriched eggs.展开更多
The origin of the marine oils in the Tarim Basin has long been a disputed topic. A total of 58 DST (drill stem test) crude oil and 8 rock samples were investigated using a comprehensive geochemical method to charact...The origin of the marine oils in the Tarim Basin has long been a disputed topic. A total of 58 DST (drill stem test) crude oil and 8 rock samples were investigated using a comprehensive geochemical method to characterize and identify the origin of the Ordovician oils in the Tazhong Uplift, Tarim Basin, northwest China. Detailed oil–oil and oil–source rock correlations show that the majority of the oils have typical biomarker characteristics of the Middle-Upper Ordovician (O2+3) source rock and the related crude oil. These characteristics include a distinct "V-shaped" relative abundance of C27, C28 and C29 regular steranes, low abundance of dinosterane, 24-norcholestanes, triaromatic dinosteroids and gammacerane. Only a few oils display typical biomarker characteristics indicating the Cambrian–Lower Ordovician (∈-O1) genetic affinity, such as linear or anti "L" shape distribution of C27, C28 and C29 regular sterane, with relatively high concentrations of dinosterane, 24-norcholestanes, triaromatic dinosteroids and gammacerane. It appears that most of the Ordovician oils in the Tazhong Uplift were derived from the O2+3 intervals, as suggested by previous studies. However, the compound specific n-alkane stable carbon isotope data indicate that the Ordovician oils are mixtures from both the ∈-O1 and O2+3 source rocks rather than from the O2+3 strata alone. It was calculated that the proportion of the∈-O1 genetic affinity oils mixed is about 10.8%-74.1%, with an increasing trend with increasing burial depth. This new oil-mixing model is critical for understanding hydrocarbon generation and accumulation mechanisms in the region, and may have important implications for further hydrocarbon exploration in the Tarim Basin.展开更多
Due to good nutritional properties and potential health benefits,quinoa has gained an increasing attention.The study aimed to analyze the effect of pressure cooking on the composition,antioxidant activity,antibacteria...Due to good nutritional properties and potential health benefits,quinoa has gained an increasing attention.The study aimed to analyze the effect of pressure cooking on the composition,antioxidant activity,antibacterial activity and bioavailability of phenolic compounds in four types of quinoa,and to evaluate the correlation between phenolics and its biological activities by correlation analysis.The results showed that different varieties of quinoa contained different phenolic components and their biological activities were different.Pressure cooking could significantly increase(P<0.05)the phenolic contents of quinoa,and decrease in vitro digestibility of protein.The antioxidant activity,antibacterial activity and bioavailability of quinoa were also enhanced which were positively related with phenolic contents.HPLC analysis indicated that at least twelve phenolic compounds were found in quinoa,and hyperoside,sinapic acid,rutin and ferulic acid occupied a majority of them.Correlation analysis suggested that hyperoside,quercetin,sinapic acid,ferulic acid and gallic acid made the key contribution to antioxidant and antibacterial activities of phenolic compounds of quinoa.The results provided valuable information for quinoa processing with phenolics as functional ingredient.展开更多
Secondary pollutant ozone (O3) formation in a particular area is often influenced by various factors. Source of emissions is one of the factors. In south east Texas, Houston-Galveston-Brazoria (HGB) is a marginal non-...Secondary pollutant ozone (O3) formation in a particular area is often influenced by various factors. Source of emissions is one of the factors. In south east Texas, Houston-Galveston-Brazoria (HGB) is a marginal non-attainment area for ozone (O3). A summer episode of May 28 to July 2, 2006 is simulated using Comprehensive Air Quality Model with extensions (CAMx). During this period O3 concentration in HGB often exceeds the National Ambient Air Quality Standards (NAAQS) 0.075 ppm of average 8 hour O3 concentration. HGB area has numerous point sources. Various studies found that some specific volatile organic compounds are very reactive in atmosphere. The objective of this study is to analyze the influence of volatile organic compounds present in point source emissions on the air quality of HGB area. For this purpose ozone sensitivity for HGB area is analyzed by the ratio of hydrogen peroxides (H2O2) to nitric acid (HNO3). HGB area is found NOx limited but reactive VOCs are found to be influential too. From (1-4 June, 2006) maximum O3 concentration was found on weekend, June 3. VOCs such as Acetaldehyde (ALD2), Formaldehyde (FORM) and Alkane (ETHA) showed good correlation with O3 concentrations on that day. In addition, Peroxyacetyl nitrate (PAN) formation was found correlated to higher ozone production. Criteria pollutant Sulfur dioxide (SO2) was found to influence the ALD2 and ETHA concentrations, and thus indirectly influenced O3 production.展开更多
During a routine inspection in a petroleum product terminal, hydrocarbon staining was found in soil along the perimeter of a diesel fuel tank. As the observation was made a few days after a magnitude 5.1 earthquake in...During a routine inspection in a petroleum product terminal, hydrocarbon staining was found in soil along the perimeter of a diesel fuel tank. As the observation was made a few days after a magnitude 5.1 earthquake in the general area of the terminal, the hydrocarbon staining in the soil was suspected to be a result of a leak from the tank. The observation triggered an immediate tank inspection, which included examination of tank exterior, piping and connections;pressure testing;wall thickness gauging;and an inventory check. Results of the initial inspection suggested that there were no integrity issues with the tank. Before more vigorous and more disruptive inspections were conducted, chemical fingerprinting was conducted to assess the nature of soil staining and potential connection with the “suspected” tank leak. Samples were collected from the site, including a diesel fuel sample from the tank, a light non-aqueous phase liquid (LNAPL) sample from the monitoring well in the immediate vicinity, and representative soil samples from the perimeter of, and beneath, the tank. A tiered laboratory analytical approach was taken, which included initial gas chromatography-flame ionization detector carbon chain analysis and final gas chromatography-mass spectrometry or detailed fingerprint analyses. Based on the results of initial inspection, knowledge of LNAPL mobility in response to earthquake seismic waves, and chemical fingerprints of representative samples, it was determined that the soil staining was not a result of suspected tank release but remobilization of hydrocarbons from the historically impacted soil beneath the tank to the soil along the perimeter of the tank.展开更多
通过对现代工艺六堡茶渥堆过程样品进行感官审评及电子舌、色差、主要生化成分测定,研究六堡茶渥堆过程中色泽及滋味成分的变化规律,并探讨了滋味属性的变化与滋味成分之间的相关性及滋味活度值(taste active value,TAV)。结果表明,现...通过对现代工艺六堡茶渥堆过程样品进行感官审评及电子舌、色差、主要生化成分测定,研究六堡茶渥堆过程中色泽及滋味成分的变化规律,并探讨了滋味属性的变化与滋味成分之间的相关性及滋味活度值(taste active value,TAV)。结果表明,现代工艺渥堆过程中,六堡茶酸味、苦味上升,涩味、鲜味及咸味下降,色差L值波动变化,a、b值逐渐升高,汤色由黄转变为橙红,游离氨基酸、黄酮、茶多酚、茶叶碱、儿茶素总量、氨基酸组分总量显著下降(P<0.05),可可碱、咖啡碱、没食子酸显著上升(P<0.05),水浸出物含量呈波动变化。游离氨基酸、黄酮、酯型儿茶素、DL-儿茶素(DL-catechin, DL-C)及部分氨基酸组分与酸味和苦味显著负相关,与涩味、鲜味及咸味显著正相关,咖啡碱与没食子酸则相反;茶多酚与涩味显著正相关。咖啡碱、可可碱、没食子酸、DL-C及酯型儿茶素对渥堆过程中六堡茶的滋味具显著贡献(TAV> 1),其中酯型儿茶素与没食子酸是六堡茶渥堆过程滋味品质形成的重要化合物,氨基酸组分对六堡茶滋味无显著贡献。展开更多
基金support from the National Key R&D Program of China (2019YFD0901903)the Innovation Team Project of Hebei (Province) Modern Agricultural Industry Technology System (HBCT2018170207)the Postgraduate Research & Practice Innovation Program of Jiangsu Province (SJCX20_1426)
文摘Shrimp sauce,one of the traditional salt-fermented food in China,has a unique flavor that is influenced by the resident microflora.The quality of salt-fermented shrimp sauce was evaluated in this work by determining the total volatile basic nitrogen(TVB-N),the amino acid nitrogen(AAN),organic acid,5’-nucleotide and free amino acids(FAA).Moreover,the dynamics of microbial diversity during processing was investigated by using high-throughput sequencing technology.The results showed that the AAN,TVB-N,organic acid,5’-nucleotide and FAA content were in range of 0.93-1.42 g/100 mL,49.91-236.27 mg/100 mL,6.65-20.68 mg/mL,3.51-6.56 mg/mL and 81.27-102.90 mg/mL.Among the microbial diversity found in the shrimp sauce,Tetragenococcus,Flavobacterium,Polaribacter,Haematospirillum and Staphylococcus were the predominant genera.Correlation analysis indicated that the bacteria Tetragenococcus and Staphylococcus were important in the formation of non-volatile compounds.Tetragenococcus positively correlated with a variety of FAAs;Staphylococcus positively correlated with 5’-nucleotides.The analysis indicated that Tetragenococcus and Staphylococcus were the core genera affecting non-volatile components.These findings indicate the dynamics of the bacterial community and non-volatile components inter-relationships during shrimp sauce fermentation and provide a theoretical basis for improving the fermentation process of shrimp sauce.
文摘The freshness and quality indices of whiting (Merlangius merlangus) influenced by a large number of chemical volatile compounds, are here analyzed in order to select the most relevant compounds as predictors for these indices. The selection process was performed by means of recent statistical variable selection methods, namely robust model-free feature screening, based on quantile correlation and composite quantile correlation. On the one hand, compounds 2-Methyl-1-butanol, 3-Methyl-1-butanol, Ethanol, Trimethylamine, 3-Methyl butanal, 2-Methyl-1-propanol, Ethylacetate, 1-Butanol and 2,3-Butanedione were identified as major predictors for the freshness index and on the other hand, compounds 3-Methyl-1-butanol, 2-Methyl-1- butanol, Ethanol, 3-Methyl butanal, 3-Hydroxy-2-butanone, 1-Butanol, 2,3-Butane- dione, 3-Pentanol, 3-Pentanone and 2-Methyl-1-propanol were identified as major predictors for the quality index.
基金supported by the Opening Project of Hubei Key Laboratory of Lipid Chemistry and Nutrition(202106).
文摘DHA-enriched eggs have gained popularity due to their unique nutritional value,but their flavor can be challenging for some consumers to accept.The study analyzed the correlation of lipids and flavors in DHA-enriched egg yolks using comprehensive lipidomics and volatile compound analysis.The results showed that 411 lipids were detected in two egg yolk samples.Among them,148 lipid species,including 48 DHA-containing lipids,were significantly higher in DHA-enriched egg yolks than in Common ones(P<0.05).Furthermore,of the 24 volatile compounds detected,the contents of benzaldehyde,heptanal,hexanal,decanal and 2-nonanone in DHA-enriched egg yolks were significantly higher than in Common egg yolks(P<0.05).The“fishy”smell characteristic of DHAenriched egg yolks was mainly caused by volatile aldehydes,which may be produced through the hydrolysis of lipids in the egg yolk to free fatty acids and further oxidation.Analysis of the correlation network diagram revealed that phospholipids containing docosahexaenoic acid(DHA),linoleic acid,or oleic acid chains were the main contributors to the characteristic flavor of DHA-enriched egg yolks.Overall,this study explored the effect of different lipids on the flavor of DHA-enriched egg yolks and provided a theoretical basis for the production and improvement of DHA-enriched eggs.
基金This study is funded by the Natural Science Research Council of China (973 State Key Research and Development Program 2006CB202308)National Natural Science Foundation of China (Grant No.40973031)
文摘The origin of the marine oils in the Tarim Basin has long been a disputed topic. A total of 58 DST (drill stem test) crude oil and 8 rock samples were investigated using a comprehensive geochemical method to characterize and identify the origin of the Ordovician oils in the Tazhong Uplift, Tarim Basin, northwest China. Detailed oil–oil and oil–source rock correlations show that the majority of the oils have typical biomarker characteristics of the Middle-Upper Ordovician (O2+3) source rock and the related crude oil. These characteristics include a distinct "V-shaped" relative abundance of C27, C28 and C29 regular steranes, low abundance of dinosterane, 24-norcholestanes, triaromatic dinosteroids and gammacerane. Only a few oils display typical biomarker characteristics indicating the Cambrian–Lower Ordovician (∈-O1) genetic affinity, such as linear or anti "L" shape distribution of C27, C28 and C29 regular sterane, with relatively high concentrations of dinosterane, 24-norcholestanes, triaromatic dinosteroids and gammacerane. It appears that most of the Ordovician oils in the Tazhong Uplift were derived from the O2+3 intervals, as suggested by previous studies. However, the compound specific n-alkane stable carbon isotope data indicate that the Ordovician oils are mixtures from both the ∈-O1 and O2+3 source rocks rather than from the O2+3 strata alone. It was calculated that the proportion of the∈-O1 genetic affinity oils mixed is about 10.8%-74.1%, with an increasing trend with increasing burial depth. This new oil-mixing model is critical for understanding hydrocarbon generation and accumulation mechanisms in the region, and may have important implications for further hydrocarbon exploration in the Tarim Basin.
基金the project of the Program of Beijing Advanced Innovation Center for Food Nutrition and Human Health(20181037)the project of Science and Technology Department of Shanxi Province(202102140601014)。
文摘Due to good nutritional properties and potential health benefits,quinoa has gained an increasing attention.The study aimed to analyze the effect of pressure cooking on the composition,antioxidant activity,antibacterial activity and bioavailability of phenolic compounds in four types of quinoa,and to evaluate the correlation between phenolics and its biological activities by correlation analysis.The results showed that different varieties of quinoa contained different phenolic components and their biological activities were different.Pressure cooking could significantly increase(P<0.05)the phenolic contents of quinoa,and decrease in vitro digestibility of protein.The antioxidant activity,antibacterial activity and bioavailability of quinoa were also enhanced which were positively related with phenolic contents.HPLC analysis indicated that at least twelve phenolic compounds were found in quinoa,and hyperoside,sinapic acid,rutin and ferulic acid occupied a majority of them.Correlation analysis suggested that hyperoside,quercetin,sinapic acid,ferulic acid and gallic acid made the key contribution to antioxidant and antibacterial activities of phenolic compounds of quinoa.The results provided valuable information for quinoa processing with phenolics as functional ingredient.
文摘Secondary pollutant ozone (O3) formation in a particular area is often influenced by various factors. Source of emissions is one of the factors. In south east Texas, Houston-Galveston-Brazoria (HGB) is a marginal non-attainment area for ozone (O3). A summer episode of May 28 to July 2, 2006 is simulated using Comprehensive Air Quality Model with extensions (CAMx). During this period O3 concentration in HGB often exceeds the National Ambient Air Quality Standards (NAAQS) 0.075 ppm of average 8 hour O3 concentration. HGB area has numerous point sources. Various studies found that some specific volatile organic compounds are very reactive in atmosphere. The objective of this study is to analyze the influence of volatile organic compounds present in point source emissions on the air quality of HGB area. For this purpose ozone sensitivity for HGB area is analyzed by the ratio of hydrogen peroxides (H2O2) to nitric acid (HNO3). HGB area is found NOx limited but reactive VOCs are found to be influential too. From (1-4 June, 2006) maximum O3 concentration was found on weekend, June 3. VOCs such as Acetaldehyde (ALD2), Formaldehyde (FORM) and Alkane (ETHA) showed good correlation with O3 concentrations on that day. In addition, Peroxyacetyl nitrate (PAN) formation was found correlated to higher ozone production. Criteria pollutant Sulfur dioxide (SO2) was found to influence the ALD2 and ETHA concentrations, and thus indirectly influenced O3 production.
文摘During a routine inspection in a petroleum product terminal, hydrocarbon staining was found in soil along the perimeter of a diesel fuel tank. As the observation was made a few days after a magnitude 5.1 earthquake in the general area of the terminal, the hydrocarbon staining in the soil was suspected to be a result of a leak from the tank. The observation triggered an immediate tank inspection, which included examination of tank exterior, piping and connections;pressure testing;wall thickness gauging;and an inventory check. Results of the initial inspection suggested that there were no integrity issues with the tank. Before more vigorous and more disruptive inspections were conducted, chemical fingerprinting was conducted to assess the nature of soil staining and potential connection with the “suspected” tank leak. Samples were collected from the site, including a diesel fuel sample from the tank, a light non-aqueous phase liquid (LNAPL) sample from the monitoring well in the immediate vicinity, and representative soil samples from the perimeter of, and beneath, the tank. A tiered laboratory analytical approach was taken, which included initial gas chromatography-flame ionization detector carbon chain analysis and final gas chromatography-mass spectrometry or detailed fingerprint analyses. Based on the results of initial inspection, knowledge of LNAPL mobility in response to earthquake seismic waves, and chemical fingerprints of representative samples, it was determined that the soil staining was not a result of suspected tank release but remobilization of hydrocarbons from the historically impacted soil beneath the tank to the soil along the perimeter of the tank.
文摘通过对现代工艺六堡茶渥堆过程样品进行感官审评及电子舌、色差、主要生化成分测定,研究六堡茶渥堆过程中色泽及滋味成分的变化规律,并探讨了滋味属性的变化与滋味成分之间的相关性及滋味活度值(taste active value,TAV)。结果表明,现代工艺渥堆过程中,六堡茶酸味、苦味上升,涩味、鲜味及咸味下降,色差L值波动变化,a、b值逐渐升高,汤色由黄转变为橙红,游离氨基酸、黄酮、茶多酚、茶叶碱、儿茶素总量、氨基酸组分总量显著下降(P<0.05),可可碱、咖啡碱、没食子酸显著上升(P<0.05),水浸出物含量呈波动变化。游离氨基酸、黄酮、酯型儿茶素、DL-儿茶素(DL-catechin, DL-C)及部分氨基酸组分与酸味和苦味显著负相关,与涩味、鲜味及咸味显著正相关,咖啡碱与没食子酸则相反;茶多酚与涩味显著正相关。咖啡碱、可可碱、没食子酸、DL-C及酯型儿茶素对渥堆过程中六堡茶的滋味具显著贡献(TAV> 1),其中酯型儿茶素与没食子酸是六堡茶渥堆过程滋味品质形成的重要化合物,氨基酸组分对六堡茶滋味无显著贡献。