Fermented sour soup is a unique traditional sour food of the Miao and Dong ethnic groups in China.However,due to the commonly used traditional fermentation,the unstable fluctuation of microbial community often leads t...Fermented sour soup is a unique traditional sour food of the Miao and Dong ethnic groups in China.However,due to the commonly used traditional fermentation,the unstable fluctuation of microbial community often leads to some unpleasant inherent off-flavours in rice sour soup.In this study,the microbial composition and volatile flavour components of off-flavour and normal rice sour soup were examined by high-throughput sequencing and headspace solid-phase microextraction coupled with gas chromatography mass spectrometry.Then,based on Pearson correlation coefficients,the correlations between fungi and bacteria and those between core microorganisms and key volatile flavour components were investigated.The dominant fungal genera included Candida,Dekkera,Pichia,Rhizopus,and Issatchenkia,whereas the dominant bacterial genera included Lactobacillus,Pectinatus,Bifidobacterium,Pseudomonas,and Acetobacter.Compared to normal rice sour soup,off-flavoured rice sour soup contained the significantly increased relative abundance of Candida and the significantly decreased relative abundance of Dkkera.In addition,80 volatile flavour compounds detected in off-flavoured rice sour soup,mainly including esters,acids,and alcohols,were different from those detected in normal rice sour soup.Especially,some substances were only detected in off-flavoured rice sour soup,such as 1-hexanol(68-207μg/kg),butyric acid(20-92μg/kg)and heptanoic acid(12-45μg/kg),which might be the main source of off-flavours.These results provide new ideas and strategies of removing or abating odour from fermented rice sour soup.展开更多
Molybdenum （Mo） is an essential trace element in plant nutrition and physiology. It affects photosynthesis and photosyn- thate accumulation, therefore also affecting fruit quality and nutritional content. This study...Molybdenum （Mo） is an essential trace element in plant nutrition and physiology. It affects photosynthesis and photosyn- thate accumulation, therefore also affecting fruit quality and nutritional content. This study assessed the effects of different sodium molybdate （Na2MoO4） concentrations on strawberry. Five different Mo concentrations were applied in this experi- ment, including 0, 67.5, 135, 168.75, 202.5 g ha-1, respectively. The mineral concentration, including nitrogen （N）, Mo, iron （Fe）, copper （Cu）, and selenium （Se） was assessed in strawberry fruit, as well as chlorophyll content, nutrition quality, taste and aroma. Results showed that net photosynthetic rate （Pn） and chlorophyll content for the strawberry plants increased with an increase in Mo concentration; and the contents of N, Mo, Fe, Cu, total soluble solids （TSS）, titratable acidity （TA）, sweetness, some sugars, organic acids, and some volatile compounds in the fruit all increased, as well. However, the Mo concentration did not significantly affect the concentrations of Se, sucrose, lactic acid, acetic acid, and some aroma compounds. Fruit sprayed with 135 g ha-1 Mo exhibited the highest TSS and sweetness values, as well as the highest N and Fe concentrations among all the treatments. P value and chlorophyll content, fructose, glucose, sorbitol and total sugar contents in fruit supplied with 135 g ha-1 Mo were also higher than that in other treatments. Fruit sprayed with a Mo concentration of 67.5 g ha-1 exhibited significantly higher ascorbic acid （AsA） values than that of control. Ninety-seven volatile compounds were identified in fruit extracted by head-space solid-phase microextraction （HS-SPME） coupled with gas chromatography-mass spectrometry （GC-MS）. Fruits sprayed with 135 g ha-1 Mo had the highest concentrations of six characteristic aroma compounds, including methyl butanoate, y-decalactone, ethyl butanoate, methyl hexanoate, y-do- decalactone, and ethyl caproate.展开更多
An assumption that <em>all</em> the six flavour quarks are attributed to be the components of <em>a same, a</em> <em>common</em> isospin multiplets space named <strong>STS<...An assumption that <em>all</em> the six flavour quarks are attributed to be the components of <em>a same, a</em> <em>common</em> isospin multiplets space named <strong>STS</strong> is proposed. Base on <strong>Pauli Exclusion Principle</strong>, every quark is assigned to different flavour marks in STS. Every flavour quark possesses <em>its own colour spectral line array</em> specially appointed. The collection of colour spectral line arrays of the six flavour quarks constructs together the <strong>CSDF</strong>, Colour Spectrum Diagram of Flavour, further baryons and mesons could be constructed from <strong>CSDF</strong>. STS, Spin Topological Space is a math frame with infinite dimensional matrix representation for spin angular momentum. Flavours is an isospin angular momentum coupling phenomena of the three-colour-quarks.展开更多
Most food flavours have been shown to contain high quantities of cooking salt, followed by flavour enhancers such as sodium glutamate, disodium inosinate, disodium guanylate and hydrogenated oils. Excess of these subs...Most food flavours have been shown to contain high quantities of cooking salt, followed by flavour enhancers such as sodium glutamate, disodium inosinate, disodium guanylate and hydrogenated oils. Excess of these substances is associated with cardiovascular diseases and neurodegenerative disorders. In an effort to reduce the harmful effects of these synthetic substances, this study therefore aimed to formulate organic, nutritious food flavours with good storage stability from less harmful locally available food ingredients. A survey was carried out in 130 households and restaurants in the city of Yaoundé Cameroon, in order to evaluate the level of consumption of industrial flavours. Certain ingredients such as prawns, onions, garlic, white peppers, gingers and salt were used in some households as organic flavours. These ingredients and others were used to prepare 5 organic flavours. Their sensory and nutritional analyses and stability to storage within 90 days were evaluated. The survey revealed that 74.6% of respondents consume industrial flavours, with the cube flavour being the most widely consumed (81%). Two of the 5 organic flavours (434 and 634) had highest scores for general acceptability. The nutritional analyses of the formulae retained (434 and 634), showed that they contained: 11.08% and 10.68% fresh weight for moisture, 47.63% and 43.53% protein, 16.52% and 13.62% lipids, 2.20% and 2.44% fibres, 11.69% and 16.39% carbohydrates. Formula 434, the most accepted, had higher contents of Ca (257.97), Mg (115.91), K (1163), Zn (2.98), Cu (1.02) and Fe (12.43 mg/100g DM) while the second (634) had higher contents of sodium (3270.48) and manganese (2.18 mg/100g). Their water activity during storage in polypropylene bags for 90 days ranged from 0.39 - 0.58 at a temperature of 26.6˚C - 37˚C. The oxidative stability (90 days), determined by the acid and peroxide indices, was 9.18 - 14.13 mg KOH/g and 1.98 - 6.46 meq O2/Kg, respectively indicating good stability for 90 days of storage. The high levels of proteins and minerals in our two products justify their umami taste and can be used as highly nutritional food flavour enhancers to prevent cardiovascular diseases, especially in the elderly.展开更多
A good flavour must taste realistic and natural as well as performing under tough conditions, says Mairi Coia.
In conjunction with texture or mouthfeel, flavour is the most important aspect of food. It is the... A good flavour must taste realistic and natural as well as performing under tough conditions, says Mairi Coia.
In conjunction with texture or mouthfeel, flavour is the most important aspect of food. It is the one thing can bring consumers back to a product again and again - or not, as the case may be. In short, taste is the number one attribute in food and that is why the global fiavour business is worth A5 billion every year as manufacturers strive to make food taste better and fresher for longer.……展开更多
Carotenoid cleavage enzymes isolated from Japanese Camellia sinensis leaves(cultivar Yabukita) were used for investigating the structural patterns of carotenoid cleavage enzymes.Fresh tea leaves were used for the isol...Carotenoid cleavage enzymes isolated from Japanese Camellia sinensis leaves(cultivar Yabukita) were used for investigating the structural patterns of carotenoid cleavage enzymes.Fresh tea leaves were used for the isolation of active enzymes and purified to single band stage in SDS PAGE gels after isoelectric focusing.The specific activity of the carotenoid cleavage enzymes was tested and the active fractions selected for further analysis.The sugar content and the amount of phosphate present in the purified enzymes were elucidated by the following methods:Phosphates were detected by phosphatase assays,fluorescence marker kits and ammoniumheptamolybdate complex measurements after incineration of the samples.Sugars were detected in gels using PAS reagent(periodide acid /Schiff reagent) staining and by GC-MS after hydrolysation of the proteins with trifluoric acid.Phosphorylations as well as glycosylations of the samples could be detected in all cases,thus giving evidence for an increasing phosphorylation level of proteins in Camellia sinensis from spring(1.84 g/mg) to autumn(2.39 g/mg) as well as the presence of at least four different sugars(arabinose,xylose,galactose and ribose).These secondary modifications of the carotenoid cleavage enzymes and their dependency on the harvesting season may well correspond to the changes on the functional level which were detected between spring(Michaelis Constant(K m) =9.45 mol/l) and autumn(K m= 17.16 mol/l) harvests.展开更多
Five groups of douchi were obtained from various origins and species and subjected to high-throughput sequencing and gas chromatography-mass spectrometry to analyse the composition of microorganisms,dou-chi flavouring...Five groups of douchi were obtained from various origins and species and subjected to high-throughput sequencing and gas chromatography-mass spectrometry to analyse the composition of microorganisms,dou-chi flavourings and the correlation between them.Experimental results indicated that the predominant genera would have a significant impact on the flavour substances of douchi.Bacillus,Tetragenococcus,Lactobacillus and Romboutsia dominated the fermentation process in all five groups.Cysteine,arabinose and 2,4-dimethyl-3-pen-tanol were the main volatile flavour substances.Notable regional and climatic variances and peculiarities were observed,and the micro-biological composition of douchi was found to be rich and diversified.The findings of this study may serve as a theoretical foundation for the commercial manufacture of traditional Chinese douchi.展开更多
The demand for plant-based meat analogues is increasing,whereas their sensory properties often fail to satisfy non-vegetarian consumers.To address this issue,this study explored how Lactiplantibacillus plantarum ferme...The demand for plant-based meat analogues is increasing,whereas their sensory properties often fail to satisfy non-vegetarian consumers.To address this issue,this study explored how Lactiplantibacillus plantarum fermen-tation affected the functional and flavour characteristics of texturized soy protein(TSP)through solid-state fermentation.TSP samples were fermented at 50%and 70%moisture content and analyzed at every 24-h in-terval up to 168 h.The analysis focused on microbial growth,functional properties,colour characteristics,and flavour profiles,including volatile compounds and free amino acids.A decrease in pH and an increase in viable cell count to 120 h indicated successful fermentation.The water-holding capacity(WHC)decreased under both moisture conditions.The oil-holding capacity(OHC)remained stable at 0.8 g/g at 50%moisture but signifi-cantly increased at 70%,peaking at 72 h before declining.Fermented TSP at 70%moisture showed higher L*(lightness)and b*(blue to yellow)colour values at 72,120,and 144 h compared to the 50%condition.Twenty-three key aroma compounds were identified,including alcohols,aldehydes,ketones,pyrazines,and furans,with several(e.g.,methyl octanal,pyrazine,2-heptanone,benzaldehyde,and hexanal)contributing to a meat-like aroma.The 50%moisture condition resulted in higher concentrations of umami and sweet-tasting amino acids,whereas the 70%condition maintained a steadier release of free amino acids.Overall,fermentation with Lactiplantibacillus plantarum demonstrated the potential to modify the flavour-related volatile profile and improve key functional properties of TSP,which increases its potential as an appealing plant-based meat alternative ingredient.展开更多
Cultivated lettuce(Lactuca sativa L.),one of the oldest vegetable crops,serves as an important dietary source of fibers,antioxidants,and bioactive compounds.Enhancing the phytonutrient content in lettuce could offer a...Cultivated lettuce(Lactuca sativa L.),one of the oldest vegetable crops,serves as an important dietary source of fibers,antioxidants,and bioactive compounds.Enhancing the phytonutrient content in lettuce could offer a potent dietary strategy for disease prevention.However,few studies have addressed the nuclear genome phylogeny,differential gene expression,and metabolite accumulation diversity among cultivated lettuce and wild Lactuca species in China.This study employed an integrated transcriptomic and quasi-targeted metabolomic approach to investigate gene expression patterns and metabolite profiles across cultivated and wild Chinese Lactuca species.Additionally,we reconstructed the first comprehensive phylogeny of Chinese Lactuca species using single-copy orthologs derived from both transcriptomic and genomic data.Phylogenetic analysis repositioned Lactuca canadensis L.and confirmed the position of the winged-achene clade within Lactuca.These winged-achene accessions,especially Lactuca indica L.,showed elevated expression of photosynthesis-related genes,enhanced photosynthetic capacity,and higher flavonoid concentrations.The cultivated varieties accumulated higher levels of fructose and glucose,contributing to a sweeter taste,whereas the wild species were enriched in secondary metabolites such as flavonoids,associated with a bitter flavour.L.indica and Lactuca tatarica(L.)C.A.Mey.are proposed as valuable genetic resources for enhancing nutritional quality,disease resistance,and stress tolerance in lettuce breeding.These findings provide fundamental insights into the divergence in photosynthetic performance and flavour-related metabolites among Chinese Lactuca species,and identify promising candidate genes and beneficial metabolites from wild lineages that could be utilized to improve yield,stress resistance,and disease resilience in cultivated lettuce.展开更多
The ever-growing consumer demand for natural food ingredients has stimulated the flavour industries to look for sources of natural flavourings.Seafood is rich in precursors of umami peptides,amino acids,and flavour 5...The ever-growing consumer demand for natural food ingredients has stimulated the flavour industries to look for sources of natural flavourings.Seafood is rich in precursors of umami peptides,amino acids,and flavour 5′-nucleotides,which can serve as worthy ingredients for the production of natural flavourings.This review provides an overview of conventional and innovative techniques used for the production of natural seafood flavourings.It was also an insight into the formation mechanisms of flavour compounds underlying the sensory characteristics of seafood flavourings.Also,an overview of food applications of natural seafood flavourings was discussed.The research outcomes showed that microbial,enzymatic,and thermal processes and their combination are major conventional processes for the bio-generation of natural seafood flavourings.Ultrasound,microwave,pressurised carbon dioxide,hot-compressed water and,subcritical water processes are key innovative techniques used for the production of natural seafood flavourings.The key compounds underlying the sensory quality of seafood flavouring are synthesised from nucleotides,amino acids,fatty acids metabolisms as well as Maillard reaction.Seafood flavourings are used to improve the sensory characteristics of various food preparations.展开更多
The rice polishing ratio has an essential effect on the flavour quality of sake.This study comprehensively describes the relationship between the polishing ratio and sake quality.As the polishing ratio decreased,the o...The rice polishing ratio has an essential effect on the flavour quality of sake.This study comprehensively describes the relationship between the polishing ratio and sake quality.As the polishing ratio decreased,the outer layer of rice suffered more structural damage.Moisture was more readily accessible to the interior of the rice.The pasting properties of the rice were significantly improved,resulting in a more complete fermentation.The above results decreased the aldehydes and ketones content in steamed rice from 65.61μg/mL to 51.82μg/mL,leading to a reduction of off-flavours caused by their over-accumulation.The polishing ratio also had a significant effect on sake flavour.A lower polishing ratio reduced higher alcohols,like 3-methyl-1-butanol.The flavour perceived in the sake changed from herbal to alcohol aroma.The final results showed that the flavour compounds in the sake were highest when the polishing ratio was 50%.Among them,the contents of key flavour compounds such as ethyl acetate and ethyl caproate were peaked.And the content of bitter amino acids was low.Therefore,rice with a polishing ratio of 50%is the most suitable for sake brewing.The results of this study provide a scientific basis for the accuracy of rice processing in sake brewing.展开更多
1.(选择性必修一P2)Sometimes the smell alone can do the trick(奏效,起作用,达到目的),not to mention the lovely creamy flavour, which works like a time machine immediately transporting me back to my sunny childhood.
This study investigated the impact of protease pre-treatment of coconut kernels(CK)on the flavour modification of the resultant coconut oil(CO).The effects of four proteases(Alcalase,Flavourzyme,Neutrase and Protamex)...This study investigated the impact of protease pre-treatment of coconut kernels(CK)on the flavour modification of the resultant coconut oil(CO).The effects of four proteases(Alcalase,Flavourzyme,Neutrase and Protamex)pre-treatment on volatile modification of CO was screened and Flavourzyme was chosen for detailed investigation.Flavourzyme was found to release not only free amino acids but also simple sugars,increasing the contents of soluble sugars and free amino acids in CK by 1.5-and 1.3-fold,respectively,compared to the untreated control.The increments of these thermal reaction precursors accelerated the Maillard reaction and caramelisation during kernel roasting,resulting in the rise of volatile compounds in obtained CO by 2.1-,1.4-and 1.4-fold with light,medium and dark kernel roastings,respectively.Besides,volatile profiles of CO extracted from Flavourzyme treated CK differed significantly from those of the untreated control by having increments in furans and pyranones but decreases in furanones and pyrazines.Principal component analysis(PCA)revealed that flavour of CO from Flavourzyme treated CK upon roasting was highly correlated with furans and pyranones.Pre-treatment by Flavourzyme of CK prior to oil production is a potential strategy to modulate and enhance the flavour of obtained CO and hence to widen its application in food industry.展开更多
Heavy flavour physics provides excellent opportunities to indirectly search for new physics at very high energy scales and to study hadron properties for deep understanding of the strong interaction.The LHCb experimen...Heavy flavour physics provides excellent opportunities to indirectly search for new physics at very high energy scales and to study hadron properties for deep understanding of the strong interaction.The LHCb experiment has been playing a leading role in the study of heavy flavour physics since the start of the LHC operations about ten years ago,and made a range of high-precision measurements and unexpected discoveries,which may have far-reaching implications on the field of particle physics.This review highlights a selection of the most influential physics results on CP violation,rare decays,and heavy flavour production and spectroscopy obtained by LHCb using the data collected during the first two operation periods of the LHC.The upgrade plan of LHCb and the physics prospects are also briefly discussed.展开更多
基金funded by National Natural Science Foundation of China(32360568)Science and Technology Plan Project of Guizhou Province(Qian Ke He Chengguo[2023]Zhongda 011)+2 种基金Guizhou Basic Research Program(Natural Science)Mianshang Project(Qiankehe Basic MS[2025]671)Guizhou Provincial Association of Science and Technology Youth Science and Technology Talent Support Project(GASTYESS202407)Guizhou University Natural Science Specialized(Te Gang)Scientific Research Fund(Gui Da Te Gang He Zi(2022)39).
文摘Fermented sour soup is a unique traditional sour food of the Miao and Dong ethnic groups in China.However,due to the commonly used traditional fermentation,the unstable fluctuation of microbial community often leads to some unpleasant inherent off-flavours in rice sour soup.In this study,the microbial composition and volatile flavour components of off-flavour and normal rice sour soup were examined by high-throughput sequencing and headspace solid-phase microextraction coupled with gas chromatography mass spectrometry.Then,based on Pearson correlation coefficients,the correlations between fungi and bacteria and those between core microorganisms and key volatile flavour components were investigated.The dominant fungal genera included Candida,Dekkera,Pichia,Rhizopus,and Issatchenkia,whereas the dominant bacterial genera included Lactobacillus,Pectinatus,Bifidobacterium,Pseudomonas,and Acetobacter.Compared to normal rice sour soup,off-flavoured rice sour soup contained the significantly increased relative abundance of Candida and the significantly decreased relative abundance of Dkkera.In addition,80 volatile flavour compounds detected in off-flavoured rice sour soup,mainly including esters,acids,and alcohols,were different from those detected in normal rice sour soup.Especially,some substances were only detected in off-flavoured rice sour soup,such as 1-hexanol(68-207μg/kg),butyric acid(20-92μg/kg)and heptanoic acid(12-45μg/kg),which might be the main source of off-flavours.These results provide new ideas and strategies of removing or abating odour from fermented rice sour soup.
基金supported by grants from the Shandong Province Modern Agricultural Industry Technology System Innovation Team-Cultivation, Soil and Fertilizer, China (SDAIT-06-01)
文摘Molybdenum （Mo） is an essential trace element in plant nutrition and physiology. It affects photosynthesis and photosyn- thate accumulation, therefore also affecting fruit quality and nutritional content. This study assessed the effects of different sodium molybdate （Na2MoO4） concentrations on strawberry. Five different Mo concentrations were applied in this experi- ment, including 0, 67.5, 135, 168.75, 202.5 g ha-1, respectively. The mineral concentration, including nitrogen （N）, Mo, iron （Fe）, copper （Cu）, and selenium （Se） was assessed in strawberry fruit, as well as chlorophyll content, nutrition quality, taste and aroma. Results showed that net photosynthetic rate （Pn） and chlorophyll content for the strawberry plants increased with an increase in Mo concentration; and the contents of N, Mo, Fe, Cu, total soluble solids （TSS）, titratable acidity （TA）, sweetness, some sugars, organic acids, and some volatile compounds in the fruit all increased, as well. However, the Mo concentration did not significantly affect the concentrations of Se, sucrose, lactic acid, acetic acid, and some aroma compounds. Fruit sprayed with 135 g ha-1 Mo exhibited the highest TSS and sweetness values, as well as the highest N and Fe concentrations among all the treatments. P value and chlorophyll content, fructose, glucose, sorbitol and total sugar contents in fruit supplied with 135 g ha-1 Mo were also higher than that in other treatments. Fruit sprayed with a Mo concentration of 67.5 g ha-1 exhibited significantly higher ascorbic acid （AsA） values than that of control. Ninety-seven volatile compounds were identified in fruit extracted by head-space solid-phase microextraction （HS-SPME） coupled with gas chromatography-mass spectrometry （GC-MS）. Fruits sprayed with 135 g ha-1 Mo had the highest concentrations of six characteristic aroma compounds, including methyl butanoate, y-decalactone, ethyl butanoate, methyl hexanoate, y-do- decalactone, and ethyl caproate.
文摘An assumption that <em>all</em> the six flavour quarks are attributed to be the components of <em>a same, a</em> <em>common</em> isospin multiplets space named <strong>STS</strong> is proposed. Base on <strong>Pauli Exclusion Principle</strong>, every quark is assigned to different flavour marks in STS. Every flavour quark possesses <em>its own colour spectral line array</em> specially appointed. The collection of colour spectral line arrays of the six flavour quarks constructs together the <strong>CSDF</strong>, Colour Spectrum Diagram of Flavour, further baryons and mesons could be constructed from <strong>CSDF</strong>. STS, Spin Topological Space is a math frame with infinite dimensional matrix representation for spin angular momentum. Flavours is an isospin angular momentum coupling phenomena of the three-colour-quarks.
文摘Most food flavours have been shown to contain high quantities of cooking salt, followed by flavour enhancers such as sodium glutamate, disodium inosinate, disodium guanylate and hydrogenated oils. Excess of these substances is associated with cardiovascular diseases and neurodegenerative disorders. In an effort to reduce the harmful effects of these synthetic substances, this study therefore aimed to formulate organic, nutritious food flavours with good storage stability from less harmful locally available food ingredients. A survey was carried out in 130 households and restaurants in the city of Yaoundé Cameroon, in order to evaluate the level of consumption of industrial flavours. Certain ingredients such as prawns, onions, garlic, white peppers, gingers and salt were used in some households as organic flavours. These ingredients and others were used to prepare 5 organic flavours. Their sensory and nutritional analyses and stability to storage within 90 days were evaluated. The survey revealed that 74.6% of respondents consume industrial flavours, with the cube flavour being the most widely consumed (81%). Two of the 5 organic flavours (434 and 634) had highest scores for general acceptability. The nutritional analyses of the formulae retained (434 and 634), showed that they contained: 11.08% and 10.68% fresh weight for moisture, 47.63% and 43.53% protein, 16.52% and 13.62% lipids, 2.20% and 2.44% fibres, 11.69% and 16.39% carbohydrates. Formula 434, the most accepted, had higher contents of Ca (257.97), Mg (115.91), K (1163), Zn (2.98), Cu (1.02) and Fe (12.43 mg/100g DM) while the second (634) had higher contents of sodium (3270.48) and manganese (2.18 mg/100g). Their water activity during storage in polypropylene bags for 90 days ranged from 0.39 - 0.58 at a temperature of 26.6˚C - 37˚C. The oxidative stability (90 days), determined by the acid and peroxide indices, was 9.18 - 14.13 mg KOH/g and 1.98 - 6.46 meq O2/Kg, respectively indicating good stability for 90 days of storage. The high levels of proteins and minerals in our two products justify their umami taste and can be used as highly nutritional food flavour enhancers to prevent cardiovascular diseases, especially in the elderly.
文摘 A good flavour must taste realistic and natural as well as performing under tough conditions, says Mairi Coia.
In conjunction with texture or mouthfeel, flavour is the most important aspect of food. It is the one thing can bring consumers back to a product again and again - or not, as the case may be. In short, taste is the number one attribute in food and that is why the global fiavour business is worth A5 billion every year as manufacturers strive to make food taste better and fresher for longer.……
文摘Carotenoid cleavage enzymes isolated from Japanese Camellia sinensis leaves(cultivar Yabukita) were used for investigating the structural patterns of carotenoid cleavage enzymes.Fresh tea leaves were used for the isolation of active enzymes and purified to single band stage in SDS PAGE gels after isoelectric focusing.The specific activity of the carotenoid cleavage enzymes was tested and the active fractions selected for further analysis.The sugar content and the amount of phosphate present in the purified enzymes were elucidated by the following methods:Phosphates were detected by phosphatase assays,fluorescence marker kits and ammoniumheptamolybdate complex measurements after incineration of the samples.Sugars were detected in gels using PAS reagent(periodide acid /Schiff reagent) staining and by GC-MS after hydrolysation of the proteins with trifluoric acid.Phosphorylations as well as glycosylations of the samples could be detected in all cases,thus giving evidence for an increasing phosphorylation level of proteins in Camellia sinensis from spring(1.84 g/mg) to autumn(2.39 g/mg) as well as the presence of at least four different sugars(arabinose,xylose,galactose and ribose).These secondary modifications of the carotenoid cleavage enzymes and their dependency on the harvesting season may well correspond to the changes on the functional level which were detected between spring(Michaelis Constant(K m) =9.45 mol/l) and autumn(K m= 17.16 mol/l) harvests.
基金supported by the National KeyR&D Program of China(2021YFD2100100).
文摘Five groups of douchi were obtained from various origins and species and subjected to high-throughput sequencing and gas chromatography-mass spectrometry to analyse the composition of microorganisms,dou-chi flavourings and the correlation between them.Experimental results indicated that the predominant genera would have a significant impact on the flavour substances of douchi.Bacillus,Tetragenococcus,Lactobacillus and Romboutsia dominated the fermentation process in all five groups.Cysteine,arabinose and 2,4-dimethyl-3-pen-tanol were the main volatile flavour substances.Notable regional and climatic variances and peculiarities were observed,and the micro-biological composition of douchi was found to be rich and diversified.The findings of this study may serve as a theoretical foundation for the commercial manufacture of traditional Chinese douchi.
文摘The demand for plant-based meat analogues is increasing,whereas their sensory properties often fail to satisfy non-vegetarian consumers.To address this issue,this study explored how Lactiplantibacillus plantarum fermen-tation affected the functional and flavour characteristics of texturized soy protein(TSP)through solid-state fermentation.TSP samples were fermented at 50%and 70%moisture content and analyzed at every 24-h in-terval up to 168 h.The analysis focused on microbial growth,functional properties,colour characteristics,and flavour profiles,including volatile compounds and free amino acids.A decrease in pH and an increase in viable cell count to 120 h indicated successful fermentation.The water-holding capacity(WHC)decreased under both moisture conditions.The oil-holding capacity(OHC)remained stable at 0.8 g/g at 50%moisture but signifi-cantly increased at 70%,peaking at 72 h before declining.Fermented TSP at 70%moisture showed higher L*(lightness)and b*(blue to yellow)colour values at 72,120,and 144 h compared to the 50%condition.Twenty-three key aroma compounds were identified,including alcohols,aldehydes,ketones,pyrazines,and furans,with several(e.g.,methyl octanal,pyrazine,2-heptanone,benzaldehyde,and hexanal)contributing to a meat-like aroma.The 50%moisture condition resulted in higher concentrations of umami and sweet-tasting amino acids,whereas the 70%condition maintained a steadier release of free amino acids.Overall,fermentation with Lactiplantibacillus plantarum demonstrated the potential to modify the flavour-related volatile profile and improve key functional properties of TSP,which increases its potential as an appealing plant-based meat alternative ingredient.
基金supported by the National Natural Science Foundation of China(31700175)Key Research and Development Project of Henan Province(221111110800)+3 种基金Key R&D and Promotion Projects in Henan Province(Grant Number:242102111146)Fostering Project for Young Teachers of Zhengzhou University(JC21343014)the Postdoctoral Fellowship Program of CPSF(GZC20232451)Henan Training Pro-gram of Innovation and Entrepreneurship for Undergraduates(S202510459200).
文摘Cultivated lettuce(Lactuca sativa L.),one of the oldest vegetable crops,serves as an important dietary source of fibers,antioxidants,and bioactive compounds.Enhancing the phytonutrient content in lettuce could offer a potent dietary strategy for disease prevention.However,few studies have addressed the nuclear genome phylogeny,differential gene expression,and metabolite accumulation diversity among cultivated lettuce and wild Lactuca species in China.This study employed an integrated transcriptomic and quasi-targeted metabolomic approach to investigate gene expression patterns and metabolite profiles across cultivated and wild Chinese Lactuca species.Additionally,we reconstructed the first comprehensive phylogeny of Chinese Lactuca species using single-copy orthologs derived from both transcriptomic and genomic data.Phylogenetic analysis repositioned Lactuca canadensis L.and confirmed the position of the winged-achene clade within Lactuca.These winged-achene accessions,especially Lactuca indica L.,showed elevated expression of photosynthesis-related genes,enhanced photosynthetic capacity,and higher flavonoid concentrations.The cultivated varieties accumulated higher levels of fructose and glucose,contributing to a sweeter taste,whereas the wild species were enriched in secondary metabolites such as flavonoids,associated with a bitter flavour.L.indica and Lactuca tatarica(L.)C.A.Mey.are proposed as valuable genetic resources for enhancing nutritional quality,disease resistance,and stress tolerance in lettuce breeding.These findings provide fundamental insights into the divergence in photosynthetic performance and flavour-related metabolites among Chinese Lactuca species,and identify promising candidate genes and beneficial metabolites from wild lineages that could be utilized to improve yield,stress resistance,and disease resilience in cultivated lettuce.
基金The German Ministry of Education and Research who made this grant award possible through UNESCO-TWAS under grant number 4500474951.
文摘The ever-growing consumer demand for natural food ingredients has stimulated the flavour industries to look for sources of natural flavourings.Seafood is rich in precursors of umami peptides,amino acids,and flavour 5′-nucleotides,which can serve as worthy ingredients for the production of natural flavourings.This review provides an overview of conventional and innovative techniques used for the production of natural seafood flavourings.It was also an insight into the formation mechanisms of flavour compounds underlying the sensory characteristics of seafood flavourings.Also,an overview of food applications of natural seafood flavourings was discussed.The research outcomes showed that microbial,enzymatic,and thermal processes and their combination are major conventional processes for the bio-generation of natural seafood flavourings.Ultrasound,microwave,pressurised carbon dioxide,hot-compressed water and,subcritical water processes are key innovative techniques used for the production of natural seafood flavourings.The key compounds underlying the sensory quality of seafood flavouring are synthesised from nucleotides,amino acids,fatty acids metabolisms as well as Maillard reaction.Seafood flavourings are used to improve the sensory characteristics of various food preparations.
基金supported by the National Natural Science Foundation of China(No.32072263)Fundamental Research Funds for the Central Universities(JUSRP622010,JUSRP124006)+2 种基金National Natural Science Foundation of Jiangsu Province(BK20241612)Wuxi Science and Technology Development Fund Project(K20231028)Key R&D Program of Jiangsu Province(BE2019395,BE2021359-2).
文摘The rice polishing ratio has an essential effect on the flavour quality of sake.This study comprehensively describes the relationship between the polishing ratio and sake quality.As the polishing ratio decreased,the outer layer of rice suffered more structural damage.Moisture was more readily accessible to the interior of the rice.The pasting properties of the rice were significantly improved,resulting in a more complete fermentation.The above results decreased the aldehydes and ketones content in steamed rice from 65.61μg/mL to 51.82μg/mL,leading to a reduction of off-flavours caused by their over-accumulation.The polishing ratio also had a significant effect on sake flavour.A lower polishing ratio reduced higher alcohols,like 3-methyl-1-butanol.The flavour perceived in the sake changed from herbal to alcohol aroma.The final results showed that the flavour compounds in the sake were highest when the polishing ratio was 50%.Among them,the contents of key flavour compounds such as ethyl acetate and ethyl caproate were peaked.And the content of bitter amino acids was low.Therefore,rice with a polishing ratio of 50%is the most suitable for sake brewing.The results of this study provide a scientific basis for the accuracy of rice processing in sake brewing.
文摘1.(选择性必修一P2)Sometimes the smell alone can do the trick(奏效,起作用,达到目的),not to mention the lovely creamy flavour, which works like a time machine immediately transporting me back to my sunny childhood.
文摘This study investigated the impact of protease pre-treatment of coconut kernels(CK)on the flavour modification of the resultant coconut oil(CO).The effects of four proteases(Alcalase,Flavourzyme,Neutrase and Protamex)pre-treatment on volatile modification of CO was screened and Flavourzyme was chosen for detailed investigation.Flavourzyme was found to release not only free amino acids but also simple sugars,increasing the contents of soluble sugars and free amino acids in CK by 1.5-and 1.3-fold,respectively,compared to the untreated control.The increments of these thermal reaction precursors accelerated the Maillard reaction and caramelisation during kernel roasting,resulting in the rise of volatile compounds in obtained CO by 2.1-,1.4-and 1.4-fold with light,medium and dark kernel roastings,respectively.Besides,volatile profiles of CO extracted from Flavourzyme treated CK differed significantly from those of the untreated control by having increments in furans and pyranones but decreases in furanones and pyrazines.Principal component analysis(PCA)revealed that flavour of CO from Flavourzyme treated CK upon roasting was highly correlated with furans and pyranones.Pre-treatment by Flavourzyme of CK prior to oil production is a potential strategy to modulate and enhance the flavour of obtained CO and hence to widen its application in food industry.
基金supported by the National Key Research and Development Program of China under Grant Nos.2017YFA0402100 and 2022YFA1601900the National Natural Science Foundation of China(NSFC)under Grant Nos.11435003,11575091,11575094,11925504,11975015,12175245,12175005,11705209,12205312,12275100,11961141015 and 12061141007Chinese Academy of Sciences,Fundamental Research Funds for the Central Universities,Peking University Funds for the New Faculty Startup program.We thank Franz Muheim and Niels Tuning for suggestions in improving the draft.
文摘Heavy flavour physics provides excellent opportunities to indirectly search for new physics at very high energy scales and to study hadron properties for deep understanding of the strong interaction.The LHCb experiment has been playing a leading role in the study of heavy flavour physics since the start of the LHC operations about ten years ago,and made a range of high-precision measurements and unexpected discoveries,which may have far-reaching implications on the field of particle physics.This review highlights a selection of the most influential physics results on CP violation,rare decays,and heavy flavour production and spectroscopy obtained by LHCb using the data collected during the first two operation periods of the LHC.The upgrade plan of LHCb and the physics prospects are also briefly discussed.
