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Literature review of unsymmetric monosulphides compounds

[196Z] Ayrey, Barnard, and Woodbridge. 2089 401. The Oxidation of

Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

if the double bond is separated from the alkoxy radical by a methylene group (allylic system), a greater variety of compounds can be formed (scheme 3); e.. detectable odor thresholds of selected lipid oxidation compounds in a meat model system.., carbonyl compounds derived from lipid oxidation), and even the matrix can influence the profile of the resulting aroma compounds. review provides an update on our understanding of the chemical reactions (lipid oxidation, strecker and maillard reactions, thiamine degradation) and a discussion of the principal aroma compounds derived from those reaction or other sources in cooked meat, mainly focused on ruminant species. among the carbonyl compounds derived from lipid oxidation, (e)-nonenal and (e,e)-2,4-decadienal stand out in both species. most important carbonyl compounds * in beef and sheep/lamb meat identified using gc-o.. indoles, phenols, terpenes and lactonesthe concentrations of indole and 3-methylindole (skatole) in sheep fat can be associated with unpleasant aromas [44,76], although these compounds do not appear to be important in beef [93]. it seems that for producing furanthiols and other impact aroma compounds, a higher concentration of available phosphates are needed [65]. those and other studies show that the distinction in the meat aroma from different animal species is not necessarily due to an aroma compound profile qualitatively different (few compounds are present only in one species), and therefore, the sensory discrimination could be rather be due to differences in the quantity of a particular compound with implication in the perceived aroma.* 1,2,3, and 4 represents the hierarchy of the carbonyl compounds within each reference; a after cooking; b cooked and stored 48 h at 4 °c; c sd: solvent distillation, dhs: dynamic headspace; shs static headspace, dc: during cooking, ac: after cooking; d da: aroma extract dilution analysis, ca: aroma extract concentration analysis, df: detection frequency; mf: modified frequency; e lo: lipid oxidation, sr: strecker reaction, mr: maillard reaction, td: thiamine degradation, b: bacterial action, cd: β-carotene degradation.. fat deposition, fatty acid composition and meat quality: a review. present review provides an updated overview of the chemical mechanisms and a discussion of the principal aroma compounds derived from those reaction or other sources in cooked meat, mainly focused in ruminant species.

Molecules | Free Full-Text | The Development of Aromas in

although, if the fat is subjected to prolonged heating, disagreeable aroma compounds can be created [15].. some novel meatlike aroma compounds from the reactions of alkanediones with hydrogen sulfide and furanthiols. 2-methyl-3-furanthiol and 2/3-mercapto-3/2-pentanone are examples of important volatiles that can arise from the degradation of thiamine [49]; however, these sulphur compounds can be derived from other pathways, e. analysis of sulfur compounds from the in-oven roast beef aroma by comprehensive two-dimensional gas chromatography. deformation history of the area put forward after the 2015 season has been reviewed, and this succession is suggested: a nw-vergent d1 north of the prøven igneous complex and channel flow in an orogen-scale nw-se compression; d2 is characterised by e-w extension near archean orthogneiss at kangiusap kuua and distal compression further to the e (previously assigned to d4); d3 is represented by structuring of the kigarsima nappe overprinting all the other structures on karrat island and the peninsula to the se (formerly described as d2); and, finally, a nw-se compression, documented in the maarmorilik area, is now relabeled as d4 (previously assigned to d3). the impact of variations in flavour compounds on meat acceptability: a comparison of japanese and new zealand consumers. the formation of those compounds is favored by some pasture diets and might be involved as well in the aroma of the ruminant meat [39]. however, comparing raw and cooked from sheep meat, no differences in the hierarchy of the carbonyl compounds is observed ([6], table 3), so it seems that lipid oxidation take place before cooking and thermal lipid oxidation is of minor importance, or that interactions between reactions took place while cooking. of impact aromatic compounds in meat from the maillard reaction. although, those compounds are individually present in low concentrations (relative to their detection thresholds), collectively, they might contribute with some aromatic notes to the meat. formation of aroma-active strecker-aldehydes by a direct oxidative degradation of amadori compounds. volatile compounds of lipid origin dominate quantitatively the others in boiled, roasted or grilled pork, under mild temperature conditions [32], and that might be the case for ruminant meat.

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other study, with beef/vegetable based gravy versus pork/vegetable based gravy indicated that most of the aroma compounds were identical, although different in aroma importance. adipose tissue can be a reservoir of aroma compounds (e. conclusionslipid oxidation, maillard and strecker reactions are the main reactions potentially responsible for the odorous compounds known to occur in cooked meat, whereas the degradation of thiamin seems to play a minor role. relationship between odour-active compounds and flavour perception in meat from lambs fed different diets. on the other hand, the table also allows analyzing that cooking method, the way in which the volatile compounds are extracted, and the type of gc-o analysis performed can affect which of the aromas are detected as important, and should be taken into account when comparing data from different studies. finally, other not lipid-derived volatile compounds, can hinder the detection of those compounds derived from lipid oxidation [33]. primary reactions involved in the formation of aroma compounds in cooked meat are the oxidation of lipids, the degradation of thiamine, the strecker reaction and the maillard reaction. thus, it can affect water-holding capacity, texture, and nutritional value, and promote the formation of toxic substances [10,11], but those aspects are not further discussed in the present review.. the effect of cooking conditions on the formation of volatile heterocyclic compounds in pork. numerous compounds have been proposed (sulphur compounds, pyrazines, aldehydes, ketones, phenols, organic acids, among others) as responsible for the aroma of the meat. review of published work on the physics and modelling of flashing flows is presented. aroma compounds of cooked meatthrough the chemical reactions mentioned and their interactions, many types of aromatic compounds (e.

Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

Spectroscopic studies of iron sulfide formation and phase relations

this kind of review is necessary and helpful for further understanding and investigation of flashing flows in more detail. maillard reactionthe maillard reaction is key in the formation of most of the aroma compounds recognized in cooked meat [79]. other aromatic compounds can come from the metabolism of the rumen, the animal itself, or directly from the food consumed by the animal, all of which accumulate in the fatty tissue in meat. a study performed with meat from 6-year old sheep, the amount of lipid oxidation derived aroma compounds present in raw were similar than in pressure-cooked meat [6], and therefore, differences in the release of compounds from the meat matrix might explain the sensorial distinction between raw and cooked meat aroma. finished on angelica archangelica, rather than traditional pasture produced meat that had a different aroma and flavour (‘spicy’), mainly, due to a higher concentrations of terpenoid compounds such as β-phellandrene and α-pinene [100]. aromatic phenolic compounds in the meat of ruminants can come directly from those present in plants or they are a product of the microbial fermentation of lignin or diterpenes [94]. 13 outlines the formation of important aroma compounds in meat that are derived from the maillard reaction. it is noteworthy that those compounds not only evoke rancid odours, they also evoke meaty odours [59,63,64]. these findings provide key information for future use of ni(co)-mn-sb-based heusler compounds in, e. the profile of the fatty acids can influence the types of aroma compounds derived, consequently, differences in fatty acid composition between species (table 2), could explain in part the species-specific aroma. oxidation can influence the formation of heterocyclic compounds, including the pyrazines. those compounds were not detected neither in the volatile analysis performed with goat meat [91,92].

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in ruminants, precursors or aroma compounds can also arise from ruminal microorganisms or by a direct transfer from feeds [8]. compounds detected by gc-o in the aroma of beef and lamb. thiamine degradationmodel systems have shown that thermally degraded thiamine (vitamin b1) produces a multitude of sulphur compounds, e., the amadori/heyns products are degraded, which leads to dehydrations and deaminations that produce carbonyl compounds such as deoxysones and deoxyreductones. maturation time of the meat and the animal’s diet can affect the natural concentrations of reducing sugars and free amino acids in muscle [115,116]; however, the differences in the volatile compounds in grilled meat are more closely associated with the effect of diet on the fatty acid composition of meat than with the effect on soluble aromatic precursors [117]. the derivatives of α-linolenic acid can reduce the concentrations of the compounds that give meat its typical aroma (thiophenes, furans) through their interactions with the products of the maillard reaction, and they are more reactive than the products of the degradation of n-6 and n-9 fatty acids [83]. the aforementioned authors, using different methods of extraction and analysis to identify potentially important odorant compounds and after performing a sensorial evaluation of the aromas in meat models, concluded that the increase of hexanal and trans-4,5-epoxy-(e)-2-decenal and the reduction of two furanones (sotolon and furaneol) were the causes of the changes in the aroma quality of reheated meat. characterization of the key aroma compounds in beef and pork vegetable gravies á la chef by application of the aroma extract dilution analysis. inhibition, addition or synergism might occur between the odorants that have been capable to release from the matrix; hence, more reconstitution studies are necessary to conduct to fully understand the role of the individual compounds in the overall aroma perception and acceptability. review provides an update on our understanding of the chemical reactions (lipid oxidation, Strecker and Maillard reactions, thiamine degradation) and a discussion of the principal aroma compounds derived from those reaction or other sources in cooked meat, mainly focused on ruminant species.. changes in the content of lipid autoxidation and sulfur-containing compounds in cooked beef during storage. the influence of grazing time on angelica archangelica on volatile compounds and sensory quality of meat from pasture lambs; icomst: copenhague, denmark, 2009.

Current status of sulphur vulcanization and devulcanization chemistry

. sulphur compoundsundoubtedly, sulphur compounds play a fundamental role in the aroma of meat because they have very low detection thresholds [49]. ovine meat has a reducing-sugar content that is lower than the concentrations in meat from other species [112], so that the addition of a minimal amount of sugar would probably increase the concentrations of pyrazines and other compounds derived from the maillard reaction. chains that have one or more double bonds can produce analogous compounds that contain double bonds, although the ultimate number of products is greater because the unsaturated chains can be further oxidized [18]., new odour active compounds are still being discovered, and further studies are necessary to quantify them.[4] jessica hermet, francois bottin, guilhem dezanneau, and gregory geneste physical review b 2012, 85, 205137.. sheepmeat flavor and the effect of different feeding systems: a review.. dietary manipulation of fatty acid composition in lamb meat and its effect on the volatile aroma compounds of grilled lamb. degradation is particularly important since produces intermediates implicated in the formation of very active compounds in meat flavour [18]. gas chromatographic-olfactometric characterisation of headspace and mouthspace key aroma compounds in fresh and frozen lamb meat. therefore, is highly relevant to understand the origin of the aroma compounds. identification of volatile flavour compounds with high aroma values from cooked beef. beef models, an increase in ph promoted the formation of heterocyclic compounds, e.

Molecules | Free Full-Text | The Development of Aromas in

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the outstanding aroma compounds detected by gc-o studies in meat from beef and lamb/sheep meat and their probable origin and overall role in the cooked meat are presented. the precursors formed from 1-deoxysones can interact with the products of the strecker reaction to produce numerous aromatic compounds (e. the last two compounds are responsible for desirable flavours in the meat, which might interact with lipid radicals. species differ in the importance of skatole, perhaps because of differences in concentrations [76] or because skatole acts synergistically with other aromatic compounds in sheep meat [93]. while some aspects of the process are understood, many others remain unclear, particularly those related to the formation of some compounds in complex real models such as meat [13].. castration and slaughter age effects on panel assessment and aroma compounds of the “mestiço” goat meat. identification and formation of some selected sulfur-containing flavor compounds in various meat model systems. gas chromatography-olfactometry analysis of the volatile compounds of two commercial irish beef meats. in grilled meat that is ‘well done’ almost 80 % of the volatile compounds are pyrazines. of impact aromatic compounds in meat from the maillard reaction. however, the aldehydes and other compounds derived from lipid oxidation form part of the typical aroma profile of the meat without deterioration of the flavour. mass spectrometry analysis of volatile compounds in raw meat for the authentication of the feeding background of farm animals.

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compounds detected by gc-o in the aroma of beef and lamb. in the case of ruminant meat, several aroma compounds or precursors can be formed in the rumen, such as 12-trimethyl-decanal, indoles or branched chain fatty acids, but their actual role in the overall cooked meat aroma is still controversial. in this progress report, the recent experimental and theoretical work related to the characterization of mirror twin boundaries is reviewed. α-aminocarbonyl compounds can be derived from the strecker reaction between an amino acid and α-carbonyl compounds, where the latter can be a product of the maillard reaction or the caramelization of carbohydrates. in the mentioned study, total compounds present were analysed and not only the ones released from the matrix, and therefore, the actual aroma hierarchy found can change (more discussion is presented in section 2. aroma compounds derived from lipid oxidationalthough only a small proportion of the fatty acids in food are oxidized, it can be sufficient to alter significantly the flavour [15].., thiazoles and pyrazines, whereas lower ph favored the formation of furanthiols and derived compounds [106].. a review of maillard reaction in food and implications to kinetic modelling. identification of volatile flavor compounds with high aroma values from shallow-fried beef. seriesnumber of carbonsmajor compoundsaldehydes3–17hexanalheptanaloctanalmethyl ketones3–172-heptanone2-nonanone2-decanoneacids2–12hexanoic acidpentanoic acid butanoic acidhydrocarbons4–17heptadecanenonanedecaneγ-lactones4–14γ-butyrolactoneγ-pentalactoneγ-heptalactonealcohols4–14octanolnonanoldecanol. [3] emile b´ evillon, guilhem dezanneau, and gr´ egory geneste, physical review b 2011, 83, 174101. dicarbonyl compounds, furfurals and furanones, in addition to the strecker aldehydes, ammonia, and hydrogen sulphide, can influence the aroma of cooked meat by themselves, but also are key intermediaries to other important components in the flavour of meat [18].

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some of those compounds at low concentrations in themselves smell like cooked meat and some of them contribute significantly to the aroma of cooked meat [48].. aroma compounds of fresh milk from new zealand cows fed different diets. odour-active compounds are present in the raw meat, such as 4-ethyloctanoic acid (mutton-smell) in sheep and are not much affected by cooking [6], however it is generally accepted that the aroma of meat is mainly developed upon heating treatment, where thiamine (vitamin b1), glycogen, glycoproteins, nucleotides, nucleosides, free sugars/phosphate, amino acids, peptides, amines, organic acids and lipids are the precursors. on the other hand, a type of phospholipid that is part of cell membranes, plasmalogens, can contain an aldehyde (12-methyltridecanal) formed by rumen microorganisms [37,38], which might be one of the main compounds that contribute to the aroma of boiled or stewed beef (table 3). most important carbonyl compounds * in beef and sheep/lamb meat identified using gc-o. in the same study, using gc-olfactometry, six of those compounds were considered to have aromatic impact. we show that depending on the incident angle, ion type and energy, sulfur atoms can be sputtered away predominantly from the top or bottom layers, creating unique opportunities for engineering mixed mosx compounds where x are chemical elements from group v or vii. the source of aromatic compounds is essential to understanding, controlling, and improving the quality of meat products. compounds formed from deoxyreductones can react with the degradation products from the strecker reaction to form pyrazines, heterocyclic compounds with nitrogen and sulphur (e. in addition, when meat is consumed, fat can affect the release or retention of aroma compounds, which can alter the sensory evaluation of the product [41]. among them, h2s and nh3 are the most reactive, and they can interact with the products of lipid degradation and, thus, affect the relative production of heterocyclic compounds that are derived from the maillard reaction [18]. sulphur in those compounds is derived from amino acids (glutathione, methionine, cysteine, and cystine) and thiamine, and it is liberated when meat is cooked, although it can be released earlier, during fermentation in the rumen [39].


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