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Showing 1 to 20 of 34 for “"diacetyl"”.
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Kinetics of 3,5-diacetyl-1,4-dihydrolutidine in formaldehyde detection
… and acetylacetone. The chromophore formed is 3,5-diacetyl-1,4-dihydrolutidine (DDL). In the AATCC test the ammonia and acetylacetone are in the Nash reagent and the formaldehyde is extracted from the fabric by trapped steam. The formaldehyde in solution and the Nash reagent are mixed and the color …
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Solution and solid phase synthesis of N,N'-diacetyl chitotetraoses
… of other protecting groups afforded the N,N’-diacetyl chitotetraoses in good yield. Successful syntheses for the protected diacetyl chitotetraoses by solid phase synthesis have also been described.
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A Modified Voges-Proskauer Method of Determining Diacetyl in Dairy Cultures
… scientists have known for a number of years that diacetyl is one of the principle flavor components of butter, buttermilk, and cheese cultures. Of the tests which have been introduced to determine diacetyl, one of the first was the heavy metal gravimetric method. This procedure involved …
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An integrative approach to identify novel target genes for reduction of diacetyl production in lager yeast
Diacetyl ist ein Nebenprodukt der Biosynthese von Valin und verursacht einen butterartigen Geschmack im Bier. Die Reduktion der Diacetylproduktion ist eine der wichtigsten Ziele der Stammoptimierung von Brauhefen, da sie hilft, die Lagerzeit zu verkürzen und die Bierproduktion zu beschleunigen. Das …
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Studies on the mode of action of diacetyl and carbon dioxide as inhibitors of meat spoilage bacteria
Carbon dioxide (CO2 and diacetyl (DA; 2, 3-butanedione) inhibit Gram-negative bacteria. Diacetyl inhibits the amino acid utilization of arginine. This inhibition occurs in the periplasmic space and CO2 may exert its influence in the periplasmic space as well. Therefore, this study investigated the …
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A Modified Prill and Hammer Method Used in The Study of Diacetyl Production by Single Strain Lactic Streptococci
… 2, 3-butanedione, commonly referred to as diacetyl or biacetyl, is considered by many to be-an important flavor constituent of butter and butter cultures. Milk fat has no natural diacetyl content and in the past the diacetyl found in butter resulted from bacterial fermentation of the cream …
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Sensory Coding and Olfactory Integration in Caenorhabditis Elegans
… odors, including the bacterial metabolite diacetyl, using the AWA sensory neurons. AWA forms chemical and electrical synapses onto several interconnected interneurons, which contribute to chemotaxis toward attractive odors like diacetyl. One AWA target is the interneuron AIA, which is …
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Investigation of Binding of Volatile Flavor Compounds by Soy Proteins in Low -Moisture Food Systems by Inverse Gas Chromatography (Igc)
… hydrogen bonding and/or ionic forces, than for diacetyl and hexanal. Presence of soy proteins did not affect binding of diacetyl and hexanal, but increased binding of gamma-butyrolactone and butyric acid. Solvent extraction data agreed with IGC results in that retention/binding of butyric acid …
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The Sensory and Analytical Analyses of Nonfat Milk Formulations: Stability to Light Oxidation and Pasteurization
… (2-butanone, 2-pentanone, acetaldehyde, diacetyl, hexanal, methyl sulfide) found in the two components. Pasteurized unoxidized skimmed milk had measurable levels of 2-butanone, acetaldehyde, and diacetyl. Pasteurization of skimmed milk increased concentration of 2-pentanone and methyl …
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The reaction of sodium on acetic anhydride
… a resinous material believed to be a polymer of diacetyl. No diacetyl has been isolated from the original products of any reaction. 3. Comparison has been made between reactions at room temperature and runs made at high temperatures. Room temperature reactions have been found to give the same …
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Pervaporation applications in food processing
… of grape juice essence and the extraction of diacetyl from aqueous solutions. The main findings of this study were: (1) It is indeed possible to manufacture grape juice essence by pervaporation. Starting with a 150x fold essence, it was possible to produce essences that were rated a 1000x fold …
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Sensory and Chemical Characteristics of Soymilk Yogurt With Different Yogurt Cultures
Analyses showed that acetaldehyde and diacetyl were predominant volatiles in soy yogurts. Acetone, ethanol, 2-heptanone, and methanol were also found. The amounts of hexanal found in yogurt samples were lower than the threshold values and did not contribute to distinctive beany flavor in soy …
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The reaction of sodium on acetic anhydride
… the products of this reaction sodium acetate, diacetyl, and resin were found. 3. Negative results for the formation of vinyl acetate and ethylidene diacetate were obtained. 4. The small amount of hydrogen produced in this reaction is believed to correspond to the presence of acetic acid as an …
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A Mechanism for Spatial Orientation Based on Sensory Adaptation in Caenorhabditis Elegans
… chemotaxis response of Caenorhabditis elegans to diacetyl. A behavioral analysis demonstrated that AWA sensory neurons drive chemotaxis over several orders of magnitude in odor concentration, providing an entry point for dissecting the mechanistic basis of chemotaxis at the level of neural …
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A Study of Some Physico-Chemical Changes in a Spread-Type Dairy Product During Storage
… reported to be connected with changes on the diacetyl level content since acetoin can be oxidized to diacetyl and diacetyl in turn readily oxidizes to 2, 3 butylene glycol. Of these three, only diacetyl contributes flavor to foodstuffs. Since ascorbic acid was known to play an important role …
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Study of the oxidative degradation of 2,2,3,4,5-pentaphenyl-3- cyclopentenone by various oxidants ; and, [1,5]-sigmatropic phenyl rearrangements in 2- and/or 5-(p- or m-substituted phenyl)-1,3,4-triphenyl-2,4- cyclopentadien-1-ols: electronic effects at the migration terminus
… all the reagents examined, with the exception of diacetyl chromate. The action of this oxidant upon the substrate produced an equimolar mixture of benzil, benzophenone, and benzoic acid in an overall yield of 40 to 42 percent.
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Metallkomplexe als Katalysatoren für selektive Olefinoligomerisierungen
… the 2,6-bis(imino)pyridines 1-2, the 2,6-diacetyl-monoiminopyridine 3, the iminophosphines 16, and the imidazo[1,5-a]pyridines 23c and 24a, and others, obtaining a range of different N,N,N- or N,N,O- or N,N,P-ligands through variation of the coordinating backbone and of the substituents. …
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ΜΕΛΕΤΗ ΟΞΕΙΔΩΣΗΣ ΟΞΙΜΙΝΙΚΩΝ ΚΑΙ ΙΜΙΝΙΚΩΝ ΠΑΡΑΓΩΓΩΝ ΚΑΡΒΟΝΥΛΙΚΩΝ ΕΝΩΣΕΩΝ
… REACTION OF LTA WITH BIS-SCHIFT BASES OF DIACETYL ANDBENZIL YIELDED SUBSTITUTED ACETANILIDE AND AZOBENZENE. PLANSIBLE MECHANISMS ARE PROPOSED FOR ALL THE ABOVE CASES.
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Effect of dough conditioners on the bread-making qualities of soft wheat flour
… used as dough conditioners: ascorbic acid and diacetyl tartaric esters of monoglycerides (DATEM). The breadmaking properties of the flours were evaluated by measuring the loaf characteristics by objective and sensory evaluation. In addition, the effect of the dough conditioners on the rate of …
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