Acetaldehyde propanal

Terpenoid DBPs were investigated by Joll et al. [124] and Qi et al. [125]. The main ozonation product of 2-methylisobomeol was camphor, which was further oxidized to formaldehyde, acetaldehyde, propanal, buntanal, glyoxal, and methyl glyoxal [125]. Chlorination of p-carotene, retinol, p-ionone, and geranyl acetate resulted in the formation of THMs [124]. 

Clausen et al. (2005) found many similarities between odorants emitted from linseed oil as well as from a floor oil made of this linseed oil, concluding that the odorants of the linseed oil are also responsible for the odor of the floor oil. Of the 139 listed perceived odorants only 45 were identified by GC—MS library search and retention characteristics. Important odorants with a high detection frequency were acetaldehyde, propanal, butanal, pentanal, 2-pentenal, hexanal, 2-hexenal, heptanal, 2-heptenal, 2,4-heptadienal, octanal, 2-octenal, nonanal, 2-nonenal, 2-decenal, benzaldehyde, l-penten-3-one, l-penten-3-ol, pentyl oxiran, acetic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, octanoic acid. 

Trace amounts of aldehydes, particularly acetaldehyde, propanal... 

Acetals are equilibrium products between aldehydes and alcohols. As discussed by Williams and Strauss (30) acetals generally have less intense aromas than the corresponding alcohols and aldehydes. 1,1,3-Triethoxypropane and diethoxybutan-2-one (derived from acrolein and diacetyl, respectively) are common acetals in the heads fractions from continuous stills acetals from other aldehydes including acetaldehyde, propanal, isobutanal, and isovaleraldeyde are also common (30). The equilibrium between the aldehyde and the acetal is highly dependent on alcohol concentration and pH, again m ng accurate quantitation of either the aldehyde or the acetal dependent on the analytical conditions (e.g., sample dilution, solvent extraction, etc.) (30). 

Hexanaone, 3-heptanaone Toluene, butanal Acetaldehyde, propane Propionic acid... 

Additional aroma components common to yeast-leavened bread are lower alcohols, acetaldehyde, propanal, pentanal, and furfural, and ethyl esters, such as ethyl acetate(19). 

Methoxymethylidene)adamantane (202) on photooxygenation in acetaldehyde, propanal and pivalaldehyde (RCHO) gives, apart from some adamantanone (203), the epimeric trioxanes (204) (Equation (29)) <85T208l>. The structures follow from the x-ray structure of the cw-epimer of (204) (R = Bu ). 

The magnitude of the supermolecule stabilization relative to the isolated reactants was calculated for hydride addition to acetaldehyde, propanal, and chloroacetalde-hyde, maintaining the H, CH3 and Cl substituents, respectively, in the conformation trans to the hydride ion (Scheme 6.15). The increase in the stabilization energy, from 35.5 kcal mol to 37.4 kcal mol to 59kcalmol , was interpreted as a result of the increase in the interactions of the hydride, the n (C=0) orbital, and the antiperi-planar o orbital of the substituent. 

C at 4°C/min used isopropanol n-Propanol, n-butane 2-Pentanaone, 2- hexanone 3- Hexanaone, 3-heptanaone Toluene, butanal Acetaldehyde, propane Propionic acid... 

A 15 ml sample of the slurry described in Method 1 was treated with 1060psi of synthesis gas (2.4 1H2—CO) at 296 K. The pressure decreased to 985 psi within 0.5 h and remained constant over the succeeding 0.5 h. The reactor was heated to about 470K and kept at that temperature for 427 min. A sample of gas for GC and GC-MS analyses was removed at this time, giving the results listed in Table 15.1. GC-MS indicated that small amounts of formaldehyde, acetaldehyde, propanal, and acetic acid were also formed. 

Aldehydes (acetaldehyde, propanal, butanal, hexanal, and heptanal)... 

In terms of key aroma components, Czerny et al. [59] conducted sensory studies using volatiles identified in previous studies as potential contributors to coffee aroma [60] to determine the odorants truly characterizing freshly brewed Colombian coffee. They found 2-furfurylthiol, 4-vinylguaiacol, several alkyl pyrazines, furanones, acetaldehyde, propanal, methylpropanal, and 2- and 3-methylbutanal had the greatest impact on the coffee flavor. 

Aroma substances are formed by the enzymatic oxidative degradation of the highly unsaturated fatty acids with the participation of lipoxygenases of varying specificity. These aroma substances contribute to the iruld green-metaUic-mushroom aroma of fresh fish. Dilution analyses have shown that these substances are acetaldehyde, propanal, l-octen-3-one, (Z)-l,5-octadien-3-one, (E,Z)-2,6-nonadienal, (Z,Z)-3,6-nonadienal and (E,E)-2,4-decadienal. 

Express the reaction in which ethanol is converted to acetaldehyde (propanal) by NAD in the presence of alcohol dehydrogenase as the difference of two half-reactions and write the corresponding reaction quotients for each half-reaction and the overall reaction. 

During heat treatment of foods, various aldehydes are formed in the head space. When pork fat was heated, various aldehydes such as formaldehyde, acetaldehyde, propanal, butanal, pentanal, and hexanal, were identified and quantitated (20). Hexanal was found in the largest amount, followed by pentanal and the other lower chain aldehydes. Both hexanid and pentanal have been commonly used as markers of lipid peroxidation in other food systems (27 j. However, irradiated cod liver oil produced malondialdehyde of which level was nearly five times higher than that of other aldehydes (22j, suggesting that different oxidative mechanisms are involved and that more Aan one spe c marker may be required to understand the formation of various aldehyde species. 

Acetaldehyde Propanal Butanal AA, C heterof green, fresh... 

Simple aldehydes, for example, formaldehyde, acetaldehyde, propanal, butanal, rendered aldol adduct (i.e., 70-75) with exquisite stereoselectivity, a fact which is... 

The reaction of NO3 with a 5 -2-penten-l-ol may lead to the formation of a series of aldehydes, such as formaldehyde, acetaldehyde, propanal, and glycolaldehyde. The reaction may also produce nitrooxy-aldehydes similarly to that observed for other unsaturated alcohols (Noda et al., 2000). 

D Anna et al. (2003) showed that the NO3 reaction with CH2O proceeds by H-atom abstraction so that the sole products of this reaction are HNO3 HCO. Mora-Diez and Boyd (2002) examined the mechanism of the reactions between NO3 and formaldehyde and acetaldehyde theoretically comparisons with experiment are consistent with a direct abstraction mechanism. Alv ez-Idaboy et al. (2001a) reached a similar conclusion for NO3 reaction with formaldehyde, acetaldehyde, propanal, n-butanal, and 2-methylpropanal. Their calculations showed that all reactions proceed via abstraction of the a-carbonyl H-atom the dependence of the rate constant on molecular size was shown to be attributable to the increase in the internal rotational partition function with the size of the aldehyde. 

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