ABSTRACT: Kefir is fermented milk that has a unique flavor because of acetaldehyde, diacetyl, acetoin and ethanol. The aim of this study was to evaluate flavor and aroma compounds present in kefir. Two types of starter (Christian Hansen and Sacco) and three levels of temperatures (30, 33 and 35oC) were used for the preparation of kefir samples. The samples were analyzed for acetaldehyde, diacet...

Emissions of acetaldehyde from tree leaves were investigated by proton-transfer-reaction mass spectrometry (PTR-MS), a technique that allows simultaneous monitoring of different leaf volatiles, and confirmed by derivatization and high-performance liquid chromatography analysis. Bursts of acetaldehyde were released by sycamore, aspen, cottonwood and maple leaves following light–dark transitions;...

The irreversible removal of acetaldehyde from indoor air via a chemical reaction with amino acids was investigated. To compare effectiveness, five types of amino acid (glycine, l-lysine, l-methionine, l-cysteine, and l-cystine) were used as the reactants. First, acetaldehyde-laden air was introduced into aqueous solutions of each amino acid and the removal abilities were compared. Among the fiv...

Incubation of human colonic contents with various ethanol concentrations (2.75-44 mM) in vitro at 37 degrees C resulted in significant accumulation of acetaldehyde--a toxic and highly reactive compound. At pH 9.6, all samples produced notable acetaldehyde concentrations (58 (13) microM; mean (SEM)) even from the lowest (2.75 mM) ethanol concentration, and the production of acetaldehyde increase...

Acetaldehyde is a highly reactive compound that causes various forms of damage to DNA, including DNA adducts, single- and/or double-strand breaks (DSBs), point mutations, sister chromatid exchanges (SCEs), and DNA-DNA cross-links. Among these, DNA adducts such as N²-ethylidene-2'-deoxyguanosine, N²-ethyl-2'-deoxyguanosine, N²-propano-2'-deoxyguanosine, and N²-etheno-2'-deoxyguanosine are centra...

Acetaldehyde-induced cytotoxicity is an important factor in pathogenesis of alcohol-related diseases; however, the mechanism of this toxicity is unknown. We recently showed that acetaldehyde increases epithelial paracellular permeability. We asked whether protein tyrosine phosphorylation via modulation of tyrosine kinases and/or PTPases is a mechanism involved in acetaldehyde-induced disruption...

Acetaldehyde (ACH) associated with alcoholic beverages is Group 1 carcinogen to humans (IARC/WHO). Aldehyde dehydrogenase (ALDH2), a major ACH eliminating enzyme, is genetically deficient in 30-50% of Eastern Asians. In alcohol drinkers, ALDH2-deficiency is a well-known risk factor for upper aerodigestive tract cancers, i.e., head and neck cancer and esophageal cancer. However, there is only a ...

Acetaldehyde, the first metabolite of ethanol, has been suggested to be involved in many behavioral effects of ethanol. However, very few studies have been published on the role of acetaldehyde in the amnesic and ataxic effects of ethanol. The aim of the present studies was to compare the profiles of ethanol and acetaldehyde in several behavioral tests, measuring motor coordination, learning an...

Pharmacokinetic models for ethanol metabolism have contributed to the understanding of ethanol clearance in human beings. However, these models fail to account for ethanol's toxic metabolite, acetaldehyde. Acetaldehyde accumulation leads to signs and symptoms, such as cardiac arrhythmias, nausea, anxiety, and facial flushing. Nevertheless, it is difficult to determine the levels of acetaldehyde...

Several cell-damaging effects of ethanol are due to its major metabolite acetaldehyde but its mechanisms are not known. We have studied the effect of acetaldehyde on p42/44 mitogen-activated protein kinase (MAPK) and p46/p54 c-Jun N-terminal kinase (JNK 1/2) in rat hepatocytes. Acetaldehyde caused peak activation of p42/44 MAPK at 10 min followed by JNK activation at 1 h. These responses were a...