High Acetaldehyde Levels Research Articles

Challenges and Perspectives of Georgian Kvevri Wine Production

This research examined the quality of Georgian Amber Kvevri wines produced in the last three years via sensory evaluation and identified common defects in Kvevri amber wines. The Georgian Wine Guild organized 32 tasting sessions, assessing 1,440 amber wines sourced from 149 cellars. Only 30.76% of the wines evaluated were free from faults. High levels of ethyl acetate, acetaldehyde, and volatile acids characterized the majority of faulty wines. Researchers collaborated with 18 local wineries to conduct a field study, revealing that errors in cellar planning, design, and winemaking contributed to defects in Kvevri Amber Wines. The identified mistakes comprised placing kvevries in close proximity, failing to adequately wash and sanitize the cellar, neglecting the use of sulfur dioxide and inert gases, fermenting wines at elevated temperatures, and excessively maturing wines with lees and solid grape components. Based on the obtained results, the study team developed a novel technique that integrates traditional and modern methods for the production of amber wine. The team implemented the traditional liming method for the installation of new wines, produced trial wines utilizing innovative approaches, and created control wines through the conventional method. Trial and control samples were prepared from Georgian endemic grape varieties Rqatsiteli, Kisi, and Khikhvi, which are typically employed in the production of kvevri amber wine. The accredited Wine Laboratory conducted the chemical analyses. The results indicated that the trial wine had three times lower levels of acetaldehyde, ethyl acetate, and volatile acids compared to the control samples. The study emphasizes the significance of reinstating authentic traditional Kvevri winemaking methods alongside contemporary practices. The research indicates that the application of the new technique enables winemakers to improve the sensory attributes of their wines and diminish off-flavors.

Gas Phase Aldehydes Detection in Exhaled Breath in Screening of Barrett's Esophagus

Aldehydes, e.g., acetaldehyde, have been classified as toxic and carcinogenic volatile organic compounds (VOCs) and are recognized as one determinant of upper aerodigestive tract cancer like Barrett's esophagus. Measuring aldehyde levels in breath provides information about the aldehydes released by abnormal cells, the level of aldehyde dehydrogenase (ALDH2) activity, and risks and diseases associated with high levels of acetaldehyde, which include liver disease and lung and upper digestive cancers. Devices currently available for breath analysis are state-of-the-art, high-resolution mass spectrometry instruments. These instruments have some drawbacks such as size, initial cost, and operational expense. Electrochemical sensors are capable of miniaturization and are available as portable and handheld breathalyzers. The non-invasive nature of breath analysis and its easy sampling makes smaller devices a more attractive alternative, particularly for continuous monitoring and point-of-care (POC) testing.1 However, the lack of an exchangeable/disposable sensing element, the resulting memory effect, and the need for frequent recalibration is the main drawback of currently available electrochemical breathalyzers.Herein we examine the feasibility of a POC testing device for aldehyde in exhaled breath to assess the medical application of such a device in noninvasive diagnostic testing for Barrett’s esophagus. To improve the selectivity of the method we harness the unique catalytic activity of the aminoxyl radical/oxoammonium redox couple toward aldehyde oxidation. The highly selective/sensitive device offers the capability for use in the detection of Barrett's esophagus, ideally at early stages, without the need for a high-cost screening test. Our functional sensing element consists of a screen-printed electrode (SPE) in which the graphene oxide-based is the working electrode. Exposing this electrode to simulated breath that contains aldehyde, while applying the required potential for oxidation of the aminoxyl radical (4-acetamido-TEMPO known as ACT), generates an electrocatalytic current proportional to the aldehyde concentration in the breath. These simple, sensitive, durable, and inexpensive electrodes may contribute to the development of a single-use reliable aldehyde sensor for personal or law enforcement applications.1. M. Mayer, M. Rafiee, Electrocatalytic Detection of Ethanol and Acetaldehyde by Aminoxyl Radicals: Utilizing Molecular Catalysis for Breath Analysis. Analyst 147, 2022, 3420 – 3423.

Hepatic progesterone receptor membrane component 1 attenuates ethanol-induced liver injury by reducing acetaldehyde production and oxidative stress.

Alcohol-associated liver disease (ALD) is caused by excessive abuse of alcohol. One of the most representative causes of ALD is the action of acetaldehyde. Acetaldehyde is a toxic material produced when alcohol is metabolized through some enzymes, and it causes endoplasmic reticulum (ER) stress, mitochondrial dysfunction, and tissue injury. In this study, we assessed the relationship between Progesterone receptor membrane component 1 (PGRMC1) and ALD because PGRMC1 is expressed in the ER and mitochondria in the liver. Using the chronic and binge alcohol feeding models, we assessed acetaldehyde level, liver damage, alcohol-degrading enzymes, and ER stress. Compared with wild-type (WT) mice ethanol-fed Pgrmc1 knockout (KO) mice had higher levels of alanine aminotransferase (ALT) and alcohol-degrading enzymes, and Pgrmc1 KO mice had high serum acetaldehyde and ER stress levels compared with WT mice with control and ethanol feeding. Loss of Pgrmc1 increased acetaldehyde production through increased expression of alcohol dehydrogenase and catalase, which led to increased ER stress and suggested that cell death was promoted. In conclusion, it has been proposed that the loss of PGRMC1 could promote ALD and cause liver damage in alcohol-abusing humans.NEW & NOTEWORTHY Loss of Pgrmc1 increased acetaldehyde production, and excess acetaldehyde consequently increased ER stress, which activates apoptosis. Since low expression of PGRMC1 is vulnerable to alcoholic liver damage, the loss of PGRMC1 expression may increase susceptibility to ALD.

Formaldehyde and Acetaldehyde Exposure in "Non-Traditional" Occupational Sectors: Bakeries and Pastry Producers.

Formaldehyde, a colorless and highly irritating substance, causes cancer of the nasopharynx and leukemia. Furthermore, it is one of the environmental mutagens to which humans are most abundantly exposed. Acetaldehyde was recently classified as carcinogen class 1B and mutagen class 2 in Annex VI EC regulation. Occupational exposure to the two aldehydes occurs in a wide variety of occupations and industries. The aim of this study is to deepen exposure to the two aldehydes in the non-traditional productive sectors of bakeries and pastry producers. The evaluation of exposure to formaldehyde and acetaldehyde was conducted in Italy in 2019, in specific tasks and positions of 11 bakeries and pastry producers (115 measures, of which 57.4% were in fixed positions and the rest were personal air sampling). The measurements were performed using Radiello© radial diffusion samplers. A logarithmic transformation of the data was performed, and the correlation between the two substances was calculated. Moreover, linear models considering the log-formaldehyde as the outcome and adjusting for log-acetaldehyde values were used. The study identified high levels of acetaldehyde and formaldehyde exposure in the monitored workplaces. Higher mean values were observed in the leavening phase (8.39 µg/m3 and 3.39 µg/m3 for log-transformed data acetaldehyde and formaldehyde, respectively). The adjusted univariate analyses show statistically significant factors for formaldehyde as the presence of yeast, the presence of type 1 flour, the use of barley, the use of fats, the type of production, the use of spelt, and the presence of type 0 flour. The measurements confirmed the release of formaldehyde and acetaldehyde in bakeries and pastry industries, especially in some phases of the work process, such as leavening.

Aldehyde dehydrogenase 2-associated changes in pharmacokinetics, locomotor function and peripheral glutamic acid and gamma-aminobutyric acid levels during acute alcohol intoxication in male mice.

The insufficiency of human aldehyde dehydrogenase 2 (ALDH2) has been consistently associated with high blood acetaldehyde levels and impaired locomotor function during acute alcohol intoxication. The ALDH2-associated change in peripheral glutamic acid (Glu) and gamma-aminobutyric acid (GABA) levels and its correlation with pharmacokinetics and psychomotor function remain unclear. In this study, ALDH2*2 mice were used to build an acute alcohol intoxication model after intraperitoneal administration. The blood ethanol and acetaldehyde concentrations were analyzed to generate concentration-time curves at two doses of alcohol (2.0 and 4.0 g/kg). The dose of 4.0 g/kg was selected in accordance with the preliminary behavioral evaluation result to perform the following behavioral tests (e.g. the rotarod test, the open field test, and the Y-maze test), so as to assess locomotor activity, anxiety and cognitive ability. Plasma Glu and GABA levels were determined through enzyme-linked immunosorbent assays. The results suggested that the ALDH2*2 mice had highly accumulated acetaldehyde levels, impaired locomotor activity and anxiety-like emotion but unimpaired cognitive function, compared to the wild type (WT) mice. The plasma Glu level and the ratio of Glu/GABA in the alcohol-treated WT and ALDH2*2 groups decreased from 2 to 5 h after intraperitoneal administration, whereas the GABA level did not change significantly. The blood alcohol concentration in the WT and ALDH2*2 mice was positively correlated with plasma Glu level, whereas the blood acetaldehyde level was found as the opposite. We speculate that the decline degree of Glu/GABA ratio could be associated with psychomotor retardation and needs to be further investigated.

Ethanol and its Nonoxidative Metabolites Promote Acute Liver Injury by Inducing ER Stress, Adipocyte Death, and Lipolysis

Binge drinking in patients with metabolic syndrome accelerates the development of alcohol-associated liver disease. However, the underlying mechanisms remain elusive. We investigated if oxidative and nonoxidative alcohol metabolism pathways, diet-induced obesity, and adipose tissues influenced the development of acute liver injury in a single ethanol binge model. A single ethanol binge was administered to chow-fed or high-fat diet (HFD)-fed wild-type and genetically modified mice. Oral administration of a single dose of ethanol induced acute liver injury and hepatic endoplasmic reticulum (ER) stress in chow- or HFD-fed mice. Disruption of the Adh1 gene increased blood ethanol concentration and exacerbated acute ethanol-induced ER stress and liver injury in both chow-fed and HFD-fed mice, while disruption of the Aldh2 gene did not affect such hepatic injury despite high blood acetaldehyde levels. Mechanistic studies showed that alcohol, not acetaldehyde, promoted hepatic ER stress, fatty acid synthesis, and increased adipocyte death and lipolysis, contributing to acute liver injury. Increased serum fatty acid ethyl esters (FAEEs), which are formed by an enzyme-mediated esterification of ethanol with fatty acids, were detected in mice after ethanol gavage, with higher levels in Adh1 knockout mice than in wild-type mice. Deletion of the Ces1d gene in mice markedly reduced the acute ethanol-induced increase of blood FAEE levels with a slight but significant reduction of serum aminotransferase levels. Ethanol and its nonoxidative metabolites, FAEEs, not acetaldehyde, promoted acute alcohol-induced liver injury by inducing ER stress, adipocyte death, and lipolysis.

Impact of the Acetaldehyde-Mediated Condensation on the Phenolic Composition and Antioxidant Activity of Vitis vinifera L. Cv. Merlot Wine.

Acetaldehyde is a critical reactant on modifying the phenolic profile during red wine aging, suggesting that the acetaldehyde-mediated condensation can be responsible for the variation of antioxidant activity during the aging of this beverage. The present study employs exogenous acetaldehyde at six levels of treatment (7.86 ± 0.10–259.02 ± 4.95 mg/L) before the bottle aging of Merlot wines to encourage phenolic modification. Acetaldehyde and antioxidant activity of wine were evaluated at 0, 15, 30, 45, 60 and 75 days of storage, while monomeric and polymeric phenolics were analyzed at 0, 30 and 75 days of storage. The loss of acetaldehyde was fitted to a first-order reaction model, the rate constant (k) demonstrated that different chemical reaction happened in wines containing a different initial acetaldehyde. The disappearance of monomeric phenolics and the formation of polymeric phenolics induced by acetaldehyde could be divided into two phases, the antioxidant activity of wine did not alter significantly in the first phase, although most monomeric phenolics vanished, but the second phase would dramatically reduce the antioxidant activity of wine. Furthermore, a higher level of acetaldehyde could shorten the reaction time of the first phase. These results indicate that careful vinification handling aiming at controlling the acetaldehyde allows one to maintain prolonged biological activity during wine aging.

Sub-ohm vaping increases the levels of carbonyls, is cytotoxic, and alters gene expression in human bronchial epithelial cells exposed at the air\u2013liquid interface

BackgroundExposure to electronic-cigarette (e-cig) aerosols induces potentially fatal e-cig or vaping-associated lung injury (EVALI). The cellular and molecular mechanisms underlying these effects, however, are unknown. We used an air–liquid interface (ALI) in vitro model to determine the influence of two design characteristics of third-generation tank-style e-cig devices—resistance and voltage—on (1) e-cig aerosol composition and (2) cellular toxicity.MethodsHuman bronchial epithelial cells (H292) were exposed to either butter-flavored or cinnamon-flavored e-cig aerosols at the ALI in a Vitrocell exposure system connected to a third-generation e-cig device. Exposures were conducted following a standard vaping topography profile for 2 h per day, for 1 or 3 consecutive days. 24 h after ALI exposures cellular and molecular outcomes were assessed.ResultsWe found that butter-flavored e-cig aerosol produced under ‘sub-ohm’ conditions (< 0.5 Ω) contains high levels of carbonyls (7–15 μg/puff), including formaldehyde, acetaldehyde and acrolein. E-cig aerosol produced under regular vaping conditions (resistance > 1 Ω and voltage > 4.5 V), contains lower carbonyl levels (< 2 μg/puff). We also found that the levels of carbonyls produced in the cinnamon-flavored e-cig aerosols were much lower than that of the butter-flavored aerosols. H292 cells exposed to butter-flavored or cinnamon-flavored e-cig aerosol at the ALI under ‘sub-ohm’ conditions for 1 or 3 days displayed significant cytotoxicity, decreased tight junction integrity, increased reactive oxygen species production, and dysregulated gene expression related to biotransformation, inflammation and oxidative stress (OS). Additionally, the cinnamon-flavored e-cig aerosol induced pro-oxidant effects as evidenced by increases in 8-hydroxy-2-deoxyguanosine protein levels. Moreover, we confirmed the involvement of OS as a toxicity process for cinnamon-flavored e-cig aerosol by pre-treating the cells with N-acetyl cysteine (NAC), an antioxidant that prevented the cells from the OS-mediated damage induced by the e-cig aerosol.ConclusionThe production of high levels of carbonyls may be flavor specific. Overall, inhaling e-cig aerosols produced under ‘sub-ohm’ conditions is detrimental to lung epithelial cells, potentially via mechanisms associated with OS. This information could help policymakers take the necessary steps to prevent the manufacturing of sub-ohm atomizers for e-cig devices.

The characteristics of inorganic gases and volatile organic compounds at a remote site in the Tibetan Plateau

Abstract In order to study the characteristics of pollutants in the remote background site of Tibetan Plateau, volatile organic compounds (VOCs), NO, NO2, SO2, CO, O3 and meteorological parameters (temperature, relative humidity, rainfall, horizontal wind speed and direction) were measured in the autumn of 2013 at Menyuan station (37.59°N, 101.29°E, 3250 m a.s.l.), which is a newly established background site located in the Tibetan Plateau. The significantly lower average concentrations of NO, NO2, SO2 and CO were observed, indicating the distinct background characteristics at Menyuan. The O3 diurnal variation pattern and correlation analyses revealed the influence of in situ photochemical reactions and vertical mixing during the daytime and the long-range and vertically downslope transport from the upper troposphere or lower stratosphere during the nighttime. A total of 30 VOCs samples were collected and 66 VOCs species were analyzed. The oxygenated VOCs (OVOCs) were the most abundant components and high levels of acetone, acetaldehyde, nonanal, hexachloro-1,3-butadiene, 1,2-dichloroethane and CCl4 were observed. The LOH and OFP analysis confirmed that OVOCs and aromatics were the most active substances, and the VOCs had relatively stable chemical compositions and low photochemical potential. The long-range transport air masses from the southeast of Menyuan station passed by some polluted areas, such as Xining, and could result in the elevated NOx, CO and SO2 concentrations at Menyuan. Therefore, this work enriches the understanding of O3 cycles and transport influence in the Tibetan Plateau.

Alcohol-based mouthwash as a risk factor of oral cancer: A systematic review.

Background Oral and pharynx cancer represent a serious global problem, reaching an incidence of half a million cases annually. The role of tobacco and alcohol have been studied and proven to be one of its risk factors. We also know that mouthwashes contain a variable percentage of alcohol, so there is a reasonable concern about their role in carcinogenesis. Material and Methods To answer the PICOS (Population; Intervention; Comparison; Outcomes; Study) question: "Do patients (Population) who use alcohol-based mouthwashes (Intervention) compared to those who do not use them (Comparison) have higher acetaldehyde levels in saliva or higher risk of oral cancer development? (Outcomes)" Meta-analyses, systematic reviews, randomized and non-randomized clinical trials, case-control studies, and prospective and retrospective cohort studies were included (Study). Two independent authors conducted literature screening through MEDLINE, Scopus and the Cochrane Library, and they also conducted article and data extraction to undertake quality analyses. The main outcome measures were salivary acetaldehyde levels or the risk of oral cancer development. The most relevant data was extracted and the risk of bias from the studies included was also evaluated. Results Out of 497 potentially eligible papers, 8 studies were included in the qualitative analysis which include a total of 43,499 subjects: two meta-analyses, a clinical trial, three case-control studies and two cohort studies. One study (n = 3,926) found a relationship between alcohol mouthwash and oral cancer, two studies (n = 25,033) found this relationship when a high frequency of mouthwash was present, three studies (n = 14,482) failed to find this relationship and 2 studies (n = 58) found a temporary increase of acetaldehyde levels in saliva after alcohol mouthwash. Conclusions It cannot be guaranteed that the use of mouthwash represents an independent risk factor for the development of head and neck cancer. However, the risk does increase when it occurs in association with other carcinogenic risk factors. Key words:Oral Cancer, Oropharyngeal Neoplasms, Mouthwashes, Mouth rinse, Ethanol, Acetaldehyde, alcohol.

Determination of acetaldehyde, methanol and fusel oils in distilled liquors and sakès by headspace gas chromatography.

In this study, a headspace gas chromatography (HS-GC) method was carried out to determine the contents of acetaldehyde, methanol and fusel oils in distilled liquors and sakès from different countries. A DB-Wax column was adopted in HS-GC, which showed good linearity, high precision and accuracy and low LOQ and LOD on all the compounds. Results showed that distilled liquors contained higher levels of acetaldehyde with the values of 12.88-35.53mg/L than sakès (0.83-29.13mg/L). Methanol was only detected in a few distilled liquors with small amounts. Amyl alcohols, including isoamyl alcohol (2-methyl-1-butanol) and active amyl alcohol (3-methyl-1-butanol), isobutanol (2-methyl-1-propanol) and 1-propanol were the main fusel oils among the distilled liquors and sakès analyzed. Amyl alcohols contents were 2 to 4 times higher in Korean distilled liquors (203.01-428.66mg/L) than that in Chinese distilled liquors (28.52-42.77mg/L) and all the sakès (61.90-166.59mg/L).

Characterization of polar metabolites and evaluation of their potential toxicity in hydrocarbon contaminated Antarctic soil elutriates

Hydrocarbon polar metabolites are gaining interest from industry and the remediation community due to their ubiquity and uncertainty around their toxicity. In this study, we used headspace-gas chromatography/mass spectrometry (HS-GC/MS) to characterize polar metabolites present in elutriates derived from uncontaminated, freshly hydrocarbon contaminated and partially remediated Antarctic soils. Elutriates represent the bioavailable fraction and may be used as a proxy for leachate runoff in environmental risk assessments. Control and contaminated soil elutriates were analysed for the presence of 12 aldehydes and two ketones, which cover a broad spectrum of metabolites, ranging from nC2 – nC12 carbon chain length. A total of nine aldehydes were detected in the soil elutriates. Types of aldehydes present in uncontaminated and hydrocarbon contaminated elutriates were similar. Among the polar metabolites measured in elutriates, acetaldehyde was most abundant in partially remediated soils. Microtox assays were used to determine the potential toxicity of elutriates. In addition, three aldehydes that were present at the highest concentrations in the contaminated and partially remediated soil elutriates (acetaldehyde, octanal and undecanal) were tested as single compounds. Contaminated soil elutriates tested were found to be toxic, with partially remediated elutriates less toxic than freshly contaminated elutriates. None of the three aldehydes tested separately were toxic at levels at which they were measured in elutriates. We infer that high levels of acetaldehyde in partially remediated soil due to hydrocarbon degradation highlight the potential of this metabolite as a useful chemical marker for hydrocarbon degradation under certain conditions. Microtox was sensitive to metabolites and provided a useful initial screening tool for elutriates.

Fenofibrate -a PPARα agonist- increases alcohol dehydrogenase levels in the liver: implications for its possible use as an ethanol-aversive drug.

After ethanol consumption, disulfiram increases blood-acetaldehyde levels, generating an aversive reaction that deters alcohol drinking. Given the major secondary effects of disulfiram, finding other effective drugs to reduce alcohol consumption in individuals with alcohol-use-disorder is highly desirable. It has been reported that administering fenofibrate to high-drinking rats increases hepatic catalase levels and blood acetaldehyde after administering ethanol and a 60-70% inhibition of voluntary alcohol intake. This work evaluated whether fenofibrate has an additional effect on the activity of other ethanol-metabolizing enzymes, which could contribute to the high acetaldehyde levels generated upon administering ethanol. Male high-drinker rats were allowed to voluntary drink 10% ethanol or water for 2 months. Subsequently, fenofibrate (100 mg/kg/day) or vehicle was administered orally for 14 days. Then, alcohol dehydrogenase (ADH1) and aldehyde dehydrogenase (ALDH2) protein levels and enzymatic activities in the livers were quantified. Fenofibrate treatment produced a marked increase in ADH1 protein levels (396% ± 18%, p < 0.001) and enzymatic activity (425% ± 25%, p < 0.001). Fenofibrate did not result in differences in ALDH2 activity or in ALDH2 protein levels. The studies show that treatment with fenofibrate not only increased the activity of catalase in the liver of alcohol-drinking rats, as reported earlier, but also increased the levels and enzymatic activity of ADH1, while ALDH2 remained unchanged. The increases in ADH1 contribute to explaining the remarkable effect of fenofibrate in raising blood levels of acetaldehyde in ethanol-consuming animals, in which a marked reduction of alcohol intake is recorded.

Effect of Alcohol Sensitivity in Healthy Young Adults on Breath Pharmacokinetics of Acetaldehyde After Mouth Washing with Alcohol.

Acetaldehyde is causally related to head and neck cancer. Individuals with aldehyde dehydrogenase 2 deficiency experience alcohol sensitivity and are referred to as "flushers" because of their skin-flushing response to high blood acetaldehyde levels after alcohol consumption. Acetaldehyde is produced in the oral cavity after local alcohol exposure without alcohol ingestion. However, the relationship between the oral acetaldehyde level after local alcohol exposure and alcohol sensitivity is unclear. Herein, sampling the exhaled breath, we evaluated the effect of alcohol sensitivity on the pharmacokinetics of ethanol (EtOH) and acetaldehyde in breath after mouth washing with alcohol. Twenty-eight healthy young adults were divided into flusher and nonflusher groups based on an EtOH patch test. The subjects washed their mouths for 30seconds with 40ml of 5% v/v alcohol, and their breath samples were collected 12 times over 20minutes after mouth washing and rinsing with water. EtOH and acetaldehyde concentrations in all breath samples were measured using sensor gas chromatography. Breath EtOH concentrations exponentially decreased in both groups after mouth washing with alcohol. Breath acetaldehyde concentrations showed an immediate increase, followed by an almost exponential decrease in both groups, but concentrations in the flusher group remained higher than those in the nonflusher group throughout the 20-minute measurement period. This was reflected in a peak concentration (Cmax ) of 808±70parts-per-billion (ppb) versus 1,715±223ppb, respectively (p=0.001), and area under the curve values of 3,528±1,399ppb minutes versus 8,637±1,293ppb minutes, respectively (p=0.002). This study revealed high concentrations of acetaldehyde in breath after local alcohol exposure in the oral cavity among flushers even without alcohol ingestion. This contributes to an increased risk among flushers of mutagenic DNA lesions in the mucosa of the upper digestive tract and cancer.

Alcohol inhibits T-cell glucose metabolism and hepatitis in ALDH2-deficient mice and humans: roles of acetaldehyde and glucocorticoids

ObjectiveAldehyde dehydrogenase 2 (ALDH2), a key enzyme to detoxify acetaldehyde in the liver, exists in both active and inactive forms in humans. Individuals with inactive ALDH2 accumulate acetaldehyde after alcohol...

The use of atmospheric and room temperature plasma mutagenesis to create a brewing yeast with reduced acetaldehyde production

High acetaldehyde levels in beer from yeast metabolism is a major concern for brewers in China. To obtain a strain with lower acetaldehyde production, this work reports a novel approach based on atmospheric and room temperature plasma mutagenesis and high-throughput screening using 4-methylpyrazole + disulphiram plating. A mutant LAL-8a with lower acetaldehyde-producing capability was obtained. The alcohol dehydrogenase activity decreased by 54% compared with the wild-type M14 and the aldehyde dehydrogenase activity increased by 64% of the wild-type strain. Through domestication and fermentation in EBC tubes, the mutant LAL-8a was shown to produce 2.2 mg/L acetaldehyde, 88.2% less than the wild-type strain M14. In addition, the ratio of higher esters to alcohols in beer fermented by the mutant LAL-8a (0.28) was higher than M14 (0.16). The fermentation performance of LAL-8a was similar to that of the wild-type M14. This work suggests strain LAL-8a a promising option for the brewing industry. © 2018 The Institute of Brewing & Distilling

E‐cigarette vapor elevates heart rate in mice with limited reactive aldehyde metabolism

BackgroundE‐cigarettes contain high levels of reactive aldehydes including acrolein, acetaldehyde and formaldehyde in addition to nicotine. However, the cardiovascular effects of e‐cigarette exposure are not well studied. Furthermore, ~560 million people of East Asian descent cannot efficiently metabolize these aldehydes in e‐cigarettes due to a genetic variant in aldehyde dehydrogenase 2, known as ALDH2*2. Therefore, we tested our hypothesis that e‐cigarette vapor exposure alters heart rates in wild type ALDH2 mice and these effects are exacerbated in ALDH2*2 knock‐in mice.MethodsTo test our hypothesis, both male and female wild type and homozygote ALDH2*2 mice (8–12 weeks old) were implanted with a mouse Biopotential Telemeter (Millar) and heart rate was acquired with LabChart 8 (AD Instruments) (n = 4/genotype). All mice were exposed to 60 puffs (5 sec duration and 60 ml puff volume) a day for 5 days. With each e‐cigarette exposure, we also monitored the reactive aldehyde levels in e‐cigarette vapor in real‐time by selective ion flow mass spectrometry. Furthermore, ALDH2 expression and activity in whole heart mitochondrial fractions were determined by biochemical assays (n= 3/genotype). Statistical analysis was performed using Graph Pad Prism 6.0. Data are expressed as mean ± SEM. Student's t‐test was used for comparison between two groups and ANOVA followed by Bonferroni correction was used for multiple variant comparisons (* indicating P value &lt;0.001).ResultsWhen compared to baseline heart rates for wild type and ALDH2*2 mice, e‐cigarette vapor exposure leads to a substantial drop in heart rate for both wild type (739 ± 6 vs. 502 ± 36* bpm, respectively) and ALDH2*2 mice (712 ± 5 vs. 500 ± 43* bpm, respectively). Additionally, 5 days of continuous e‐cigarette exposure increased the resting heart rate by 49 ± 9* bpm in wild type and 163 ± 9* bpm in ALDH2*2 mice respectively. Quantification of reactive aldehyde levels in e‐cigarettes revealed that e‐cigarette vapor contained high levels of acetaldehyde (1506 ± 179.1* ppb), acrolein (38.2 ± 4.7* ppb) and formaldehyde (52.7 ± 3.7* ppb) in contrast to ambient air (acetaldehyde 35.5 ± 4.6 ppb, acrolein 8.5 ± 1.3 ppb, and formaldehyde 7.1 ± 0.3 ppb). Furthermore, compared to wild type mice, both heart ALDH2 expression (1.3 ± 0.2 vs. 0.5 ± 0.04* ADU) and activity (3 ± 0.2 vs. 1.1 ± 0.07* μmol/min/mg) were markedly lower in ALDH2*2 mice.ConclusionTogether, these findings suggest that e‐cigarette vapor exposure triggers changes in heart rate that is more pronounced in ALDH2*2 mice. Moreover, e‐cigarettes contain reactive aldehydes, including high levels of acetaldehyde. Therefore, e‐cigarette smoking/exposure may increase the risk of developing cardiovascular disease in individuals with ALDH2*2 variant.Support or Funding InformationTobacco‐Related Disease Research Program, California, United States.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

High CO2impact on low-temperature induced volatile esters in strawberries

Strawberries are characterized by an intense flowery odor, which is associated with specific ester species. In this study, the effect of high CO2 atmospheres (0, 20 or 40 kPa) at 0°C on alcohol dehydrogenase (ADH) gene expression and on selected volatile esters of 'Mara des Bois' strawberries was analyzed. Acetaldehyde and ethanol concentrations, and those of hexanal and 1-hexanol were compared in strawberries stored under different high CO2 atmospheres. The abundance of each detected volatile esters varied as a function of CO2 concentration during storage. When compared with fruit at harvest, those stored at low temperature without added CO2 had a marked induction of ADH expression that was associated with the accumulation of 1-hexanol and esters typically related to fatty acid breakdown. Moreover, these fruit had the lowest concentrations of ethanol and some ethyl esters, such as ethyl butanoate. In contrast, a moderate accumulation of ethanol and specific esters associated with strawberry flavor were observed in fruit stored in a 20 kPa CO2. The shift towards ethanolic fermentation in fruit treated with 20 kPa CO2 for 3 days was associated with 1-hexanol accumulation. However, 40 kPa-treated fruit accumulated the lowest levels of octyl 3-methyl butanoate, the volatile ester with the strongest flavor in this cultivar. This reduction in conjunction with the accumulation of higher levels of acetaldehyde, ethanol and ethyl acetate could explain the negative impact on such fruits maintained in an excessively high CO2 atmosphere.

Reduced acetaldehyde production by genome shuffling of an industrial brewing yeast strain

High levels of acetaldehyde produced by yeast during fermentation can be of concern to product quality. A novel approach, based on genome shuffling, was applied to reduce the production of acetaldehyde by industrial brewing strain YS86. Four isolates with different impacts of acetaldehyde concentration were obtained from populations generated by ultraviolet irradiation and nitrosoguanidine mutagenesis. These yeast strains were then subjected to recursive pool-wise protoplast fusion. A strain library that was likely to yield positive colonies was created by fusing the lethal protoplasts obtained from both UV irradiation and heat treatments. After two rounds of genome shuffling, a recombinant YSF2–9 strain produced less acetaldehyde than wild-type strain YS86, by 64.5 and 66.2% in laboratory and pilot plant fermentations, respectively. The shuffled yeast strain YSF2–9 was genetically stable and may have a potential application in brewing industry for managing acetaldehyde in beer. Copyright © 2017 The Institute of Brewing & Distilling

Carbonyl Compounds Produced by Vaporizing Cannabis Oil Thinning Agents.

Cannabis use has increased in the United States, particularly the use of vaporized cannabis oil, which is often mixed with thinning agents for use in vaporizing devices. E-cigarette research shows that heated thinning agents produce potentially harmful carbonyls; however, similar studies have not been conducted (1) with agents that are commonly used in the cannabis industry and (2) at temperatures that are appropriate for cannabis oil vaporization. The goal of this study was to determine whether thinning agents used in the cannabis industry produce potentially harmful carbonyls when heated to a temperature that is appropriate for cannabis oil vaporization. Four thinning agents (propylene glycol [PG], vegetable glycerin [VG], polyethylene glycol 400 [PEG 400], and medium chain triglycerides [MCT]) were heated to 230°C and the resulting vapors were tested for acetaldehyde, acrolein, and formaldehyde. Each agent was tested three times. Testing was conducted in a smoking laboratory. Carbonyl levels were measured in micrograms per puff block. Analyses showed that PEG 400 produced significantly higher levels of acetaldehyde and formaldehyde than PG, MCT, and VG. Formaldehyde production was also significantly greater in PG compared with MCT and VG. Acrolein production did not differ significantly across the agents. PG and PEG 400 produced high levels of acetaldehyde and formaldehyde when heated to 230°C. Formaldehyde production from PEG 400 isolate was particularly high, with one inhalation accounting for 1.12% of the daily exposure limit, nearly the same exposure as smoking one cigarette. Because PG and PEG 400 are often mixed with cannabis oil, individuals who vaporize cannabis oil products may risk exposure to harmful formaldehyde levels. Although more research is needed, consumers and policy makers should consider these potential health effects before use and when drafting cannabis-related legislation.