Changes in acetaldehyde and formaldehyde contents in foods depending on the typical home cooking methods

Associations between cooking method of food and type 2 diabetes risk: A prospective analysis focusing on cooking method transitioning

Cooking process for food significantly impacts household air and increases exposure to endocrine disruptors such as acrylamide, consequently affecting human health. In the past 30 years, the transformation of cooking methods to high-temperature thermal processing has occurred widely in China. Yet the transition of cooking methods on the onset of type 2 diabetes (T2D) remains unclear, which may hinder health-based Sustainable Development Goals. We aimed to estimate the associations between dietary intake with different cooking methods and T2D risk. We included 14,745 participants (>20 y) from the China Health and Nutrition Survey (1991-2015). Food consumption was calculated using three consecutive 24-h dietary recalls combined with both individual participant level and household food inventory. Cooking methods, including boiling, steaming, baking, griddling, stir-frying, deep-frying, and raw eating, were also recorded. The consumption of baked/griddled and deep-fried foods was positively associated with 39% and 35% higher of T2D risk by comparing the highest with the lowest category of food consumption, respectively. The use of unhealthy cooking methods for processing foods including baked/griddled and deep-fried foods was attributable for 15 million T2D cases of the total T2D burden in 2011, resulting in a medical cost of $2.7 billion and was expected to be attributable for 39 million T2D cases in 2030, producing a medical cost of $223.8 billion. Replacing one serving of deep-fried foods and baked/griddle foods with boiled/steamed foods was related to 50% and 20% lower risk of T2D, respectively. Our findings recommend healthy driven cooking methods for daily diet for nourishing sustainable T2D prevention in China.

Urinary Thioproline and Thioprolinyl Glycine as Specific Biomarkers of Formaldehyde Exposure in Humans

Assessment of personal formaldehyde (FA) exposure is most commonly carried out using formate as a biomarker, as it is the major product from FA metabolism. However, formate could also have originated from the metabolism of other endogenous and exogenous substances or from dietary intake, which may give rise to overestimated results with regard to FA exposure. We have developed and validated a liquid chromatography-tandem mass spectrometry (LC-MS/MS) coupled with an isotope-dilution method for rigorous quantitation of two major urinary FA conjugation products: thioproline (SPro) and thioprolinyl glycine (SPro-Gly), formed in the reaction between FA and endogenous cysteine or cysteinyl glycine, respectively, as marker molecules to assess personal FA exposure. Using this newly developed method, we measured the FA exposure levels in cigarette smokers, occupants of a chemistry research laboratory and typical domestic household, and visitors to a Chinese temple with a Pearson correlation coefficient greater than 0.94, showing a strong linear correlation between urinary adduct levels and the airborne FA level. It is believed that quantitation of urinary SPro and SPro-Gly may represent a noninvasive, interference-free method for assessing personal FA exposure.

Food contaminants: Impact of food processing, challenges and mitigation strategies for food security

Food preparation involves the blending of various food ingredients to make more convenient processed food products. It is a long chain process, where each stage posing a risk of accumulating hazardous contaminants in these food systems. Protecting the public health from contaminated foods has become a demanding task in ensuring food safety. This review focused on the causes, types, and health risks of contaminants or hazardous chemicals during food processing. The impact of cooking such as frying, grilling, roasting, and baking, which may lead to the formation of hazardous by-products, including polycyclic aromatic hydrocarbons (PAHs), heterocyclic amines (HCAs), acrylamide, advanced glycation end products (AGEs), furan, acrolein, nitrosamines, 5-hydroxymethylfurfural (HMF) and trans-fatty acids (TFAs). Potential health risks such as carcinogenicity, genotoxicity, neurotoxicity, and cardiovascular effects are emerging as a major problem in the modern lifestyle era due to the increased uptakes of contaminants. Effects of curing, smoking, and fermentation of the meat products led to affect the sensory and nutritional characteristics of meat products. Selecting appropriate cooking methods include temperature, time and the consumption of the food are major key factors that should be considered to avoid the excess level intake of hazardous contaminants. Overall, this study underscores the importance of understanding the risks associated with food preparation methods, strategies for minimizing the formation of harmful compounds during food processing and highlights the need for healthy dietary choices to mitigate potential health hazards.

Reduction of toxic aldehydes in heated flaxseed oil using sesame and perilla protein enzymatic hydrolysates

Reducing ability of sesame meal protein enzymatic hydrolysates (SMH) and perilla protein enzymatic hydrolysates (PMH) on the content of toxic aldehydes including acetaldehyde, formaldehyde, 2-hydroxylhexenal (HHE), and 2-hydroxyl nonenal (HNE), were evaluated in heated flaxseed oil at concentrations ranging from 0.01 to 1.0 g. Adding SMH and PMH decreased the formation of secondary oxidation products and toxic aldehydes during heating. In particular, HHE and HNE were not detected, even at 0.01 g of protein concentration. Free radical scavenging activities in heated flaxseed oil significantly increased when 1.0 g of SMH and PMH were added (p < 0.05). Some volatiles including 2-ethylpyridine, pyrazines, and trimethylamine were formed or increased substantially in flaxseed oils with higher concentrations of SMH and PMH. In general, SMH showed higher antioxidative activity and reducing ability on the toxic aldehydes than PMH. Plant protein enzymatic hydrolysate could control the formation of toxic aldehydes during oxidation of ω-3 edible oil.

Exposure assessment and monitoring of formaldehyde in agricultural products for the general Korean population

Formaldehyde is naturally present as a product of common metabolism in a diverse range of foods, including meat, fish, vegetables, and processed foods, and can also be introduced to food unintentionally due to its ubiquity in the environment. There has been increased interest in dietary exposure to formaldehyde because of its adverse health effects via multiple sources. The aim of this study was to evaluate the formaldehyde levels in various agricultural products and conduct a deterministic exposure assessment for the South Korean population. Formaldehyde levels were measured using high-performance liquid chromatography, with the samples extracted using water and then derivatized with 2,4-dinitrophenylhydrazine. The levels of formaldehyde were found to range from 0.006 to 25.6 µg/g in agricultural food products (n = 480). For the deterministic exposure assessment, multiple sources for point estimation were employed, with consumption data taken from the 2017 Korean Nutrition Survey. The mean daily formaldehyde exposure per each person was 127.5 µg for the South Korean, constituting approximately 1.4% of the tolerable daily intake (TDI). The hazard index (the ratio of the entire formaldehyde exposure to the TDI) normally fell within the range from 0.01 to 0.22 based on assumptions employed in the deterministic estimation of dietary intake. Based on these estimates, the exposure of the general South Korean to formaldehyde was considered to be safe.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-024-01547-7.

Monitoring, exposure and risk assessment of formaldehyde in alcoholic beverages in Korea

Formaldehyde occurs naturally in food and alcoholic beverages. Formaldehyde and alcoholic beverages can cause various health problems, including irritation of the eyes, nose, and throat, respiratory problems, and skin rashes. Alcoholic beverage samples (N = 236) were collected and analyzed for formaldehyde by liquid chromatography-tandem mass spectrometry. The highest average concentrations were detected in fruit wines (1.71 µg/g), followed by wines (1.15 µg/g), cheongju (0.95 µg/g), soju (0.85 µg/g), takju (0.64 µg/g) and beers (0.61 µg/g). We assessed the exposure and risk assessment to formaldehyde from alcoholic beverages based on the monitoring data for the general population and consumers in Korea using various schemes for point estimation. The daily intakes of formaldehyde for the general population and consumers were estimated to be 83 µg and 1202 µg, respectively. The mean hazard indexes (HI) for the general population and consumers in Korea were 0.009 and 0.132, respectively. On the other hand, the mean hazard indexes (HI) for the general population and consumers in Korea were 0.009 and 0.132, respectively. The exposure to formaldehyde in these alcoholic beverages for the Korean population was shown to be of low concern, but it is necessary to monitor the level of formaldehyde in alcoholic beverages and continuously conduct exposure assessment for consumers.

Recent advances in inspection technologies of food safety health hazards for fish and fish products

The development of reliable and sensitive detection methods is essential for addressing the escalating concerns surrounding fish and fish products, driven by increasing market demands. This comprehensive review presents recent advances in detection approaches, specifically focusing on microplastic, biological, and chemical hazards associated with these products. The overview encompasses 21 distinct detection methods, categorized based on the type of hazard they target. For microplastic hazards, six methods are visual, spectroscopic, and thermal analyses. Biological hazard identification relies on six approaches employing nucleic-acid sequence, immunological, and biosensor technologies. The investigation of chemical hazards encompasses ten methods, including chromatography, spectroscopy, mass spectrometry, immunological, biosensor, and electrochemical techniques. The review provides in-depth insights into the basic principles, general characteristics, and the recognized advantages and disadvantages of each method. Moreover, it elaborates on recent advancements within these methodologies. The concluding section of the review discusses current challenges and outlines future perspectives for these detection methods. Overall, this comprehensive summary not only serves as a guide for researchers involved in fish safety and quality control but also emphasizes the significance of staying abreast of evolving detection technologies to ensure the continued safety of fish and fish products in response to emerging food safety hazards.

Online Exploring the Gaseous Oil Fumes from Oleic Acid Thermal Oxidation by Synchrotron Radiation Photoionization Mass Spectrometry

Cooking oil fumes are an intricate and dynamic mixture containing a variety of poisonous and hazardous substances, and their real-time study remains challenging. Based on tunable synchrotron radiation photoionization mass spectrometry (SR-PIMS), isomeric/isobaric compounds in the gaseous oil fumes from oleic acid thermal oxidation were determined in real time and distinguished by photoionization efficiency (PIE) curve simulation combined with multiple linear regression (MLR) analysis. A series of common carcinogens such as formaldehyde, acetaldehyde, acrolein, and several unreported chemicals including diethyl ether and formylcyclohexane were successfully characterized. Moreover, time-resolved profiles of certain components in gaseous oil fumes were monitored for 55 h. Distinct evolutionary processes were observed, indicating the consumption and formation of parent molecules, intermediates, and final products.

Comparative Analysis of Volatile Organic Compound Purification Techniques in Complex Cooking Emissions: Adsorption, Photocatalysis and Combined Systems

Volatile organic compounds (VOCs) are molecules present in our everyday life, and they can be positive, such as in the formation of odour and food flavour, or harmful to the environment and humans, and research is focusing on limiting their emissions. Various methods have been used to achieve this purpose. Firstly, we review three main degradation methods: activated carbon, photocatalysis and a synergetic system. We provide a general overview of the operative conditions and report the possibility of VOC abatement during cooking. Within the literature, none of these systems has ever been tested in the presence of complex matrices, such as during cooking processes. The aim of this study is to compare the three methods in order to understand the behaviour of filter systems in the case of realistically complex gas mixtures. Proton transfer reaction-mass spectrometry (PTR-MS) has been used in the real-time monitoring of volatilome. Due to the fact that VOC emissions are highly dependent on the composition of the food cooked, we evaluated the degradation capacity of the three systems for different burger types (meat, greens, and fish). We demonstrate the pros and cons of photocatalysis and adsorption and how a combined approach can mitigate the drawbacks of photocatalysis.

Study on the thermal oxidation of oleic, linoleic and linolenic acids by synchrotron radiation photoionization mass spectrometry

RATIONALE

Cooking oil fumes contain numerous hazardous and carcinogenic chemicals, posing potential threats to human health. However, the sources of these species remain ambiguous, impeding health risk assessment, pollution control and mechanism research.

METHODS

To address this issue, the thermal oxidation of three common unsaturated fatty acids (UFAs), namely oleic, linoleic and linolenic acids, present in vegetable oils was investigated. The volatile and semi-volatile products were comprehensively characterized by online synchrotron radiation photoionization mass spectrometry (SR-PIMS) with two modes, which were validated and complemented using offline gas chromatography (GC)/MS methods. Tunable SR-PIMS combined with photoionization efficiency curve simulation enabled the recognition of isomers/isobars in gaseous fumes.

RESULTS

SR-PIMS revealed over 100 products, including aldehydes, alkenes, furans, aromatic hydrocarbons, etc., such as small molecules of formaldehyde, acetaldehyde, acrolein, ethylene and furan, which are not readily detected by conventional GC/MS; and some unreported fractions, e.g. ketene, 4-ethylcyclohexene and cycloundecene(E), were also observed. Furthermore, real-time monitoring of product emissions during the thermal oxidation of the three UFAs via SR-PIMS revealed that linolenic acid may be the major source of acrolein.

CONCLUSION

SR-PIMS has been demonstrated as a powerful technique for online investigation of cooking oil fumes. This study achieved comprehensive characterization of volatile and semi-volatile products from the thermal oxidation of oleic, linoleic and linolenic acids, facilitating the traceability of species in cooking fumes and aiding in exploring the thermal reactions of different vegetable oils.

An update on formaldehyde adulteration in food: sources, detection, mechanisms, and risk assessment

Formaldehyde is added illegally to food to extend its shelf life due to its antiseptic and preservation properties. Several research has been conducted to examine the consequences of adulteration with formaldehyde in food items. These findings suggest that adding formaldehyde to food is considered harmful as it accumulates in the body with long-term consumption. In this review includes study findings on food adulteration with formaldehyde and their assessment of food safety based on the analytical method applied to various geographical regions, food matrix types, and their sources in food items. Additionally, this review sought to assess the risk of formaldehyde-tainted food and the understanding of its development in food and its impacts on food safety in light of the widespread formaldehyde adulteration. Finally, the study would be useful as a manual for implementing adequate and successful risk assessment to increase food safety.

Findings of indoor air pollution and childhood obesity in a cross-sectional study of Chinese schoolchildren

BACKGROUND

Air pollution exposures are increasingly suspected to influence the development of childhood adiposity, especially focusing on outdoor exposure, but few studies investigated indoor exposure and childhood obesity.

OBJECTIVES

We aimed to examine the association between exposure to multiple indoor air pollutants and childhood obesity in Chinese schoolchildren.

METHODS

In 2019, we recruited 6499 children aged 6-12 years from five Chinese elementary schools in Guangzhou, China. We measured age-sex-specific body mass index z score (z-BMI), waist circumference (WC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR) on standard procedures. Four different indoor air pollution (IAP) exposures, including cooking oil fumes (COFs), home decoration, secondhand smoke (SHS), and incense burning, were collected by questionnaire and then converted into an IAP exposure index with four categories. Association between indoor air pollutants and childhood overweight/obesity as well as four obese anthropometric indices were assessed by logistic regression models and multivariable linear regression models, respectively.

RESULTS

Children exposed to ≥3 types of indoor air pollutants had higher z-BMI (coefficient [β]:0.142, 95% confidence interval [CI]:0.011-0.274) and higher risk of overweight/obesity (odd ratio [OR]:1.27, 95%CI:1.01-1.60). And a dose-response relationship was discovered between the IAP exposure index and z-BMI as well as overweight/obesity (p_{for trend}<0.05). We also found that exposure to SHS and COFs was positively associated with z-BMI and overweight/obesity (p < 0.05). Moreover, there was a significant interaction between SHS exposure and COFs on the higher risk of overweight/obesity among schoolchildren. Boys appear more susceptible to multiple indoor air pollutants than girls.

CONCLUSIONS

Indoor air pollution exposures were positively associated with higher obese anthropometric indices and increased odds of overweight/obesity in Chinese schoolchildren. More well-designed cohort studies are needed to verify our results.

Biodegradation of low-density polyethylene plastic waste by a constructed tri-culture yeast consortium from wood-feeding termite: Degradation mechanism and pathway

Polyethylene (PE) is one of the most common synthetic polymers, and PE waste pollution has been an environmental and health concern for decades. Biodegradation is the most eco-friendly and effective approach for plastic waste management. Recently, an emphasis has been placed on novel symbiotic yeasts isolated from termite guts as promising microbiomes for multiple biotechnological applications. This study might be the first to explore the potential of a constructed tri-culture yeast consortium, designated as DYC, isolated from termites for the degradation of low-density polyethylene (LDPE). The yeast consortium DYC stands for the molecularly identified species Sterigmatomyces halophilus, Meyerozyma guilliermondii, and Meyerozyma caribbica. The LDPE-DYC consortium showed a high growth rate on UV-sterilized LDPE as a sole carbon source, resulting in a reduction in tensile strength (TS) of 63.4% and a net LDPE mass reduction of 33.2% compared to the individual yeasts. All yeasts, individually and in consortium, showed a high production rate for LDPE-degrading enzymes. The hypothetical LDPE biodegradation pathway that was proposed revealed the formation of several metabolites, including alkanes, aldehydes, ethanol, and fatty acids. This study emphasizes a novel concept for using LDPE-degrading yeasts from wood-feeding termites for plastic waste biodegradation.

Engineered acetaldehyde dehydrogenase for the efficient degradation of acetaldehyde

Acetaldehyde is highly cytotoxic and widely presents in food and the environment. Aldehyde dehydrogenase (ALDH) can degrade acetaldehyde to non-toxic acetic acid, showing potential for acetaldehyde elimination. However, a lack of high-throughput methods for screening efficient variants is a significant obstacle to ALDH design. Here, we established a visualized high-throughput method to screen recombinantly expressed ALDH variants in Bacillus subtilis by fluorescent probes of dual-acceptor cyanine-based in response to NADH, the acetaldehyde degradation product. Molecular docking revealed key amino acids in the binding region of acetaldehyde to ALDH. Combined with saturation mutagenesis and visualization high-throughput methods, a variant ALDH^S273N with an activity of 119.82 U·mL^-1 was screened. The optimal reaction temperature and pH of ALDH^S273N were 60 °C and 9.0, respectively. ALDH^S273N showed stability at 30-50 °C and pH 5.0-9.0. The activity of ALDH^S273N was increased to 263.52 U∙mL^-1 by fermentation optimization, which was 5.58 times that of ALDH^WT. The degradation rate of ALDH^S273N to 100 mmol L^-1 acetaldehyde was 87.34% within 2 h, which was 4.2 times that of the wild enzyme (20.81%). As far as we know, this is the ALDH with the highest activity reported so far, and it is also the first time that ALDH has been used for the efficient degradation of acetaldehyde. Overall, the reported high-throughput screening method and developed mutants represent a significant advance in green bio-elimination technologies of acetaldehyde.

Electrochemical and Optical Sensors for the Detection of Chemical Carcinogens Causing Leukemia

The incidence and mortality due to neoplastic diseases have shown an increasing tendency over the years. Based on GLOBOCAN 2020 published by the International Agency for Research on Cancer (IARC), leukemias are the thirteenth most commonly diagnosed cancer in the world, with 78.6% of leukemia cases diagnosed in countries with a very high or high Human Development Index (HDI). Carcinogenesis is a complex process initiated by a mutation in DNA that may be caused by chemical carcinogens present in polluted environments and human diet. The IARC has identified 122 human carcinogens, e.g., benzene, formaldehyde, pentachlorophenol, and 93 probable human carcinogens, e.g., styrene, diazinone. The aim of the following review is to present the chemical carcinogens involved or likely to be involved in the pathogenesis of leukemia and to summarize the latest reports on the possibility of detecting these compounds in the environment or food with the use of electrochemical sensors.

Ozone catalytic oxidation of low-concentration formaldehyde over ternary Mn-Ce-Ni oxide catalysts modified with FeOx

Manganese oxide-based catalysts have attracted extensive attention due to their relatively low cost and remarkable performance for removing VOCs. In this research, we used the Pechini method to synthesize manganese-cerium-nickel ternary oxide catalysts (MCN) and evaluated the effectiveness of catalytic destruction of formaldehyde (HCHO) and ozone at room temperature. FeO_x prepared by the impregnation method was applied to modify the catalyst. After FeO_x treatment, the catalyst represented the best performance on both HCHO destruction and ozone decomposition under dry conditions and exhibited excellent water vapor resistance. The as-prepared catalysts were next characterized via H₂-temperature programmed reduction (H₂-TPR), temperature programmed desorption of O₂ (O₂-TPD), and X-ray photoelectron spectroscopy (XPS), and the results demonstrated that addition of FeO_x increased Mn³⁺ and Ce³⁺ concentrations, oxygen vacancies and surface lattice oxygen species, facilitated adsorption, and redox properties. Based on the results of in situ diffuse reflectance infrared Fourier transform spectrometry (DRIFTS), possible mechanisms of ozone catalytic oxidation of HCHO were proposed. Overall, the ternary mixed-oxide catalyst developed in this study holds great promise for HCHO and ozone decomposition in the indoor environment.

Effect of acrolein on the formation of harman and norharman in chemical models and roast beef patties

Harman and norharman were the most abundant β-carboline-type heterocyclic amines (HCAs) detected in various foodstuffs. Unsaturated fatty acids in foods may undergo rapid oxidative deterioration during transportation, storage and heat treatment, forming reactive carbonyl species (RCS). This work studied the effects of acrolein, a highly reactive RCS, on the formation of harman and norharman in the tryptophan model system. Results showed that 0.005, 0.01, 0.015, 0.02, 0.05, 0.1 and 0.2 mmol of acrolein led to harman production increased by 528 %, 752 %, 981 %, 1172 %, 1375 %, 1288 % and 768 % respectively, and led to norharman formation increased by 116 %, 129 %, 152 %, 169 %, and 197 %, 185 % and 157 %, respectively. Furthermore, acrolein addition reduced the residue of tryptophan (up to 63.19 %), but increased the level of the intermediates including formaldehyde (up to 352 %), acetaldehyde (up to 491 %), (1S,3S)-1-Methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (MTCA, up to 1936 %), and 1,2,3,4-tetrahydro-β-carboline-3-carboxylicacid (THCA, up to 2142 %) in the tryptophan model system. Acrolein might react with tryptophan, harman and norharman to eliminate them directly. These data suggested that acrolein may contribute to harman and norharman formation through participating in the above complex chemical reactions. In addition, the content of harman and norharman produced in roast beef patties made of minced beef oxidized for 2, 4, 6, 8, and 10 days increased by 118 %, 188 %, 267 %, 137 %, and 48 %, respectively, and led to norharman formation increased by 140 %, 132 %, 90 %, 86 %, and 74 %, respectively compared with those made of fresh minced beef, which further illustrated that lipid oxidation products potentially contributed to harman and norharman formation.

Simultaneous quantification of 24 aldehydes and ketones in oysters (Crassostrea gigas) with different thermal processing procedures by HPLC-electrospray tandem mass spectrometry

Aldehydes and ketones are secondary oxidation products resulting from lipid oxidation that occurs during food processing. These small molecule compounds not only have an impact on the quality, odor and flavor of food, but also play a role in the pathogenesis of many human diseases. In this study, a HPLC-MS/MS analytical method was developed and validated for the simultaneous determination of 24 aldehydes and ketones. The coefficients of determination (R²) for all aldehydes and ketones were higher than 0.9975 at the range of 0.2-2000 ng/mL. The recoveries were in the range 71.20-108.13% with RSD < 10%. The method was tested by analyzing lipids from oysters with different thermal processing (boiling, frying, roasting and air frying) procedures; the highest concentration for saturated aldehydes and ketones while the highest content of unsaturated aldehydes in boiling treatment. Meanwhile, fatty acid oxidative decomposition was in agreement with aldehydes and ketones formation. Moreover, principal component analysis, orthogonal partial least-squares discriminant analysis and variable importance in projection value showed that lipid oxidation is positively related to the formation of a variety of aldehydes and ketones.