Emissions of volatile aldehydes from heated cooking oils

Removing volatile organic compounds in cooking fume by nano-sized TiO2 photocatalytic reaction combined with ozone oxidation technique

Chinese cooking fume is one of the sources of volatile organic compounds (VOCs) in the air. An innovative control technology combining photocatalytic degradation and ozone oxidation (UV/TiO₂+O₃) was developed to decompose VOCs in the cooking fume. Fiberglass filter (FGF) coated with TiO₂ was prepared by an impregnation procedure. A continuous-flow reaction system was self-designed by combining photocatalysis with advanced ozone oxidation technique. By passing the simulated cooking fume through the FGF, the VOC decomposition efficiency in the cooking fume could be increased by about 10%. The decomposition efficiency of VOCs in the cooking fume increased and then decreased with the inlet VOC concentration. A maximum VOC decomposition efficiency of 64% was obtained at 100 ppm. Similar trend was observed for reaction temperature with the VOC decomposition efficiencies ranging from 64 to 68%. Moreover, inlet ozone concentration had a positive effect on the decomposition of VOCs in the cooking fume for inlet ozone≤1000 ppm and leveled off for inlet ozone>1000 ppm. 34% of VOC decomposition efficiency was achieved solely by ozone oxidation with or without near-UV irradiation. A maximum of 75% and 94% VOC decomposition efficiency could be achieved by O₃+UV/TiO₂ and UV/TiO₂+O₃ techniques, respectively. The maximum decomposition efficiencies of VOCs decreased to 79% for using UV/TiO₂+O₃ technique with adding water in the oil fume. Comparing the chromatographical species of VOCs in the oil fume before and after the decomposition of VOCs by using UV/TiO₂+O₃technique, we found that both TVOC and VOC species in the oil fume were effectively decomposed.

Preparation of a Natural Candy from Date (Phoenix dactyliferaL.), Olive (Olea europaeaL.), and Carob (Ceratonia siliquaL.) Fruits

Until the early 1960s, the traditional recipe “Arkouy” from the mixture of carob (Ceratonia siliquaL.) powder and olive (Olea europaeaL.) oil represented a sought-after food product in some localities of the Kabylian region (Northeastern Algeria). The present work attempted to improve this traditional recipe to obtain a natural candy from date (Phoenix dactyliferaL.), olive (Olea europaeaL.), and carob (Ceratonia siliquaL.) fruits. For this, different formulations with various proportions of the date paste, olive paste, and carob powder were obtained using a constrained mixture design (proportion of date paste ≥ 0.7). The hardness and total color difference in the CIELab system were adopted as dependent variables. For comparison purpose, the local commercial candy “Caprice” was taken as reference. In addition, the two formulations containing the three basic ingredients were analyzed for the overall acceptability, reducing power, and thermal analysis. At first approximation, it can be said that the formulation containing 75% date paste, 20% carob powder, and 5% olive paste ensures a balance between the target values of texture and color. The obtained candy can be used as a dietary supplement for all categories of consumers, especially patients with swallowing difficulties.

Volatile molecular markers of VOO Thermo-oxidation: Effect of heating processes, macronutrients composition, and olive ripeness on the new emitted aldehydic compounds

Heating operation has been applied to Chétoui extra-virgin olive oils (EVOOs) extracted from fruits with several ripening stages (RS). The studied samples, were subjected to microwave and conventional heating. Results showed that heated VOOs after 2.5 h and 7 min of conventional and microwave heating, respectively, gave rise to a drastically decrease of LOX products and allowed the detection of toxic new formed aldehydic volatiles (alkanal: nonanal, alkenals: (Z)-2-heptenal and (E)-2-decenal, and alkadienals: (E.E)-2.4-decadienal), which can be used as markers of VOO degradation. Their abundance in the VOO headspaces depends on their boiling points, the rate of their possible degradation to yield other compounds, on the heating processes and on the rate of macronutrients. The emission rate of the new synthesized volatiles during heating processes was mainly attributed to enzymatic oxidation of some fatty acids. Hexanal, (Z)-2-heptenal, (E)-2-octenal, (E)-2-nonenal, (E,E) and (E,Z)-2,4-decadienal, and (E,E)-2,4-nonadienal, derived from linoleic acid, and heptanol, octanal, nonanal, decanal, (E) and (Z)-2-decenal, (E)-2-undecenal, and (E,E)-2,4-nonadienal, are emitted after degradation of oleic acid. During thermo-oxidation, the ECN₄₄ (LLO, and OLnO), and the ECN₄₆ (OLO, and PLO + SLL) compounds decreased, whereas, the ECN₄₈ (OOO, and PPO), and the ECN₅₀ (SOO) compounds increased when temperature and heating time increased. The several variations of the studied biochemical compounds depend to the heating processes. Ripening stage of olive fruits can be used as a tool to monitor the emission rate of the aldehydic volatiles, but cannot be used for a chemometric discrimination.

Oxygenated VOCs, aqueous chemistry, and potential impacts on residential indoor air composition

Dampness affects a substantial percentage of homes and is associated with increased risk of respiratory ailments; yet, the effects of dampness on indoor chemistry are largely unknown. We hypothesize that the presence of water-soluble gases and their aqueous processing alters the chemical composition of indoor air and thereby affects inhalation and dermal exposures in damp homes. Herein, we use the existing literature and new measurements to examine the plausibility of this hypothesis, summarize existing evidence, and identify key knowledge gaps. While measurements of indoor volatile organic compounds (VOCs) are abundant, measurements of water-soluble organic gases (WSOGs) are not. We found that concentrations of total WSOGs were, on average, 15 times higher inside homes than immediately outside (N = 13). We provide insights into WSOG compounds likely to be present indoors using peer-reviewed literature and insights from atmospheric chemistry. Finally, we discuss types of aqueous chemistry that may occur on indoor surfaces and speculate how this chemistry could affect indoor exposures. Liquid water quantities, identities of water-soluble compounds, the dominant chemistry, and fate of aqueous products are poorly understood. These limitations hamper our ability to determine the effects of aqueous indoor chemistry on dermal and inhalation exposures in damp homes.

Coconut Products Improve Signs of Diet-Induced Metabolic Syndrome in Rats

Increasing prevalence of obesity and metabolic syndrome warrants identification of potential therapeutic options for intervention. This study tested commercially available Virgin Coconut Oil and Coconut Nourish, as coconuts are rich sources of lauric and myristic acids. Male Wistar rats were fed either corn starch diet (C); high-carbohydrate, high-fat diet (H); high-carbohydrate, high-virgin coconut oil diet (HV); or high-carbohydrate, high-coconut Nourish diet (HN) for 16 weeks. Metabolic, liver, and cardiovascular health parameters were measured during and at the end of the study. Virgin coconut oil lowered body weight (C 386±8g, H 516±13g, HV 459±10g), blood glucose concentrations (C 4.2±0.1 mmol/L, H 5.4±0.2 mmol/L, HV 4.6±0.2 mmol/L), systolic blood pressure (C 127±5mmHg, H 149±4mmHg, HV 133±3mmHg,) and diastolic stiffness (C 25.0±1.7, H 31.4±1.2, HV 25.2±2.3,) with improved structure and function of the heart and liver. Coconut Nourish increased total body lean mass (C 255±10g, H 270±16g, HN 303±15g) and lowered plasma total cholesterol concentrations (C 1.6±0.2 mmol/L, H 1.7±0.1 mmol/L, HN 1.0±0.0 mmol/L), systolic blood pressure (C 127±5mmHg, H 149±4mmHg, HN 130±3mmHg) and diastolic stiffness (C 25.0±1.7, H 31.4±1.2, HN 26.5±1.0), improved structure and function of the heart and liver but increased plasma concentrations of triglycerides (C 0.3±0.1 mmol/L, H 1.1±0.4 mmol/L, HN 1.8±0.2 mmol/L) and non-esterified fatty acids (C 1.2±0.3 mmol/L, H 3.3±0.8 mmol/L, HN 5.6±0.4 mmol/L). Thus, the fiber and protein in coconut Nourish and the medium-chain saturated fatty acids in virgin coconut oil may improve cardiovascular and liver complications in obesity.

Emission of volatile organic compounds and production of secondary organic aerosol from stir-frying spices

Cooking is an important source of volatile organic compounds (VOCs) and a potential source of secondary organic aerosol (SOA) both indoors and outdoors. In this study, VOC emissions from heating corn oil and stir-frying spices (i.e. garlic, ginger, myrcia and zanthoxylum piperitum (Sichuan pepper)) were characterized using an on-line membrane inlet vacuum ultraviolet single-photon ionization time-of-flight mass spectrometer (VUV-SPI-TOFMS). VOC emissions from heating corn oil were dominated by aldehydes, which were enhanced by factors of one order of magnitude when stir-frying spices. Stir-frying any of the spices studied generated large amounts of methylpyrrole (m/z 81). In addition, stir-frying garlic produced abundant dihydrohydroxymaltol (m/z 144) and diallyldisulfide (DADS) (m/z 146), while stir-frying ginger, myrcia and zanthoxylum piperitum produced abundant monoterpenes (m/z 136) and terpenoids (m/z 152, 154). SOA formed from emissions of stir-frying spices through reactions with excess ozone in a flow reactor as well as primary organic aerosol (POA) emissions were characterized using a scanning mobility particle sizer (SMPS) and a high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS). Stir-frying garlic and ginger generated similar POA concentrations to those from heating corn oil while stir-frying myrcia and zanthoxylum piperitum generated double the amount of emissions. No SOA was observed from stir-frying garlic and ginger. The rates of SOA production from stir-frying myrcia and zanthoxylum piperitum were 1.8μgmin^-1g_spice^-1 and 8.7μgmin^-1g_spice^-1, equivalent to 13.4% and 53.1% of their own POA emission rates, respectively. Therefore, the contribution of stir-frying spices to ambient organic aerosol levels is likely dominated by POA. The rates of total terpene emission from stir-frying myrcia and zanthoxylum piperitum were estimated to be 5.1μgmin^-1g_spice^-1 and 24.9μgmin^-1g_spice^-1, respectively. Our results suggest that stir-frying spices could be an important source of terpenes in indoor environments in Hong Kong, at least during cooking.

Formation of potentially toxic carbonyls during oxidation of triolein in the presence of alimentary antioxidants

ABSTRACT

A relation between oil uptake and cancer as well as induction of hepatic inflammation was shown earlier. It is discussed that the main oil oxidation products-hydroperoxides and carbonyls-might be the reason for the mentioned diseases. In this manuscript quantitative determination of aldehydes which are formed during oxidation of triolein-as a model substance-using the Rancimat 679 is described. The oxidation of 11 g of triolein is carried out at 120 °C sparging air with a flow of 20 dm3/h for 10 h. A series of aliphatic aldehydes starting from hexanal to decanal as well as decenal was identified by LC-MS/MS and quantified as DNPH derivatives. In addition, the total amount of carbonyls was determined. Based on the calibration with hexanal, all other dominant substances were in the similar concentration range with maximum concentrations of 1.6 µmol/cm3 of hexanal, 2.3 µmol/cm3 of heptanal, 2.5 µmol/cm3 of octanal, 3.2 µmol/cm3 of nonanal, 4.0 µmol/cm3 of decanal after 6 h. The total amount of carbonyls reached a maximum after 6 h being 27 µmol/cm3 for triolein without antioxidant. The results of this investigation will be a basis for further toxicological studies on oxidized oils.

GRAPHICAL ABSTRACT

Reaction pathway mechanism of thermally induced isomerization of 9,12-linoleic acid triacylglycerol

BACKGROUND

To clarify the formation mechanism of trans linoleic acid isomers in edible oils during the heating process, trilinolein and trilinoelaidin, as representative oils, were placed in glass ampoules and sealed before heating at 180, 240 and 320 °C. The glass ampoules were removed at regular time intervals, and the contents were analyzed by infrared spectroscopy. The samples were then subjected to derivatization into their methyl esters for gas chromatographic analysis.

RESULTS

Analysis results show that 9c,12c and 9t,12t fatty acids from trilinolein and trilinoelaidin molecules undergo chemical bond rotation, migration and degradation, leading to the formation of non-conjugated linoleic acids (NLAs), conjugated linoleic acids (CLAs) and aldehydes. The formation rate of isomers from the 9c,12c fatty acid is higher than that of the 9t,12t fatty acid. The production of aldehydes increases with heating temperature and time. The isomerization pathways involved in the formation of NLAs and CLAs during heating are clearly presented.

CONCLUSION

These findings suggest possible pathways of NFA and CFA formation from heated trilinolein and trilinoelaidin, complement the mechanistic studies previously published in the literature, and provide a theoretical basis for future control of the quality and safety of fats and oils. © 2016 Society of Chemical Industry.

Lipidomic Analysis of Oxidized Fatty Acids in Plant and Algae Oils

Linoleic acid (LA) and α-linolenic acid (ALA) in plant or algae oils are precursors to oxidized fatty acid metabolites known as oxylipins. Liquid chromatography tandem mass spectrometry was used to quantify oxylipins in soybean, corn, olive, canola, and four high-oleic acid algae oils at room temperature or after heating for 10 min at 100 °C. Flaxseed oil oxylipin concentrations were determined in a follow-up experiment that compared it to soybean, canola, corn, and olive oil. Published consumption data for soybean, canola, corn, and olive oil were used to estimate daily oxylipin intake. The LA and ALA fatty acid composition of the oils was generally related to their respective oxylipin metabolites, except for olive and flaxseed oil, which had higher LA derived monohydroxy and ketone oxylipins than other oils, despite their low LA content. Algae oils had the least amount of oxylipins. The change in oxylipin concentrations was not significantly different among the oils after short-term heating. The estimated oxylipin intake from nonheated soybean, canola, corn, and olive oil was 1.1 mg per person per day. These findings suggest that oils represent a dietary source of LA and ALA derived oxylipins and that the response of oils to short-term heating does not differ among the various oils.

Effects of cooking method, cooking oil, and food type on aldehyde emissions in cooking oil fumes

Cooking oil fumes (COFs) contain a mixture of chemicals. Of all chemicals, aldehydes draw a great attention since several of them are considered carcinogenic and formation of long-chain aldehydes is related to fatty acids in cooking oils. The objectives of this research were to compare aldehyde compositions and concentrations in COFs produced by different cooking oils, cooking methods, and food types and to suggest better cooking practices. This study compared aldehydes in COFs produced using four cooking oils (palm oil, rapeseed oil, sunflower oil, and soybean oil), three cooking methods (stir frying, pan frying, and deep frying), and two foods (potato and pork loin) in a typical kitchen. Results showed the highest total aldehyde emissions in cooking methods were produced by deep frying, followed by pan frying then by stir frying. Sunflower oil had the highest emissions of total aldehydes, regardless of cooking method and food type whereas rapeseed oil and palm oil had relatively lower emissions. This study suggests that using gentle cooking methods (e.g., stir frying) and using oils low in unsaturated fatty acids (e.g., palm oil or rapeseed oil) can reduce the production of aldehydes in COFs, especially long-chain aldehydes such as hexanal and t,t-2,4-DDE.

Characterization of the variation of carbonyl compounds concentrations before, during, and after the renovation of an apartment at Niterói, Brazil

The present work reports the variation of 31 carbonyl compounds (CC) in an apartment located at Niterói City, Rio de Janeiro State, Brazil. Eight sampling campaigns were conducted through a 1-year period, and three areas (living room, kitchen, and bedroom) were evaluated before, during, and after the renovation activities and reoccupation of the apartment. Samples were collected using SEP-PAK cartridges impregnated with 2,4-dinitrophenylhydrazine, and the hydrazones were analyzed using rapid resolution liquid chromatography with UV detection. The lowest total concentration of CC (19.0 ± 1.5 μg m(-3)) was found before the renovation when the apartment was empty, but door varnishing resulted in highest contamination of the apartment (1386 ± 384 μg m(-3)); however, an important dispersion of CC was observed in the subsequent sampling (148 ± 1.8 μg m(-3)). After apartment reoccupation, the indoor contamination seemed to depend on the routine activities taken there, such as household product use and cooking activities, but apparently, local temperature increase favored the vaporization of the volatile CC from the building materials in the apartment. As far as we are concerned, this is the first study comparing the concentrations of 31 CC in residential areas before, during, and after renovation activities taken in Brazil.

Comparative study of oxidative stress biomarkers in urine of cooks exposed to three types of cooking-related particles

OBJECTIVES

To evaluate how exposure to deep-frying oils, repeated frying oil (RFO) and restaurant waste oil (RWO) affects emission of polycyclic aromatic hydrocarbons (PAHs) and oxidative stress in male restaurant workers.

METHODS

The study participants included 236 male restaurant workers in 12 restaurants in Shenzhen. Airborne particulate PAHs were measured over 12h on each of two consecutive work days. Urinary 1-hydroxypyrene (1-OHP) measurements were used to indicate cooking oil fumes (COF) exposure, and urinary malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were adopted as oxidative stress markers.

RESULTS

The production and emission rates of ultrafine particles (UFPs) and PM2.5 were higher in the exposed groups than in the control group. The concentrations of summed PAHs were in the order of RFO-frying group>RWO-frying group>deep-frying group>unexposed control group. Urinary 1-OHP was found to be a significant predictor of elevated urinary MDA and 8-OHdG concentrations (all, P<0.05). UFPs were a significant predictor of elevated urinary 8-OHdG for restaurant workers (P<0.05). The RFO- and RWO-frying groups had higher mean urinary concentrations of 1-OHP, MDA and 8-OHdG than the control group (P<0.05). RFO exposure was found to be a significant risk factor for elevated urinary 8-OHdG and RWO exposure was found to be a significant risk factor for elevated urinary MDA (both, P<0.001).

CONCLUSIONS

Concentrations of urinary 1-OHP, MDA and 8-OHdG reflect occupational exposure to PAHs from COFs and oxidative stress in restaurants workers. Exposure to RFO may cause increased oxidative DNA damage, and exposure to RWO might cause increased lipid peroxidation.

Carbonyl compounds in dining areas, kitchens and exhaust streams in restaurants with varying cooking methods in Kaohsiung, Taiwan

Eighteen carbonyl species in C1-C10 were measured in the dining areas, kitchens and exhaust streams of six different restaurant types in Kaohsiung, southern Taiwan. Measured results in the dining areas show that Japanese barbecue (45.06ppb) had the highest total carbonyl concentrations (sum of 18 compounds), followed by Chinese hotpot (38.21ppb), Chinese stir-frying (8.99ppb), Western fast-food (8.22ppb), Chinese-Western mixed style (7.38ppb), and Chinese buffet (3.08ppb), due to their different arrangements for dining and cooking spaces and different cooking methods. On average, low carbon-containing species (C1-C4), e.g., formaldehyde, acetaldehyde, acetone and butyraldehyde were dominant and contributed 55.01%-94.52% of total carbonyls in the dining areas of all restaurants. Meanwhile, Chinese-Western mixed restaurants (45.48ppb) had high total carbonyl concentrations in kitchens mainly because of its small kitchen and poor ventilation. However, high carbon-containing species (C5-C10) such as hexaldehyde, heptaldehyde and nonanaldehyde (16.62%-77.00% of total carbonyls) contributed comparatively with low carbon-containing compounds (23.01%-83.39% of total carbonyls) in kitchens. Furthermore, Chinese stir-frying (132.10ppb), Japanese barbecue (125.62ppb), Western fast-food (122.67ppb), and Chinese buffet (119.96ppb) were the four restaurant types with the highest total carbonyl concentrations in exhaust streams, indicating that stir-frying and grilling are inclined to produce polluted gases. Health risk assessments indicate that Chinese hotpot and Japanese barbecue exceeded the limits of cancer risk (10(-6)) and hazard index (=1), mainly due to high concentrations of formaldehyde. The other four restaurants were below both limits.

Characterization of Gas-Phase Organics Using Proton Transfer Reaction Time-of-Flight Mass Spectrometry: Cooking Emissions

Cooking processes produce gaseous and particle emissions that are potentially deleterious to human health. Using a highly controlled experimental setup involving a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS), we investigate the emission factors and the detailed chemical composition of gas phase emissions from a broad variety of cooking styles and techniques. A total of 95 experiments were conducted to characterize nonmethane organic gas (NMOG) emissions from boiling, charbroiling, shallow frying, and deep frying of various vegetables and meats, as well as emissions from vegetable oils heated to different temperatures. Emissions from boiling vegetables are dominated by methanol. Significant amounts of dimethyl sulfide are emitted from cruciferous vegetables. Emissions from shallow frying, deep frying and charbroiling are dominated by aldehydes of differing relative composition depending on the oil used. We show that the emission factors of some aldehydes are particularly large which may result in considerable negative impacts on human health in indoor environments. The suitability of some of the aldehydes as tracers for the identification of cooking emissions in ambient air is discussed.

A comparative study on the in vitro antioxidant activity of tocopherol and extracts from rosemary and Ferulago angulata on oil oxidation during deep frying of potato slices

There is a tendency towards the use of natural antioxidative substances due to toxic effects of synthetic antioxidants. The purpose of this research was to evaluate the effects of tocopherol and extracts from rosemary and ferulago on oxidation in a mixture (1:1, w/w) of sunflower seed oil and palm olein, during deep frying of potato slices. Besides the control groups, tertiary butylhydroquinone (TBHQ) served as a standard for comparison. The DPPH radical scavenging activities of extracts followed the order of rosemary10% > rosemary1% > rosemary0.1 % > ferulago 10 % > ferulago 1 % > ferulago 0.1 %. Frying performance of antioxidants were tested with regards to primary (peroxide value (PV)) and secondary (anisidine value (AnV), free fatty acids (FFA), total polar compounds (TPC) and volatile oxidation compounds such as hexanal and heptanal) oxidation products and by sensory evaluation. After frying process, rosemary extract treatment exhibited PV (1.2 meq O2/kg), FFA content (0.124 %), TPC (12.2 %), hexanal concentration (62.4 ng/g) and heptanal concentration (73.8 ng/g), which were significantly equal or sometimes less than those of TBHQ treatment ((1.23 meq O2/kg), (0.123 %), (12.6 %), (64.4 ng/g) and (74.1 ng/g), respectively). Whilst the ferulago extract showed higher PV (2 meq O2/kg) than the control sample, it was efficient in delaying secondary oxidative changes. Tocopherol markedly retarded primary stage but its activity fell down toward secondary oxidation products. The overall results of this research suggest that rosemary extract may be a good natural alternative to TBHQ, but further studies are necessary to investigate the use of ferulago extract.

The changes in the volatile aldehydes formed during the deep-fat frying process

Volatile aldehydes (VAs) formed during soybean oil (SBO) heating, wheat dough (WD) frying, and chicken breast meat (CBM) frying processes were comparatively investigated by solid-phase micro-extraction-gas chromatography-mass spectrometry (SPME-GC-MS). The results showed that relative amounts (RAs) of the most detected VAs were firstly increased to maximum values in oil samples collected at the second hour of the seventh day and the values were then decreased with the increase in the time of oil heating process (control). However, for food frying processes, the time needed for reaching maximum RAs of VAs was shorter and the values were decreased with the increase in frying time. Significant change in contents of the VAs was observed for oil samples fried with CBM due to the high contents of water, protein, and lipid content compared to oil samples fried with WD. Based on the obtained results, free radical reaction, particularly positional isomerization and cis-trans isomerization, was deduced to occur when WD or CBM was fried in SBO. The relatively high RAs of VAs formed during the deep-fat frying process presented certain invaluable measures for evaluating of frying oil and fried food quality and safety.

Indoor air quality in a restaurant kitchen using margarine for deep-frying

Indoor air quality has a great impact on human health. Cooking, in particular frying, is one of the most important sources of indoor air pollution. Indoor air CO, CO2, particulate matter (PM), and volatile organic compound (VOC) concentrations, including aldehydes, were measured in the kitchen of a small establishment where a special deep-frying margarine was used. The objective was to assess occupational exposure concentrations for cooks of such restaurants. While individual VOC and PM2.5 concentrations were measured before, during, and after frying events using active sampling, TVOC, PM10, CO, CO2, temperature, and relative humidity were continuously monitored through the whole period. VOC and aldehyde concentrations did not increase to considerable levels with deep-frying compared to the background and public indoor environment levels, whereas PM10 increased significantly (1.85 to 6.6 folds). The average PM2.5 concentration of the whole period ranged between 76 and 249 μg/m(3). Hence, considerable PM exposures could occur during deep-frying with the special margarine, which might be sufficiently high to cause health effects on cooks considering their chronic occupational exposures.

Evaluation of the concentrations and distribution of carbonyl compounds in selected areas of a Brazilian bus terminal

This study describes the determination of 30 carbonyl compounds (CCs) in three areas (bus boarding platform, passenger circulation area, and a pastry shop) of the Presidente João Goulart Bus Terminal, located at Niterói City, RJ, Brazil, and in an open area 700 m distant from the terminal. Samples were collected using SEP-PAK cartridges impregnated with 2,4-dinitrophenylhydrazine, during May to July 2012. The hydrazones formed were analyzed using rapid resolution liquid chromatography with UV detection. The studied locations showed distinct profiles of distribution of CC. The circulation area, which is influenced by different pollution sources, presented an intermediate profile between that of the pastry shop and boarding platform. Formaldehyde and acetaldehyde were the most abundant CC, but acetaldehyde predominated in the pastry shop once it is a by-product of baking yeast fermentation. Samples taken in the pastry shop and circulation area showed significant concentrations of hexanaldehyde and nonanaldehyde emitted during cooking. The pastry shop showed the largest level of total CC among the studied areas followed by the circulation area, the boarding platform, and the open area.

Elevated levels of mercapturic acids of acrolein and crotonaldehyde in the urine of Chinese women in Singapore who regularly cook at home

Lung cancer is unusually common among non-smoking women in Southeastern Asia but the causes of this frequently fatal disease are not well understood. Several epidemiology studies indicate that inhalation of fumes from high temperature Chinese style cooking with a wok may be a cause. Only one previous study investigated uptake of potential toxicants and carcinogens by women who cook with a wok. We enrolled three-hundred twenty-eight non-smoking women from Singapore for this study. Each provided a spot urine sample and answered a questionnaire concerning their cooking habits and other factors. The urine samples were analyzed by liquid chromatography-tandem mass spectrometry for mercapturic acid metabolites of acrolein (3-hydroxypropylmercapturic acid), crotonaldehyde (3-hydroxy-1-methylpropylmercapturic acid), and benzene (S-phenylmercapturic acid), accepted biomarkers of uptake of these toxic and carcinogenic compounds. We observed statistically significant effects of wok cooking frequency on levels of 3-hydroxypropylmercapturic acid and 3-hydroxy-1-methylpropylmercapturic acid, but not S-phenylmercapturic acid. Women who cooked greater than 7 times per week had a geometric mean of 2600 (95% CI, 2189-3090) pmol/mg creatinine 3-hydroxypropylmercapturic acid compared to 1901 (95% CI, 1510-2395) pmol/mg creatinine when cooking less than once per week (P for trend 0.018). The corresponding values for 3-hydroxy-1-methylpropylmercapturic acid were 1167 (95% CI, 1022-1332) and 894 (95% CI, 749-1067) pmol/mg creatinine (P for trend 0.008). We conclude that frequent wok cooking leads to elevated exposure to the toxicants acrolein and crotonaldehyde, but not benzene. Kitchens should be properly ventilated to decrease exposure to potentially toxic and carcinogenic fumes produced during Chinese style wok cooking.

In vitro effects of low-level aldehyde exposures on human umbilical vein endothelial cells

Aldehydes cause gene expression changes for genes associated with cardiovascular disease. Exposure to aldehydes from tobacco smoke needs to be controlled.

Can rapeseed oil replace olive oil as part of a Mediterranean-style diet?

The present narrative review compares evidence from experimental, epidemiological and clinical studies of the health benefits of rapeseed oil (RO) (known as canola oil) and olive oil (OO) in order to assess whether rapeseed oil is suitable as a sustainable alternative to OO as part of a Mediterranean-style diet in countries where olive trees do not grow. From epidemiological studies, the evidence for cardiovascular protection afforded by extra-virgin OO is 'convincing', and for cancers 'limited-suggestive', especially oestrogen receptor-negative breast cancer, but more studies are required in relation to cognitive impairment. Evidence for RO is limited to short-term studies on the biomarkers of risk factors for CVD. Any benefits of RO are likely to be due to α-linolenic acid; however, it is prone to oxidation during frying. We conclude that due to a lack of evidence from observational or intervention studies indicating that RO has comparable health benefits to extra-virgin OO, RO cannot currently be recommended as a suitable substitute for extra-virgin OO as part of a Mediterranean-style diet.

Determination of toxic α-dicarbonyl compounds, glyoxal, methylglyoxal, and diacetyl, released to the headspace of lipid commodities upon heat treatment

Toxic α-dicarbonyl compounds, glyoxal, 2-methylglyoxal, and diacetyl, released from the headspace from butter, margarine, safflower oil, beef fat, and cheese heated at 100 and 200 °C were analyzed by gas chromatography as quinoxaline derivatives. Total amounts of α-dicarbonyl compounds ranged from 40.5 ng/g (butter) to 331.2 ng/g (beef fat) at 100 °C and from 302.4 ng/g (safflower oil) to 4521.5 ng/g (margarine) at 200 °C. The total amount of α-dicarbonyl compounds increased approximately 55- and 15-fold in the headspace of heated butter and margarine, respectively, when the temperature was increased from 100 to 200 °C. However, only slight differences associated with temperature variation were observed in the cases of safflower oil and beef fat (1.3- and 1.1-fold, respectively). Diacetyl was found in the highest amounts among all samples, ranging from 13.9 ± 0.3 ng/g (butter) to 2835.7 ng/g (cheese) at 100 °C and from 112.5 ± 102 ng/g (safflower oil) to 2274.5 ± 442.6 ng/g (margarine) at 200 °C, followed by methylglyoxal, ranging from 13.0 ± 0.5 to 112.7 ± 10.1 ng/g (cheese) at 100 °C and from 34.7 ± 5.0 ng/g (safflower oil) to 1790 ± 372.3 ng/g (margarine) at 200 °C. Much less glyoxal formed, in amounts ranging from 13.6 ± 0.7 ng/g (butter) to 53.4 ± 11.2 ng/g (beef fat) at both temperatures. The amounts of α-dicarbonyl compounds released into the vapor phase from lipid commodities during heating were satisfactorily analyzed.

The modern paradox of unregulated cooking activities and indoor air quality

Pollutant emission from domestic and commercial cooking activities is a previously neglected area of concern with respect to human health worldwide. Its health effects are relevant to people across the globe, not only those using low quality food materials in lesser-developed countries but also to more affluent people enjoying higher quality food in developed countries. Based on the available database of pollutant emissions derived from fire-based cooking, its environmental significance is explored in a number of ways, especially with respect to the exposure to hazardous vapors and particulate pollutants. Discussion is extended to describe the risk in relation to cooking methods, cooking materials, fuels, etc. The observed pollutant levels are also evaluated against the current regulations and guidelines established in national and international legislation. The limitations and future prospects for the control of cooking hazards are discussed.