Natural antioxidants from residual sources.

The sentiment that woodsmoke, being a natural substance, must be benign to humans is still sometimes heard. It is now well established, however, that wood-burning stoves and fireplaces as well as wildland and agricultural fires emit significant quantities of known health-damaging pollutants, including several carcinogenic compounds. Two of the principal gaseous pollutants in woodsmoke, CO and NOx, add to the atmospheric levels of these regulated gases emitted by other combustion sources. Health impacts of exposures to these gases and some of the other woodsmoke constituents (e.g., benzene) are well characterized in thousands of publications. As these gases are indistinguishable no matter where they come from, there is no urgent need to examine their particular health implications in woodsmoke. With this as the backdrop, this review approaches the issue of why woodsmoke may be a special case requiring separate health evaluation through two questions. The first question we address is whether woodsmoke should be regulated and/or managed separately, even though some of its separate constituents are already regulated in many jurisdictions. The second question we address is whether woodsmoke particles pose different levels of risk than other ambient particles of similar size. To address these two key questions, we examine several topics: the chemical and physical nature of woodsmoke; the exposures and epidemiology of smoke from wildland fires and agricultural burning, and related

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Woodsmoke Health Effects: A Review

Understanding the fundamental chemical and physical aging mechanisms is necessary to learn how to produce a bio-oil that is more stable during shipping and storage. This review provides a basis for this understanding and identifies possible future research paths to produce bio-oils with better storage stability.

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A review of the chemical and physical mechanisms of the storage stability of fast pyrolysis bio-oils

Antioxidant activity of compounds isolated from the pyroligneous acid, Rhizophora apiculata

Optimization of microencapsulation of seed oil by response surface methodology

A commercial aqueous smoke preparation was exhaustively extracted, using dichloromethane as solvent, until the carrier had totally lost its smoky odor. Qualitative and quantitative characterizations of the extract were performed by means of gas chromatography/mass spectrometry and gas chromatography with flame ionization detector, respectively. Carbonyl derivatives including aldehydes and ketones as well as acids and esters are almost absent; however, the high proportion of phenol, guaiacol, and syringol derivatives is noticeable. The presence of di-tert-butylhydroxytoluene, several hopanes, and a number of lignin dimers must be pointed out; these latter components had apparently not been detected before either in smoke flavorings or in wood smoke. The mass spectral data of the compounds considered as lignin dimers and of the unidentified components are given. The presence of lignin dimers is very interesting from the point of view of health and food technology for their therapeutic, organoleptic, and antioxidant properties.

New Components with Potential Antioxidant and Organoleptic Properties, Detected for the First Time in Liquid Smoke Flavoring Preparations

The static headspace composition of sunflower oil throughout the oxidation process at 70 °C with circulating air is studied by means of solid-phase microextraction followed by gas chromatography−mass spectrometry (SPME-GC-MS); at the same time the liquid phase of the same oil is studied by means of Fourier transform infrared (FTIR) spectroscopy. Each technique provides complementary information about the process; FITR spectroscopy detects changes in the functional groups of the liquid matrix in a global way and SPME/GC-MS provides information about the different components present in the volatile phase during the oxidation process. Concordance between the timing of the changes produced in both liquid and gaseous phases is observed, as well as agreement and complementarity in the results obtained from both phases. The formation of some well-known genotoxic and cytotoxic oxygenated aldehydes in this process and their presence in the oil headspace are proved. Keywords: Sunflower oil; oxidation process; Fouri...

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Study of both sunflower oil and its headspace throughout the oxidation process. Occurrence in the headspace of toxic oxygenated aldehydes.

Commercial smoke flavorings were extracted with dichloromethane and the remaining aqueous phase was evaporated at room temperature; the residues obtained were dissolved in methanol and studied by gas chromatography/mass spectrometry. The composition of these residues was totally different from that of the dichloromethane extracts, constituting a small number of compounds that were also detected in the dichloromethane extract, as well as a large number of compounds not described before as components of either smoke for food smoking or smoke flavorings. Among those compounds not previously described there are some furan, pyran, and phenolic derivatives, as well as some pyridine and carbohydrate derivatives. The main component of these fractions is 1,6-anhydro-β-d-glucopyranose, or levoglucosan. Likewise, aqueous residues of liquid smoke flavorings, prepared at a laboratory scale from beech, vine shoots, thyme, and sage, were studied in the same way. These contained compounds of the same groups cited above, ...

Carbohydrate and nitrogenated compounds in liquid smoke flavorings

Components detected by means of solid-phase microextraction and gas chromatography/mass spectrometry in the headspace of artisan fresh goat cheese smoked by traditional methods.

Vitis vinifera L shoots and Fagus sylvatica L wood were used to obtain aqueous smoke flavouring preparations. Both flavourings have a gold colour and pleasant odour. The flavour components of both samples are extracted with dichloromethane. The identification and quantitation of the components of the extracts are carried out by means of gas chromatography/mass spectrometry, and gas chromatography with flame ionisation detection. In both preparations carbonyl derivatives are in higher concentrations than phenol derivatives. Compounds that confer sweet, burnt and pungent flavours are in higher concentrations in the Vitis vinifera L shoots smoke flavouring, and compounds that give smoky flavours are in higher concentrations in the Fagus sylvatica L wood smoke flavouring. Ratios between the concentrations of the main components are proposed as parameters in order to characterise smoke and smoke flavourings, manufactured under specific conditions, from a specific wood. Finally, the yield of some components from a fixed amount of wood is also given.

María L. Ibargoitia

Papers

New Components with Potential Antioxidant and Organoleptic Properties, Detected for the First Time in Liquid Smoke Flavoring Preparations

Study of both sunflower oil and its headspace throughout the oxidation process. Occurrence in the headspace of toxic oxygenated aldehydes.

Carbohydrate and nitrogenated compounds in liquid smoke flavorings

Components detected by means of solid-phase microextraction and gas chromatography/mass spectrometry in the headspace of artisan fresh goat cheese smoked by traditional methods.

Volatile components of aqueous liquid smokes from Vitis vinifera L shoots and Fagus sylvatica L wood