The ability of foods and beverages to reduce allyl methyl disulfide, diallyl disulfide, allyl mercaptan, and allyl methyl sulfide on human breath after consumption of raw garlic was examined. The treatments were consumed immediately following raw garlic consumption for breath measurements, or were blended with garlic prior to headspace measurements. Measurements were done using a selected ion f...

Plant volatiles (PVs) mediate manifold interactions between plants and their biotic and abiotic environments (Dicke and Baldwin, 2010; Holopainen and Gershenzon, 2010). An understanding of the physiological and ecological functions of PVs must therefore be based on measurements of PV emissions under natural conditions. Yet sampling PVs in natural environments is difficult, limited by the need t...

In this study, the effect of glycerol (0.5, 1 and 1.5% w/w) and vegetable oil (2, 3 and 4% w/w) on the equilibrium headspace concentration of target volatile flavor compounds released from the orange beverage emulsions during storage was investigated by using the headspace solid phase microextraction (HS-SPME). The peak areas of 13 target orange flavor compounds (i.e. ethyl acetate, α-pinene, e...

The 5-day biochemical oxygen demand (BOD5) test has been used for over a century to evaluate the concentration of biodegradable organic matter in wastewater effluents. The BOD test is a simple batch test, but it is also time consuming, labor intensive, imprecise, and, due to the dilution of the wastewater, takes a relatively long time to complete. Advances in laboratory instruments and lab ware...

The aim of this study was to compare two extraction procedures: dynamic headspace-purge and trap (PT) and headspace solid-phase microextraction (HS-SPME) for gas chromatographic determination of benzene, toluene, ethylbenzene, and isomeric xylenes (BTEX) in urine with photoionization (PID) and mass spectrometric (MS) detection, respectively. Both methods showed linearity in the range of interes...

Soybean oils were packaged in polyvinylchloride, acrylonitrile, clear glass and amber glass bottles and their flavor stabilities were evaluated by a trained sensory panel. Hydrogenated and unhyrdogenated oils showed similar patterns of flavor deterioration regardless of container or type of aging. In accelerated light-exposure tests with air in the headspace, oils in plastic bottles showed flav...

A dynamic headspace solid-phase microextraction methodology was developed for analysis of varietal aroma compounds in must and Madeira wine samples, a spirit wine with an ethanol content of 18% (v/v). The factors with influence in the headspace solid-phase microextraction efficiency such as: fibre coating, extraction time and temperature, pH, ionic strength, ethanol content, desorption time and...

Volatile organic compounds (VOCs) in cut onions (Allium cepa L.) were continuously measured by PTR-MS during the first 120 min after cutting. The headspace composition changed rapidly due to the very reactive volatile sulfurous compounds emitted from onion tissue after cell disruption. Mass spectral signals corresponding to propanethial S-oxide (the lachrymatory factor) and breakdown products o...

The formation of acrylamide was measured in real time during thermal treatment (120-170 degrees C) of potato as well as in Maillard model systems composed of asparagine and reducing sugars, such as fructose and glucose. This was achieved by on-line monitoring of acrylamide released into the headspace of the samples using proton transfer reaction mass spectrometry (PTR-MS). Unambiguous identific...