Occurrence of 13 volatile organic compounds in foods from the Canadian total diet study

Abstract

Volatile organic compounds (VOCs) are ubiquitous in the environment due to evaporation and incomplete combustion of fuels, use of consumer and personal care products, etc. and they can accumulate in foods. Some VOCs in foods can also be formed during food processing and preparation and migrate from food packaging. In this pilot study, a GC-MS method based on headspace solid-phase microextraction (SPME) was validated and used to analyse selected individual foods which can be consumed directly and 153 different total diet composite food samples for 13 VOCs. Vinyl chloride was not detected in any of the 153 composite food samples, while the other 12 VOCs were detected at various frequencies, with m-xylene being the most frequently detected (in 151 of the 153 samples), followed by toluene (145), 1,3,5-trimethylbenzene (140), ethylbenzene (139), styrene (133), 1,2,4-trimethylbenzene (122), benzene (96), p-dichlorobenzene (95), n-butylbenzene (55), chloroform (45), naphthalene (45) and trichloroethylene (31). Concentrations of the 12 VOCs in most of the food composite samples were low, with the 90th percentiles from 1.6 ng g(-1) for n-butylbenzene to 20 ng g(-1) for toluene. However, some VOCs were detected at higher levels with maxima, for example, of 948 ng g(-1) for m-xylene and 320 ng g(-1) for ethylbenzene in chewing gum, 207 ng g(-1) for styrene and 157 ng g(-1) for toluene in herbs and spices. VOCs were detected at higher levels in most of the individual food items than their corresponding composite samples, for example, the average chloroform concentration in the individual canned soft drinks was 20 ng g(-1) compared with 3.0 ng g(-1) in their composite, and the average toluene concentration in the individual canned citrus juice was 96 ng g(-1) compared with 0.68 ng g(-1) in their composite. Thus, for determination of VOCs in foods which can be consumed directly, their individual food items should be analysed whenever possible for accurate exposure assessment.

Evaluation of potential health effects associated with occupational and environmental exposure to styrene – an update

“…In a recent updated evaluation of styrene migration from polystyrene food contact materials, Genualdi, Nyman, and Begley (2014) measured styrene concentrations in wrapped food products and chewing gum (which contains styrene-butadiene as a gum base). The generally similar styrene concentrations reported by Cao, Sparling, and Dabeka (2016) in similar food items are provided for comparison in Table S20.…”

“…However, only "negligible" concentrations (<0.1 µg/L) of styrene were identified in bottled waters purchased in Missouri (Ikem 2010). Similarly, styrene was below the detection limit (<0.025 µg/L) in samples of "natural spring" waters (presumed to be bottled) purchased in Canada (Cao, Sparling, and Dabeka 2016;Cao et al 2018). Therefore, it does not appear that bottled water is likely to be a significant source of styrene exposure in the U.S. Melski, Zabielski, and Kubera (2003) evaluated three styrenic objects commonly used for food packaging.…”

“…Styrene appears to occur naturally in many foods and beverages, although it is not clear in some cases whether it is formed endogenously or if its presence is the result of partitioning from the environment (including both air and polystyrene food contact materials) (Cao, Sparling, and Dabeka 2016;Cao et al 2018;Jickells et al 1993Jickells et al , 1992Lickly, Breder, and Rainey 1995;Miller, Newhook, and Poole 1994;Steele et al 1994;Tang, Hemm, and Eisenbrand 2000).…”

“…Most informative with respect to current total dietary exposure in the U.S. are recent results from the Canadian Total Diet Study (Cao, Sparling, and Dabeka 2016;Cao et al 2018). In food samples collected from four stores in Vancouver, Canada in 2007, styrene was detected in 133 of 153 different total diet composite food samples (87%).…”

p‐Cymene, a natural antioxidant, in Canadian total diet foods: occurrence and dietary exposures

“…Assuming p ‐cymene is not present or present at low levels in the other herbs and spices (black pepper, basil, cinnamon) of the composite sample, p ‐cymene concentration in oregano could theoretically be as high as 294 μg g −1 . The herbs and spices composite sample is also known to contain other VOCs at high levels, such as styrene, which is present in cinnamon …”