Development of an analytical method and survey of foods for furan, 2-methylfuran and 3-methylfuran with estimated exposure.

Furan has been found to form in foods during thermal processing. These findings, a classification of furan as a possibly carcinogenic to humans, and a limited amount of data on the concentration of furan in products on the Canadian market prompted the authors to conduct a survey of canned and jarred food products. Methyl analogues of furan, 2-methylfuran and 3-methylfuran, were analysed concurrently with furan via a newly developed isotope dilution method, as these analogues were detected in foods in the authors' earlier work and are likely to undergo a similar metabolic fate as furan itself. The paper reports data on 176 samples, including 17 samples of baby food. The vast majority of samples were packaged in cans or jars. Furan was detected above 1 ng g(-1) in all non-baby food samples with a median of 28 ng g(-1) and concentrations ranging from 1.1 to 1230 ng g(-1). Also, 96% of these samples were found to contain 2-methylfuran above 1 ng g(-1) with a median of 12.8 ng g(-1) and a maximum concentration of 152 ng g(-1), while 81% of samples were found to contain 3-methylfuran above 1 ng g(-1) with a median of 6 ng g(-1) and a maximum concentration of 151 ng g(-1). Similarly, furan was detected above 1 ng g(-1) in all baby food samples with a median of 66.2 ng g(-1) and concentrations ranging from 8.5 to 331 ng g(-1). Also, 100% of these samples were found to contain 2-methylfuran above 1 ng g(-1) with a median of 8.7 ng g(-1) and a maximum concentration of 50.2 ng g(-1), while 65% of samples were found to contain 3-methylfuran above 1 ng g(-1) with a median of 1.6 ng g(-1) and a maximum concentration of 22.9 ng g(-1). Additionally, three coffee samples were analysed 'as is', without brewing, and were found to have high levels of furans, especially 2-methylfuran, at a maximum of 8680 ng g(-1). Using this data set, dietary exposures to furan and total furans were calculated. Average furan and total furan intakes by adults (> or = 20 years) were estimated at approximately 0.37 and 0.71 microg kg(-1) of body weight day(-1) respectively.