Analysis of furan and its major furan derivatives in coffee products on the Chinese market using HS-GC-MS and the estimated exposure of the Chinese population.

The current study analysed concentrations of furan and its derivatives in coffee products commercially available in China based on an improved headspace gas chromatography-mass spectrometry (HS-GC-MS) method and estimated health risks. A total of 101 samples of coffee products on the Chinese market was analysed. Furan (98%, ND-6569 µg/kg) and 2-methylfuran (100%, 2-29639 µg/kg) were the compounds with the highest concentrations and detection rates in coffee products. The mean dietary exposure of Chinese consumers to furan and the sum of furan, 2-methylfuran and 3-methylfuran in coffee products was 0.09 and 0.46 µg/kg bw/day, respectively. For the neoplastic effects of furan, the margin of exposure (MOE) was 14,556 for the mean dietary exposure of consumers. For the non-neoplastic effects of furan, MOEs were 711 and 139 for furan and the sum of furan, 2-methylfuran and 3-methylfuran, respectively. Overall, a health concern is indicated for coffee consumers with MOEs below 10000.

Particle size and variety of coffee used as variables in mitigation of furan and 2-methylfuran content in espresso coffee.

In this study, the concentration of furan and 2-methylfuran in espresso coffee (EC) obtained from Arabica and Robusta coffee varieties was determined as a function of specific particle size. The particle size and coffee variety significantly influenced the level of furan and 2-methylfuran. In Arabica variety, furan and 2-methylfuran level increased with increasing particle size. Particularly, from C<200µm to C>425µm fractions, furan increased from 68.27 to 91.48 ng mL-1 while 2-methylfuran from 404.31 to 634.64 ng mL-1. In Robusta variety, the highest concentration of furan and 2-methylfuran occurred in ECs prepared using C300-425µm fraction showing values of 116.39 ng mL-1 and 845.14 ng mL-1, respectively, for furan and 2-methylfuran. On the basis of this experiment, it is possible to establish a mitigation strategy by manipulating the particle size and coffee variety in order to reduce the level of furan and 2-methylfuran in EC up to 11.4% and 18.8%, respectively.

Volatile biomarkers for early-stage detection of insect-infested brown rice: Isopentenols and polysulfides.

To reduce food loss from stored products by insect attack, monitoring and early detection of insects are essential. Presently, monitoring with pheromone traps is the primary method for detection; however, traps are effective only after the insects propagate. Detection and identification of the early volatile biomarkers arising from insect-infested brown rice was performed in this study to develop an alternative detection strategy. Brown rice was infested with eggs of seven insect species, including Sitophilus zeamais and Plodia interpunctella. Infested rice emitted at least one of the volatile compounds prenol, isoprenol, dimethyl disulfide, and dimethyl trisulfide (DMTS). In particular, isopentenols were generated by moths within one week of infestation, whereas they were not released from non-infested rice. DMTS was detected from all insect-infested brown rice, especially S. zeamais and P. interpunctella. These volatiles are potential early biomarkers for the presence of insects in brown rice.

Influence of lipid content and stirring behaviour on furan and furan derivative exposure in filter coffee.

Coffee has been determined as the dominant source of furan within an adult's diet. This study investigates the influence of coffee condiment use and stirring on the retention of furan. Three condiment lipid compositions were investigated, 0%, 3.5% and 35%, and kept at either 4 °C, 20 °C or 70 °C before addition to a freshly brewed cup of filter coffee which was subsequently mechanically stirred at three intensities, not stirred and moderately or heavily stirred. While five furans were monitored, furan, 2-methylfuran, 3-methylfuran, 2,5-dimethylfuran and 2,3-dimethylfuran, only two were quantifiable: furan and 2-methylfuran. Increasing condiment lipid concentration significantly increased retention of furan and 2-methylfuran, whereas stirring the coffee significantly increased furan release. A condiment temperature of 70 °C was found to significantly increase furan release.

Impact of consumer behavior on furan and furan-derivative exposure during coffee consumption. A comparison between brewing methods and drinking preferences.

This study examined the influence of consumer behavior on furan, 2-methylfuran, 3-methylfuran, 2,5-dimethylfuran and 2,3-dimethylfuran exposure in coffee. Coffees brewed using a filter, fully automatic, capsule machine or reconstituted instant coffee were found to have a significant different cup concentrations of furan derivatives. Coffee brewed with the fully automatic machine contained the highest furan and furan derivative concentrations (99.05 µg/L furan, 263.91 µg/L 2-methylfuran, 13.15 µg/L 3-methylfuran and 8.44 µg/L 2,5-dimethylfuran) whereas soluble coffee did not contain detectable levels, thereby contributing least to a consumer's dietary exposure. Furan and furan derivative concentrations were found to decrease significantly upon cooling, reducing consumer exposure by 8.0-17.2 % on average once the coffee reached drinking temperature 55-60 °C, in ceramic cups. Serving coffee in a ceramic or disposable cup were found to influence the cooling dynamics of the coffee but did not statistically influence the consumers exposure at a given temperature.

Determination of furan and furan derivatives in baby food.

A Headspace-Solid Phase Microextraction-Gas Chromatography-Mass Spectrometry (HS-SPME-GC-MS) method was developed and validated for the simultaneous determination of furan, 2-methylfuran, 2-ethylfuran, 2-butylfuran, 2-pentylfuran, 2-acetylfuran, furfural and furfuryl alcohol in jarred baby food. The method was specific for the analytes. Good precision was obtained both in terms of intra-day repeatability (RSD ≤ 5.02) and inter-day precision (RSD ≤ 5.55%). The recovery values were between 98.42% and 99.8%. Linearity was established over two order of magnitude, and the achieved LODs and LOQs ranged between 0.018 and 0.035 ng/g and 0.060-0.117 ng/g, respectively, depending on the analyte. Finally, the method was successfully applied to investigate the content of furan and furan derivatives in several commercial baby food samples containing fruit or meat. The results showed that this simple, rapid and solvent free procedure could be used routinely for the analysis of baby food providing competent quantitative data functional to risk assessment.

An efficient method for the simultaneous determination of furan, 2-methylfuran and 2-pentylfuran in fruit juices by headspace solid phase microextraction and gas chromatography-flame ionisation detector.

A headspace solid phase microextraction (HS-SPME) procedure followed by gas chromatography-flame ionisation detector (GC-FID) analysis was developed and validated for the simultaneous analysis of furan, 2-methylfuran and 2-pentylfuran from juice samples. Extraction at 32 °C for 20 min with stirring at 600 rpm and NaCl concentration 15% (W/V) was the optimal HS-SPME condition for all the three compounds by using a carboxen/polydimethylsiloxane fused silica fibre (75 µm). The extracted compounds were base line separated on a SPB-1 GC column within 12 min. The relative standard deviations of all analytes were less than 6.7%. The recovery rates were between 90.2% and 110.1%. The limits of detection and limits of quantification were 0.056-0.23 ng/mL and 0.14-0.76 ng/mL, respectively. The results showed that the developed method was sensitive, precise, accurate and robust for the determination of furan, 2-methylfuran and 2-pentylfuran in complex matrices without interferences from other components.