ABSTRACT
Furan was classified as "possibly carcinogenic to humans" by the International Agency for Research on Cancer in 1995. The joint FAO/WHO Committee set the maximum permissible furan at 2 mcg/kg body weight/day in 2010. The furan content of coffee is high as compared to other processed foods. Considering the increasing trend of coffee consumption in Iran, this study was initiated to determine the furan content of different kinds of coffee powder available in Tehran Market by headspace liquid-phase microextraction coupled with gas chromatography mass spectrometry [HS-LPMEGC-MS]. The e CCD mployed included 32 treatments at 5 levels for 4 factors with 8 replicates of center point. The furanic compounds from 66 different coffee samples were extracted by HSLPME atoptimal extraction conditions [salt 0 gram, stirrer rate 700 rpm, extraction temperature 45°C, and extraction time 15 min]. The effect of coffee brewing and coffee mix preparation on furanic compound content of coffee was also determined. The proposed method was validated by determining linearity, repeatability, recovery, enrichment factor, LOD, and LOQ. Determination of furan in coffee samples showed that there were significant differences [p<0.05] in furan concentration of different coffees [prepared by different methods] and that preparation method was the most important factor influencing the furan content of coffee. The coffee brewing and preparation of instant coffee and coffee mixes reduced furanic compounds concentration except furfural. The lowest and highest concentrations of furan in commercial coffee products were10 and 6320 ppb, respectively. In the present work, a simple, fast micro-extraction method [HS-LPME] for extraction and pre-concentration of furanic compounds in coffee samples was developed and validated. The advantages of this method are reduced solvent use, low-cost equipment use, simple experimental setup, acceptable precision and accuracy, a high enrichment factor, and no matrix interference. Differences detected in the furanic compound contents in the coffee samples are due to different green coffee bean species, coffee production process [roasting condition [time and temperature], time of degassing, and grade of grinding process]. Brewing coffee in open systems can result in decreases in the content of these compounds to an acceptable level