Wednesday, January 4, 2012


There are increasing concerns among the consumers regarding the safety of many processed food products they consume every day. In many wealthy countries processed foods form more than 80% of their daily diet and it is easy to comprehend what would be the consequences if unsafe foods are ingested day in day out. While most concerns are based on the food industry practices of using hundreds of chemicals while manufacturing or cross contamination of foods with deadly bacteria and mold, there is also grave apprehension regarding the potential health damage some of the artifacts generated during processing can cause. Recent focus on such chemicals like acrylamide, polycyclic aromatic hydrocarbons, benzene and furan is because of the above concerns. 

Furan is not a new chemical discovered as it was known for ages and lot of studies regarding its synthesis and properties have been published. Furan and its derivatives are naturally occurring compounds found at very low levels in many foods and drinks and their association with the typical flavor of many foods is well known. They are a major class of compounds formed during the Maillard reactions and under pyrolytic conditions. Ascorbic acid and related compounds and Maillard type systems containing amino acids and reducing sugars, lipid oxidation of unsaturated fatty acids or triglycerides and carotenoids all contribute to formation of Furan during processing. Ionising radiation on the Furan formation in apple and orange juice products as well as in model systems has also been reported. Of course these basic knowledge did not raise much concern earlier but their detection in many industry processed foods became a matter of speculation regarding their effect on human health.

What is new is the detection of Furan in some foods using sophisticated analytical techniques in 2004 which raised some alarm regarding its impact on human health. It is rather surprising that a simple hetero cyclic organic compound like Furan with a 5-membered aromatic structure, made of 4 carbon atoms and an oxygen atom, can be a potentially toxic artifact capable of causing harm to human beings. Furan should not be confused with Furans, a separate category of chemical compounds broadly called Chlorinated di benzofurans coming under Dioxins. They however do not occur in any foods and hence not of much concern to the food industry as of now. According to International Agency for Research on Carcinogens, Furan is considered a carcinogen in human beings though evidence is yet to emerge with studies using human subjects.

Of a number of food samples from the industry analysed by the US Authorities, occurrence of Furan was confirmed in all products in concentrations in the range of 3 parts per billion (ppb) to 112 ppb. Almost all these products are either canned or bottled having undergone the sterilization process at high temperatures. Interestingly products containing sweet potato as a component invariably showed higher levels of Furan. Also Coffee, meat soups, stews, Chilli are other major sources of Furan. One redeeming feature in this scenario is that Furan is highly volatile and due to this furan is easily analyzed using a head space or SPME coupled with gas chromatography-mass spectrometry. Furan is rapidly and extensively absorbed from the intestine and the lung. It can pass through biological membranes and enter various organs.  Experiments have shown that furan is carcinogenic to rats and mice, showing a dose-dependent increase in hepatocellular adenomas and carcinomas, though preliminary exposure data suggest that the levels of Furan found in foods are well below the levels that would cause harmful effects.

What is the consumer to make out of these startling revelations? Probably sufficient data still do not exist to try for a zero tolerance level of Furan in foods though efforts are being made to find more about the safety aspects of this chemical. Since Furan is highly volatile normal open pan cooking and vigorous stirring can be expected to expel most of it through evaporation. A safe guideline is not to consume foods found to be very rich in Furan  and for maintaining good health consumer is well advised to eat a balanced diet, choosing a variety of foods that are low in trans-fat and saturated fat, and rich in high-fibre grains, fruits, and vegetables. Of course this easier said than done!


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