FURAN UPDATE-LATEST RISK ASSESSMENT

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!

V.H.POTTY
http://vhpotty.blogspot.com/
http://foodtechupdates.blogspot.com

MALTED MILK-AN OVERHYPED PRODUCT?

The promotional thrust in India of a particular product which is globally marketed, reads some thing like this: "consumption of this product makes children taller, stronger, sharper than other kids". Interestingly the promoters roped in some professionals in the ads to make the claim all the more convincing. What is this product? A distinct category of beverages popular in India under the category ' Malted Milk' containing malt extract and milk solids. It also claims A-Z nutrition to pre-school children guaranteeing 100% of daily needs of 'key' nutrients, promoting sleep if consumed at bed time and increased growth and alertness amongst children. While in India such claims go unchallenged, UK Authorities have termed these claims as 'unsubstantiated'!

No doubt the combination of malt and milk can be a good base for an attractive product with high sensory quality. Malted milk was originally developed in 1873 by a UK entrepreneur, after shifting to America, by name James Horlick and the product was patented in 1883. Originally marketed under the name 'Diastoid', it was later branded as 'Malted Milk'. There are many variants of malted milk and generally they contain about 7% fat, 70% carbohydrates ( starch and sugars), 12% proteins and other ingredients. The process of manufacture involves blending of milk, malt extract and sugar, drying the blend under vacuum and milling to desired particle size. Some use spray drying also. The malt extract used is not an active malt preparation with diastatic activity but made from roasted malted cereals by extraction and vacuum concentration into 78%-80% solids thick syrup. It contains about 1-3% fructose, 30-42% maltose, 15% maltotriose, 7-10% glucose and rest higher saccharides, all of them reducing sugars. The typical flavor associated with malt extract is due to aldehydes and pyrazines generated during roasting of the malt before extraction.

Coming to the nutrition part, any food scientist worth his salt knows that malt extract owes its color to Maillard reaction, first discovered by the French Biochemist Louis-Camille Maillard, that is triggered by presence of reducing sugars and amino acids present in proteins at temperatures of 235C-255C that exists in the kilns used for roasting. But even at lower temperatures like ambient conditions the reaction takes place, albeit slowly. For every 10C rise in temperature, the reaction rate increases 2-3 times. When such a material like malt extract and milk are mixed and heated even at lower temperatures, the Maillard reaction is bound to be accelerated. What are the consequences of Maillard reaction on the nutrition of a product like Malted Milk?

Protein-reducing sugar reaction generally contributes to deterioration and loss of nutritional value of proteins during processing and storage, a fact well known to food scientists. More disturbing is the reported involvement of Maillard reaction products causing chemical aging of long-lived proteins in human tissues. Products of sequential glycation and oxidation of proteins, known as glycoxidation products accumulate in these long-lived proteins with advancing age and at an accelerated rate in diabetes. The precise implication of these artifacts on the health of consumers is still not well understood, raising uncertainties regarding their real nutritive impact. Reduced availability of Lysine and some of the essential amino acids and formation of inhibitory chemicals or anti-nutritional compounds during processing and storage may be of real concern when any judgment is made regarding the relevance of malted milk products as a regular item of consumption in the diet. Probably milk consumed alone may be more nutritious than the so called malted milk. Viewed in this context the health claims by the malted milk industry are not vindicated by science and hence will remain unsubstantiated unless such claims are validated by studies as per international protocols.

The purpose of this blog is not to indict any brand of products in the market but to focus on the inadequacies of data based on which special nutritional claims can be made. Probably stoichiometrically the Maillard reaction may not be affecting very significantly the absolute quantum of protein available and the artifacts produced may not be as harmful as they are thought to be. But the scientific arguments based on existing data as articulated above, do support the theory that Maillard reaction is not desirable if nutritional value is the main concern in products like malted milk.

V.H.POTTY
http://vhpotty.blogspot.com/