What happen when we heat sugar? It will undergo a reaction called caramelization. This imparts a brown color and a unique taste to every food preparation. As far as my knowledge was concern, I believed that there was only one kind of caramel. Hmm… I was wrong cause there are four classification depending on how the caramels are made.
The simplest is the plain. Has an E Number of E150a. The second, caustic sulfite caramel, has E Number E 150b. This is manufactured in the presence of sulfite compounds. The third, ammonia caramel, has E number E 150c. It is manufactured in the presence of ammonium compounds. The fourth and the last, sulfite ammonia caramel. It is manufactured in the presence of both sulfite and ammonia.
The plain caramel sounds safe but the second to the last are scary. They are manufactured with the presence of sulfite, ammonia and both. Hazardous substances may rise during manufacturing.
Every type of caramel has its own purpose. However, every products with caramel ingredient only declare the word “caramel” on their label. How lame! It should be “sulfite ammonia caramel” for sofdrinks and “ammonia caramel” for beer. On the manufacturer’s point of view, doing so may repel lot of potential customers. Money comes first before health. Huh!
The current acceptable daily intake (ADI) of caramel colors is 300 mg per kg body weight per day (mg/kg bw/day). The ADI is set on the basis that there are no concluded evidence that it may harm humans. The caramel E 150c has a lower limit, an ADI of 150 mg/kg bw/day. It has a lower set limit due to its 2-acetyl-4-tetrahydroxibutylimidazole (THI). Its possible side effects are uncertain.
Another by-product in question is 4-methylimidazole (4-MEI), present in E150c and E150d. It has carcinogenic effects in some animal studies.
Jonh (wiki.answers) mentioned that caramel acts as vitamin B6 and may prevent treating asthma. No further studies found to prove the claim.