Biological caramel

The resulting reduction in caloric value of browned or caramelized foods is of little significance for well-fed Americans. Loss of biologically available amino acids is of concern only for those consuming diets of marginal protein quality. 

Caramel is unintentionally generated in burnt carbohydrate foods (rice, oatmeal, cornmeal, etc.) and molasses (Kowkabany et al., 1953) it is the source of maple flavor and color in the concentration of maple sap to maple syrup (Stinson and Willits, 1965). In industrial manufacturing, the intended application is taken into account, because reaction conditions help determine the properties of the pyrolysate, e.g., its tinctorial value, water solubility, and alcohol stability. Tinctorial value refers to the absorbance at 560 nm of a 0.1-wt/vol% solution in a 1-cm cell. Tinctorial strength increases with acidity, temperature, and duration of heating. Caramel manufactured above pH 6.3 is biologically unstable and much below pH 3.1, it is a resin. 

Ever since it was suspected that caramels are biologically active, the daily uptake levels for them have been calculated, and announced (for instance, in Austria ). 

The unfavorable biological activity of caramels may be caused by some by-products formed in the course of caramelization. 4(5)-Methylimidazole is a well known, neurotoxic by-product present in ammonia and ammonia sulfite caramels. For this reason, these commonly used caramels are banned by the Food Laws of some countries, and, in others, serious limits have been put on accepted levels of that compound in caramels, as well as on the daily uptake of food finished with such caramels. Although 4(5)-methylimidazole can eventually be removed from caramel, or its content diminished by adsorption, extraction, centrifugation, or ultrafiltration, still other components of caramel may appear to be active in unfavorable ways. For instance,... 

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