Caramel chemistry

P. Caramel la. P. Grunanger, / J-Dipolar Cycloaddition Chemistry, A. Padwa, F.d, Wiley. New York 1984. 

Pyrazines. In the thirties, the attention on pyrazines was focused on its industrial role in dyes, photographic emulsions and chemotherapy. Its importance in life processes was indicated in its derivative, vitamin B2 (riboflavin, 6,7-dimethyl-9-(l -D-ribityl isoalloxazine). Later,in the midsixties, it was identified in foods and its contributions to the unique flavor and aroma of raw and processed foods attracted the attention of flavor chemists Pyrazine derivatives contribute to the roasting, toasting, nutty, chocolaty, coffee, earthy, caramel, maple-like, bread-like, and bell pepper notes in foods. The reader is referred to the reviews on Krems and Spoerri (88) on the chemistry of pyrazines, and the review of pyrazines in foods by Maga and Sizer (89, 90) Table XVI summaries sensory description and threshold of selected pyrazines. 

Article Caramel. Thoipe s Dictionary of Applied Chemistry."... 

The nonvolatile, high-molecular-weight fraction of caramel produced without any catalyst seems to contain three components. They are called caramelan, caramelen, and caramelin. Thus far, the problem of their chemical structure remains an intriguing, unsolved part of the chemistry of caramel. 

YAYLAYAN, V. A. and KAMINSKY, E. (1998). Isolation and structural analysis of Maillard polymers caramel and melanoidin formation in glycine/glucose model system. Food Chemistry, 63, 25-31. 

Casier J.P.J., Zenous A.A. and de Paepe G.M.J. (1978) The chemistry of the black-caramel colour substances of several human foods. In Flavor of Foods and Beverages, Chemistry and Technology (Athens, 27-29.6.78). Char-alambous G. and Inglett Eds, Academic Press, New York, pp. 169-97. 

Apart from the derivatives of p-carotene, other pigments are the anthocyanins, the chlorophylls, cochineal, the betalaines, turmeric, caramel and riboflavin. In this account the historical background in brief, the chemistry of these pigments, their extraction from natural sources and their synthesis will be discussed. The present permitted natural substances and nature-identical synthetic materials (also described by the Food and Drugs Administration, the FDA, as colorants exempt from certification ) is quite small in number. Reference is also made to colourants no longer listed but which have an historical organic chemical significance such as for example brazilin and its relative haematoxylin. 

The colour of beer is largely determined by the melanoidins and caramel present in the malt and adjuncts used but further caramelization occurs during wort boiling. Minor adjustments of the colour of beer can be made by the addition of caramel either to the copper or with primings. The chemistry of melanoidin and caramel formation is discussed in Chapter 14. 

Fig. 10 Generation of graphene-sepiolite nanocomposites using sucrose or caramel as precursors. Reproduced from [252] with permission from The Royal Society of Chemistry...

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