Abstract
Melanoidins (condensation products of amino acids and sugars) have been suggested as an important sink of proteins and polysaccharides in geological environments. Though evidence has contradicted this view, melanoidins may be an abundant source of macromolecules of fossils (e.g. shells) in which the proteins and polysaccharides have been preserved from microbial degradation. Diagenetic changes in a biomineral have been modelled by heating at 90 degrees C mixtures of protein, polysaccharides and calcite. In part, the model simulated natural diagenesis. From the results it is estimated that 2.4 x 10 (super 6) tonnes of calcified tissue matrix glycoproteins are processed annually through the melanoidin pathway, equivalent to 7 per mille of the total flux of organic C into marine sediments.