[Furane compounds formed upon heating highly-sugared fermented media].

5-Methylfurfural diethyl acetal, 5-methylfuran acid ester, and 4-hydroxypentanoic acid ethyl ester were first identified in high-sacchariferous corn media subjected to alcoholic fermentation by Mucor X-I culture and in aged sweet wines by means of GLC, GLC-MS, and TLC, as well as by UV and IR spectroscopic examinations. These substances are products of enzymatic esterification of sugars followed by their dehydration by heat treatment or long seasoning of grape wines.