riboflavin Codex::101(i) <small>D</small>-Ribitol in which the hydroxy group at position 5 is substituted by a 7,8-dimethyl-2,4-dioxo-3,4-dihydrobenzo[<em>g</em>]pteridin-10(2<em>H</em>)-yl moiety. It is a nutritional factor found in milk, eggs, malted barley, liver, kidney, heart, and leafy vegetables, but the richest natural source is yeast. The free form occurs only in the retina of the eye, in whey, and in urine; its principal forms in tissues and cells are as flavin mononucleotide and flavin-adenine dinucleotide. D-Ribitol in which the hydroxy group at position 5 is substituted by a 7,8-dimethyl-2,4-dioxo-3,4-dihydrobenzo[g]pteridin-10(2H)-yl moiety. It is a nutritional factor found in milk, eggs, malted barley, liver, kidney, heart, and leafy vegetables, but the richest natural source is yeast. The free form occurs only in the retina of the eye, in whey, and in urine; its principal forms in tissues and cells are as flavin mononucleotide and flavin-adenine dinucleotide. Europe::101 LanguaL term definition: Food additive; technological purpose(s): colour. riboflavin, synthetic vitamin b2 vitamin B2 flavin