Abstract
The water-soluble carotenoid crocin is used to color foods. Crocin in foods is mixed with salivary nitrite in the oral cavity and is then mixed with gastric juice in the stomach, suggesting the occurrence of reactions between crocin and nitrite in the gastric lumen. Crocin reduced nitrite to nitric oxide (NO) under the conditions simulating the gastric lumen (pH 2.0). Starch suppressed the redox reaction, and this suppression was due to the formation of starch/crocin complexes. Based on these results, it is proposed that crocin transported to the intestine is increased through the formation of starch/crocin complexes.