Abstract: This study aims to explore the potential factors resulting in selective uptake and deposition of carotenoids by animals. The results showed that absorption mechanism of carotenoids was passive. There were significant differences in the intestinal environment between different species, such as, pH, bile salt content, free fatty acid composition. The results also showed that these intestinal factors affect absorption of carotenoids. Therefore the hypothesis was put forward that the absorption of carotenoids was controlled by intestinal environment in the first time.

Key words: intestinal environment, carotenoids, absoption