In vitro digestive stability and uptake by Caco-2 human intestinal cells of nonfluorescent chlorophyll catabolites

Nonfluorescent chlorophyll catabolites (NCCs) are commonly considered to be the final tetrapyrrolic products of chlorophyll catabolism in higher plants. This study describes two different NCCs, Ca-NCC-1 and Ca-NCC-2, during the ripening of pepper fruits. Although NCCs are present in fruits and vegetables that are or were green, and are part of our daily diet, no information is available about their bioavailability. After in vitro digestion of an extract of pepper NCCs (which reproduces the gastric and intestinal phases of physiological digestion), both have shown resistance to the digestive process and are efficiently incorporated into the aqueous micellar fraction. Assays of absorption by Caco-2 cell monolayers were performed, showing that only Ca-NCC-1 is efficiently absorbed. This is the first time that NCCs have been shown to be absorbed by human intestinal cells, in the same way as other chlorophyll catabolites from plants and vegetables.