Intestinal transit and systemic metabolism of apple polyphenols.

Background: Apples are the most widely consumed fruits in Germany and various other countries. Positive health effects of apple-derived polyphenols in vivo depend on their absorption, metabolism, distribution, and elimination from the body after consumption. Data on the metabolism of these polyphenols in humans are scarce.

Content and mean polymerization degree of procyanidins in extracts obtained from clear and cloudy apple juices.

The polyphenol profile of apples and that of technologically differently treated apple juices has already been studied thoroughly; nevertheless, the content of polymeric procyanidins has not received much attention up to date. Therefore, procyanidins in extracts made from six blended apple juices and two authentic clear as well as cloudy apple juices (Malus domestica cv. Bohnapfel and Bittenfelder) were investigated.

Polyphenols are intensively metabolized in the human gastrointestinal tract after apple juice consumption.

Polyphenols are secondary plant compounds showing anticarcinogenic effects both in vitro and in animal experiments and may thus reduce the risk of colorectal cancer in man. The identification of polyphenol metabolites formed via their passage through the small intestine of healthy ileostomy subjects after apple juice consumption is presented. Identification and quantification of polyphenols and their metabolites were performed using HPLC-DAD as well as HPLC-ESI-MS/MS.