Assessing potential bioavailability of raspberry anthocyanins using an in vitro digestion system

Area of Science:

• Nutritional Science
• Food Chemistry
• Pharmacokinetics

Background:

• Anthocyanins, potent antioxidants found in raspberries, are known for their health benefits.
• Understanding their bioavailability is crucial for maximizing their health impact.
• The gastrointestinal tract (GIT) presents a challenging environment for polyphenol stability.

Purpose of the Study:

• To assess the bioavailability of anthocyanins from raspberry extracts using an in vitro digestion model.
• To investigate the impact of co-ingestion with common foodstuffs on anthocyanin stability and absorption.
• To analyze the anthocyanin composition and stability throughout the simulated upper GIT.

Main Methods:

• An in vitro digestion procedure mimicking upper gastrointestinal tract (GIT) conditions was employed.
• Raspberry extract was digested alone and co-digested with bread, breakfast cereal, ice cream, and minced beef.
• Anthocyanin composition was monitored using liquid chromatography-mass spectrometry (LC-MS).

Main Results:

• Nearly all total phenols and anthocyanins survived gastric digestion.
• Approximately 5% of anthocyanins entered the serum-available (IN) fraction, with ~70% recovered in IN and GIT-remaining (OUT) samples.
• Co-digestion with foodstuffs, particularly ice cream and cereal, did not reduce, and sometimes increased, anthocyanin content in IN samples, suggesting protection.

Conclusions:

• Raspberry anthocyanins exhibit stability during gastric digestion.
• Food matrices can transiently bind polyphenols, potentially protecting labile anthocyanins from degradation.
• This interaction may enhance anthocyanin bioavailability, though individual anthocyanin profiles vary in stability.