Varietal Effect on Composition and Digestibility of Seedless Table Grapes (Vitis vinifera L.) under In Vitro...

Area of Science:

• Food Science
• Nutritional Biochemistry
• Plant Chemistry

Background:

• Grapes are a significant source of polyphenols and antioxidants within the Mediterranean diet.
• The increasing market for seedless grape varieties necessitates characterization of their unique compositions.
• Polyphenol bioavailability and bioactivity are influenced by in vitro digestion processes.

Purpose of the Study:

• To analyze the effect of grape variety on initial polyphenol composition.
• To determine the absorbable polyphenol fraction reaching the intestine after in vitro digestion.
• To assess the impact of digestion on the antioxidant potential of different grape varieties.

Main Methods:

• In vitro digestion model simulating human gastrointestinal conditions.
• Analysis of polyphenol profiles in grape extracts before and after digestion.
• Quantification of absorbable polyphenol fractions.

Main Results:

• Black and red grape varieties exhibit high potential for enhancing dietary antioxidant content.
• In vitro digestion significantly reduced the bioavailable fraction of most polyphenols.
• Flavanols were an exception, showing less reduction in their bioavailable fraction post-digestion.

Conclusions:

• Grape variety significantly influences polyphenol composition and post-digestion bioavailability.
• Black and red grapes are valuable sources of dietary antioxidants.
• Digestive processes, particularly in vitro, can diminish the bioavailability of various polyphenols, except flavanols.