Caffeic Acid Release from Inulin Caffeate: A Comparative Study with Spray-Dried Inulin Microparticles Under...

Area of Science:

• Food Science & Technology
• Biomaterials Engineering
• Pharmacology

Background:

• Phenolic compounds, like caffeic acid (CA), possess antioxidant properties but often exhibit poor bioavailability.
• Inulin, a prebiotic fiber, can be modified to improve the delivery of bioactive compounds.
• Developing strategies for controlled release of phenolic compounds in the gastrointestinal tract is crucial for enhancing their health benefits.

Purpose of the Study:

• To compare the physicochemical properties and in vitro gastrointestinal release profiles of covalently bound caffeic acid-inulin (CA-Inu) with spray-dried CA-inulin microparticles (Mp(CA/Inu)).
• To evaluate the potential of covalent conjugation for targeted delivery of phenolic compounds.

Main Methods:

• Synthesis of inulin caffeate (CA-Inu) with a degree of substitution of 0.07.
• Optimization of spray-drying encapsulation of CA with inulin (Mp(CA/Inu)) using Central Composite Design.
• In vitro simulated gastrointestinal digestion to assess CA release from both formulations.

Main Results:

• Spray-dried microparticles (Mp(CA/Inu)) showed rapid CA release during oral and gastric phases, with a slight decrease in the intestinal phase.
• Covalently bound inulin caffeate (CA-Inu) exhibited no CA release in oral and gastric phases.
• Approximately 30% CA release occurred in the intestinal phase from CA-Inu, increasing in the colonic phase, particularly with inulinase.

Conclusions:

• Covalent binding of CA to inulin provides a robust strategy for delaying the release of phenolic compounds.
• This approach enables targeted delivery of bioactive compounds to the later stages of gastrointestinal digestion.
• The developed CA-Inu conjugate shows potential for enhanced delivery and efficacy of phenolic compounds.