From Synthesis Optimization to Chelation Mechanism: A Rice Protein Peptide-Calcium Complex Enhances Intestinal...

Area of Science:

• Biochemistry
• Nutritional Science
• Materials Science

Background:

• Traditional calcium supplements suffer from low bioavailability.
• Rice protein peptides are abundant, sustainable byproducts of rice processing.
• Developing effective calcium delivery systems is crucial for nutritional health.

Purpose of the Study:

• To fabricate a high-performance calcium-chelating complex using rice protein peptides (RPP-Ca).
• To elucidate the functional mechanism of RPP-Ca in promoting calcium bioavailability and osteogenesis.
• To evaluate the potential of RPP-Ca as a functional food ingredient.

Main Methods:

• Optimization of synthesis conditions for maximum calcium-binding capacity.
• Physicochemical characterization using SEM and FTIR.
• In vitro studies with Caco-2 cell models and in vivo studies with calcium-deficient mouse models.

Main Results:

• Optimal conditions yielded a maximum calcium-binding capacity of 93.98 ± 1.99 mg/g.
• Characterization confirmed successful chelation, enhanced microstructural organization, and improved thermal stability.
• RPP-Ca significantly promoted intestinal calcium absorption and osteogenesis in vitro and in vivo.

Conclusions:

• RPP-Ca effectively enhances calcium absorption and osteogenesis by activating the TRPV6-Calbindin9k signaling axis.
• Industrial rice protein peptides can be utilized to create bioavailable calcium fortification ingredients.
• This study provides a basis for the high-value utilization of rice byproducts in functional foods.