Unveiling a new chapter for collagen peptides: Comprehensive insights into oral bioavailability and the enhancement via encapsulation systems

Abstract

Background

Collagen peptides (CPs), valued for their health-promoting properties, are ubiquitously applied in nutritional supplements and functional foods. However, their potential benefits are often limited by impoverished oral bioavailability (OB). While the hydroxyproline (Hyp) enhances their resistance to gastrointestinal tract (GIT) degradation, CPs frequently fail to achieve and sustain effective levels in the bloodstream. Small peptides, such as dipeptides and tripeptides, are rapidly absorbed in the small intestine, causing transient spikes in blood levels that quickly decline, reducing their effectiveness. Larger peptides (MW > 1 kDa) exhibit low OB due to high enzymatic degradation and limited GIT absorption. These challenges often necessitate higher doses and frequent intake, increasing costs and potential side effects. Encapsulation systems (ESs) can protect peptides from GIT degradation and enable sustained release.

Scope and approach

This review highlights the role of ESs in enhancing the OB of CPs across molecular sizes. It examines four critical stages influencing OB: bioaccessibility, absorption, first-pass metabolism, and bioactivity. Five ESs (microcapsules, W1/O/W2 emulsions, hydrogels, nanoliposomes, and electrospinning) are critically reviewed for their effectiveness in addressing these challenges.

Key findings and conclusions

ESs significantly enhance the OB of CPs by extending circulation time for small peptides and ensuring the integrity and absorption of larger peptides in the intestine. However, current research is primarily based on in vitro and animal models, which may not fully represent human physiology. Future studies should focus on clinical validation and scaling up production to thoroughly comprehend the functional benefits of collagen peptides in food applications.