Mutual interactions between HG-LG gellan gum and tea polyphenols: Concentration-dependent structural modulation and...

Area of Science:

• Food Science
• Materials Science
• Biochemistry

Background:

• Tea polyphenols (TPs) offer health benefits but degrade during food processing due to thermal and pH instability.
• Developing protective matrices is crucial for preserving TPs in functional food products.

Purpose of the Study:

• To create and evaluate a composite hydrogel system using low- and high-acyl gellan gums (HG-LG) as a protective matrix for tea polyphenols.
• To investigate the structural, textural, and stability characteristics of the TP-loaded hydrogel.

Main Methods:

• Fabrication of a composite hydrogel using a 1:1 w/w mixture of low- and high-acyl gellan gums.
• Characterization of hydrogel properties, including texture analysis and rheological measurements.
• Molecular dynamics simulations to elucidate interactions between TPs and gellan gum.
• Assessment of DPPH radical scavenging activity after thermal treatment.

Main Results:

• Incorporation of TPs improved gel texture and water retention, though higher TP content decreased moduli and texture parameters.
• Stable 3D network formation confirmed via hydrogen bonding.
• Molecular dynamics simulations showed strong interactions between TPs (epigallocatechin gallate) and gellan gum, enhancing stability.
• Over 90% DPPH radical scavenging activity was retained after prolonged heating, indicating significant thermal stability.

Conclusions:

• The HG-LG composite hydrogel serves as an effective and thermally stable carrier for tea polyphenols.
• This system demonstrates potential for enhancing the stability and bioavailability of TPs in functional food applications.
• The study highlights the role of gellan gum-TP interactions in stabilizing bioactive compounds.