The interaction between tea polyphenols and rice starch during gelatinization.

Area of Science:

• Food Science
• Biochemistry
• Material Science

Background:

• Rice starch (RS) gelatinization is crucial for food texture and digestibility.
• Tea polyphenols (TPLs) are known for their health benefits and potential as functional food ingredients.
• Understanding the interaction between TPLs and RS is vital for developing novel food products.

Purpose of the Study:

• To investigate the interaction between tea polyphenols (TPLs) and rice starch (RS) during the gelatinization process.
• To elucidate the structural and chemical changes occurring due to TPLs-RS interactions.

Main Methods:

• Rheological analysis using a Rapid Visco Analyzer (RVA) to assess viscosity changes.
• Nuclear Magnetic Resonance ((1)H-NMR) spectroscopy to analyze molecular interactions and coupling constants.
• Fourier Transform Infrared (FT-IR) spectroscopy to identify changes in chemical bonds and functional groups.

Main Results:

• TPLs-fortified RS showed altered viscosity profiles, lacking clear peak and hot paste viscosity, indicating strong interactions.
• RVA results suggested irregular viscosity changes attributed to RS and TPLs interactions during pasting/gelatinization.
• (1)H-NMR and FT-IR analyses revealed differences in H-H interactions and hydrogen bonding, with sample A (gelatinized TPLs-RS blend) exhibiting stronger interactions and broadened O-H stretching compared to sample B (TPLs with gelatinized RS).

Conclusions:

• Tea polyphenols (TPLs) and rice starch (RS) exhibit significant hydrogen bonding interactions during gelatinization.
• These interactions influence the rheological properties and structural characteristics of rice starch.
• The findings provide insights into the molecular mechanisms governing TPLs-starch interactions, relevant for food processing and formulation.