Differences in structure, antioxidant capacity and gut microbiota modulation of red raspberry pectic polysaccharides...

Area of Science:

• Food Science and Technology
• Nutritional Biochemistry
• Microbiology

Background:

• Red raspberries are rich in pectic polysaccharides, known for potential health benefits.
• Understanding the structure-function relationship of these polysaccharides is crucial for harnessing their effects.

Purpose of the Study:

• To evaluate the antioxidant and prebiotic potential of four red raspberry pectic polysaccharides (RP) extracted using different methods (enzyme, acid, alkali, ultrasound).
• To elucidate the relationship between the structural characteristics of RPs and their biological functions.

Main Methods:

• Extraction of four types of red raspberry pectic polysaccharides (EN-RP, AC-RP, AL-RP, US-RP).
• Analysis of polysaccharide structure, including homogalacturonan (HG) and rhamnogalacturonan-I (RG-I) content.
• Assessment of antioxidant activity (DPPH, hydroxyl radical scavenging).
• Evaluation of prebiotic potential through in vitro fermentation and gut microbiota analysis (metagenomics).

Main Results:

• All four RPs exhibited significant antioxidant and prebiotic properties.
• AL-RP showed the highest DPPH radical scavenging, while US-RP had the highest hydroxyl radical scavenging ability.
• RPs modulated gut microbiota, enriching beneficial bacteria like Bacteroides and Bifidobacterium, and promoting propionic acid production.
• Higher RG-I proportion and Rha/GalA ratio were linked to increased beneficial microbes and propionic acid.

Conclusions:

• Red raspberry pectic polysaccharides possess significant antioxidant and prebiotic potential, influenced by their extraction method and structural composition.
• The findings highlight the potential of RPs for gut microbiota modulation and health promotion through targeted dietary strategies.
• Understanding the structure-function relationship allows for the development of functional foods and precise dietary interventions.