Buckwheat grain phenolics: Composition, bioactivity, and processing

Area of Science:

• Food Science
• Nutritional Biochemistry
• Agricultural Science

Background:

• Buckwheat (Fagopyrum spp.) is a gluten-free pseudocereal valued for its phenolic compounds.
• Existing research on buckwheat's phenolic profiles and bioactivities shows significant inconsistencies.
• Variability stems from differences in species, tissues, analytical techniques, and processing methods.

Purpose of the Study:

• To critically review and synthesize current evidence on buckwheat phenolic composition.
• To identify factors contributing to variability in reported phenolic profiles and bioactivities.
• To highlight knowledge gaps and propose priorities for standardization and food design.

Main Methods:

• Systematic literature review of recent studies on buckwheat phenolic compounds.
• Analysis of phenolic composition across different buckwheat matrices (husk/bran, groats/flour, sprouts).
• Emphasis on soluble free, soluble-bound, and insoluble-bound phenolic fractions and analytical method influence.

Main Results:

• Significant species- and tissue-dependent variations in phenolic content were observed, especially between common and Tartary buckwheat.
• Processing methods (germination, fermentation, thermal, physical) profoundly impact phenolic extractability, profiles, and bioavailability.
• The conversion of rutin to quercetin is a critical factor influencing sensory attributes and bioaccessibility.

Conclusions:

• Standardization of analytical methods and processing protocols is crucial for consistent buckwheat phenolic profiles.
• Further research is needed on underutilized Fagopyrum species to broaden their application.
• Optimizing processing can enhance buckwheat's phenolic bioactivity and food applications.