Buckwheat Husk: An Underexplored Source of Bioactive Compounds and Functional Food Applications

Buckwheat husk is the major by-product produced during buckwheat processing. However, despite its high nutritional and functional value, it remains underutilized as an ingredient in functional foods. This review summarizes current knowledge on the botanical origin, chemical composition, extraction approaches, and bioactive properties of buckwheat husk. Particular emphasis is placed on its high content of insoluble dietary fiber and phenolic compounds, especially rutin, which contribute to antioxidant, anti-inflammatory, and antimicrobial activities. Advances in conventional and green extraction techniques used to obtain buckwheat husk concentrates, including ultrasound- and microwave-assisted methods, are discussed. The techno-functional properties of buckwheat husk, such as water- and oil-holding capacity, emulsifying potential, and texture modification, are evaluated in relation to food applications. Reported uses in bakery products, pasta, dairy foods, beverages, and meat systems are critically reviewed. Safety aspects, allergenicity, and antinutritional factors are also considered. Overall, buckwheat husk is positioned as an underutilized resource with significant potential for sustainable functional food development.