Rationale for the use of buckwheat husk for the production of functional food colors

Abstract

The aim of the work was to substantiate the use of buckwheat husk for obtaining a functional food colorant melanin. The objects of the study were samples of buckwheat husk Fagopýrum esculéntum and isolated water-soluble melanin. The isolation of melanin was carried out by extraction of buckwheat husk with 4% NaOH at a hydraulic modulus of 1:20. The sorption capacity of the melanin extract was determined by its interaction with copper salt solutions in an alkaline medium. It has been established that a distinctive feature of buckwheat hulls is its low ash content, a rather high fiber content – 24.7–26.5%, and a sufficient content of pectin substances – 7.2–7.7% and melanin – 15.7–16.2%. The husk can be used for further processing in order to obtain the food coloring melanin. The experiment proved the ability of a melanin sample to bind copper ions: one gram of a 0.5% solution of buckwheat husk melanin extract bounded 966.6 mg/ml copper, and the antioxidant activity of one gram of melanin extract corresponds to the antioxidant activity of 0.056 g of rutin. Thus, water-soluble samples of melanin isolated from buckwheat hulls can be used as food coloring agents, as well as antioxidants and biosorbents, which makes it possible to recommend them as functional food ingredients in food.