Use of Sieving as a Valuable Technology to Produce Enriched Buckwheat Flours: A Preliminary Study

Abstract

Fractionation processes based on physical separation are a good strategy to produce enriched cereal flours. Therefore, the aim of this work is to evaluate the suitability of sieving of buckwheat flours to produce protein and phenolic (especially rutin) enriched fractions. Because of that, dehulled whole buckwheat flour (GSTQ) was sieved obtaining fractions with a particle size of 215 um, 160 um, 85 um, and 45 um (GS215, GS160, GS85, and GS45). For that purpose, the determination of protein, ash, and total starch content and free and bound phenolic compounds was carried out. The highest content of total phenolic compounds was obtained in GS215 (3118.84 mg kg-1 d.w.), followed by GS160 (2499.11 mg kg-1 d.w.), GS85 (989.46 mg kg-1 d.w.), GSTQ (983.15 mg kg-1 d.w.), and GS45 (481.31 mg kg-1 d.w.). Therefore, the phenolic content decreased with the particle size decrease from 215 um to 45 um. Besides, there were no significant differences between the total phenolic content in GS85 and GSTQ. The fraction with 215 um reported the highest protein and mineral salt content and presented rutin amounts four times higher than GSTQ.