Processing of alfalfa seeds by convective hot air drying, vacuum drying and germination: Proximate composition, techno-functional, thermal and structural properties evaluation

Abstract

The effect of convective hot air and vacuum drying alone and combined with germination on alfalfa seeds' proximate composition, techno-functional, thermal and structural properties was investigated. Corresponding properties of treated alfalfa samples were compared with those of commercially available alfalfa sprouts. Both drying and combined germination and drying treatments resulted in increased carbohydrates (41.99-48.82 %), TDF (10.51-12.51 %) and Mg contents (789.49-2119.24 mg/kg), while the reduction in ash, lipid and Fe content compared to raw alfalfa seeds was observed. Alfalfa seeds subjected to combined germination and drying treatment exhibited higher water and oil binding capacities, as well as emulsions with smaller volume mean droplet diameters compared to the raw and dried samples. Conducted treatments resulted in greater thermal stability of globulins and a slight decrease in crystallinity index, although alfalfa seeds' structure did not change significantly according to FTIR analysis. Differences in applied drying techniques on alfalfa seeds' properties were not observed.

Keywords: Alfalfa; Composition; Drying; Germination; Structure; Thermal properties.