Composition, viscosity and solubility of saleps from twenty different orchid (Orchidaceae) species

Abstract

The quality of salep depends on its chemical composition, especially its glucomannan content, which varies according to the species. Saleps from 20 different orchid species collected from various regions in Turkey were analyzed for dry matter, ash, protein, glucomannan and starch contents. Moreover, viscosity and solubility of these saleps (1% w/v) in water and milk with different sucrose levels (15-25% w/v) were investigated. Starch and glucomannan contents of the species were found between 4.58-43.98 and 7.84-48.54%, respectively. Saleps obtained from Dactylorhizaromana ssp. georgica, Orchis tridentata and Serapiasvomeracea ssp. vomeracea species were identified as the species that contained the highest glucomannan content (42-48%) which could provide the highest viscosity in water and milk solutions. Additionally, despite having relatively lower glucomannan and starch content (36 and 35%), the water solution made with salep from Himantoglossum affine exhibited high viscosity and suggested that a synergistic effect existed between starch and glucomannan. Saleps from nine orchid species contained more than 40% glucomannan but only three of them exhibited good thickening properties and can provide ideal viscosity in water and milk with the addition of sucrose (658-690 cP).