Physicochemical and textural quality attributes of gluten-free bread formulated with guar gum

The objective of this study was to assess the combined effect of guar gum (GG) and water content (WC) on the rheological properties of batter, and the physicochemical and textural properties of bread. Batches of gluten-free bread used a base formulation of rice (50%), maize (30%) and quinoa flour (20%), with different levels of GG (2.5, 3.0 or 3.5%) and water (90, 100 or 110%) in a full factorial design. Higher GG doses (p<0.001) tended to produce batters of lower stickiness, work of adhesion and cohesive strength; yet, of higher firmness, consistency, cohesiveness and viscosity index. These batters yielded loaves of lower (p<0.001) specific volume and baking loss; and crumbs of lower (p<0.001) aw, pH, mean cell area, void fraction, mean cell aspect ratio; and higher (p<0.001) hardness, adhesiveness, springiness, cohesiveness, chewiness, resilience, mean cell density, cell size uniformity and mean cell compactness. The sticker and less consistent batters produced with higher WC rendered larger bread loaves of softer and more cohesive and springy/resilient crumbs with greater mean cell size and void fraction. Gluten-free loaves of good appearance in terms of higher specific volume, lower crumb hardness, higher crumb springiness, and open grain visual texture were obtained in formulations with 110% WC and GG doses between 2.5 and 3.0%.Eng. Encina-Zelada acknowledges the financial aid provided by the Peruvian National Programme of Scholarships and Student Loans (PRONABEC) in the mode of PhD grants (Presidente de la República-183308). The authors are grateful to Eng. Andrea Oliveira from Prodipani, Portugal, for her kind advice and providing breadmaking ingredients.info:eu-repo/semantics/publishedVersio

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

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)