Rheological and physical properties of spray-dried mucilage obtained from Hylocereus undatus cladodes

• Published in: Carbohydrate polymers Vol. 91; no. 1; pp. 394 - 402
• Main Authors: García-Cruz, E.E., Rodríguez-Ramírez, J., Méndez Lagunas, L.L., Medina-Torres, L.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 02-01-2013
• Subjects: Cactaceae - chemistry; cladodes; Cross model; drying; Hylocereus undatus; Mechanical Phenomena; Optimization; Particle Size; Physical Phenomena; Physical properties; Pitahaya mucilage; Plant Mucilage - chemistry; Powders; response surface methodology; Rheological properties; Rheology; Transition Temperature; Viscosity; Pitahaya mucilage; Physical properties; Optimization; Cross model; Rheological properties
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2012.08.048

► The rheological behavior of reconstituted spray-dried mucilage was studied. ► The reconstituted mucilage exhibited non-Newtonian shear-thinning behavior. ► The steady-shear viscosity and dynamic response were correlated to the Cox–Merz rule. ► Mucilage recovers its elastic properties at concentrations of 7% and 8%. ► The viscous component G′′ predominated over the elastic component G′.
This study examines the rheological behavior of reconstituted spray-dried mucilage isolated from the cladodes of pitahaya (Hylocereus undatus), the effects of concentration and its relationship with physical properties were analyzed in reconstituted solutions. Drying process optimization was carried out through the surface response method, utilizing a factorial 23 design with three central points, in order to evaluate yield and rheological properties. The reconstituted mucilage exhibited non-Newtonian shear-thinning behavior, which adequately fit the Cross model (R2>0.95). This dynamic response suggests a random coil configuration. The steady-shear viscosity and dynamic response are suitably correlated through the Cox–Merz rule, confirming the mucilage's stability of flow. Analysis of the physical properties of the mucilage (Tg, DTP, and particle morphology) explains the shear-thinning behavior.