title: Sorption isotherms, thermodynamic properties and glass transition temperature of mucilage extracted from chia seeds (Salvia hispanica L.).
abstract: Freeze-dried chia mucilage adsorption isotherms were determined at 25, 35 and 40°C and fitted with the Guggenheim-Anderson-de Boer model. The integral thermodynamic properties (enthalpy and entropy) were estimated with the Clausius-Clapeyron equation. Pore radius of the mucilage, calculated with the Kelvin equation, varied from 0.87 to 6.44 nm in the temperature range studied. The point of maximum stability (minimum integral entropy) ranged between 7.56 and 7.63kg H2O per 100 kg of dry solids (d.s.) (water activity of 0.34-0.53). Enthalpy-entropy compensation for the mucilage showed two isokinetic temperatures: (i) one occurring at low moisture contents (0-7.56 kg H2O per 100 kg d.s.), controlled by changes in water entropy; and (ii) another happening in the moisture interval of 7.56-24 kg H2O per 100 kg d.s. and was enthalpy driven. The glass transition temperature Tg of the mucilage fluctuated between 42.93 and 57.93°C.
authors: Departamento de Ingeniería Química, Facultad de Química, Universidad Autónoma del Estado de México, Paseo Colón esq. Paseo Tollocan s/n, Col. Residencial Colón, C.P. 50120 Toluca, Estado de México, Mexico.
authors: Sandra Karina
authors: SK
authors: Velázquez-Gutiérrez
authors: CIEO, Centro de Investigação sobre o Espaço e Organizações e Departamento de Engenharia Alimentar, Universidade do Algarve-Campus da Penha, Estrada da Penha, 8005-139 Faro, Portugal.
authors: Ana Cristina
authors: AC
authors: Figueira
authors: Departamento de Ingeniería Química y Bioquímica, Tecnológico de Estudios Superiores de Ecatepec, Av. Tecnológico s/n, Col. Valle de Anáhuac, C.P. 55210 Ecatepec de Morelos, Estado de México, Mexico.
authors: María Eva
authors: ME
authors: Rodríguez-Huezo
authors: Departamento de Biotecnología, Universidad Autónoma Metropolitana-Iztapalapa, San Rafael Atlixco No. 186, Col. Vicentina, C.P. 09340 México, D.F., Mexico.
authors: Angélica
authors: A
authors: Román-Guerrero
authors: Departamento de Ingeniería de Procesos e Hidráulica, Universidad Autónoma Metropolitana-Iztapalapa, San Rafael Atlixco No. 186, Col. Vicentina, C.P. 09340 México, D.F., Mexico.
authors: Hector
authors: H
authors: Carrillo-Navas
authors: Departamento de Ingeniería Química, Facultad de Química, Universidad Autónoma del Estado de México, Paseo Colón esq. Paseo Tollocan s/n, Col. Residencial Colón, C.P. 50120 Toluca, Estado de México, Mexico. Electronic address: cesar_perezalonso@yahoo.com.mx.
authors: César
authors: C
authors: Pérez-Alonso
mesh_terms: D062087:Plant Mucilage / Q000737:chemistry*; D027544:Salvia / Q000737:chemistry*; D012639:Seeds / Q000737:chemistry; D044366:Transition Temperature; D058989:Vitrification
chemical_list: D062087:Plant Mucilage
keywords: Enthalpy–entropy compensation; Glass transition temperature; Minimum integral entropy; Mucilage; Sorption isotherms; Thermodynamic properties