title: Physicochemical, morphological and rheological properties of canned bean pastes "negro Queretaro" variety (Phaseolus vulgaris L.).
abstract: Proximate, thermal, morphological and rheological properties of canned "negro Querétaro" bean pastes, as a function of fat content (0, 2 and 3 %) and temperature (60, 70 and 85 °C), were evaluated. Raw and precooked bean pastes were characterized by scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). Well-defined starch granules in the raw bean pastes were observed, whereas a gelatinized starch paste was observed for the canned bean pastes. The DSC analysis showed that the raw bean pastes had lower onset peak temperatures (79 °C, 79.1 °C) and gelatinization enthalpy (1.940 J/g), compared to that precooked bean pastes (70.4 °C, 75.7 °C and 1.314 J/g, respectively) thermal characteristics. Moreover, the dynamic rheological results showed a gel-like behavior for the canned bean pastes, where the storage modulus (G') was frequency independent and was higher than the loss modulus (G″). The non-linear rheological results exhibited a shear-thinning flow behavior, where the steady shear-viscosity was temperature and fat content dependent. For canned bean pastes, the shear-viscosity data followed a power law equation, where the power law index (n) decreased when the temperature and the fat content increased. The temperature effect on the shear-viscosity was described by an Arrhenius equation, where the activation energy (Ea) was in the range from 19.04 to 36.81 KJ/mol. This rheological behavior was caused by gelatinization of the starch during the cooking and sterilization processes, where starch-lipids and starch-proteins complex were formed.
authors.affiliation: Departamento de Ingeniería Química, Universidad de Guadalajara, Blvd. M. García Barragán # 1451, Guadalajara, Jal. 44430 Mexico.
authors.forename: A H
authors.initials: AH
authors.lastname: Martínez-Preciado
authors.affiliation: Departamento de Ingeniería Química, Universidad de Guadalajara, Blvd. M. García Barragán # 1451, Guadalajara, Jal. 44430 Mexico.
authors.forename: Y
authors.initials: Y
authors.lastname: Estrada-Girón
authors.affiliation: Departamento de Ingeniería Química, Universidad de Guadalajara, Blvd. M. García Barragán # 1451, Guadalajara, Jal. 44430 Mexico.
authors.forename: A
authors.initials: A
authors.lastname: González-Álvarez
authors.affiliation: Departamento de Ciencias Tecnológicas, Universidad de Guadalajara, Av. Universidad # 1115, Ocotlán, Jal. 47810 Mexico.
authors.forename: V V A
authors.initials: VV
authors.lastname: Fernández
authors.affiliation: Departamento de Ingeniería Química, Universidad de Guadalajara, Blvd. M. García Barragán # 1451, Guadalajara, Jal. 44430 Mexico.
authors.forename: E R
authors.initials: ER
authors.lastname: Macías
authors.affiliation: Departamento de Ingeniería Química, Universidad de Guadalajara, Blvd. M. García Barragán # 1451, Guadalajara, Jal. 44430 Mexico.
authors.forename: J F A
authors.initials: JF
authors.lastname: Soltero
keywords: Canned bean pastes (Phaseolus vulgaris L.); Fat content; Morphology; Rheology; Temperature