Modelado de la biodegradación en biorreactores de lodos de hidrocarburos totales del petróleo intemperizados en suelos y sedimentos (Biodegradation modeling of sludge bioreactors of total petroleum hydrocarbons weathering in soil and sediments)

Apple starch films were obtained from apples harvested at 60, 70, 80 and 90 days after full bloom (DAFB). Mechanical properties and water vapor permeability (WVP) were evaluated. The apple starch films at 70 DAFB presented higher values in the variables of tensile strength (8.12 MPa), elastic modulus (3.10 MPa) and lower values of water vapor permeability (6.77 × 10−11 g m−1 s−1 Pa−1) than apple starch films from apples harvested at 60, 80 and 90 DAFB. Therefore, these films were chosen to continue the study incorporating ellagic acid (EA). The EA was added at three concentrations [0.02% (FILM-EA0.02%), 0.05% (FILM-EA0.05%) and 0.1% (FILM-EA0.1%) w/w] and compared with the apple starch films without EA (FILM-Control). The films were characterized by their physicochemical, optical, morphological and mechanical properties. Their thermal stability and antioxidant capacity were also evaluated. The FILM-Control and FILM-EA0.02% showed a uniform surface, while FILM-EA0.05% and FILM-EA0.1% showed a rough surface and insoluble EA particles. Compared to FILM-Control, EA modified the values of tensile strength, elasticity modulus and elongation at break. The antioxidant capacity increased as EA concentration did. EA incorporation allowed obtaining films with higher antioxidant capacity, capable of blocking UV light with better mechanical properties than film without EA.

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Modelado de la biodegradación en biorreactores de lodos de hidrocarburos totales del petróleo intemperizados en suelos y sedimentos (Biodegradation modeling of sludge bioreactors of total petroleum hydrocarbons weathering in soil and sediments)

Amyloses were isolated from diverse botanical sources (apple, mango, maize, and potato), and they were studied in their molecular characteristics (amylose content, molar mass, and molecular weight) using high-performance size-exclusion chromatography as a repetitive and faster protocol. The amylose purity ranged between 85.6-92.6 %, in agreement with the λ max values (601-610 nm), showing that some impurities with molecules of higher molar mass (amylopectin) were present. The standard curve of pullulan showed a high regression coefficient (0.998) inside of the limits of molar mass of amylose. Chromatograms of amylose showed the presence of components of high molar mass with a principal peak that corresponds to amylose. Molar mass of amylose ranged between 1.2 and 8.5 × 10 5 g/mol with polydispersity values between 1.3-4.1, indicating a narrow range of molar mass distribution of the amyloses analyzed. The high-performance size-exclusion chromatography coupled with a refractive index methodology used in this study may be considered simple and rapid for molecular studies of amylose.