Navegando por Autor "Asevedo, Estefani Alves de"

Agora exibindo 1 - 2 de 2

Exploiting films based on pectin extracted from yellow mombin (Spondias mombin L.) peel for active food packaging
(Springer Nature, 2021-01-30) Santos, Everaldo Silvino dos; Oliveira Júnior, Sérgio Dantas de; Araújo, Jaciara Silva de; Asevedo, Estefani Alves de; Medeiros, Fábio Gonçalves Macêdo de; Santos, Vinícius Silva dos; Sousa Júnior, Francisco Canindé de; Araújo, Nathália Kelly de
In this study, the potential of yellow mombin (Spondias mombin L.)–extracted pectin as a film-forming matrix for the elaboration of edible coatings was investigated. The films of chitosan, citric pectin, and carboxymethylcellulose (Sigma/USA) and natural pectin were prepared by casting. The film morphological characterization was performed by scanning electron microscopy (SME), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and atomic force microscopy (AFM). Additionally, total phenolic compounds (TPC), total antioxidant activity (TAC), DPPH scavenging capacity, and antimicrobial activity were assayed for the natural pectin–based films. The results showed that the film based on natural pectin presented a 46% degree of esterification that was higher than commercial (34%), showing its capacity of forming gels. The film formed by chitosan presented a very different behavior for loss of mass during TGA when compared to the other films, occurring a mass loss completely at 647.7 °C in 61 min. The value obtained from the concentration of total phenolics (mg GAE/100 g dried) found in the formulated film based on pectin was 3998.99 ± 42.64 and with solubility in water of almost 100%. Additionally, the scavenging of the DPPH radical with a value of 15.48 ± 1.48 μmol TE/g was found on the film based on natural pectin thus showing antioxidant capacity. Finally, this film showed less significant mechanical properties when compared to other films and a good pronounced antimicrobial effect against the gram-negative bacteria tested. Therefore, it could be potentially used for producing food-active packages
Recovery and purification of cellulolytic enzymes from Aspergillus fumigatus CCT 7873 using an aqueous two-phase micellar system
(Annals of Microbiology, 2020-05-04) Santos, Everaldo Silvino dos; Oliveira Júnior, Sérgio Dantas de; Padilha, Carlos Eduardo de Araújo; Asevedo, Estefani Alves de; Macedo, Gorete Ribeiro de
Purpose: In this study, an aqueous two-phase micellar system (ATPMS), formed by the non-ionic surfactant Triton X-114, was used to investigate the partitioning of cellulolytic enzymes produced by the filamentous fungus Aspergillus fumigatus CCT 7873. Methods: Performance of the ATPMS on the partitioning of CMCase (activity on carboxymethyl cellulose) and FPase (activity on filter paper) was investigated by varying the temperature (35, 40, 45, 50, 55, 60, and 65 °C), enzyme crude extract concentration (20, 40, 60, and 80% w/w), and Triton X-114 concentration (2, 4, 6, and 8% w/w) and by adding different inorganic salts (NaCl, CaCl2, MgSO4, and MnSO4) in the system. Results: An ATPMS formed with 8% (w/w) Triton X-114 and 40% (w/w) enzymatic crude extract at a system temperature of 55 °C was most favorable for partitioning the tested enzymes. Under these conditions, a purification factor for CMCase and FPase of 10.89 and 0.65 was reached, respectively. The addition of inorganic salts changed the distribution of enzymes. Of these, CaCl2 contributed to a higher distribution coefficient (50.0), whereas for FPase, the presence of MnSO4 in the system improved the purification factor to 3.94. Conclusion: The highest values obtained for the yield and purification factors demonstrate that ATPMS is an interesting option for recovering and purifying cellulolytic enzymes

SIGAA

Navegando por Autor "Asevedo, Estefani Alves de"