RESUMO
A 23 factorial design was used to evaluate the influence of temperature, catalyst and time and esterification degree (DE) of pectin obtained from mango, orange and tangerine peels as well as tamarind seeds by using the acid hydrolysis method. The study showed that a high temperature positively influenced the percentage of pectin yield for the four second generation biomasses. Nevertheless, the temperature showed a greater influence in the solubility and diffusion of the acid solvent in the tamarind seed matrix, resulting a pectin recovery 32.9%. Concerning the %DE, the most statistically significant value observed was dependent on the type of biomass studied. The %DE and the nature of the pectin are determining factors in the pectin's final use, in the present work the pectin extracted was used to produce furfural, a precursor of high value chemicals. The furfural production was achieved through alkaline hydrolysis and enhanced using the Maillard reaction, reaching a maximum concentration of 71.8 g/L which represents a 42.1% increase from the alkaline hydrolysis.
Assuntos
Mangifera , Pectinas , Reação de Maillard , Furaldeído , EsterificaçãoRESUMO
En este trabajo se revisa la evaluación de la calidad de los estudios primarios incluidos en los metaanálisis publicados en las principales revistas españolas de psicología. Concretamente se analiza la codificación y evaluación de la calidad de los estudios en metaanálisis sobre eficacia de intervenciones, así como el propósito de esta evaluación y la relación entre la calidad y tamaños del efecto. Se encuentra que el 79% de los metaanálisis analizados incluyeron una evaluación de la calidad. Se discute la relación entre la menor calidad de los estudios en los metaanálisis y los resultados con mayores tamaños del efecto. Finalmente, se enfatiza la necesidad de mejorar el informe de los metaanálisis aportando evidencias de gran calidad. (AU)
In this paper, we reviewed primary study quality assessments in meta-analyses published in the main Spanish psychology journals. Specifically, we analyzed whether the coding and evaluation of the quality of the primary studies in meta-analysis based on the efficacy of interventions is a common practice. The purpose of this evaluation is also to report the relationship between quality and the reported results (effect sizes). It is found that 79% of the meta-analyses analyzed included a quality assessment. The relationship between the lowest quality of studies included in meta-analyses and larger effect sizes is also discussed. Finally, we stress the need to improve the reporting of meta-analyses including high-quality evidence. (AU)
