Evaluation of the effect of experimental conditions on the total reductive capacity of extracts of lettuce through an experimental design

• Type: Article in International Conference Proceedings Book
• Date: 2014

Authors

Delgado, T (Author) Other; Ferreira, A (Author) Other; Pereira, JA (Author) Other; Baptista, P (Author) Other; Susana Casal (Author) FFUP; Ramalhosa, E (Author) Other

Conference proceedings International

Title: VII CONGRESO IBERICO DE AGROINGENIERIA Y CIENCIAS HORTICOLAS: INNOVAR Y PRODUCIR PARA EL FUTURO. INNOVATING AND PRODUCING FOR THE FUTURE

Pages: 967-971

7th Iberian Congress of Agricultural Engineering and Horticultural Sciences

Madrid, SPAIN, AUG 26-29, 2013

Indexing

ISI Web of Knowledge - 0 Citations

Other information

Authenticus ID: P-00P-AG1

Abstract (EN): The main aim of the present work was to use a 2-level factorial design to determine the effect of certain operating conditions in the extraction of compounds with antioxidant activity of lettuce, its importance and possible interactions. The factors studied were the extraction temperature (30 and 60 degrees C), solvent type (methanol and water), extraction time (10 and 30 minutes), sample type (dried or fresh) and the ratio of sample vs. solvent (1:1 and 1:4, w/v). The total reducing capacity (TRC) was determined by the colorimetric method using the Folin-Ciocalteu reagent. Taking into account the Pareto and Normal Probability of Standardized Effects charts it was found that among the factors and interactions studied, the only significant (p < 0.05) was the sample type. The model developed allowed to predict TRC values similar to the experimental ones, resulting in a linear relationship with a correlation coefficient (r) equal to 0.916 and confidence intervals for the slope and origin ordinate between 0.628 and 1.05, and -0.0199 to 0.110, respectively, including the one and zero values, as desired. To further evaluate the effect of the sample type on the TRC, the main effects graph showed that the dehydrated samples showed a higher TRC than the fresh ones. The absence of TRC decrease in the extracts prepared from dried lettuce samples, provides also an important fact to be taken into account in future studies, indicating that dried samples may be used in antioxidant capacity determinations.

Language: Portuguese

Type (Professor's evaluation): Scientific

No. of pages: 5