caa a22 4500 60624364X CHVBK 20210128101325.0 cr unu---uuuuu 210128e20150601xx s 000 0 eng 10.1007/s11694-015-9225-8 doi (NATIONALLICENCE)springer-10.1007/s11694-015-9225-8 Antioxidant activity of butterhead lettuce: evaluation of significant factors affecting antioxidant extraction and quantification [Elektronische Daten] [Gabriela Viacava, Sara Roura, María Agüero] This work presents a standardized methodology for both the extraction of antioxidants from butterhead lettuce and the evaluation of the antioxidant capacity through DPPH methodology. The standardized extraction of antioxidants requires processing the fresh lettuce leaves (1g) for 1min, mixing with 10mL of acidified ethanol (0.5 or 1% citric acid) maintaining this mixture with continuous shaking during 1h at 2°C. After that, a centrifugation at 8,000rpm for 15min is necessary to obtain a fist supernatant (antioxidant source). A second extraction step with acetone:water (70:30 v/v) improves the extraction yield. Extracts can be stored for 14days at −20°C without changes in its antioxidant capacity. For quantification, a mixture 1:4 of lettuce extract and DPPH (100μM) must be incubated for 60min at 2°C in dark before reading at 517nm. Expression of results in terms of mg ascorbic acid equivalents/100g fresh weight is recommended in order to compare results from different studies. A kinetic study of the reaction between lettuce antioxidants and DPPH was adjusted to a biphasic first-order kinetic model and showed evidence of the presence of antioxidants of slow and rapid antioxidants in lettuce extracts. Springer Science+Business Media New York, 2015 Lettuce nationallicence Antioxidants nationallicence Radical scavenging capacity nationallicence DPPH nationallicence Viacava Gabriela Grupo de Investigación en Ingeniería en Alimentos, Facultad de Ingeniería, Universidad Nacional de Mar del Plata, Juan B. Justo 4302, B7608FDQ, Mar del Plata, Argentina aut Roura Sara Grupo de Investigación en Ingeniería en Alimentos, Facultad de Ingeniería, Universidad Nacional de Mar del Plata, Juan B. Justo 4302, B7608FDQ, Mar del Plata, Argentina aut Agüero María Laboratorio de Microbiología Industrial: Tecnología de Alimentos, Facultad de Ingeniería, Universidad de Buenos Aires, Int. Guiraldes 2630 (Pabellón de Industrias, Ciudad Universitaria), C1428EGA, Buenos Aires, Argentina aut Journal of Food Measurement and Characterization Springer US; http://www.springer-ny.com 9/2(2015-06-01), 206-214 2193-4126 9:2<206 2015 9 11694 https://doi.org/10.1007/s11694-015-9225-8 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s11694-015-9225-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Viacava Gabriela Grupo de Investigación en Ingeniería en Alimentos, Facultad de Ingeniería, Universidad Nacional de Mar del Plata, Juan B. Justo 4302, B7608FDQ, Mar del Plata, Argentina aut NATIONALLICENCE 700 1- Roura Sara Grupo de Investigación en Ingeniería en Alimentos, Facultad de Ingeniería, Universidad Nacional de Mar del Plata, Juan B. Justo 4302, B7608FDQ, Mar del Plata, Argentina aut NATIONALLICENCE 700 1- Agüero María Laboratorio de Microbiología Industrial: Tecnología de Alimentos, Facultad de Ingeniería, Universidad de Buenos Aires, Int. Guiraldes 2630 (Pabellón de Industrias, Ciudad Universitaria), C1428EGA, Buenos Aires, Argentina aut NATIONALLICENCE 773 0- Journal of Food Measurement and Characterization Springer US; http://www.springer-ny.com 9/2(2015-06-01), 206-214 2193-4126 9:2<206 2015 9 11694