Adapting the Accelerated Solvent Extraction Method for Resin and Rubber Determination in Guayule Using the BÜCHI Speed Extractor
Juana Rozalén,
María de las Mercedes García-Martínez,
María Engracia Carrión,
Manuel Carmona,
Horacio López-Córcoles,
Katrina Cornish,
Amaya Zalacain
Affiliations
Juana Rozalén
Catedra de Química Agrícola, Escuela Técnica Superior de Ingenieros Agrónomos y de Montes, Universidad de Castilla-La Mancha, Campus Universitario s/n, 02071 Albacete, Spain
María de las Mercedes García-Martínez
Food Quality Research Group, Institute for Regional Development (IDR), Universidad de Castilla-La Mancha, 02071 Albacete, Spain
María Engracia Carrión
Food Technology Lab, School of Architecture, Engineering and Design, Universidad Europea de Madrid, C/Tajo s/n, 28670 Villaviciosa de Odón, Spain
Manuel Carmona
Food Quality Research Group, Institute for Regional Development (IDR), Universidad de Castilla-La Mancha, 02071 Albacete, Spain
Horacio López-Córcoles
Research Department, Instituto Técnico Agronómico Provincial de Albacete (ITAP), Parque Empresarial Campollano, 2<sup>a</sup> Avenida, 61, 02007 Albacete, Spain
Katrina Cornish
Departments of Horticulture and Crop Science and of Food Agricultural and Biological Engineering, College of Food, Agricultural and Environmental Sciences, The Ohio State University, Wooster, OH 44691, USA
Amaya Zalacain
Catedra de Química Agrícola, Escuela Técnica Superior de Ingenieros Agrónomos y de Montes, Universidad de Castilla-La Mancha, Campus Universitario s/n, 02071 Albacete, Spain
Guayule (Parthenium argentatum Gray) is a promising alternative source to Hevea brasiliensis for the production of natural rubber, which can reach levels of 8–9% under industrialized farming conditions. The most common method for determining rubber concentration is by accelerated solvent extraction (ASE), a technique developed by the Dionex Corporation and almost exclusively performed with the Dionex ASE-200 or 350 systems. Herein, it is sought to apply and adapt the most common methods used in the literature for the Dionex system to another extraction platform, the BÜCHI Speed Extractor E-914. Results showed that using a sand sandwich method to confine the sample in the center and exploiting a larger cell volume (80 mL) for extraction prevents the occurrence of overpressure and problems with clogging. Under optimized conditions, the coefficient of variation was <15% for both resin quantification for samples containing 5.0–15.8% of resin and for rubber quantification for samples with 1.7–10.3% rubber content. The extraction time for resin (2 cycles of 5 min each) was smaller than for rubber (2 cycles of 20 min each). It would be interesting to carry out interlaboratory comparisons to standardize the method at an international level.
