Salma Saoudi1, Nadia Chammem1, Ines Sifaoui2, Ignacio A Jiménez3, Jacob Lorenzo-Morales4, José E Piñero5, Maha Bouassida-Beji5, Moktar Hamdi1, Isabel L Bazzocchi3. 1. Laboratoire d'Ecologie et de Technologie Microbiennes, Institut National des Sciences Appliquées et de Technologie, INSAT, University of Carthage, 1080, Tunis, Tunisia. 2. Laboratoire Matériaux-Molécules et Applications, IPEST, University of Carthage, 2070, La Marsa, Tunisia. 3. Instituto Universitario de Bio-Orgánica Antonio González, Universidad de La Laguna, Tenerife, Canary Islands, Spain. 4. University Institute of Tropical Diseases and Public Health, University of La Laguna, 38271, La Laguna, Tenerife, Canary Islands, Spain. 5. Etablissements Slama Frères, Nejma Huiles, Oued Ellil-Manouba, Tunisia.
Abstract
BACKGROUND: Oxidation taking place during the use of oil leads to the deterioration of both nutritional and sensorial qualities. Natural antioxidants from herbs and plants are rich in phenolic compounds and could therefore be more efficient than synthetic ones in preventing lipid oxidation reactions. This study was aimed at the valorization of Tunisian aromatic plants and their active compounds as new sources of natural antioxidant preventing oil oxidation. RESULTS: Carnosol, rosmarinic acid and thymol were isolated from Rosmarinus officinalis and Thymus capitatus by column chromatography and were analyzed by nuclear magnetic resonance. Their antioxidant activities were measured by DPPH, ABTS and FRAP assays. These active compounds were added to soybean oil in different proportions using a simplex-centroid mixture design. Antioxidant activity and oxidative stability of oils were determined before and after 20 days of accelerated oxidation at 60 °C. CONCLUSION: Results showed that bioactive compounds are effective in maintaining oxidative stability of soybean oil. However, the binary interaction of rosmarinic acid and thymol caused a reduction in antioxidant activity and oxidative stability of soybean oil. Optimum conditions for maximum antioxidant activity and oxidative stability were found to be an equal ternary mixture of carnosol, rosmarinic acid and thymol.
BACKGROUND: Oxidation taking place during the use of oil leads to the deterioration of both nutritional and sensorial qualities. Natural antioxidants from herbs and plants are rich in phenolic compounds and could therefore be more efficient than synthetic ones in preventing lipid oxidation reactions. This study was aimed at the valorization of Tunisian aromatic plants and their active compounds as new sources of natural antioxidant preventing oil oxidation. RESULTS:Carnosol, rosmarinic acid and thymol were isolated from Rosmarinus officinalis and Thymus capitatus by column chromatography and were analyzed by nuclear magnetic resonance. Their antioxidant activities were measured by DPPH, ABTS and FRAP assays. These active compounds were added to soybeanoil in different proportions using a simplex-centroid mixture design. Antioxidant activity and oxidative stability of oils were determined before and after 20 days of accelerated oxidation at 60 °C. CONCLUSION: Results showed that bioactive compounds are effective in maintaining oxidative stability of soybeanoil. However, the binary interaction of rosmarinic acid and thymol caused a reduction in antioxidant activity and oxidative stability of soybeanoil. Optimum conditions for maximum antioxidant activity and oxidative stability were found to be an equal ternary mixture of carnosol, rosmarinic acid and thymol.
Authors: Ines Sifaoui; Eulalia Capote Capote Yanes; María Reyes-Batlle; Rubén L Rodríguez-Expósito; José E Piñero; Jacob Lorenzo-Morales Journal: Pathogens Date: 2020-03-17