Valorization of tunisian plants for their accumulation of oils and bioactive compounds during their development : application in food protection

Cette étude a pour objectif la recherche d’huiles et de composés bioactifs dans des graines provenant de la région semi-aride à aride « Regueb » située au centre de la Tunisie. Plusieurs graines sont riches en huiles principalement composées d'acides gras classiques. Des teneurs élevées en acide pétrosélinique, un acide gras inhabituel, ont été détectées chez les espèces appartenant à la famille des Apiaceae, en particulier P. major et P. saxifraga. Les graines de d’Ap. graveolens, An. graveolens, P. saxifraga et L. sativum sont à la fois riches en huiles et en composés phénoliques fonctionnels. L’accumulation de ces composés dans les graines en développement a été étudiée pour P. major, P. saxifraga et L. sativum. Certaines graines contiennent également des huiles essentielles ayant un pouvoir antibactérien comme celles de P. saxifraga, Ap. graveolens et C. sativum qui sont riches en anéthol, dillapiole et linalol. L’huile essentielle des graines de P. saxifraga (PSEO) a été, pour la première fois, testée dans un enrobage comestible à base d’alginate de sodium pour la conservation du fromage frais. Une évaluation de sa toxicité chez les souris a permis la détermination de la plage de doses sans effet nocif. L’enrobage comestible d'alginate de sodium enrichi en PSEO a amélioré la conservation du fromage frais "Sicilien de Bèja" en permettant de préserver le pH et la couleur, de diminuer la péroxydation lipidique et d’améliorer la stabilité bactérienne. L'analyse sensorielle a montré une forte appréciation du fromage enrobé en présence de PSEO.The aim of this study is to identify bioactive oils and compounds in seeds from the semi-arid to arid region of "Regueb" in central Tunisia. Several species contained high amounts of oil mainly composed of classic fatty acids. High amounts of petroselinic acid, an unusual fatty acid, have been detected in species of the family Apiaceae, in particular P. major and P. saxifraga. The seeds ofAP. graveolens, An. graveolens, P. saxifraga and L. sativum were rich in oil and functional phenolic compounds. The accumulation of these compounds in growing seeds has been studied for P. major, P. saxifraga and L. sativum. Several seed contained essential oils with antibacterial properties such as those of P. saxifraga, AP. graveolens and C. sativum, which contained anethole, dillapiole and linalool. The essential oil of P. saxifraga seeds (PSEO) was, for the first time, tested in an edible coating based on sodium alginate for the preservation of fresh cheese. An evaluation of its toxicity in the mice allowed the determination of the dose range without any harmful effect. The edible coating of sodium alginate enriched with PSEO has improved the preservation of the fresh Sicilian cheese by preserving pH and color, reducing lipid peroxidation and improving bacterial stability. Sensory analysis showed a strong appreciation of coated cheese in presence of PSE

Composition, antibacterial and antioxidant activities of Pimpinella saxifraga essential oil and application to cheese preservation as coating additive

International audienceThe effect of Pimpinella saxifraga essential oil (PSEO) addition (1–3%) in sodium alginate coating on the bacterial and oxidative stability of cheese was studied during refrigerated storage. The GC–HRMS analysis of PSEO showed that anethole, pseudoisoeugenol and p-anisaldehyde were the main components. The PSEO exhibited strong in vitro DPPH radical scavenging activity (IC50 = 6.81 µg/mL), β-carotene bleaching inhibition (IC50 = 206 µg/mL), ferric reducing power (EC50 = 35.20 µg/mL), total antioxidant activity (213.96 ± 11.12 µmol/mL α-tocopherol equivalent) and notable DNA protection potential. Additionally, PSEO displayed potent antibacterial activity against 3 Gram-positive and 3 Gram-negative bacteria (MICs = 0.78–3.12 mg/mL). The acute toxicity of PSEO was determined using mice model (LD50 = 976.2 mg/kg). The enrichment of sodium alginate coating with PSEO, particularly at 3%, improved cheese preservation by reducing the weight loss, preserving the pH and color and enhancing oxidative and bacterial stability without unpleased flavor for consumers