Identification and characterisation of bioactive compounds in thyme

Abstract

Thyme (Thymus vulgaris) is a very diverse species that is known and used as a medical plant due to its high amount of therapeutic compounds. Its essential oil contains substances with antioxidative properties as thymol (about 50%). The objective is to take advantage of that potential by incorporating sustainably produced additives based on thyme e.g. in food packaging. Compounds with antioxidative, antimicrobial and UV absorbing effects are of special interest as those substances protect the product from oxidative stress, microbial degradation and loss of quality.
Therefore, six variants of thyme are analysed with regard to different parameters to choose a superior variant to conduct further research on.
The essential oil is extracted by steam distillation and analysed via GC-MS. Additionally, solvent extracts are analysed with regard to total antioxidant capacity (TAC), UV absorption and chemical composition. The volatile compounds are determined as well. In general, there are little differences in quality but in quantity as one variant’s oil contains a considerably higher amount of thymol (about 65 %); the same variant‘s methanol extract proves to have a high TAC. Thus, a promising variant for further development and optimisation of biobased, bioactive additives is identified in this study.