In vitro plantlets and callus of M. longifolia were established and their volatile constituents characterized by GC-MS analysis of their headspaces (HSs) and essential oils (EOs). Significant quali-quantitative differences were found in the aromatic fingerprints in comparison with the M. longifolia parent plants. In fact, limonene and carvone were the main constituents in the EOs of the mother plants, while the aroma of the in vitro plant material were especially enriched in oxygenated terpenes. In particular, huge amounts of piperitenone and piperitenone oxide (75 %) were found for in vitro plantlets, while trans-carvone oxide (19 %) and trans-piperitone epoxide (9 %) were found in callus EO. However, the established in vitro plant material showed lack of pulegone and menthofurane, thus preserving an important feature observed in the volatile fingerprint of the parent plants. In fact, because of their well-known toxicity significant amounts of pulegone and menthofurane may compromise the safety using of mint essential oil. Therefore the in vitro M. longifolia plantlets and callus may be regarded as a potential source of a safe flavouring agent.
The qualitative and quantitative analysis of polycyclic aromatic hydrocarbons contamination in selected popular brands of fruit and herbal teas was performed using GC-MS method. Among all teas similar quality profiles of PAHs were observed. In all determined compounds 4 light PAHs (phenanthrene, anthracene, fluoranthene, pyrene) from the group of PAHs listed by EPA were predominant. From group of 15 PAHs, marked out for analysis by The UE Scientific Committee on Food, only benzo[a]anthracene, chrysene, 5-metylchrysene, benzo[b]fluoranthene and benzo[k]fluoranthene were stated, although, their levels were relatively low. Benzo[a]pyrene and the most carcinogenic PAHs, namely dibenzopyrenes, were not detected. Moreover, the GC-MS analysis revealed significant differences in contamination level of particular brands of teas among all fruit and herbal teas under investigation.