Oregano (Origanum vulgare and O. onites) is one of the most frequently counterfeited herbs in the world and is diluted with the leaves of a wide variety of plants. In addition to olive leaves, marjoram (O. majorana) is often used for this purpose in order to achieve a higher profit. However, apart from arbutin, no marker metabolites are known to reliably detect marjoram admixtures in oregano batches at low concentrations. In addition, arbutin is relatively widespread in the plant kingdom, which is why it is of great relevance to look for further marker metabolites in order to secure the analysis accordingly. Therefore, the aim of the present study was to use a metabolomics-based approach to identify additional marker metabolites with the aid of an ion mobility mass spectrometry instrument. The focus of the analysis was on the detection of non-polar metabolites, as this study was preceded by nuclear magnetic resonance spectroscopic investigations of the same samples based mainly on the detection of polar analytes. Using the MS-based approach, numerous marjoram specific features could be detected in admixtures of marjoram >10% in oregano. However, only one feature was detectable in admixtures of >5% marjoram. This feature was identified as blumeatin, which belongs to the class of flavonoid compounds. Initially, blumeatin was identified based on MS/MS spectra and collision cross section values using a database search. In addition, the identification of blumeatin was confirmed by a reference standard. Moreover, dried leaves of olive, myrtle, thyme, sage and peppermint, which are also known to be used to adulterate oregano, were measured. Blumeatin could not be detected in these plants, so this substance can be considered as an excellent marker compound for the detection of marjoram admixtures.

Background/Objectives: Strawberries (Fragaria × ananassa) are among the most commonly consumed fruits due to their taste and nutritional benefits. However, their high rate of spoilage poses a major problem during the period from harvest and transport to further processing or marketing. The aim of this study was, therefore, to investigate the effects of passive modified atmosphere packaging on the metabolome and shelf life of strawberries as a more sustainable alternative compared to standard market storage conditions. Methods: A total of 99 strawberry samples were analyzed for microbial viable counts, water content, and metabolomic changes using non-targeted low-resolution near-infrared spectroscopy, high-resolution mass spectrometry, and microbial culture-based methods. Results: Using near-infrared spectroscopy as a rapid screening method, the linear regression model indicated that strawberries stored under modified atmosphere packaging conditions had a longer shelf life. Furthermore, lipidomic analysis using mass spectrometry showed that the levels of spoilage biomarkers, such as oxidized phosphatidylcholines and lysophosphatidylcholines, were increased under common market storage conditions without a controlled atmosphere. In contrast, the levels of these metabolites were reduced when strawberries were stored in modified atmosphere packaging. Moreover, the strawberries stored under modified atmosphere packaging had a lower number of bacteria, yeasts, and molds as well as a lower water loss throughout the entire storage period. Conclusions: Overall, the study highlights the potential of passive modified atmosphere packaging films to extend the shelf life and thus maintain the edibility of strawberries over a longer period.