RESUMO
The broad variability of Cucumis melo (melon, Cucurbitaceae) presents a challenge to conventional classification and organization within the species. To shed further light on the infraspecific relationships within C. melo, we compared genotypic and metabolomic similarities among 44 accessions representative of most of the cultivar-groups. Genotyping-by-sequencing (GBS) provided over 20,000 single-nucleotide polymorphisms (SNPs). Metabolomics data of the mature fruit flesh and rind provided over 80,000 metabolomic and elemental features via an orchestra of six complementary metabolomic platforms. These technologies probed polar, semi-polar, and non-polar metabolite fractions as well as a set of mineral elements and included both flavor- and taste-relevant volatile and non-volatile metabolites. Together these results enabled an estimate of "metabolomic/elemental distance" and its correlation with the genetic GBS distance of melon accessions. This study indicates that extensive and non-targeted metabolomics/elemental characterization produced classifications that strongly, but not completely, reflect the current and extensive genetic classification. Certain melon Groups, such as Inodorous, clustered in parallel with the genetic classifications while other genome to metabolome/element associations proved less clear. We suggest that the combined genomic, metabolic, and element data reflect the extensive sexual compatibility among melon accessions and the breeding history that has, for example, targeted metabolic quality traits, such as taste and flavor.
RESUMO
Food fraud is perpetrated with increasing frequency along the food chain, triggering the need for new and modern tools to detect food authenticity. Chia, flax and sesame seeds are well known for the good nutritional characteristics of their oils, but there is a lack of knowledge regarding the authenticity of these seeds and food products containing them as well. In the present work, we propose a method based on targeted metabolomics to identify the polyphenols present in seeds, which can be used as markers of authenticity. We tentatively identified 44 polyphenols in the different seeds by HPLC-DAD-ESI-qTOF (MS/MS). Chemometrics allowed the selection of 12 compounds, which are nominated as novel markers for seed authentication. Some of these compounds were also found in a lab-scale preparation of cookies supplemented with the studied seeds. The proposed chemical markers resisted the baking process, representing good candidates to be used in the authentication of raw material and bakery products containing these seeds.