Food metabolomics by GCXGC-TOF MS and tandem ionization: understanding the impact of climate events on edible crops quality

The increased frequency and severity of extreme climate events around the world, as well as crop diseases and pests caused by climate change, have an impact on global food security and quality. A better and comprehensive understanding of the relationship between climate conditions and nutrition is necessary to provide the human population with safe and secure access to food. The goal of the current study is to understand the effects of climate change on the detectable metabolome of a selection of edible crops. Hazelnuts and peanuts were selected to understand post- harvest practices impact on aroma precursors; soy was investigated for its metabolic profile in relation to insect bites due to migrations caused by global warming [1]. To validate the hypothesis of a climate change impact on aroma quality, hazelnuts and peanuts were roasted and the key-odorants patterns correlated to aroma precursors distribution [2]. The analytical strategy, aligned to food-metabolomics principles, exploits the information potential of multi-dimensional analysis that combine physicochemical discrimination/separation of analytes with spectrometric detection by comprehensive two-dimensional gas chromatography coupled to time-of- flight mass spectrometry (GC×GC-TOFMS) featuring Tandem ionisation™. The process known as untargeted and targeted (UT) fingerprinting is used in combination with chemometric algorithms to highlight metabolomic variations between composite-class images generated by re-alignment and fusion of raw data collected from samples belonging to distinct classes, thus highlighting metabolites pattern differences [3]. Results indicate that post-harvest connoted by higher relative humidity has an impact on hazelnut metabolome resulting in an up-regulation of about 22 targeted features belonging to different classes (organic acids, amino acids, and mono- and disaccharides), with the latter showing 2-4 fold increment, evidence of a metabolic activation. Metabolism activation in peanuts, resulting in “split” seeds during industrial processing, showed higher concentration in sugars and specifically in ribose, while aroma precursors (L-Val, L-Thr, and saccharose) were present in lower amounts. Soy samples attacked by Halyomorpha halys (Stål), the brown marmorated stink bug, showed clear activation of primary metabolism with a general up-regulation of many chemical classes.