Adding extra-dimensions to hazelnuts primary metabolome fingerprinting by comprehensive two-dimensional gas chromatography combined with time-of-flight mass spectrometry featuring tandem ionization: Insights on the aroma potential.

The information potential of comprehensive two-dimensional gas chromatography combined with time of flight mass spectrometry (GC × GC-TOFMS) featuring tandem hard (70 eV) and soft (12 eV) electron ionization is here applied to accurately delineate high-quality hazelnuts (Corylus avellana L.) primary metabolome fingerprints. The information provided by tandem signals for untargeted and targeted 2D-peaks is examined and exploited with pattern recognition based on template matching algorithms. EI-MS fragmentation pattern similarity, base-peak m/z values at the two examined energies (i.e., 12 and 70 eV) and response relative sensitivity are adopted to evaluate the complementary nature of signals. As challenging bench test, the hazelnut primary metabolome has a large chemical dimensionality that includes various chemical classes such as mono- and disaccharides, amino acids, low-molecular weight acids, and amines, further complicated by oximation/silylation to obtain volatile derivatives. Tandem ionization provides notable benefits including larger relative ratio of structural informing ions due to limited fragmentation at low energies (12 eV), meaningful spectral dissimilarity between 12 and 70 eV (direct match factor values range 222-783) and, for several analytes, enhanced relative sensitivity at lower energies. The complementary information provided by tandem ionization is exploited by untargeted/targeted (UT) fingerprinting on samples from different cultivars and geographical origins. The responses of 138 UT-peak-regions are explored to delineate informative patterns by univariate and multivariate statistics, providing insights on correlations between known precursors and (key)-aroma compounds and potent odorants. Strong positive correlations between non-volatile precursors and odorants are highlighted with some interesting linear trends for: 3-methylbutanal with isoleucine (R2 0.9284); 2,3-butanedione/2,3-pentanedione with monosaccharides (fructose/glucose derivatives) (R2 0.8543 and 0.8860); 2,5-dimethylpyrazine with alanine (R2 0.8822); and pyrroles (1H-pyrrole, 3-methyl-1H-pyrrole, and 1H-pyrrole-2-carboxaldehyde) with ornithine and alanine derivatives (R2 0.8604). The analytical work-flow provides a solid foundation for a new strategy for hazelnuts quality assessment because aroma potential could be derived from precursors' chemical fingerprints.

Validation of a General and Sports Nutrition Knowledge Questionnaire in Italian Early Adolescents.

To the best of our knowledge, no specific questionnaires on sports nutrition knowledge (NK) have been validated so far in Italian early adolescents. The aim of the present study was to validate a short (26-item) general and sports NK questionnaire in a group of Italian early adolescents. To this aim, the questionnaire was administered to 264 subjects for analysis of internal consistency, and in a subgroup (n = 39) for evaluating the reliability over time. The questionnaire revealed good overall internal consistency and reliability (Cronbach's α = 0.684) and a highly significant correlation over time (r = 0.977, p < 0.001). Comparison with other validated questionnaires is tricky, because the previous questionnaires were validated in different populations, such as middle or late adolescents or adults, with a higher number of items compared to our questionnaire. Furthermore, data on adolescent NK in Italy are very limited. This study provides a brief, feasible, and validated questionnaire that can be used for investigating sports NK in young subjects. It could be used for evaluating the efficacy of education on general and sports nutrition in both the general population and athletes, and for investigating the relationship between NK and different sports in early adolescence.