Metabolomic characterization of Italian sweet pepper (Capsicum annum L.) by means of HRMAS-NMR spectroscopy and multivariate analysis.
HRMAS-NMR spectroscopy was used to assess the metabolic profile of sweet pepper (Capsicum Annum L.). One-dimensional and two-dimensional NMR spectra, performed directly on sample pieces of few milligrams, hence without any chemical and/or physical manipulation, allowed the assignment of several compounds. Organic acids, fatty acids, amino acids, and minor compounds such as trigonelline, C4-substituted pyridine, choline, and cinnamic derivatives were observed with a single experiment. A significant discrimination between the two sweet pepper varieties was found by using partial least-squares projections to latent structures discrimination analysis (PLS-DA). The metabolites contributing predominantly to such differentiation were sugars and organic and fatty acids. Also a partial separation according to the geographical origin was obtained always by analyzing the NMR data with PLS-DA. Some of the discriminating molecules are peculiar for pepper and contribute to define the overall commercial and organoleptic quality so that HRMAS-NMR proved to be a complementary analysis to standard tools used in food science and, in principle, can be applied to any foodstuff.
Ritota
Mena
M
Agricultural Research Council, Research Centre for the Soil-Plant System, Instrumental Centre of Tor Mancina, Strada della Neve Km 1, 00015 Monterotondo, Rome, Italy.
Marini
Federico
F
Sequi
Paolo
P
Valentini
Massimiliano
M
D002212:Capsicum / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D055432:Metabolomics; D015999:Multivariate Analysis