Metabolic Profiling of Sweet Pepper (Capsicum annuum L.) by Means of HRMAS-NMR Spectroscopy

HRMAS-NMR spectroscopy was used to assess the metabolic profile of sweet pepper (Capsicum annuum L.). 1D and 2D NMR spectra were performed directly on a few milligrams of fruit pieces without any chemical and/or physical manipulation of the sample, allowing the assignment of several compounds. Organic acids, fatty acids, amino acids and minor compounds as trigonelline, C4-substituted pyridine, choline and cinnamic derivatives were observed within a single experiment. Some compounds are peculiar for pepper and contribute to define its overall quality, proving that HRMAS-NMR is a reliable analysis complementary to standard tools used in food science, in principle applicable to any foodstuff.