ASSESSING THE ORIGIN OF VEGETABLES BASED ON ¹H/¹³C-NMR PROFILING AND CHEMOMETRICS: PRELIMINARY RESULTS

Oana Romina Botoran, Raluca Popescu, Diana Costinel, Marius Miricioiu, Roxana Elena Ionete^*

National Research and Development Institute for Cryogenics and Isotopic Technologies – ICSI Rm. Valcea, 4 Uzinei Street, P.O. Box Râureni 7, 240050, Rm. Valcea, Romania

ABSTRACT

Nuclear magnetic resonance technique has been applied for the origin assignment and to verify the geographical origin and cultivation agriculture regime of vegetables that are today important parameters for consumers when selecting the foodstuff. ¹H- and ¹³C-NMR profiling to differentiate vegetables in terms of origin, vintage and declared organic practices is discussed in this work. Data interpretation demonstrated the efficacy of ¹H/¹³C-NMR together with chemometrics in achieving reliable information for traceability of origin. Important peaks from the ¹H-NMR profile for differentiation (p-value <0.05) of the geographical origin were attributed to carbohydrates (glucose, fructose, sucrose, inulin) and cyclic polyalcohol (inositol), to amino acids (valine, threonine, tryptophan, tyrosine, asparagine) and their salts (aspartic acid, aspartate) and organic acids (malic acid, citric acid). Also, it was observed that the compound signal is lower in the samples maturing in the summer season versus those that reached maturation during winter. Important for the organic-conventional differentiation, were found to be several amino acids (tyrosine, phenylalanine, tryptophan, glutamic acid/glutamate, methionine, glutamine, isoleucine and lysine) and an organic acid, the malic acid.

Keywords: NMR, origin, cultivation regime, vegetables.