Characterization of Capparis spinosa oil by cis-vaccenic triglyceride synthesis

The objective of the present work was to conduct an in-depth evaluation of Capparis spinosa seed oil, with particular attention to the chemical characterization and determination of cis-vaccenic acid. This omega-7 monounsaturated fatty acid is known for its biological and nutritional properties, including its potential effect on lipid metabolism and cardiovascular health benefits. The chemical characterization of caper oil was carried out by NMR spectroscopy, which allowed the lipid composition of the oil to be described in detail and compared with that of olive oil. The data collected by 13C-NMR spectroscopy were analyzed using the MARA (Method for Automatic Resonance Assignment) method [1]. Another phase of the study was the chemical synthesis of the cis-vaccenic triglyceride, carried out to obtain a stable and precise chemical reference, essential to confirm the attribution of the signals detected in the 13C-NMR analysis and to allow the identification and accurate quantification of the compound in natural samples. 13C-NMR analysis highlighted significant differences in lipid composition between Capparis spinosa oil (CSO) and extra virgin olive oil (EVOO). The cis-vaccenic acid signals, located at approximately 129.8 and 129.9 ppm, corresponding to carbon 11 and 12, were particularly more intense in CSO than in EVOO. The MARA methodology allowed an accurate quantitative characterization. In CSO, cis-vaccenic acid constitutes 35-40% of the lipid composition, compared to 3% in EVOO. Analysis of the previously synthesized vaccenic acid triglyceride confirmed the assignment of signals between 129.9 ppm and 129.8 ppm. Spectroscopic confirmation of the product identity was essential not only to validate the synthetic process, but also to guarantee the suitability of the compound for future biological studies, ensuring its quality and structural conformity. In summary, the study aims to demonstrate how Capparis spinosa oil can be valorized through advanced chemical analysis, highlighting its nutritional qualities and potential commercial applications. This work aims to significantly contribute to the scientific knowledge of a highly valuable natural product, opening new opportunities for its inclusion in high-quality production chains.[2]