Application of chemometrics in quality control of Turmeric (Curcuma longa) based on Ultra-violet, Fourier transform-infrared and 1H NMR spectroscopy

- Metabolic profiling of Turmeric by UV, FT-IR and 1H NMR in comparison to HPLC.
- PCA and HCA were applied to discriminate high quality samples from low quality ones.
- UV discriminated between samples, as simple fast technique alternative to HPLC.
- Metabolic variability was evident in essential oils/fatty acid region in 1H NMR.
- First time to apply UV, FT-IR and 1H NMR for the quality control of Turmeric.

Turmeric (Curcuma longa L.) belongs to the family Zingiberaceae that is widely used as a spice in food preparations in addition to its biological activities. UV, FT-IR, 1H NMR in addition to HPLC were applied to construct a metabolic fingerprint for Turmeric in an attempt to assess its quality. 30 samples were analyzed, and then principal component analysis (PCA) and hierarchical clustering analysis (HCA) were utilized to assess the differences and similarities between collected samples. PCA score plot based on both HPLC and UV spectroscopy showed the same discriminatory pattern, where the samples were segregated into four main groups depending on their total curcuminoids content. The results revealed that UV could be utilized as a simple and rapid alternative for HPLC. However, FT-IR failed to discriminate between the same species. By applying 1H NMR, the metabolic variability between samples was more evident in the essential oils/fatty acid region.