Metabolomics and Chemometrics as Tools for Chemo(bio)diversity Analysis - Maize Landraces and Propolis

Phenolic content and ferric reducing–antioxidant power of cow's milk produced in different pasture‐based production systems in southern Brazil

“…between 200 and 300 nm, with low relative intensities at 300 nm (data not shown). The separation of certain phenolic subgroups by monitoring the UV–visible λ max has been employed in some studies . The λ max for benzoic acid and dihydrochalcones, for instance, is approximately 280 nm, for cinnamic acid derivatives it is close to 320 nm and for flavonols it is around 360 nm .…”

“…The λ max for benzoic acid and dihydrochalcones, for instance, is approximately 280 nm, for cinnamic acid derivatives it is close to 320 nm and for flavonols it is around 360 nm . Hence the spectral profile for a complex matrix may be used as an indication of its chemical composition, also known as the metabolic fingerprint . Thus, to extract the maximum amount of information from the ultraviolet absorption spectra, principal components were identified from the spectroscopic dataset.…”

“…Thus, to extract the maximum amount of information from the ultraviolet absorption spectra, principal components were identified from the spectroscopic dataset. PCA is considered to be an important tool to improve the analysis of very extensive datasets generated by non‐selective analytical techniques such as UV–visible, MS, NMR and FTIR . Figure (A) shows a scatter plot of the PCA scores for the crude extracts using the spectral window dataset at between 200 and 350 nm.…”

“…The separation of certain phenolic subgroups by monitoring the UV-visible max has been employed in some studies. 31,32 The max for benzoic acid and dihydrochalcones, for instance, is approximately 280 nm, for cinnamic acid derivatives it is close to 320 nm and for flavonols it is around 360 nm. 33 Hence the spectral profile for a complex matrix may be used as an indication of its chemical composition, also known as the metabolic fingerprint.…”

“…33 Hence the spectral profile for a complex matrix may be used as an indication of its chemical composition, also known as the metabolic fingerprint. 31 Thus, to extract the maximum amount of information from the ultraviolet absorption spectra, principal components were identified from the spectroscopic dataset. PCA is considered to be an important tool to improve the analysis of very extensive datasets generated by non-selective analytical techniques such as UV-visible, MS, NMR and FTIR.…”