The spectrometry of isomers of triglycerides of fatty acids in fatty buttery products: butter and palm oil.

Abstract

In organism, differences in physical chemical properties and physiological role of positional isomeric forms of triglycerides of fatty acids consumed with food are well known. The Raman spectroscopy to analyze there is possible to be applied. Both of these circumstances are to be considered and applied in resolving practical issues of dietetics, i.g., in detection of falsification and replacement of butter and spreads with palm oil, as well as in monitoring ratio of fatty consumed by patients with cardiologic and oncologic pathology. The purpose of study is to determine possibilities of analyzing positional fatty acids isomers specific for butter and palm oil using portable and operational spectrometers of absorption in near infrared range. The technique of projections on latent structures was applied to obtain calibrations of spectrometers to detect content of 7 regulated fatty acids and percentage of milk fat and palm oil in fat-oil mixtures according specters of Raman and near infrared range spectrometers. The possibility of identifying positional isomers of animal and vegetable triglycerides according Raman spectra was confirmed. Besides, it is established that efficiency of determining (reliability, accuracy and selectivity) the proportions of the above oils using both Raman spectra and near-infrared optical density spectra was much higher than when calculating the percentage of the same oils using the content of 7 fatty acids. This fact reflects sensitivity of near infrared range absorption spectra both to length of the carbon chain and degree of unsaturation (number of double bonds C=C) of fatty acids and positional isomeric forms of triglycerides. The obtained data are used in formulating technical requirements and conditions for application of portable near infrared range spectrometer for mass analysis of fat-oil products.