Multivariate study of spectral data of oils

Abstract

Abstract. In this paper the study of structural differences and thermal degradation of edible oils during heating is presented. The study is performed on five types of vegetable oil: extra virgin olive oil, pomace olive oil, sunflower, canola and palm oil. The oils were measured by Raman spectroscopy. This method brings advantages as rapidity, independence on chemicals, provides specific information on chemical composition and structure of material and is able to detect structural changes. For the processing of large data sets multivariate analytical method as Principal component analysis and Cluster analysis are applied to find the patterns within the data. The evaluation of process of thermal degradation is also based on the major decomposition product of oxidized linoleate appearing in spectra via band 1640 cm -1 . Mathematically processed data indicate the least effect of heating for olive oils, the greatest degradation and loss of unsaturation for sunflower oil.

Analysis of Pork Adulteration In Recycled Frying Oils Using Raman Spectroscopy

“…This shows that the resulted peaks of palm frying oil in this study might indicate the significant Raman spectra characteristics of vegetable oils. Similar pattern of Raman spectrum of palm oil which exhibited the similar significant peaks were also reported in other studies [17,[19][20]. There were also studies which reported some similar patterns of the Raman spectra of animal fats or oils such as desi ghee, pork lard, beef tallow, duck oil and chicken fat [21][22].…”

“…At Raman peak of 1303 cm -1 , it was reported that the peak is assigned for the vibration of saturated CH2 in-plane twist [17]. The region from 1640 cm -1 to 1680 cm -1 reported to be the C=C stretching region to detect cis or trans isomers [26].…”

“…The PCA converts the set of data into a new set of PCs [29]. It also assesses the patterns in the data set and identifies the hidden similarities and differences [17]. Figure 2 shows the PCA of recycled frying oils.…”

“…All measurements were collected with 10 s exposure time and 1 accumulation by using 50x magnification. The samples were scanned in extended range of 800 to 1800 cm -1 with 1 cm -1 spectral resolution for triplicates reading [17]. WiRE 4.0 software (Renishaw, UK) was used to focus the spot.…”

A preliminary study of counterfeit electronic components using Raman spectroscopy

“…Raman spectroscopy has a great potential in nondestructive material analysis. This experience we already have with other type of surveyed materials [9,10]. Therefore its application on electronic components is being studied to extend the range of methods for deviation detection from original electronic components.…”