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Tesi etd-05192014-100230

Thesis type
Tesi di laurea magistrale
UV-vis and 1H-NMR spectroscopic methods applied to the study of extra-vergin olive oil produced in Tuscany and Apulia
Corso di studi
controrelatore Dott.ssa Biver, Tarita
relatore Dott.ssa Domenici, Valentina
Parole chiave
  • geographical origin
  • Olive oil
  • Tuscany
  • Apulia
  • UV-Vis
  • NMR
  • relaxation
  • diffusion
  • PCA
Data inizio appello
Riassunto analitico
Extra virgin olive oils are high price commodities, because of their production process combined with corresponding nutritional properties and sensorial quality. As a consequence this led to adulterations of extra virgin olive oils with low-grade oils of different botanical origin (e.g. seed oil) or refined olive oils. Olive oil is the most adulterated matrix on the food field. Different types of analysis could potentially guarantee the authenticity of the product, the geographical and botanical origin of the sample.
In this thesis a total of eighty-six samples were analysed within a maximum of six months from oils collection. Seventy-nine of extra-virgin olive oils were collected directly and personally from farmers and oil mills in two Italian Regions: Apulia and Tuscany. Additionally, a sample of virgin (VO), one of lamp (LaO) and one of refined (RO) olive oil, plus some samples of seed oils, sunflowers (SuO), linseed (LO), soybean (SO) and macadamia nut (MO) were included in our collection and analyzed in the same way as extra-virgin olive oils.
Oil samples were studied by means of UV-vis and NMR spectroscopy without any sample preparation and at room temperature.
The absorption spectra of all samples were recorded in the range 200 – 800 nm, by using a Jasco UV-vis V-550 spectrophotometer. Absorption UV-vis pigments content. In particular, a mathematical treatment of the spectra was developed in order to quantify four main pigments: pheophytin-a, pheophytin-b, β-carotene and lutein.
Proton NMR measurements on oil samples were performed by using three instruments at different frequency (2MHz, 100MHz and 500MHz). 1H NMR investigation focuses on the relaxation and diffusion properties of oil samples.
In order to discriminate the two geographical origin of the sample a test by means of statistical analysis was done.