Author: HİCRAN
Last saved by: Saritas, Sevim
Company: F_s_M

Spectroscopic Analysis of Hazelnut Oil after Ozone Treatment by 
FT-IR and NMR
Hicran U. Karka, Esra Ibanoglu, Food Engineering Department, Gaziantep University
Gaziantep, Turkey.

Ozone treatment has been used commonly in food industry as a disinfecting and sanitizing purpose for food storage and processing since FDA granted generally recognized as safe (GRAS) status for use of ozone in food processing and preservation systems. Ozone is a strong antimicrobial substance due to the its potential oxidizing capacity. However, there are limited knowledge about the effects of ozone on the food components. In this study, the effect of ozone treatment on hazelnut oil was studied. Ozone chemically reacts with carbon double bonds present in unsaturated fatty acids leading to ozonated derivatives such as hydroperoxides, ozonides, aldehydes, peroxides, diperoxides and polyperoxides. The effects of ozone treatment on the hazelnut oil were analyzed by ^1H, ^13C NMR and FT-IR. The reaction of ozone with double bonds in the oils is known as Crieege mechanism. Reaction products were estimated according to Crieege mechanism. In ^1H and ^13C NMR, new signal at 5.15 and 104.35 ppm were found in ozonated hazelnut oils. The new signal was assigned to the ring proton of 1,2,4- trioxolane (primary ozonide). Ozonated hazelnut oils also exhibited peaks at 9.75 and 2.43 ppm in ^1H NMR, and at 202.5 and 43.9 ppm in ^13C NMR corresponding to aldehydic proton and α-methylene group, respectively. Area of the new peaks increased with ozone treatment time. The new signals formed in ozonation process gradually increased with ozone treatment time. After 360 min. ozone treatment, the signals of unsaturated bonds at 2.00 and 5.30 ppm in 1H NMR spectra and 27.1 and 128-130 ppm in 13C NMR spectra dramatically decreased and finally disappeared after 360 min. of ozonation. In the absence of unsaturation, ozonide formed in the early stage of ozone treatment was cleaved to give carboxylic acid.

Key Words: Ozone, oxidation, hazelnut oil, FT-IR, NMR.