Chemical and structural variations in hazelnut and soybean oils after ozone treatments

Abstract

SUMMARY:In the present work, the effect of ozone treatments on the structural properties of soybean oil (SBO) and hazelnut oil (HO) were investigated. The study presents the findings and results about the oxidation of HO and SBO with ozone, which has not been fully studied previously. The HO and SBO were treated with ozone gas for 1, 5, 15, 30, 60, 180 and 360 min. The ozone reactivity with the SBO and HO during the ozone treatment was analyzed by 1 H, 13 C NMR, FTIR and GC. The iodine value, viscosity and color variables (L*, a* and b*) of untreated and ozone treated oils were determined. Reaction products were identified according to the Criegee mechanism. New signals at 5.15 and 104.35 ppm were assigned to the ring protons of 1,2,4-trioxolane (secondary ozonide) in the ozonated oils in 1 H and 13 C NMR, respectively. Ozonated oils exhibited peaks at 9.75 and 2.43 ppm in 1 H and NMR, which corresponded to the aldehydic proton and α-methylene group and to the carbonyl carbon, respectively. The peak at 43.9 ppm in 13 C NMR was related to the α-methylene group and to the carbonyl carbon. The new signals formed in the ozonation process gradually increased with respect to ozone treatment time. After 360 min of ozone treatment, the carbon-carbon double bond signal, which belongs to the unsaturated fatty acids, disappeared completely in the spectrum. An increase in viscosity, a decrease in iodine value and a dramatic reduction in b* of the oil samples on (+) axis were observed with increased ozone treatment time. KEYWORDS: FTIR; GC; Hazelnut oil; NMR; Ozone; Soybean oil; Viscosity RESUMEN:Variaciones químicas y estructurales de aceites de avellana y soja después de tratamientos con ozono. En el presente trabajo se investigó el efecto de tratamientos con ozono sobre las propiedades estructurales de aceites de soja (SBO) y avellana (HO). El estudio muestra hallazgos y resultados sobre la oxidación de HO y SBO con ozono que no se habían presentado previamente. Los aceites HO y SBO son tratados con ozono gaseoso durante 1, 5, 15, 30, 60, 180 y 360 min. La reactividad del ozono con SBO y HO durante el tratamiento se analizó mediante 1 H, 13 C NMR, FTIR y GC. Se midieron las variables: índice de yodo, viscosidad y color (L *, a * y b *) de los aceites no tratados y tratados con ozono. Los productos de reacción se identificaron de acuerdo con el mecanismo de Criegee. Se asignaron nuevas señales a 5,15 y 104,35 ppm a los anillos protónicos de 1,2,4-trioxolano (ozónido secundario) en aceites ozonizados en 1 H y 13 C RMN, respectivamente. Los aceites ozonizados también mostraron picos a 9,75 y 2,43 ppm en 1 H NMR correspondientes al protón aldehídico y al grupo α-metileno, respectivamente. El pico a 43,9 ppm en 13 C RMN se relacionó con el C carbonilo del grupo α-metileno. Las nuevas señales formadas en el proceso de ozonización aumentaron gradualmente con respecto al tiempo de tratamiento con ozono. Después de un tratamiento de 360 minutos con ozono, la señal del doble enlace C=C que pertenece a los ácidos grasos insaturados ...

High Efficacy of Ozonated Oils on the Removal of Biofilms Produced by Methicillin-Resistant Staphylococcus aureus (MRSA) from Infected Diabetic Foot Ulcers

“…In general, the content of identified unsaturated fatty acid in oil decreased with the increase of ozonation time and, consequently, the peroxide value increased. On the contrary, almost all saturated fatty acids, except C20:0, increased significantly with the time of ozonation, reaching its highest value in sample 6 (360 min of ozonation), which is consistent with other studies, because oxidation causes the increase in relative percentages of saturated fatty acids and a decrease of relative percentages of unsaturated fatty acids [32,33]. All unsaturated fatty acids, except the α-linolenic acid (C18:3n3), were detected in all samples, which indicates that ozone did not react with all double bonds of these acids, which remained as modified triglycerides and non-modified triglycerides, and can then be oxidized by the oxygenated compounds formed [31].…”

“…All unsaturated fatty acids, except the α-linolenic acid (C18:3n3), were detected in all samples, which indicates that ozone did not react with all double bonds of these acids, which remained as modified triglycerides and non-modified triglycerides, and can then be oxidized by the oxygenated compounds formed [31]. The percentages of identified unsaturated fatty acids in samples 5 and 6 (160 and 320 min of treatment) decreased rapidly, which is in accordance with the results obtained in other studies, leading to a decrease in the percentages of oleic and linoleic acids [32,34]. The oxidation of oleic acid comprises the break of the carbon-carbon double bond at position nine of the carbon backbone [35].…”

Evaluation of different ozonation on aflatoxin degradation and physicochemical characteristics of hazelnuts

“…The significant decline in the content of α-tocopherol in oil was noted after 10 and 20 ppm, especially 20 min of ozonation. It was agreed that previously studied, the tocopherol content of hazelnut samples has decreased with storage time (Enami et al, 2009;Uzun et al, 2018).…”

Low concentration short time ozonation of rapeseed seeds reduces the stability of the oil and content of some antioxidant components

“…() have suggested that α‐tocopherol does not react directly with ozone in biological systems, but is consumed instead by free radical reactions secondary to ozonation. The FTIR analysis (Uzun et al ., ) confirmed that the intensity and frequency of the bands related to the carbon‐carbon double bonds decreased or these bands became overlapping and broadened as ozone treatment time was extended. In our studies we observed the same dependence.…”