Removal of di‐2‐ethylhexyl phthalate (DEHP) and mineral oil from crude hazelnut skin oil using molecular distillation–multiobjective optimization for DEHP and tocopherol

Abstract

Different distillation conditions of DEHP were investigated to decrease concentration in hazelnut skin oil. In a short-path distillation column, different absolute pressures (1-3 mbar) and evaporator temperatures (200-230°C) were used. When distilled at 230°C under 1 mbar of absolute pressure, a reduction of 98.95% of initial DEHP concentration was achieved. At this condition, DEHP concentration was found 0.32 mg/kg. Tocopherols were also removed by molecular distillation inevitably. At 220°C temperature and 3 mbar absolute pressure, total tocopherols were reduced from initial concentration of 780.63-419.24 mg/kg. Since tocopherols were desired to remain in hazelnut skin oil, a multiobjective optimization process was performed. When upper DEHP boundary was set to 1.5 mg/kg, 15 different alternative paths were reached while maximizing total tocopherol amount within pressure-temperature boundaries. After each molecular distillation, mineral oil content was reduced nearly by sixfold from an initial concentration of 64 mg/kg. Even when distillation temperature was set to 200°C, mineral oil content was drastically reduced to approximately 10 mg/kg level.Practical applications: DEHP is a common contaminant in oil materials packed with plastic packages. Removal of DEHP is of great importance due to negative health impacts. Since tocopherol loss should be kept minimum while processing oil for removal of DEHP, process conditions should be carefully selected. This study reveals optimum molecular distillation conditions for this purpose. These conditions could be evaluated in industrial plants for producing best quality products with maximum tocopherol content as possible.

Oxidative stability of high oleic palm and hazelnut skin oil blends

“…Özdemir et al (2014) reported that the content of α‐tocopherol, β‐tocopherol, γ‐tocopherol, and δ‐tocopherol of solvent‐extracted HSO was 1250, 850, 1290, and 0.14 mg/kg, respectively. In another study, total tocopherol content of crude HSO was reported as 780.63 ppm, consisting of 461.76 ppm α‐tocopherol, 15.25 ppm β‐tocopherol, and 303.62 ppm γ‐tocopherol (Gelmez et al, 2017). In this study, lower tocopherol contents were found for HSO, since refined HSO was used in this study.…”

“…It is defined as a brown‐colored layer that surrounds the kernel and composed of 67.7% dietary fiber, 8.2% protein, 14.5% oil and different polyphenolic compounds such as flavan‐3‐ols, phenolic acids, and procyanidins (Özdemir et al, 2014). The skin is extracted by hexane to obtain crude hazelnut skin oil that is rich in tocopherols, mainly α and γ‐tocopherols (Gelmez et al, 2017). The crude oil is then refined for the human consumption.…”

Review on Occurrence, Sources of Contamination, and Mitigation Strategies of Phthalates in Vegetable Oils

“…At the same time, squalene loss in tea seed oil is 71.35%, ergosterol loss is 71.73%, and the removal of tocopherol is as high as 89.53%. [25] Gelmez [58] and others reduced DEHP content in hazelnut peel oil to 1.43 mg kg −1 at 230 PA, 207 °C, and 3 mL min −1 , and the loss rate of tocopherol was from 47% to 36%, through optimizing the molecular distillation process.…”

Removal of DBP from evening primrose oil with activated clay modified by chitosan and CTAB

“…Adsorption, steam distillation and molecular distillation are the three most widely investigated methods. Among them, molecular distillation has the highest removal efficiency of PAEs, generally up to 90% or more (Chen et al, 2019;Xiong et al, 2013;Gelmez et al, 2017), but this method is difficult to be widely used due to its high cost and difficulties in industrialization. Adsorption and steam distillation are widely used in the refining process of de-coloration and deodorization processes in edible oil.…”