Effect of refining processes on the total and individual tocopherol content in sunflower oil

Abstract

Total and individual tocopherol contents of sun¯ower oil, processed either by chemical re®ning (CR), physical re®ning (PR) or soft column deodorization (SCD) methods were investigated. Total tocopherol content gradually decreased until the end of the re®ning process (the deodorization stage). Among the re®ning methods used CR and PR caused higher losses in the tocopherol content when compared with the SCD method. The content of a-, b-, c-and d-tocopherols also decreased as a result of the re®ning process. These signi®cant losses in b-and c-tocopherol contents were determined after the deodorization stage.

Changes in α-, β-, γ- and δ-tocopherol contents of mostly consumed vegetable oils during refining process

“…Among these tocopherols, α-tocopherol is the most active form of vitamin E and γ-and δ-tocopherols have shown better antioxidant activities than the others (Chu & Lin, 1993;Gimeno, Castellote, Raventos, de la Torre, & Sabater, 2000). These important natural antioxidants are decreased during each step of refining processes and markedly reduced during deodorizing (Alpaslan, Tepe, & Simsek, 2001;Kellens, 1997).…”

“…12, No. 2, 199-202, http://dx.doi.org/10.1080/19476337.2013 loss of tocopherols results in a serious decrease in the protective power against autoxidation (Alpaslan et al, 2001). Moreover, tocopherols provide immunoprotection, antiproliferative and anticlotting effects and reduce LDL oxidation, platelet adhesives and thrombosis (Swiglo & Skorska, 2004).…”

“…The concentration of α-tocopherol, reported in the literature for good-quality, is usually in the range of 100 to 300 mg/kg, β-and γ-tocopherols are found in smaller amounts and δ-tocopherol is found only in traces (Boskou, Blekas, & Tsimidou, 2006;Psomiadou, Tsimidou, & Boskou, 2000). Additionally, tocopherols are sensitive to light, air, alkaline media and various metals, primarily the iron and copper (Alpaslan et al, 2001;Gimeno et al, 2000). The high *Corresponding author.…”

“…It is known that refining may affect stability of oils (Hamm & Hamilton, 2000). Although the purpose of refining is to extend shelf-life of oils by removing undesirable compounds, it also results in losses in antioxidant content such as tocopherols and phenolics (Alpaslan et al, 2001). Total and individual tocopherols are lost during refining process and vary from 30% to 70%.…”

Optimisation of sunflower oil deodorising: balance between oil stability and other quality attributes

“…A fully refined oil contains low levels of FFA (usually<0.05%) and has also light colour, which can be evaluated through Lovibond colour yellow (LCY) and red (LCR) (Hrastar et al, 2011). Although this operation aims to remove only the unwanted components, a simultaneous loss of valuable minor components such as tocopherols was unfortunately unavoidable (Alpaslan et al, 2001).…”