Effects of the industrial refining process on some properties of hazelnut oil

Abstract

Abstract Hazelnut ( Corylus avellana L.) oil was chemically refined using industrial refining conditions. Crude hazelnut oil was obtained by pre‐pressing‐solvent extraction methods and refined by neutralization, bleaching and deodorization in industrial scale. The changes in color, free fatty acids, fatty acid composition, tocopherol and phytosterol contents were determined after each step of refining. The main color change was observed during bleaching. Fatty acid composition, mainly oleic acid (81%), did not change significantly during the process. At the end of the refining, the amounts of total tocopherol and phytosterol decreased from 51.89 to 46.67 mg/100 g and from 168.04 to 141.48 mg/100 g, respectively. The biggest losses of both tocopherols and sterols were observed after neutralization. Deodorization caused a slight decrease in the amount of sterols. α‐Tocopherol (36.19 mg/100 g), β‐tocopherol (9.3 mg/100 g), and γ‐sitosterol (120.28 mg/100 g) were the predominant unsaponifiables in refined hazelnut oil.