Instrumental Evaluation of Selected Properties of Oil Extracted from Walnuts before and after the Roasting Process

Abstract

Walnuts (Juglans regia) are characterized by a high fat content of approximately 73%. The oil contained in the nuts is rich in unsaturated fatty acids, including monounsaturated oleic acid and polyunsaturated fatty acids, both of the n-3 and n-6 family. One important thermal process for nuts is roasting, which significantly increases their palatability. Technically, roasting is a drying process at high temperatures. The purpose of roasting is to reveal new flavor and aroma properties of the raw material. The aim of the current study was to determine and compare the fatty acid composition and oxidative and hydrolytic stability of oils extracted from both roasted and raw walnuts.

Keywords

• walnut oil
• acid value
• peroxide value
• oxidative stability
• fatty acid composition