Comparison of aroma, aroma‐active, and phenolic compounds of crude and refined hazelnut oils

Abstract

Hazelnut (Corylus avellana L.) is an important shelled nut with its pleasant aroma. The refining process causes significant changes in the quality attributes of hazelnut oil. The aim of this study was to assess the aroma, aroma‐active, and phenolic compounds of the crude and refined hazelnut oils by using gas chromatography–mass spectrometry (GC–MS), GC–MS‐olfactometry (GC–MS‐O), and liquid chromatography–mass spectrometry (LC–MS/MS). The antioxidant capacities were also determined by DPPH and ABTS methods. Results showed that terpenes and aldehydes constituted a significant portion of the aroma profile. Refining process dramatically reduced the numbers (from 63 to 25) and amounts of aroma compounds (from 36,769 to 4461 μg/kg). Similarly, the numbers of aroma‐active compounds were reduced from 22 to 8 by the refining process. Their flavor dilution factors ranged from 2 to 1024 for crude oil and from 2 to 32 in the refined oil. As of the phenolics, five and two compounds were quantified in the crude and refined oil samples, respectively. In sum, the refining process had a considerable adverse effect on the aroma, aroma‐active, and phenolic constituents of the hazelnut oil; hence, the refining process has to be planned with minimal negative effect on its organoleptic properties.

Phytoextracts for Human Health from Raw and Roasted Hazelnuts and from Hazelnut Skin and Oil: A Narrative Review

“…During processing, especially in heat treatment, flavor constituents are often degraded or evaporated, causing a deterioration in product quality that may not be accepted by consumers. In the 2022 study by Kesen, S. et al, it was observed that the refining process reduced the amounts of aroma constituents by about eight times [33].…”

Developmenet of Aromatic Components – Rich Extract Specially for Chocolate Products from Hazelnut Grows Giresun, Türkiye with Supercritical CO2 Extraction

“…Türkiye is the largest producer and exporter country of various types of hazelnuts in the world, contributing to approximately 70% of the total world production. Among the 18 hazelnut varieties grown in Türkiye; these hazelnuts are classified as premium quality due to its high oil content, unique taste, and aroma [1] Different aroma extraction methods were used successfully in the seeds [2]. Taste and aroma of hazelnut extracts are caused by their taste-active components (free amino and phenolic acids, sugars, organic acids, and condensed tannins) and aroma-active components (ketones, aldehydes, pyrazines, alcohols, aromatic hydrocarbons, furans, pyrroles, terpenes, and acids) [1].…”