HPLC-MSn identification and quantification of phenolic compounds in hazelnut kernels, oil and bagasse pellets

Ana Slatnar; Maja Mikulic-Petkovsek; Franci Stampar; Robert Veberic; Anita Solar

doi:10.1016/j.foodres.2014.08.009

HPLC-MSⁿ identification and quantification of phenolic compounds in hazelnut kernels, oil and bagasse pellets

Food Res Int. 2014 Oct:64:783-789. doi: 10.1016/j.foodres.2014.08.009. Epub 2014 Aug 27.

Authors

Ana Slatnar¹, Maja Mikulic-Petkovsek², Franci Stampar², Robert Veberic², Anita Solar²

Affiliations

¹ University of Ljubljana, Biotechnical Faculty, Agronomy Department, Jamnikarjeva 101, SI-1000 Ljubljana, Slovenia. Electronic address: ana.slatnar@bf.uni-lj.si.
² University of Ljubljana, Biotechnical Faculty, Agronomy Department, Jamnikarjeva 101, SI-1000 Ljubljana, Slovenia.

PMID: 30011716
DOI: 10.1016/j.foodres.2014.08.009

Abstract

The paper reports the phenolic content of kernels, bagasse pellets (residue of oil pressing) and oils from five different cultivars and a mix of cultivars. Phenolic compounds were identified by high-performance liquid chromatography coupled with mass spectrometry. Two compounds, glansreginin A and glansreginin B, were detected for the first time in hazelnuts. The main polyphenolic subclass comprised of mono- and oligomeric flavan 3-ols, which accounted between 34.2 and 58.3% in hazelnut kernels and between 36.7 and 48.6% in pellets of the total phenolics detected. In hazelnut oils four compounds have been detected, their content levels ranged from 0.97 to 0.01μgg^-1. Total phenolic content ranged from 491.2 to 1700.4mgGAEkg^-1 in kernels, from 848.4 to 1148.5mgGAEkg^-1 in pellets and only from 0.14 to 0.25mgGAEg^-1 in oils. The percentage of radical scavenging activity ranged from 60.0 to 96.4% for kernels, 63.0 to 73.2% for pellets and from 17.7 to 29.9% for oil. The study provides clear evidence on high phenolic contents and similarly high antioxidant potential of hazelnut kernels and bagasse pellets. The latter could be used as ingredients in cooking and baking or even for production of plant-based pharmaceuticals.

Keywords: Corylus avellana; DPPH; Flavan 3-ols; Flavanols; HPLC-MS; Hydrolyzable tannins; Total phenolic content.