Changes in cold-pressed oil due to roasting of hazelnut kernels

Hazelnut oil is a high-quality nutritional product, especially the oil obtained by cold pressing. Cold-pressed oils generally retain the original chemical composition and nutritional value of the hazelnut kernel. Due to the presence of unsaturated fatty acids, hazelnut oil is subject to oxidative an...

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Main Authors: Radovanović Mirjana, Kurtić Jelena, Petković Marko, Miletić Nemanja, Đurović Vesna
Format: Article
Language:English
Published: University of Kragujevac, Faculty of Agronomy, Cacak 2024-01-01
Series:Acta Agriculturae Serbica
Subjects:
Online Access:https://scindeks-clanci.ceon.rs/data/pdf/0354-9542/2024/0354-95422458085R.pdf
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author Radovanović Mirjana
Kurtić Jelena
Petković Marko
Miletić Nemanja
Đurović Vesna
author_facet Radovanović Mirjana
Kurtić Jelena
Petković Marko
Miletić Nemanja
Đurović Vesna
author_sort Radovanović Mirjana
collection DOAJ
description Hazelnut oil is a high-quality nutritional product, especially the oil obtained by cold pressing. Cold-pressed oils generally retain the original chemical composition and nutritional value of the hazelnut kernel. Due to the presence of unsaturated fatty acids, hazelnut oil is subject to oxidative and thermo-oxidative changes depending on whether the oil or kernels have been subjected to inappropriate storage or heat treatment. In this study, the influence of roasting hazelnut kernels at 180 °C for 24 minutes on cold-pressed oil was investigated. Roasting hazelnut kernels caused an increase in acid value in cold-pressed oil, which could indicate hydrolytic changes in triacylglycerols. There was a decrease in the refractive index, which also indicates changes in triacylglycerols and fatty acids. Roasting the kernels had no effect on the content of water and volatile matter. No peroxides were detected either, regardless of whether the kernels were subjected to heat treatment. However, it is clear from the specific absorbance values that the roasting of the hazelnut kernels initiated oxidative processes, and the change in the UV/Vis spectrum clearly indicates that the heat treatment of the kernels led to a deterioration of the oil, possibly as a result of changes in unsaturated bonds. However, the quality parameters of the cold-pressed oil from heat-treated kernels, i.e., the water and volatile matter content as well as the acidity and peroxide values, are in accordance with the regulations, as the changes in these parameters were minor or non-existent.
format Article
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institution Kabale University
issn 0354-9542
2560-3140
language English
publishDate 2024-01-01
publisher University of Kragujevac, Faculty of Agronomy, Cacak
record_format Article
series Acta Agriculturae Serbica
spelling doaj-art-592d2cb8b7c2497d959951ef533f93792025-01-08T14:35:23ZengUniversity of Kragujevac, Faculty of Agronomy, CacakActa Agriculturae Serbica0354-95422560-31402024-01-012958859010.5937/AASer2458085R0354-95422458085RChanges in cold-pressed oil due to roasting of hazelnut kernelsRadovanović Mirjana0https://orcid.org/0000-0003-0337-8706Kurtić Jelena1Petković Marko2https://orcid.org/0000-0001-8490-4602Miletić Nemanja3https://orcid.org/0000-0002-6373-7849Đurović Vesna4https://orcid.org/0000-0003-3448-056XUniversity of Kragujevac, Faculty of Agronomy, Department of Food Technology, Čačak, SerbiaUniversity of Kragujevac, Faculty of Agronomy, Čačak, SerbiaUniversity of Kragujevac, Faculty of Agronomy, Department of Food Technology, Čačak, SerbiaUniversity of Kragujevac, Faculty of Agronomy, Department of Food Technology, Čačak, SerbiaUniversity of Kragujevac, Faculty of Agronomy, Department of Microbial Biotechnology and Plant Protection, Čačak, SerbiaHazelnut oil is a high-quality nutritional product, especially the oil obtained by cold pressing. Cold-pressed oils generally retain the original chemical composition and nutritional value of the hazelnut kernel. Due to the presence of unsaturated fatty acids, hazelnut oil is subject to oxidative and thermo-oxidative changes depending on whether the oil or kernels have been subjected to inappropriate storage or heat treatment. In this study, the influence of roasting hazelnut kernels at 180 °C for 24 minutes on cold-pressed oil was investigated. Roasting hazelnut kernels caused an increase in acid value in cold-pressed oil, which could indicate hydrolytic changes in triacylglycerols. There was a decrease in the refractive index, which also indicates changes in triacylglycerols and fatty acids. Roasting the kernels had no effect on the content of water and volatile matter. No peroxides were detected either, regardless of whether the kernels were subjected to heat treatment. However, it is clear from the specific absorbance values that the roasting of the hazelnut kernels initiated oxidative processes, and the change in the UV/Vis spectrum clearly indicates that the heat treatment of the kernels led to a deterioration of the oil, possibly as a result of changes in unsaturated bonds. However, the quality parameters of the cold-pressed oil from heat-treated kernels, i.e., the water and volatile matter content as well as the acidity and peroxide values, are in accordance with the regulations, as the changes in these parameters were minor or non-existent.https://scindeks-clanci.ceon.rs/data/pdf/0354-9542/2024/0354-95422458085R.pdfhazelnut oilroastingoil oxidationtriacylglycerol hydrolysis
spellingShingle Radovanović Mirjana
Kurtić Jelena
Petković Marko
Miletić Nemanja
Đurović Vesna
Changes in cold-pressed oil due to roasting of hazelnut kernels
Acta Agriculturae Serbica
hazelnut oil
roasting
oil oxidation
triacylglycerol hydrolysis
title Changes in cold-pressed oil due to roasting of hazelnut kernels
title_full Changes in cold-pressed oil due to roasting of hazelnut kernels
title_fullStr Changes in cold-pressed oil due to roasting of hazelnut kernels
title_full_unstemmed Changes in cold-pressed oil due to roasting of hazelnut kernels
title_short Changes in cold-pressed oil due to roasting of hazelnut kernels
title_sort changes in cold pressed oil due to roasting of hazelnut kernels
topic hazelnut oil
roasting
oil oxidation
triacylglycerol hydrolysis
url https://scindeks-clanci.ceon.rs/data/pdf/0354-9542/2024/0354-95422458085R.pdf
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AT petkovicmarko changesincoldpressedoilduetoroastingofhazelnutkernels
AT mileticnemanja changesincoldpressedoilduetoroastingofhazelnutkernels
AT đurovicvesna changesincoldpressedoilduetoroastingofhazelnutkernels