How to choose your culinary oil – sensory and analytical characteristics of hempseed oil

Dorota Majchrzak, Petra Mitmannsgruber, Lisa-Maria Oberrauter, Klaus Fronius, Karl-Heinz Wagner

Hempseed oil has been dubbed "Nature's most perfectly balanced oil", since it contains a nutritionally optimal balanced 3:1 ratio of Omega 6 (linoleic/LA) to Omega 3 (alpha-linolenic/LNA) essential fatty acids. Due to the high content of long chain polyunsaturated fatty acids (PUFAs) and the low smoke point hemp oil is not suitable for high temperature cooking but it can be the perfectly used as salad oil. However, hemp oil has a rich peculiar flavor and green tint as well as it is strong astringent, which might limit consumer acceptance.
In order to overcome this limitation we tried to combine the cold pressed hempseed oil with an odor -and flavorless refined sunflower oil in order to increase its practicability for high temperature cooking and to improve its flavor quality.
The investigation included smoke point, the fatty acid profile and a sensory evaluation, as well as consumer’s preference test.
The fatty acid profile was analysed by FID gas chromatography, the smoke point by AOCS/DGF standard method. In the Quantitative Descriptive Analysis (QDA) 10 trained individuals evaluated the attributes intensity of the pure hempseed oil (HO) and four variety of this oil with refined sunflower oil (SO): MixHO:SO=1:4; MixHO:SO=1:3; MixHO:SO=1:2; MixHO:SO=1:1). Preference of the consumers (n=70) was evaluated by ranking test.
The total amount of 71.5% PUFAs/total fatty acids (TFA) of the pure hempseed oil (HO) decreased to 61.1%, 57.7%, 56.1% and 55.5% in the mix with the sunflower oil (SO) MixHO:SO=1:1; MixHO:SO=1:2; MixHO:SO=1:3; MixHO:SO=1:4; whereas the smoke point increased from 167°C in the pure HO oil to 187°C, 197°C, 201°C and 209°C for the respective mixtures (from MixHO:SO=1:1 to MixHO:SO=1:4). The results of the sensory evaluation show that by mixing hemp and sunflower oil it was possible to decrease the intensity of undesirable flavor descriptors. The Mix HO:SO=1:2. was most preferred by the consumers. Based on the obtained results from the chemical and sensory evaluation we can conclude that a mixture of hempseed oil with refined sunflower oil is suitable for higher heat cooking but also as salad oil.

Department für Ernährungswissenschaften
ÖFOS 2012
303009 Ernährungswissenschaften
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