THE COMPARISON OF PRESSED SEED OILS FEATURES

Abstract

The grape seed oils are characteristic by a very high content of substances. However, a lipid oxidation is the fundamental problem of the seed oils quality degradation. The important indicator for determining the specific type’s purity, stability and level of oil degradation might be its colour parameter. The aim of this study was to identify the different varieties of oils, to evaluate its development during storage and to identify changes in different pressed seed oils. The CIELAB method and NIR spectroscopy were used during the research. Its main advantages include speed, accuracy and simplicity. The use of NIR seemed to be unsuitable as it could not reliably identify different kinds of grape seed oils. Only three kinds of grape seed oils out of six were identified. Contrary, the colour values obtained, using the CIELAB method, correlated significantly with the maturity of the individual varieties. This method can help to verify the authenticity of the oil. The CIELAB method also enabled colour changes in storage. The results show that after six months of storage, the oil got browner and the L* value had decreased. After another 6 months, the shift in values was not so significant. Similarly, the values of other parameters had changed. Using the CIELAB method can be recommended for testing of larger sample sizes for future use in the evaluation of the authenticity and quality of seed oils. The CIELAB method will not replace the standard methods but it might be used for pre-selection of tested samples.

Keywords: CIELAB method, colour parameter, grape seed oils, NIR spectroscopy, oil degradation

Article DOI:

Article DOI: http://doi.org/10.15544/RD.2017.038