FOOD. Science. Technology. Quality

Food. SCIENCE. Technology. Quality

Food. Science. TECHNOLOGY. Quality

Food. Science. Technology. QUALITY

Authors

MARIA SIELICKA, MARIA MAŁECKA

Title

Role of sensory and physicochemical properties in determining shelf-life of cold-pressed flaxseed oil

Abstract

The objective of the research study was to assess the changes in physicochemical and sensory properties in terms of their usefulness in determining the shelf-life of cold-pressed flaxseed oils. The research material consisted of oils produced from two flaxseed varieties: ‘Oliwin’ high-linolenic acid flaxseed var. and ‘Linola’ low-linolenic acid flaxseed var. The oil samples were analyzed for their physicochemical and sensory parameters during the storage under practical conditions at 5 and 25 °C for 112 days. The following was analyzed: intensity of bitter taste; nutty, oxidized, and grassy flavours; the overall quality was also determined with the use of quantitative descriptive analysis (QDA). In the analyses performed during the storage of flaxseed oils, there were reported no intensive oxidative changes expressed as a content of oxidation products, i.e. of the primary oxidation products (the level of peroxides in the samples did not exceed 4.59 ± 0.08 meq O2/kg) and of the secondary oxidation products (the maximum anisidine value was 2.64 ± 0.01). There were reported significant changes in the flavour profile and a decrease in the overall quality of the samples. The changes in the bitter taste of flaxseed oils were the most significant compared to other sensory attributes analyzed (in the case of the ‘Linola’ oil stored at 25 °C, the intensity of its bitter taste increased 8 times). The bitter taste was the most negatively correlated with the overall quality of oils (r = -0.98). The shelf-life of individual flaxseed oils, determined on the basis of the acceptable level of bitterness, varied between 42 and 112 days and was dependent on the storage conditions and the flaxseed variety used to produce oils. Based on the results obtained, it is concluded that for the purpose of determining the shelf-life of coldpressed flaxseed oil, the sensory analysis is more useful than the analysis of physicochemical properties.

Keywords

cold-pressed flaxseed oil, bitter taste, oxidative stability, shelf-life, quantitative descriptive analysis (QDA)

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