# The Influence of Storage Conditions of Cold-Pressed Rapeseed Oil on Its Quality Parameters
###### Abstract  
Stored vegetable oil undergoes numerous processes, i.e., oxidation, hydrolysis, and thermal polymerization. As a result, its quality and organoleptic parameters deteriorate. The content of natural chlorophyll and carotenoid pigments determines the color of rapeseed oil. Almost imperceptible changes in the color of the oil may indicate the deterioration of its quality. Therefore, vegetable oils must be stored in the appropriate conditions to protect them against unfavorable factors leading to deterioration. This publication examines and describes the influence of storage temperature, type of packaging (clear glass, colored glass, PET), and presence of an oxygen-free atmosphere on the quality of stored cold-pressed rapeseed oil for three and six months. Changes in the following parameters were verified: the content of chlorophyll and carotenoid pigments, oil color (measured by the CIE Lab method), acid value, and radical scavenging activity (\(\%\)RSA) by the ABTS (diammonium 2,2\({}^{\prime}\)-azinobis[3-ethyl-2,3-dihydrobenzodiazep-6-sulphonate) method. The decrease in the content of natural dyes was 7 to 87% after three months, depending on storage conditions, and after six months, from 12 to 97%. To determine which factors were responsible for the change in the physicochemical properties of the oil during storage, a principal component analysis (PCA) was performed. cold-pressed rapeseed oil; edible oil storage conditions; natural dyes; oxidative stability 20231  
conditions to protect them against unfavorable factors (i.e., temperature, UV radiation, and oxygen) that could lead to deterioration [15; 16]. Vegetable oils are stored in packaging that differs in volume and the material from which it is made. These include bottles made of colored and colorless glass and bottles made of plastics--most often polyethylene terephthalate (PET) [17]. This last group of packaging types is prevalent due to its high mechanical strength, low production price, and ability to form the desired shape quickly. The disadvantages of packaging made of plastic include the possibility of interactions with the oil [18; 19]  
Stored vegetable fat undergoes processes over time, i.e., oxidation, hydrolysis, and thermal polymerization, as a result of which its quality and organoleptic parameters deteriorate. Phosphidates, free fatty acids, volatile fragrances, waxes, and metal ions contained in oils are undesirable substances that adversely affect the physicochemical and sensory properties during the storage of rapeseed oil [20; 21]. The most common form of deterioration of vegetable oils is their oxidation, which involves the spontaneous addition of oxygen molecules by unsaturated fatty acids, forming hydroperads. Oxidation of cold-pressed vegetable oils with atmospheric oxygen and without the participation of enzymes is called autoxidation, and its products can catalyze this process [22]. They result mainly from unfavorable changes in fatty acids, which are characterized by different positions of multiple bonds and the length of carbon chains. A cis configuration describes the fatty acids contained in fresh vegetable oils. The oxidative stability of an oil is the resistance to oxidation during its processing and storage. It can be expressed as the time required to reach the critical oxidation point, whether it is a sudden acceleration of the oxidation process or a sensory change [23; 24; 25]. Based on the literature analysis, we found that there is a lack of comprehensive studies on the impact of storage conditions on cold-pressed vegetable oils based on their quality parameters. Therefore, this publication aims to present the impact of changes in storage parameters (i.e., temperature, presence of oxygen, and type of packaging) on the quality of cold-pressed rapeseed oil during three- and six-month periods of storage.