The European Parliament and Council Directive 2003/30/EK ‘On the promotion of the use of biofuels and other renewable fuels for transport’ determines that pure or straight vegetable oil, produced from oil plants by pressing, extracting or comparable procedures, crude or refined but chemically unmodified, compatible with common engines, and corresponding to emission requirements, is also considered as biofuel. The biggest problems imposed by these conditions are directly associated with the carrying-out of the emission requirements, because when using vegetable oil as a fuel, usually increases the composition of the solid particles and nitrogen oxides in exhaust gases, that not only adversely affect the environment, but also is a serious threat to human health, and as a result trying to save the world from the global warming, human health continues to deteriorate. It is therefore necessary to carry out studies and find solutions to reduce harmful emissions from diesel engines when using vegetable oil fuel. For more qualitative and effective research on vegetable oil fuel emissions, the equipment for vegetable oil fuel testing has been developed. This equipment allows fast checking of theoretically proposed hypotheses and detailed calculations for vegetable oil fuel combustion processes and objective data acquisition. The equipment consists of the classic diesel engine adapted for work with vegetable oil and is equipped with several high-precision devices to get and store the measuring data. During pilot tests the optimal measuring modes (engine rotation frequencies, number and duration of repetitions) for further research are estimated.

Free radicals can rapidly and irreversibly oxidize various structures, including unsaturated fatty acids in vegetable oils, which affect the sensory properties. Spectrophotometry is the most widely used method for the determination of free radical scavenging activity (RSA) using 2,2-diphenyl-1-picrylhydrazyl (DPPH). Barrier to the further use of classical analytical methods to analyse biologically active compounds in foodstuffs is that equipment requires high cost and has limited mobility. One of solutions is to replace classical methods, such as spectroscopy, with smartphonebased colorimetry. Huawei P30 Lite smartphone was used for colorimetric detection. The free radical scavenging activity (RSA) in vegetable oil was detected using an application ‘Color Picker’, with image matching algorithm for red, green, and blue (RGB) model. RSA was expressed as percentage and measured by the DPPH method. The aim of the study was to determinate the total free radical scavenging activity with smartphone-based colorimetry. For the data comparison and accuracy spectrophotometer as analytical optical instrument was used. Eleven vegetable oils: sea buckthorn, sunflower, rice, macadamia nut, hemp, corn, grape, linseed, rapeseed, olive and milk thistle oils were selected for analysis. The best results with no significant differences (p is greater than 0.05) compared to smartphone-based colorimetry from spectrophotometry were determined using RG values. The poor results were detected by using B value (p is less than 0.05) and were not suitable for determination of RSA. Smartphone-based colorimetry can be used in the determination of the RSA in vegetable oils.

In 2018, the Polish Trade Inspection in the whole country carried out an assessment of unrefined vegetable oils and olive oils of various categories. First of all, the correctness of marking, physicochemical parameters, storage conditions, traceability of products and their dates of minimum durability were assessed. In total 380 batches of products were inspected. Results of the examination show that producers cheat consumers by providing, for example, untrue nutritional values or false information about dietetic or health traits. The purpose of this article is to determine what consumers should know to verify the correctness of information on product labels independently. The theoretical part of the article was based on the EU regulations analysis regarding vegetable oils properties, including the characteristics of olive oil. The empirical part concerned data from Polish Trade Inspection reports, as well as statistical data on production and sale of oil and olive oil from the portal Statista. In this article methods of documentary research and comparative analysis were used. For the main conclusion it can be assumed that products of poor quality or incorrect labeling can be found in each product category; therefore, consumers should pay attention to such elements as information in their native language, a full list of ingredients, or correct indication of nutritional values.

Vegetable oils are essential providers of energy to a human body; they play important role as a foodstuff. During processing and storage of vegetable oils, they may undergo molecular changes adverse to the human organism affecting the quality of the oils. The content of fatty acids of fresh rapeseed, linseed and hemp oils and of the mixture of rapeseed (800 g kgE-1) and linseed (200 g kgE-1) oils was determined by the method of gas chromatography (GH). Alpha - , delta - and gamma - tocopherols were analyzed in the vegetable oils by the methods of the highly effective liquid chromatography (HPLC). The hemp oils contain the indispensable polyunsaturated fat acids: linoleic acid - 53.0%, and linolenic acid - 23.2%. Such proportion of the fatty acids (3:1) is considered optimal in the nutrition. When using both hot and cold pressure technology for the obtaining of oil, it is possible that the polycyclical aromatic hydrocarbon - Benzo[a]pyrene - may be created and influenced the quality of the oil. The environment also affects the content of the lead in the oils. The density of the various vegetable oils at the temperature of 20 +- deg C proved to be within the limits of 0.917 and 0.942 kg dmE-3.

This research presents the antiradical activity and fatty acids changes of vegetable oils. Natural antiradical activity and its changes during storage for one and two years of rapeseed, linseed and hemp oils were determined with 1.1-diphenyl-2-picrylhydrazyl (DPPH). Fresh hemp oil shows the higher antiradical activity. The content of fatty acids of fresh rapeseed, linseed and hemp oils and of the mixture of rapeseed (800 g kgE-1) and linseed (200 g kgE-1) oils was determined by the method of gas chromatography. After heating the mixture of rapeseed and linseed oils at the temperature of 160-180 deg C, changes proportions in saturated and unsaturated fatty acids.