Comprehensive two-dimensional gas chromatography-time of flight mass spectrometry as a tool for tracking roasting-induced changes in the volatilome of cold-pressed rapeseed oil.

The aim of this study was to track changes in the volatilome of cold-pressed oil and press cakes obtained from roasted seeds and to combine it with the profile of non-volatile metabolites in a single study, in order to understand pathways of volatile organic compound (VOC) formation caused by thermal processing. Comprehensive two-dimensional gas chromatography-time of flight mass spectrometry was used for the analysis of VOCs in cold-pressed oils and corresponding press cakes obtained after roasting of seeds at 140 and 180 °C prior to pressing. Contents of primary metabolites (amino acids, saccharides, fatty acids) as well as selected secondary metabolites (glucosinolates, polyphenols) were determined, as many of them serve as precursors to volatile compounds formed especially in thermal reactions. After roasting, the formation of Maillard reaction products increased, which corresponded to the reduction of free amino acids and monosaccharides. Moreover, levels of the products of thermal oxidation of fatty acids, such as aldehydes and ketones, increased with the increasing temperature of roasting, although no significant changes were noted for fatty acids. Among sulphur-containing compounds, contents of the products and intermediates of methionine Strecker degradation increased significantly with the increasing temperature of roasting. Degradation of glucosinolates to nitriles occurred after thermal treatment. The results of this study confirmed that seed roasting before cold pressing has a significant effect on the volatiles, but also indicated roasting-induced changes in non-volatile metabolites of oil and press cake. Such an approach helps to understand metabolic changes occurring during rapeseed processing in cold-pressed oil production.

Effect of Heating Temperature of High-Quality Arbequina, Picual, Manzanilla and Cornicabra Olive Oils on Changes in Nutritional Indices of Lipid, Tocopherol Content and Triacylglycerol Polymerization Process.

The aim of the study was to determine the stability and heat resistance of extra premium olive oil. The study material consisted of six extra virgin olive oils (EVOO) obtained from Spain. Four samples were single-strain olive oils: Arbequina, Picual, Manzanilla, and Cornicabra. Two samples were a coupage of Arbequina and Picual varieties: Armonia (70% Arbequina and 30% Picual) and Sensation (70% Picual and 30% Arbequina). Olive oil samples were heated at 170 °C and 200 °C in a pan (thin layer model). In all samples, changes in indexes of lipid nutritional quality (PUFA/SFA, index of atherogenicity, index of thrombogenicity, and hypocholesterolemic/hypercholesterolemic ratio), changes in tocopherol, total polar compounds content, and triacylglycerol polymers were determined. Heating olive oil in a thin layer led to its degradation and depended on the temperature and the type of olive oil. Increasing the temperature from 170 to 200 °C resulted in significantly higher degradation of olive oil. At 200 °C, deterioration of lipid nutritional indices, total tocopherol degradation, and formation of triacylglycerol polymers were observed. A twofold increase in the polar fraction was also observed compared to samples heated at 170 °C. The most stable olive oils were Cornicabra and Picual.

Free and Esterified Tocopherols, Tocotrienols and Other Extractable and Non-Extractable Tocochromanol-Related Molecules: Compendium of Knowledge, Future Perspectives and Recommendations for Chromatographic Techniques, Tools, and Approaches Used for Tocochromanol Determination.

Free and esterified (bound) tocopherols, tocotrienols and other tocochromanol-related compounds, often referred to "tocols", are lipophilic antioxidants of great importance for health. For instance, α-tocopherol is the only tocochromanol with vitamin E activity, while tocotrienols have a positive impact on health and are proposed in the prevention and therapy of so-called modern diseases. Tocopherols, tocotrienols and plastochromanol-8 are the most well-known tocochromanols; in turn, knowledge about tocodienols, tocomonoenols, and other rare tocochromanol-related compounds is limited due to several challenges in analytical chemistry and/or low concentration in plant material. The presence of free, esterified, and non-extractable tocochromanols in plant material as well as their biological function, which may be of great scientific, agricultural and medicinal importance, is also poorly studied. Due to the lack of modern protocols as well as equipment and tools, for instance, techniques suitable for the efficient and simultaneous chromatographical separation of major and minor tocochromanols, the topic requires attention and new solutions, and/or standardization, and proper terminology. This review discusses the advantages and disadvantages of different chromatographic techniques, tools and approaches used for the separation and detection of different tocochromanols in plant material and foodstuffs. Sources of tocochromanols and procedures for obtaining different tocochromanol analytical standards are also described. Finally, future challenges are discussed and perspective green techniques for tocochromanol determination are proposed along with best practice recommendations. The present manuscript aims to present key aspects and protocols related to tocochromanol determination, correct identification, and the interpretation of obtained results.

The Stability of Refined Rapeseed Oil Fortified by Cold-Pressed and Essential Black Cumin Oils under a Heating Treatment.

Polar compounds and polymers are regarded as the most reliable indicators of oil degradation during heating, and it is desirable to find methods to reduce these undesirable changes. The aim of this study was (1) to determine the effect of enrichment with black cumin cold-pressed oil (CP) or essential oil obtained from black cumin cold-pressed oil in an equivalent amount (ES) on limiting the polar compounds and polymers content in blends based on refined rapeseed oil during high-temperature heating in a thin layer; (2) to determine tocochromanol losses and their effect on the change content of the polar compounds and polymers. Four fortified oils were made from refined rapeseed oil and one of the four additives (10% CP, 20% CP, 0.1% ES, and 0.2% ES). All fortified oils and refined rapeseed oil as a control sample were heated at 170 and 200 °C on the pan in a thin layer and evaluated regarding loss of individual tocochromanol homologs by HPLC-FL, polar compounds content, oxidized triacylglycerols (TAG), and polymers content by HPSEC-ELSD. Additionally, the fatty acid profile in nonheated oil was investigated. Tocochromanol analysis showed loss in all the samples. At 170 °C polymers were not detected; no difference was noted for polar compounds and oxidized TAG content; only the 20% CP sample showed a higher level. At 200 °C the 10% CP sample exhibited a significant protective effect with the lowest content of polar compounds, oxidized TAG, and dimers.

How to Identify Roast Defects in Coffee Beans Based on the Volatile Compound Profile.

The aim of this study was to detect and identify the volatile compounds in coffee that was obtained in defect roast processes versus standard roasting and to determine the type and strength of the correlations between the roast defects and the volatile compound profile in roasted coffee beans. In order to achieve this goal, the process of coffee bean roasting was set to produce an underdeveloped coffee defect, an overdeveloped coffee defect, and defectless coffee. The "Typica" variety of Arabica coffee beans was used in this study. The study material originated from a plantation that is located at an altitude of 1400-2000 m a.s.l. in Huehuetenango Department, Guatemala. The analyses were carried out with the use of gas chromatography/mass spectrometry (GC-MS) and an electronic nose. This study revealed a correlation between the identified groups of volatile compounds and the following coffee roasting parameters: the time to the first crack, the drying time, and the mean temperatures of the coffee beans and the heating air. The electronic nose helped to identify the roast defects.

Characterization of New Egyptian Linseed Varieties and the Effects of Roasting on Their Pigments, Tocochromanols, Phytosterols, Omega-3 Fatty Acids, and Stability.

The purpose of this study was to explore the effects of roasting linseeds on the pigment, lipid profile, bioactive components, and oxidative stability of the extracted oils. The linseed varieties Giza 11, Giza 12, Sakha 3, and Sakha 6 were roasted at 180 °C for 10 min, and the oils were extracted by cold pressing. The results showed that, after roasting, there was an increase in oil percentage and peroxide value, as well as small increases in p-anisidine and acid values. Roasting also caused an increase in chlorophyll content, while lutein and ß-carotene tend to slightly decrease, except in the Giza 11 variety. The total phenolics content was markedly enhanced after roasting. Omega-3 fatty acids were not affected by the roasting process. The total amounts of tocochromanol were found to decrease in the Giza 12 and Sakha 6 varieties after roasting. Plastochromanol-8 increased in all varieties after roasting. The phytosterol composition was minimally affected by roasting. Roasting enhanced the stability of the extracted oils, increasing the induction period and decreasing EC50 values. These results may thus help to discriminate between the different linseed varieties and serve to recommend the use of roasting to enhance the oxidative stability of extracted oil.

Water content, critical micelle concentration of phospholipids and formation of association colloids as factors influencing autoxidation of rapeseed oil.

BACKGROUND: The exact mechanism of lipid autoxidation in vegetable oils, taking into account physical aspects of this phenomenon, including the role of association colloids, is still not fully understood. The purpose of this study was to consider changes in moisture content and DOPC phospholipid (1,2-dioleoyl-sn-glycero-3-phosphocholine) critical micelle concentration (CMC) in rapeseed oil during autoxidation as well as to find the relationship between these parameters and the accumulation of primary and secondary lipid oxidation products. RESULTS: The experiments were performed at initial oil humidity 220 ppm and 700 ppm, with DOPC below and above CMC. The increase in water concentration was favored by the presence of phospholipids above CMC and, at the same time, high initial water level, which favored oxidation processes and the creation of amphiphilic autoxidation products. At relatively high water level and low amphiphilic DOPC concentration, the growth of water content does not affect the concentration of oxidation products. CONCLUSION: Amphiphilic substances play a significant role in increasing the water content of oil. Autoxidation products may reduce CMC of DOPC, but water is able to compensate for the CMC-reducing effect of oxidation products. The presence of association colloids and initial water content play a crucial role in the oxidation process of rapeseed oil. The increase in water concentration does not cause a sufficiently large increase in the number of micelles or sufficiently significant changes in their structure to effect an increase in the level of oxidation products. The formation of micelles requires an appropriate content of both water and amphiphilic substances derived from seeds (phospholipids). © 2021 Society of Chemical Industry.

Nɛ-(carboxymethyl)lysine, Available Lysine, and Volatile Compound Profile of Biscuits Enriched with Grape by-Product During Storage.

We investigated the changes in Nɛ-(carboxymethyl)lysine (CML) and available lysine content, antioxidant properties, volatiles, and oxidation products of biscuits enriched with grape by-product (GP), stored for six months under a modified atmosphere of 0%/30%/70% O2/CO2/N2 and in air. Fresh GP-formulated biscuits showed lower concentrations of CML (89%), available lysine (40%), and pyrazines (75%), but higher antioxidant capacities (~ sixfold), furans (12-fold), and lipid-derived compounds (three-fold) than the control. Although ~ 15% higher losses of Maillard-type volatiles were identified in the air atmosphere during storage, lipid oxidation was ~ 30% less pronounced in the modified atmosphere. A significant correlation of 0.994 between the reduction in CML and the available lysine suggest further CML reactions with the ɛ-NH2 group of amino acids. Significant correlations (of -0.550 to -0.980) between oxidation products, antioxidant capacities, and changes in CML content during storage suggest that these parameters might be involved in the CML elimination mechanism.

Effect of Supplementation of Flour with Fruit Fiber on the Volatile Compound Profile in Bread.

This paper presents the analyses of the effect of fiber additives on volatile organic compounds in bread. The bread was baked from wheat flour with the addition of 3% of fruit fiber, following common procedures. After baking, volatile organic compounds contained in the control bread and breads supplemented with cranberry, apple, and chokeberry fiber were determined. The SPME/GC-MS technique was used for the identification of the odor profile, and the electronic nose Agrinose (e-nose) was used to assess the intensity of the aroma. The results of the analyses revealed the profile of volatile organic compounds in each experimental variant, which was correlated with responses of the electronic nose. The results indicate that the volatile compound profile depends on the bread additives used and influences the intensity of bread aroma. Moreover, the profile of volatile organic compounds in terms of their amount and type, as well as the intensity of their interaction with the active surface of the electrochemical sensors, was specific exclusively for the additive in each case.

Identification of the Olfactory Profile of Rapeseed Oil as a Function of Heating Time and Ratio of Volume and Surface Area of Contact with Oxygen Using an Electronic Nose.

The process of deep fat frying is the most common technological procedure applied to rapeseed oil. During heat treatment, oil loses its nutritional properties and its original consumer quality is lowered, which is often impossible to determine by organoleptic assessment. Therefore, the aim of the study was to correlate markers of the loss of the nutritional properties by rapeseed oil related to the frying time and the surface area of contact with oxygen with changes in the profile of volatile compounds. The investigations involved the process of 6-, 12-, and 18-h heating of oil with a surface-to-volume ratio (s/v ratio) of 0.378 cm-1, 0.189 cm-1, and 0.126 cm-1. Samples were analysed to determine changes in the content of polar compounds, colour, fatty acid composition, iodine value, and total chromanol content. The results were correlated with the emission of volatile compounds determined using gas chromatography and an electronic nose. The results clearly show a positive correlation between the qualitative degradation of the oil induced by prolonged heating and the response of the electronic nose to these changes. The three volumes, the maximum reaction of the metal oxide semiconductor chemoresistors, and the content of polar compounds increased along the extended frying time.

Maillard Reaction Products in Gluten-Free Bread Made from Raw and Roasted Buckwheat Flour.

The formation of Maillard reaction products (MRPs) in gluten-free bread made from roasted and raw buckwheat flour was examined. The levels of phenolic compounds such as flavonoids (catechin, naringenin, quercetin, rutin, and others) and phenolic acids (like 4-hydroxybenzoic, caffeic, dihydroxybenzoic, ferulic, gallic, syringic, vanillic, and p-coumaric) were measured using reversed-phase ultra-high performance liquid chromatography-electrospray ionization mass spectrometry (RP-UHPLC-ESI-MS). Early and advanced Maillard reaction products were analyzed using HPLC, whereas spectrofluorimetric analysis was used to determine the levels of fluorescent intermediate compounds (FIC). The total levels of phenolic compounds were higher in the case of buckwheat bread prepared from roasted buckwheat flour (156 and 140 µg/g of crumb and crust, respectively). Rutin, gallic acid, and catechin were the most abundant phenolic compounds detected in roasted buckwheat bread. The roasting process resulted in significantly lower radical scavenging capacities (ABTS) of the total phenolics and flavonoids in the buckwheat bread. Taking into consideration these Maillard reaction products, we observed a significant increase in FIC level in roasted buckwheat crumb and crust (at about 40%, and 38%, respectively). At the same time, the Nε-(carboxymethyl)lysine (CML) level did not change in roasted or raw buckwheat bread crumb, though in roasted buckwheat crust the concentration of CML increased by about 21%.

Physicochemical Properties, Fatty Acid Composition, Volatile Compounds of Blueberries, Cranberries, Raspberries, and Cuckooflower Seeds Obtained Using Sonication Method.

Every year, thousands of tons of fruit seeds are discarded as agro-industrial by-products around the world. Fruit seeds are an excellent source of oils, monounsaturated fatty acids, and n-6 and n-3 polyunsaturated essential fatty acids. This study aimed to develop a novel technology for extracting active substances from selected seeds that were obtained after pressing fruit juices. The proposed technology involved sonification with the use of ethyl alcohol at a low extraction temperature. Seeds of four species-blueberry (Vaccinium myrtillus L.), raspberry (Rubus idaeus), cranberry (Vaccinium macrocarpon), and cuckooflower (Cardamine pratensis)-were used for extraction. Following alcohol evaporation under nitrogen, the antioxidant activity, chemical composition, and volatile compounds of the obtained extracts were analyzed using chromatographic methods, including gas chromatography (GC)-mass spectrometry (MS) (GC-MS/MS), and high-performance liquid chromatography-MS. We analyzed physicochemical properties, fatty acid, and volatile compounds composition, sterol and tocochromanol content of blueberry, cranberry, raspberry, and cuckooflower seed oils obtained by sonication. This method is safe and effective, and allows for obtaining valuable oils from the seeds.

The effect of drying on the native tocopherol and phytosterol content of Sinapis alba L. seeds.

BACKGROUND: Postharvest processing, including drying, has a significant effect on the processability of oil crop seeds. High drying air temperature may significantly affect the levels of bioactive compounds in plant raw materials. We decided to investigate the subject given the lack of data on the drying of mustard seeds. The aim was to determine the effect of drying temperature on free fatty acid, phytosterol and tocopherol levels in the oil obtained from white mustard seeds. Seeds were dried in a thin layer at 40, 60, 80, 100, 120 and 140 °C. Changes in phytosterol levels were assessed using gas chromatography-mass spectrometry and changes in tocopherol levels by high-performance liquid chromatography. RESULTS: The analysis showed that, upon completion of air drying at 40-100 °C, losses of sterols did not exceed 5%, while upon completion of drying at 120 °C and 140 °C these losses amounted to 17-50%. Our investigation also showed that during drying of white mustard seed the total tocopherol levels increased, and the higher the drying temperature, the greater the increment. In seeds air-dried at 120 °C and 140 °C, the increase in tocopherol amounted to 7-9%. CONCLUSION: We also showed that the temperature of the drying agent significantly affects the tocopherol and phytosterol levels. It was found that a maximum temperature of 100 °C provides optimal drying conditions for mustard seeds. Principal component analysis identified two subgroups of oils obtained from seeds dried at 120 °C and 140 °C, which differed considerably from the other samples in terms of their bioactive component contents. © 2019 Society of Chemical Industry.

The effect of drying temperature of milk thistle seeds on quality and bioactive compounds in the lipid fraction.

Milk thistle oils are available on the market and appeal to consumers because of their healthy properties as cold-pressed oils. The raw material for producing such oils is purchased from a range of domestic and foreign sources. The aim of this work was to determine the effect of drying temperature on the peroxide value, acid value, fatty acid composition, tocopherol and phytosterol contents in the lipid fraction extracted from milk thistle seeds. The seeds were purchased in three different farms and were dried in a thin layer at 40 °C, 60 °C, 80 °C, 100 °C, 120 °C, and 140 °C. The level of phytosterols and the fatty acid composition were determined using GC-FID, while tocopherols concentrations were determined using HPLC. The study showed that the quality of seeds used in the production of oil varies. The drying of milk thistle seeds using air cooler than 80 °C caused no statistically significant changes in AV, p-AnV, phytosterol levels, tocopherols, or SFA levels. Drying temperatures in the 100-140 °C range caused significant losses of phytosterols and tocopherols and also resulted in changes in fatty acid composition. When seeds were dried at 140 °C, phytosterol levels dropped by 19-23%, tocopherols by 10-23%, MUFA by 30%, and PUFA by 11%.

Degradation of Tocopherol Molecules and Its Impact on the Polymerization of Triacylglycerols during Heat Treatment of Oil.

The aim of the study was to analyze the influence of the surface area to volume ratio of pressed and refined rapeseed oils on the changes in tocopherol content and polymerization of triacylglycerols during heating. In the study the pressed and refined rapeseed oil was heated at 170 °C, during 6, 12, and 18 h with three different surface area to volume (s/v) ratios (0.378, 0.189, and 0.126 cm-1). During heating, a decrease in tocopherols and increases in dimers, trimers, and oligomers of triacylglycerols were observed. However, the changes were dependent on the surface area to volume ratio used, type of oil and time of heating. The biggest changes were observed in oil with the biggest s/v ratio (0.378 cm-1), and the lowest when the s/v ratio was 0.126 cm-1. The pressed oil was characterized by faster degradation of tocopherols and slower increase of triacylglycerol polymer levels compared to refined oil.

Genotype × environment interaction on tocochromanol and plastochromanol-8 content in seeds of doubled haploids obtained from F1 hybrid black × yellow seeds of winter oilseed rape (Brassica napus L.).

BACKGROUND: The aim of the study was to determine the effect of genotype × environment interaction on the levels of α-, ß-, γ- and δ-tocopherol (α-T, ß-T, γ-T and δ-T, respectively) and plastochromanol-8 (PC-8) in seeds of 17 doubled haploids (DHs) obtained from the F1 hybrid derived from crossing black (DH H2 -26) × yellow (DH Z-114) seeds of winter oilseed rape. RESULTS: The content of tocopherols in the tested DH lines ranged from 415.6 to 540.1 mg kg-1 seeds, while PC-8 content ranged from 56.3 to 89.0 mg kg-1 seeds. The α-T/γ-T ratio reached a level of 0.78-1.29. Studies have shown that heritability for α-T, ß-T, γ-T, total-T and PC-8 is mainly due to genotypic variation. For the δ-T homologue the level was dependent on environmental effect. CONCLUSION: The obtained DH lines population of oilseed rape is characterized by high heritability coefficients for α-T, ß-T, γ-T, total-T and PC-8 levels, which indicates a greater influence of genotype than the environment on the content of these compounds. Among all studied doubled haploids, seven DHs were selected which were characterized by stable contents of α-T, ß-T, γ-T, δ-T and total-T with the simultaneous stable content of PC-8. © 2017 Society of Chemical Industry.

Effect of Replacing Cocoa Powder by Carob Powder in the Muffins on Sensory and Physicochemical Properties.

The increasing demand for cocoa and search for ingredients rich in bioactive compounds encouraged us to investigate the possibility of replacing it by carob powder in the muffins containing soy beans, sesame oil and flaxseeds. There was 5% addition of carob or cocoa powder to the individual doughs. The muffins with the addition of carob were characterized by improved antiradical activity (by 36% - 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) method, by 83% - 2,2-diphenyl-1-picrylhydrazyl (DPPH) method), higher content of genistein (18%) and total phytosterols (17%) in the dry mass. The color differences in the carob muffins crusts were not perceptible by consumers (ΔE = 0.70 for crust, ΔE = 5.6 for crumb) and their taste was found to be less bitter and sweeter than the taste of cocoa muffins. Moreover, the addition of carob powder as well as cocoa powder resulted in good sensory quality. The high content of phytosterols, genistein and improved antiradical properties proved carob to be a source of bioactive compounds. The results show that carob powder may be used as valuable alternative muffin ingredient to cocoa.

Mechanical hulling and thermal pre-treatment effects on rapeseed oil antioxidant capacity and related lipophilic and hydrophilic bioactive compounds.

In this study, the effect of rapeseed mechanical hulling and thermal pre-treatment by microwaves (from 2 to 10 min with 2-min intervals, 800 W) and roasting (from 20 to 100 min with 20-min intervals, 165 °C) on the content of phytochemicals in the oil was investigated. Results showed that both pre-treatments applied differentiated the oils in terms of the content of bioactive compounds. In general, oils pressed from hulled and thermally pre-treated seeds contained higher content of tocopherols, PC-8 and phytosterols, while oils pressed from non-hulled and pre-processed seeds had significantly higher concentration of polyphenols. Both microwaving and roasting contributed to an increase of antioxidant capacity of studied oils. The increase of radical scavenging activity of oils was seen mainly in hydrophilic fraction of oil, which was highly positively correlated with the amount of canolol formed during seeds heating.

Antioxidant (Tocopherol and Canolol) Content in Rapeseed Oil Obtained from Roasted Yellow-Seeded Brassica napus.

In this study, the effect of temperature (140, 160, 180 °C) and roasting time (5, 10, 15 min) on the bioactive compound content (canolol, tocopherol and plastochromanol-8) of cold-pressed oil from yellow-seeded rapeseed lines of different colors was investigated. Roasting increased the peroxide value in the seed oils compared to the oils from the control samples. However, roasting did not affect the acid values of the oils, which were 1.15-1.47 and 1.30-1.40 mg KOH/g, for line PN1 03/1i/14 (yellow seeds) and line PN1 563/1i/14 (brown seeds), respectively. In this study, the seeds of line PN1 03/1i/14 were characterized by different changes in canolol content during roasting than the seeds of PN1 563/1i/14. There was a 90-fold increase in canolol for the line PN1 03/1i/14 (768.26 µg/g) and a 46-fold increase for the line PN1 563/1i/14 (576.43 µg/g). Changes in tocopherol and PC-8 contents were also observed. There was an increase in the contents of γ-T and PC-8 in the oils obtained from the seeds roasted at 180 °C for 10 and 15 min. γ-T content increased by 17-18% after 15 min of roasting, whereas the PC-8 content increased twofold.

Dehulling and microwave pretreatment effects on the physicochemical composition and antioxidant capacity of virgin rapeseed oil.

The effect of microwave heating (800 W) of whole and dehulled rapeseeds for 2 to 8 min was investigated in order to evaluate the impact of dehulling in conjunction with microwaving on the nutritional value, antioxidant activity and physicochemical properties of virgin rapeseed oil. Control oil produced from dehulled seeds (DRO) had higher amounts of bioactive compounds, such as tocochromanols and phytosterols, lower content of pigments, and higher content of primary and secondary oxidation products compared to oil pressed from whole seeds (WRO). Oils pressed from seeds that had previously undergone thermal treatment demonstrated gradual increase of oxidative stability, radical scavenging activity, moreover microwave treatment to caused darkening of oil, assessed in terms of changes in L*a*b* coordinates as well as browning index. Thermally-induced compositional changes were seen mainly in canolol, phytosterols, and carotenoids content, while only slight increase of tocopherols and phenolics was observed. The most pronounced effect of microwave pretreatment was noted for canolol formation-for 8-min MV exposure canolol quantity was approximately 7- and 23-fold higher, in comparison with control WRO and DRO samples, respectively (increase from 61.39 to 456.04 µg/g, and from 13.39 to 320.44 µg/g).