CHEMICAL TRANSFORMATIONS OF VEGETABLE OILS DURING COOKING: IMPLICATIONS FOR CARDIOVASCULAR DISEASES AND TYPE 2 DIABETES

ABSTRACT

The degradation of vegetable oils during cooking is a complex phenomenon influenced by cooking methods, food components, and the oil's fatty acid composition. This review explores how thermal oxidation, hydrolysis, and polymerization processes alter vegetable oils under high-temperature cooking conditions, resulting in the formation of harmful compounds such as aldehydes, polar compounds, and trans fats. These byproducts are associated with adverse health outcomes, including oxidative stress, cardiovascular diseases (CVD), and type 2 diabetes (T2D). This review emphasizes the need for dietary and cooking interventions to minimize health risks, offering strategies for oil selection, management practices, and public health recommendations to mitigate the growing burden of CVD and T2D.

АННОТАЦИЯ

Деградация растительных масел во время приготовления пищи — это сложное явление, на которое влияют методы приготовления пищи, компоненты пищи и жирнокислотный состав масла. В этом обзоре рассматривается, как процессы термического окисления, гидролиза и полимеризации изменяют растительные масла в условиях высокотемпературной готовки, что приводит к образованию вредных соединений, таких как альдегиды, полярные соединения и трансжиры. Эти побочные продукты связаны с неблагоприятными последствиями для здоровья, включая окислительный стресс, сердечно-сосудистые заболевания (ССЗ) и диабет 2 типа (СД2). В этом обзоре подчеркивается необходимость диетических и кулинарных вмешательств для минимизации рисков для здоровья, предлагаются стратегии выбора масла, методы управления и рекомендации общественного здравоохранения для смягчения растущего бремени ССЗ и СД2.

Keywords: vegetable oil degradation, thermal oxidation, hydrolysis, cooking methods, cardiovascular diseases, type 2 diabetes, trans fats.

Ключевые слова: деградация растительного масла, термическое окисление, гидролиз, методы приготовления пищи, сердечно-сосудистые заболевания, сахарный диабет 2 типа, трансжиры.

Introduction

Vegetable oils play a pivotal role in culinary practices, not only as cooking mediums but also as sources of essential nutrients and bioactive compounds. Their unique chemical composition, dominated by triglycerides and enriched with unsaturated fatty acids, makes them ideal for imparting flavor, texture, and aroma to food. The global culinary tradition of frying, in particular, heavily relies on vegetable oils, contributing to their widespread use across diverse cuisines​ [1, 2]. However, the high thermal demands of cooking methods such as frying, roasting, and baking pose significant challenges to the stability of these oils, triggering chemical transformations with potential health implications [1, 4].

High-temperature cooking methods are well-known to accelerate the degradation of vegetable oils through oxidative, hydrolytic, and polymerization reactions. During these processes, unsaturated fatty acids within the oil are particularly prone to oxidation, forming primary and secondary products such as hydroperoxides, aldehydes, and ketones. These chemical reactions not only deteriorate the sensory quality of oils but also lead to the accumulation of polar compounds, including oxidized monomeric triglycerides and polymerized compounds ​[1, 4, 5]. Importantly, the interplay between the food matrix and cooking methods significantly influences these reactions, as the release of water, lipids, and trace metals from food into the oil can either accelerate or mitigate oxidative degradation ​[1, 24].

The formation of harmful compounds during oil degradation poses substantial health risks. Research has identified toxic substances such as aldehydes, trans fats, and polycyclic aromatic hydrocarbons as byproducts of high-temperature cooking. These compounds have been implicated in adverse health outcomes, including oxidative stress, cardiovascular diseases, and certain cancers​ [1, 5, 6]​. Notably, reused or inadequately managed frying oils, which often exceed the legal threshold for total polar compounds, can significantly amplify these risks ​[1, 4].

This study aims to investigate the complex interactions between food matrices, cooking methods, and oil degradation to provide a deeper understanding of how these factors collectively influence the formation of potentially harmful compounds. By bridging gaps in existing literature, the research will offer insights into optimizing oil usage during cooking to enhance food safety and health outcomes.

Degradation of Vegetable Oils

The degradation of vegetable oils during cooking is a complex phenomenon influenced by chemical reactions, food components, and cooking methods. Understanding the processes that govern oil degradation, the role of food matrices, and the health risks posed by harmful byproducts is crucial for improving food safety and quality [16].

Vegetable oil degradation during cooking involves three primary chemical pathways: thermal oxidation, hydrolysis, and polymerization.

Thermal oxidation occurs when oils are exposed to high temperatures (150–200°C) in the presence of oxygen. Unsaturated fatty acids are particularly vulnerable, undergoing a series of free radical chain reactions that produce primary oxidation products like hydroperoxides, which subsequently degrade into secondary products such as aldehydes, ketones, and alcohols ​[1, 2, 24]. Oils rich in polyunsaturated fatty acids (PUFAs), such as sunflower and soybean oils, are especially prone to oxidation compared to monounsaturated fatty acid (MUFA)-rich oils like olive oil​ [1, 13, 18, 24].

Hydrolysis is facilitated by moisture released from food during cooking. Water interacts with triglycerides in oils, breaking them into free fatty acids (FFAs), monoglycerides, and diglycerides ​[1, 4, 18]. These products lower the smoke point of oils and contribute to further oxidative degradation. The hydrolysis rate is higher when frying high-moisture foods like potatoes and chicken​ [6, 24].

Polymerization occurs at prolonged high temperatures, resulting in the formation of high-molecular-weight compounds such as triglyceride dimers and oligomers​ [1, 6]. These compounds increase oil viscosity and reduce the oil's quality and safety. Oils with a high degree of unsaturation are more prone to polymerization​ [1, 4]. At the legal threshold for total polar compounds (TPCs), polymerized triglycerides constitute up to 15% of the oil content ​[1, 3, 25].

Role of Food Components in Oil Degradation

Food components, including moisture, proteins, and carbohydrates, significantly influence oil degradation processes during cooking.

Proteins released into oils during cooking catalyze degradation reactions. Amino acids from protein interact with reducing sugars in the Maillard reaction, producing reactive carbonyl compounds that accelerate oxidation​ [1, 24]. These interactions are particularly relevant when frying protein-rich foods such as meats, which contribute to higher levels of polar compounds and aldehydes in oils​ [1, 6].

Starch-rich foods, such as potatoes and bread, release reducing sugars during cooking, which react with oil to form acrylamide and other degradation products [1, 24]. Additionally, these interactions lead to physical changes in oils, including increased viscosity and darkening due to the accumulation of polymerized and caramelized compounds ​[1, 4].

The combined presence of moisture, proteins, and carbohydrates enhances oil degradation, especially during the cooking of complex foods like battered or breaded items​ [1, 4].

Health Risks of Oil Degradation Products

The degradation of oils during cooking generates harmful compounds, including acrylamide, aldehydes, and polar compounds, all of which pose significant health risks.

Formed during the Maillard reaction between reducing sugars and amino acids, acrylamide is a probable human carcinogen linked to an increased risk of cancers, including ovarian and renal cancers ​[4, 5, 9]​. Neurotoxic effects of acrylamide have also been documented in animal and human studies, underscoring its potential as a public health concern​ [1].

Aldehydes such as malondialdehyde and acrolein, produced during the thermal oxidation of oils, are associated with oxidative stress, inflammation, and DNA damage​ [4–6]. These compounds are implicated in cardiovascular diseases, neurodegenerative disorders, and cancer development ​[1, 24]. Oils subjected to prolonged or repeated frying exhibit significantly higher aldehyde concentrations​ [1].

Polar compounds, including oxidized triglycerides and polymerized products, are key markers of oil degradation. Studies link these compounds to oxidative stress, lipid peroxidation, and disruptions in liver function​ [4, 6]. Their accumulation in reused oils poses serious health risks, emphasizing the importance of monitoring TPC levels ​[1, 22, 26].

Previous Studies on Specific Cooking Methods

The choice of cooking method has a profound impact on the extent of oil degradation and the formation of harmful compounds.

Deep frying is one of the most detrimental cooking methods for oil stability due to high temperatures and continuous exposure to oxygen and food components​ [1, 24]. Repeated frying exacerbates degradation, leading to the rapid accumulation of acrylamide, aldehydes, and polar compounds. Oils with higher MUFA content, such as olive oil, exhibit better stability under frying conditions than PUFA-rich oils like sunflower oil ​[1, 4, 12].

Roasting typically involves lower moisture release compared to frying, reducing the rate of hydrolysis. However, the high temperatures used during roasting still promote oxidation and polymerization, particularly in oils with high PUFA content​ [3, 24].

Baking generally involves lower temperatures compared to frying and roasting, resulting in less severe oil degradation. However, the presence of carbohydrates in baked goods can promote Maillard reactions, leading to acrylamide formation ​[1]. The choice of oil significantly influences the extent of degradation, with MUFA-rich oils showing better stability ​[4, 24].

Each cooking method presents unique challenges for maintaining oil stability, underscoring the need for careful oil selection and proper management practices to minimize degradation.

Impact of Dietary Fatty Acid Composition in Vegetable Oils on Cardiovascular Health

The composition of fatty acids in vegetable oils plays a pivotal role in cardiovascular health. With increasing global consumption of vegetable oils, their impact on lipid profiles, vascular health, and risk factors associated with cardiovascular diseases (CVD) has garnered significant attention in recent years. [8, 21].

Fatty Acid Composition and Lipid Profiles

Vegetable oils predominantly consist of saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), and polyunsaturated fatty acids (PUFA). The relative proportions of these fatty acids determine their influence on lipid metabolism.

High intake of Saturated Fatty Acids (SFA), commonly found in palm oil and hydrogenated oils, has been linked to elevated low-density lipoprotein cholesterol (LDL-C), a major risk factor for atherosclerosis and coronary artery disease. However, the specific source of SFA may modulate its effects. For instance, SFAs derived from dairy products show a weaker association with CVD risk compared to those from partially hydrogenated oils​ [7, 19].

Oils rich in Monounsaturated Fatty Acids (MUFA), such as olive and canola oils, are associated with improved lipid profiles, characterized by reduced LDL-C and increased high-density lipoprotein cholesterol (HDL-C). These oils also enhance endothelial function, reduce inflammation, and lower blood pressure​ [10, 19, 20].

Polyunsaturated Fatty Acids (PUFA), particularly omega-6 (e.g., linoleic acid) and omega-3 fatty acids, exert cardioprotective effects by reducing triglycerides, LDL-C, and overall systemic inflammation. Sunflower, safflower, and soybean oils are rich sources of omega-6 PUFAs, which have been shown to decrease cardiovascular mortality when they replace SFAs in the diet​ [14, 23].

Trans-fatty Acids and Cardiovascular Risk

Partially hydrogenated vegetable oils, a significant source of trans-fatty acids (TFA), are associated with an increased risk of CVD. TFAs raise LDL-C, lower HDL-C, and promote systemic inflammation and endothelial dysfunction. Observational studies highlight that populations with high TFA consumption, such as in developing countries using partially hydrogenated oils, exhibit elevated incidences of dyslipidemia and hypertension​ [7, 11, 14, 17].

Role of Omega-3 and Omega-6 Fatty Acids

Marine-sourced omega-3 fatty acids, such as eicosatetraenoic acid (EPA) and docosahexaenoic acid (DHA), are effective in reducing triglycerides and improving vascular function. While vegetable oils like flaxseed and canola contain alpha-linolenic acid (ALA), a precursor to EPA and DHA, their conversion efficiency is limited. Nevertheless, ALA-rich oils exhibit cardioprotective properties​ [20, 23].

Linoleic acid (LA), the primary omega-6 PUFA, reduces LDL-C and CVD risk when substituted for SFA. However, concerns about excessive omega-6 intake leading to pro-inflammatory effects have been largely dispelled by recent systematic reviews, which affirm their net benefits in cardiovascular health ​[15, 19, 23].

Comparative Effects of Common Vegetable Oils

Olive Oil is high in MUFA, olive oil is central to the Mediterranean diet and consistently linked to reduced CVD risk and mortality ​[14]. Sunflower and Safflower Oils are rich in omega-6 PUFAs, these oils effectively reduce LDL-C but may lack the broader health benefits of MUFA-rich oils​ [7, 19]. Palm Oil is economical and widely used, palm oil's high SFA content is a concern for its atherogenic potential, although unrefined forms may retain some beneficial phytochemicals​[14, 19]. Canola Oil is a favorable balance of omega-3 and omega-6 PUFAs, canola oil offers lipid-lowering effects and anti-inflammatory benefits ​[20].

Dietary Recommendations and Public Health Implications

Substituting SFAs and TFAs with MUFAs and PUFAs from vegetable oils is a cornerstone of dietary guidelines aimed at reducing CVD risk. The promotion of non-hydrogenated oils and education on balanced fatty acid intake are critical for mitigating the global burden of cardiovascular diseases. Public health initiatives in some countries have successfully reduced TFA consumption, resulting in measurable declines in CVD prevalence​ [7, 23].

Dietary Intake of Vegetable Oils and Its Impact on Insulin Sensitivity and Type 2 Diabetes Risk

The consumption of vegetable oils plays a significant role in modulating insulin sensitivity and the risk of type 2 diabetes (T2D). The type and proportion of fatty acids in vegetable oils significantly influence their impact on insulin sensitivity. Oils rich in monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) are associated with improved metabolic outcomes, while saturated fatty acids (SFA) and trans fatty acids (TFA) are linked to insulin resistance and increased diabetes risk.

MUFA-rich oils, such as olive and canola oils, enhance insulin sensitivity by improving lipid profiles and reducing systemic inflammation. Randomized controlled trials have shown that replacing dietary saturated fat with MUFA improves insulin signaling and reduces fasting glucose levels​ [19, 20].

PUFAs, particularly omega-6 (e.g., linoleic acid) and omega-3 fatty acids (e.g., alpha-linolenic acid), promote insulin sensitivity by modulating cell membrane fluidity, enzyme activity, and gene expression​ [20, 23]. Sunflower, safflower, and soybean oils, rich in PUFAs, have demonstrated beneficial effects on insulin resistance when substituted for saturated fats​ [14, 23].

Diets high in SFA, often found in palm oil and partially hydrogenated oils, are associated with increased insulin resistance. SFAs contribute to the accumulation of lipotoxic intermediates in muscle and liver, impairing insulin signaling​ [7, 14].

Partially hydrogenated vegetable oils, a source of TFA, exacerbate insulin resistance by promoting systemic inflammation and endothelial dysfunction. High TFA consumption is consistently associated with an increased risk of T2D​ [7, 20].

Mechanisms Linking Vegetable Oils to Insulin Sensitivity

Dietary fatty acids influence the composition of cell membranes, altering fluidity and the activity of insulin receptors. PUFAs enhance membrane fluidity, improving insulin receptor function, while SFAs reduce fluidity, impairing glucose uptake​ [20, 23]. Omega-3 and omega-6 PUFAs exert anti-inflammatory effects by reducing the production of pro-inflammatory cytokines such as TNF-α and IL-6, which are linked to insulin resistance ​[19, 23]. In contrast, SFAs and TFAs promote chronic low-grade inflammation, exacerbating metabolic dysfunction​[7, 20]. PUFAs modulate the expression of genes involved in lipid metabolism, glucose homeostasis, and insulin sensitivity via activation of peroxisome proliferator-activated receptors (PPARs). This leads to improved insulin action and glucose utilization​ [20, 23].

Epidemiological Evidence on Vegetable Oils and Type 2 Diabetes Risk

Large-scale prospective cohort studies indicate that higher intakes of PUFA-rich oils, such as sunflower, soybean, and canola oils, are associated with a reduced risk of T2D. Substituting SFAs with PUFAs reduces diabetes risk by 20-30%​ [7, 14]. High consumption of palm oil, hydrogenated oils, and other SFA-rich fats is linked to increased T2D incidence. The adverse effects are mediated by insulin resistance, ectopic fat deposition, and chronic inflammation​ [19, 20]. In developing countries, the widespread use of partially hydrogenated oils as a low-cost cooking medium has contributed to a higher prevalence of T2D and metabolic syndrome ​[7, 14]. Public health initiatives to replace TFAs with non-hydrogenated oils have shown promise in mitigating this risk ​[7, 23].

Intervention Studies on Vegetable Oils and Insulin Sensitivity

Intervention trials show that diets enriched with olive oil improve insulin sensitivity and reduce fasting insulin levels compared to high-carbohydrate or SFA-rich diets​ [20, 23]. Diets supplemented with omega-6 and omega-3 PUFAs improve glucose homeostasis and reduce markers of insulin resistance. Studies on canola and flaxseed oils have demonstrated significant reductions in fasting glucose and HOMA-IR scores​ [19, 20]. Replacing TFA-containing oils with PUFA- and MUFA-rich alternatives improves insulin sensitivity and reduces systemic inflammation, highlighting the need for regulatory actions to limit TFA use​ [14, 23].

Public Health Implications

Public health strategies promoting the use of MUFA- and PUFA-rich vegetable oils while reducing SFA and TFA consumption are critical for reducing the global burden of T2D. Educational campaigns, labeling reforms, and subsidies for healthier oils can support dietary shifts, especially in low- and middle-income countries where TFA consumption remains high ​[7, 14, 23].

Discussion

The degradation of vegetable oils during cooking is a complex interplay of chemical reactions, food matrices, and cooking methods, leading to significant health implications. High-temperature processes such as frying, roasting, and baking induce thermal oxidation, hydrolysis, and polymerization, resulting in the formation of harmful compounds like aldehydes, trans fats, and polar compounds. These byproducts not only compromise oil quality but also pose substantial risks to cardiovascular and metabolic health. Repeated use of oils in frying exacerbates the accumulation of these toxic substances, emphasizing the need for regulated oil usage and management.

The role of food matrices, particularly the presence of moisture, proteins, and carbohydrates, further accelerates oil degradation. Moisture promotes hydrolysis, proteins catalyze oxidative reactions, and carbohydrates contribute to Maillard reactions, leading to acrylamide formation. These interactions highlight the importance of considering both the food being cooked and the oil used to minimize harmful compound generation.

The fatty acid composition of oils is pivotal in determining their stability and health impacts. Oils rich in monounsaturated and polyunsaturated fatty acids, such as olive and canola oils, exhibit greater stability under heat and confer protective effects against cardiovascular diseases and type 2 diabetes. Conversely, saturated, and trans-fat-rich oils, such as palm and hydrogenated oils, exacerbate oxidative stress, inflammation, and insulin resistance, increasing the risk of chronic diseases.

Public health strategies to mitigate these risks should focus on promoting healthier oils, optimizing cooking practices, and reducing the reuse of oils. Additionally, public education campaigns and regulatory measures to limit trans-fat content in cooking oils are essential. Further research is needed to explore innovative approaches to improve oil stability and understand the long-term health impacts of different cooking methods and oil compositions.

Conclusion

The degradation of vegetable oils during cooking is a multifaceted process influenced by cooking methods, food matrices, and oil composition. Thermal oxidation, hydrolysis, and polymerization under high-temperature conditions lead to the formation of harmful compounds such as aldehydes, polar compounds, and trans fats, which pose significant risks to cardiovascular and metabolic health. Food components like moisture, proteins, and carbohydrates exacerbate oil degradation, while cooking practices such as frying intensify the generation of toxic byproducts. Oils rich in monounsaturated and polyunsaturated fatty acids, such as olive and canola oils, offer protective health benefits, whereas saturated and trans-fat-rich oils heighten the risks of cardiovascular diseases and type 2 diabetes. To mitigate these health impacts, it is essential to adopt healthier cooking practices, regulate oil usage, and promote public education on the importance of selecting stable and nutritionally beneficial oils. Our future research should explore mechanisms of chemical changes in oils and innovative strategies to enhance oil stability and minimize health risks associated with oil degradation during cooking.

References:

1. Abrante-Pascual S., Nieva-Echevarría B., Goicoechea-Oses E. Vegetable Oils and Their Use for Frying: A Review of Their Compositional Differences and Degradation // Foods. 2024. № 24 (13). - PP. 41-86.
2. Ansorena D. [et al.]. Oxidative Stability and Genotoxic Activity of Vegetable Oils Subjected to Accelerated Oxidation and Cooking Conditions // Foods. 2023. № 11 (12). - PP. 21-86.
3. Bordin K. [et al.]. Changes in food caused by deep fat frying – A review.
4. Chen J. [et al.]. The formation, determination and health implications of polar compounds in edible oils: Current status, challenges and perspectives // Food Chemistry. 2021. (364). - PP. 130-451.
5. Dobarganes C., Márquez-Ruiz G. Oxidized fats in foods: // Current Opinion in Clinical Nutrition and Metabolic Care. 2003. № 2 (6). - PP.157–163.
6. Dobarganes C., Márquez-Ruiz G. Possible adverse effects of frying with vegetable oils // British Journal of Nutrition. 2015. № S2 (113). - PP. 49–57.
7. Esmaillzadeh A., Azadbakht L. Different kinds of vegetable oils in relation to individual cardiovascular risk factors among Iranian women // British Journal of Nutrition. 2011. № 6 (105). - PP. 919–927.
8. Ganesan K., Sukalingam K., Xu B. Impact of consumption and cooking manners of vegetable oils on cardiovascular diseases- A critical review // Trends in Food Science & Technology. 2018. (71). - PP. 132–154.
9. Ghane E. T. [et al.]. Concentration of Potentially Toxic Elements in Vegetable Oils and Health Risk Assessment: a Systematic Review and Meta-analysis // Biological Trace Element Research. 2022. № 1 (200). - PP. 437–446.
10. Huth P. J., Fulgoni V. L., Larson B. T. A Systematic Review of High-Oleic Vegetable Oil Substitutions for Other Fats and Oils on Cardiovascular Disease Risk Factors: Implications for Novel High-Oleic Soybean Oils // Advances in Nutrition. 2015. № 6 (6). - PP. 674–693.
11. Laake I. [et al.]. A prospective study of intake of trans -fatty acids from ruminant fat, partially hydrogenated vegetable oils, and marine oils and mortality from CVD // British Journal of Nutrition. 2012. № 4 (108). - PP. 743–754.
12. Li X. [et al.]. Effects of frying oils’ fatty acids profile on the formation of polar lipids components and their retention in French fries over deep-frying process // Food Chemistry. 2017. (237). - PP. 98–105.
13. Martín-Torres S. [et al.]. A Comparison of the Stability of Refined Edible Vegetable Oils under Frying Conditions: Multivariate Fingerprinting Approach // Foods. 2023. № 3 (12). - PP. 604.
14. Misra A., Singhal N., Khurana L. Obesity, the Metabolic Syndrome, and Type 2 Diabetes in Developing Countries: Role of Dietary Fats and Oils // Journal of the American College of Nutrition. 2010. № sup3 (29). - PP. 289-301.
15. Mozaffarian D., Clarke R. Quantitative effects on cardiovascular risk factors and coronary heart disease risk of replacing partially hydrogenated vegetable oils with other fats and oils // European Journal of Clinical Nutrition. 2009. № S2 (63). - PP. 22–33.
16. Negash Y. A. [et al.]. Assessment of quality of edible vegetable oils accessed in Gondar City, Northwest Ethiopia // BMC Research Notes. 2019. № 1 (12). - PP. 793.
17. Ng C.-Y. [et al.]. Heated vegetable oils and cardiovascular disease risk factors // Vascular Pharmacology. 2014. № 1 (61). - PP. 1–9.
18. Oh W. Y., Kim M.-J., Lee J. Approaches of lipid oxidation mechanisms in oil matrices using association colloids and analysis methods for the lipid oxidation // Food Science and Biotechnology. 2023. № 13 (32). - PP. 1805–1819.
19. Okuyama H. [et al.]. Medicines and Vegetable Oils as Hidden Causes of Cardiovascular Disease and Diabetes // Pharmacology. 2016. № 3–4 (98). - PP. 134–170.
20. Risérus U., Willett W. C., Hu F. B. Dietary fats and prevention of type 2 diabetes // Progress in Lipid Research. 2009. № 1 (48). - PP. 44–51.
21. Sacks F. M. [et al.]. Dietary Fats and Cardiovascular Disease: A Presidential Advisory From the American Heart Association // Circulation. 2017. № 3 (136).
22. Sayon-Orea C., Carlos S., Martínez-Gonzalez M. A. Does cooking with vegetable oils increase the risk of chronic diseases?: a systematic review // British Journal of Nutrition. 2015. № S2 (113). - PP. 36–48.
23. Schwab U. [et al.]. Effect of the amount and type of dietary fat on cardiometabolic risk factors and risk of developing type 2 diabetes, cardiovascular diseases, and cancer: a systematic review // Food & Nutrition Research. 2014. № 1 (58). - PP. 25-145.
24. Tsai Y.-H. [et al.]. Thermal Degradation of Vegetable Oils // Foods. 2023. № 9 (12). - PP. 18-39.
25. Zhang Q. [et al.]. Chemical alterations taken place during deep-fat frying based on certain reaction products: A review // Chemistry and Physics of Lipids. 2012. № 6 (165). - PP. 662–681.
26. Zhou Y. [et al.]. Edible Plant Oil: Global Status, Health Issues, and Perspectives // Frontiers in Plant Science. 2020. (11). - PP. 13-15.