Method for producing an additive-containing vegetable oil for frying carbohydrate-rich foods

Abstract

The present invention relates to a method for producing an enriched vegetable oil for frying carbohydrate-rich foods. The method comprises preparing different additives by freeze-drying, which additives comprise essential oils, such as thymol or eugenol, the essential oils being encapsulated in β-cyclodextrins. Said additives are added to a vegetable oil, such as virgin olive oil or sunflower oil, to produce the enriched vegetable oil. Advantageously, using the enriched vegetable oil to fry carbohydrate-rich foods at temperatures between 175°C and 190°C reduces the concentration of acrylamide present in the fried food by at least 77% compared with the acrylamide produced in frying processes using additive-free vegetable oils.

Description

[0001] QUALIFICATION

[0002] Process for obtaining an additive-enhanced vegetable oil for frying carbohydrate-rich foods

[0003] DESCRIPTION

[0004] Process for obtaining an additive-enhanced vegetable oil for frying carbohydrate-rich foods

[0005] FIELD OF INVENTION

[0006] The present invention relates to a process for obtaining vegetable oils enriched with various additives that reduce the concentration of acrylamide during frying or cooking of carbohydrate-rich foods, such as potatoes, compared to the acrylamide concentration produced during frying with conventional oils. Specifically, the additives in the enriched vegetable oils of the invention are based on essential oils encapsulated in p-cyclodextrins obtained by forming inclusion complexes and subsequent freeze-drying.

[0007] PRIOR ART

[0008] Acrylamide (2-propenamide, C3H5NO, CAS 79-06-01) is a neurotoxic and genotoxic organic molecule for humans, classified since 1994 by the International Agency for Research on Cancer (IARC) in group 2A, as a probable carcinogen for humans based on studies carried out in animals [World Health Organization, “IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. Some Industrial Chemicals”, 60, (1994)].

[0009] In 2002, the World Health Organization (WHO) registered acrylamide as a new toxic compound in food when a study conducted between the Swedish National Food Administration (SNFA) and researchers from Stockholm University showed that carbohydrate-rich foods have high levels of acrylamide when subjected to a thermal process above 120°C and low humidity [E. Tareke et al., “Analysis of acrylamide; a carcinogen formed in heated foodstuffs”, Journal of Agricultural and Food Chemistry, 50 (17),4998-5006, (2002)].

[0010] In 2002, it was shown that acrylamide could be naturally generated from food components such as amino acids and reducing sugars, such as asparagine, during heat treatment as a result of the Maillard reaction [DS. Mottram et al., “Acrylamide is formed in the Maillard reaction”, Nature, 419, 448-449, (2002)].

[0011] The Maillard reaction, also known as the non-enzymatic browning reaction, was discovered in 1912 by Louis Camille Maillard and is a process that occurs in both food and living organisms. This reaction constitutes the main pathway for acrylamide formation in food and is related to lipid oxidation since both processes share common polymerization mechanisms, forming similar reaction byproducts [LC. Maillard, “Action of amino acids on sugars. Formation of melanoidins in a methodical way”, Comptes Rendus-Académie des Sciences, 154, 66-68, (1912)].

[0012] Acrylamide is found in foods such as cooked potato products, biscuits, cereals, bread, pastries, nuts, coffee, infant dairy products, fruits and vegetables, meat products, and fish [“Acrylamide in Food: Analysis, Content and Potential Health Effects. (Second Edition)”, V. Gokrnen and B. Atag Mogol (eds.), Academic Press, 1-618, (2023); AM Khaneghah et al., “The Concentration of Acrylamide in Different Food Products: A Global Systematic Review, Meta-Analysis, and Meta-Regression”, Food Reviews International, 38(6), 1286-1304, (2022)].

[0013] Due to scientific evidence on the effects of acrylamide consumption by humans, as well as the wide variety of foods containing this molecule, international authorities such as the Food and Agriculture Organization of the United Nations (FAO), the European Food Safety Authority (EFSA) of the European Union, and the Food and Drug Administration (FDA) of the United States government, as well as the European Commission and the Spanish Agency for Food Safety and Nutrition (AESAN) of the Government of Spain, have approved different recommendations, assessments, and regulations to reduce the concentration of acrylamide in products, which are mandatory for all economic operators [Official Journal of the European Union,“Regulation (EU) 2017 / 2158: Mitigation measures and benchmark levels for reducing the presence of acrylamide in food”, (2017); Center for Food Safety and Applied Nutrition, Food and Drug Administration, “FDA-2013-D-0715: Guidance for Industry Acrylamide in Foods”, (2016); Food and Agriculture Organization, “CAC / RCP 67-2009. Code of Practice for the Reduction of Acrylamide in Foods”, (2009)].

[0014] Since the link between acrylamide formation and the cooking process of carbohydrate-rich foods was demonstrated in 2002, numerous studies have been conducted to reduce acrylamide concentrations. It is important to note that FoodDrinkEurope regularly compiles the various methodologies developed in this field in the Acrylamide Toolbox [FoodDrinkEurope, “Acrylamide Toolbox 2019”, 1-64, (2019)]. This toolbox highlights methods developed to reduce the amount of acrylamide in French fries, regardless of their form.

[0015] Mitigation strategies for acrylamide formation in potatoes are based on the study of different potato varieties, type of cut (shape and thickness), optimization of humidity and temperature storage conditions, cooking method (pan, conventional or air fryer, oven and microwave), type of oil (olive, virgin olive, extra virgin olive, high oleic, linseed, rapeseed, sunflower, sesame, mixtures, among others), cooking time, application of additives to raw potatoes and post-cooking treatments [ES2673634; JP2005261397; W02017056096; ES2336784; JS. Elmore et al., “Effects of sulphur nutrition during potato cultivation on the formation of acrylamide and aroma compounds during cooking”, Food Chemistry, 122 (3), 753-760, (2010); RJ. Root et al., “Acrylamide in fried and roasted potato products: A review on progress in mitigation”, Food Additives & Contaminants: Part A, 24, 37-46, (2007); Y. Yuan et al., “Impact of selected additives on acrylamide formation in asparagine / sugar Maillard model systems", Food Research International, 44 (1), 449-455, (2011); FoodDrinkEurope, “Acrylamide Toolbox 2019", 1-64, (2019)].

[0016] Another strategy that has been developed on an industrial scale is the implementation of different stages of pre-treatment, including washing (also called bleaching) and fermentation, with synthetic and natural additives such as antioxidants, plant extracts, phenolic compounds, enzymes, probiotics, amino acids, divalent and trivalent acids and cations, and microbiological methods, with the aim of reducing the acrylamide content in potatoes [US20040058045A1; US20040109926A1; W02006099798; ES2336784; JP2005278448; MXPA / A / 2005 / 005391; MXPA / A / 2006 / 000181; ES2335500; MX2022009063; N. Khorshidian et al., “Using probiotics for mitigation of acrylamide in food products: a mini review”, Current Opinion in Food Science, 32, 67-75, (2020); E. Rottmann et al., “Enzymatic acrylamide mitigation in French fries -An industrial-scale case study”, Food Control, 123, 107739, (2021); ACE. Albedwawi et al., An overview of microbial mitigation strategies for acrylamide: Lactic acid bacteria, yeast, and cell-free extracts", LWT, 143, 111159, (2021)].

[0017] Furthermore, and due to the high level of technological development, techniques such as ultrasonic waves before a bleaching stage and subsequent vacuum frying (CN110037263), ionizing radiation to potatoes before cooking [X. Fan et al., “Effectiveness of ionizing radiation in reducing furan and acrylamide levels in foods”, Journal of Agricultural and Food Chemistry, 54 (21), 8266-8270, (2006); V. Gokrnen et al., “Effects of controlled atmosphere storage and low-dose irradiation of potato tuber components affecting acrylamide and color formations upon frying”, European Food Research and Technology, 224 (6), 681-687, (2007)] and a pre-treatment stage of freezing and defrosting potatoes by microwave [Y. Yuan et al., “Study of the methods for reducing the acrylamide content in potato slices after microwaving and frying processes”, RSC Advances, 4 (2), 1004-1009, (2014)].

[0018] However, although significant reductions have been achieved, the industrial application of these methods and technologies described has some drawbacks for producers:

[0019] The potato variety cannot be kept stable for a whole year, so manufacturers select potatoes from different origins, with different compositions of reducing sugars, even if the variety is maintained.

[0020] Maintaining sharp cutting blades.

[0021] The chemical properties of each type of oil mean that the methods applied are not effective for everyone.

[0022] The variation in cooking temperature (decrease) and time (increase) has led to an increase in production costs due to higher energy consumption, without maintaining the same properties in the potatoes.

[0023] Loss of up to 20-25% of production due to the decrease in cooking temperature.

[0024] Procedures based on a washing stage cause the potatoes to soften and, therefore, modify the organoleptic properties of the products.

[0025] Processes based on the addition of additives to potatoes cause a change in the organoleptic properties of the products and, therefore, consumer rejection.

[0026] Increased production costs due to the reagents used in the washing or bleaching stages.

[0027] - High economic cost of techniques based on ionizing radiation and microwaves, as well as the difficulty in scaling up these technologies.

[0028] No reduction in acrylamide concentration is achieved that complies with the new recommendations and / or legislation by public bodies.

[0029] Therefore, we can say that the main method to reduce the concentration of acrylamide corresponds to a bleaching process with a high economic cost and a loss of the organoleptic parameters and quality of the final product.

[0030] One of the alternative technologies with the greatest potential, although little used in the reduction of acrylamide concentration, is the encapsulation of compounds using extrinsic cyclodes as a host or guest molecule.

[0031] Cyclodextrins are natural compounds formed from naturally occurring cyclic oligosaccharides composed of 6, 7, and 8 glucose units (α-, β-, and γ-CD, respectively). These units form inclusion complexes with various hydrophobic host molecules, thereby improving the solubility and stability of these compounds. The application of cyclodextrins in the food industry began in 1970 with the discovery of their ability to retain volatile compounds that affected food flavor, and their use is now widespread globally.Examples of industrial-level use include: protection of bioactive compounds against oxidation and pro-oxidant mechanisms such as light-induced reactions, thermal decomposition, and loss of volatiles in certain foods; reduction and elimination of unwanted flavors and odors, as well as contaminants, increasing product shelf life; enrichment of vitamins with a high percentage of encapsulated antioxidant compounds in juices; improvement of the sensory parameters of food by solubilizing bitter and unpleasant substances for the consumer, as well as hydrophobic substances rich in fatty acids; and stabilization of fragrances, vitamins, and essential oils against physicochemical changes [JM. López-Nicolás et al., “Cyclodextrins and antioxidants”, Critical Reviews in Food Science and Nutrition, 54 (2), 251-256, (2014); A. Matencio et al., “Applications of cyclodextrins in food science.A review”, Trends in Food Science & Technology, 104, 132-143, (2020); Y. Kumar et al., “Food applications of cyclodextrins”, Sustainable Agriculture Reviews, 55, 201-238, (2021); A. González-Pereira et al., “Main applications of cyclodextrins in the food industry as the compounds of choice to form host-guest complexes”, International Journal of Molecular Sciences, 22 (3), 1339, (2021); A. Cid-Samamed et al., “Cyclodextrins inclusion complex: Preparation methods, analytical techniques and food industry applications”, Food Chemistry, 384 (1), 132-467, (2022)]. More recently, in addition to the above, developments have focused on the field of encapsulation of compounds (functional ingredients, metals, with antimicrobial, antiseptic or antioxidant activity) for the improvement of product packaging [G. Astray et al., “A review on the use of cyclodextrins in foods”, Food Hydrocolloids, 23 (7), 1631-1640, (2009); C. Rannou et al., “Mitigation strategies of acrylamide, furans, heterocyclic amines and browning during the Maillard reaction in foods", Food Research International, 90, 154-176, (2016)].

[0032] Debido a esta gran aplicabilidad, desde 1998, están admitidas como “Generalmente reconocido como seguro” (GRAS, por sus siglas en inglés) en la lista de aditivos alimentarios de la FDA permitidos para uso alimentario [Office of Food Additive Safety, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, “Agency Response Letter Gras notice GRN No. 155", Silver Spring, MD, (2004); Office of Food Additive Safety, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, “Agency Response Letter Gras notice GRN No. 74”, Silver Spring, MD, (2001); Office of Food Additive Safety, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, “Agency Response Letter Gras notice GRN No. 46”, Silver Spring, MD, (2000)].In Europe, the three parental cyclodextrins (a-, - and y-) are registered in the Codex Alimentarius of the Joint FAO / WHO Expert Committee on Food Additives with the International Numbering System (INS) E-457, E-459 and E-458, respectively [Joint FAO / WHO Expert Committee on Food Additives, “Evaluation of certain food additives: sixty-third report of the Joint FAO / WHO Expert Committee on Food Additives”, 1-156 (2004)].

[0033] In three studies found in the state of the art, the use of cyclodextrins as a host molecule or cavity to mitigate acrylamide formation in carbohydrates has been investigated [W02004080205A1; AJ. Pérez-López et al., “Acrylamide content in French fries prepared with vegetable oils enriched with / 3-cyclodextrin or / 3-cyclodextrin-carvacrol complexes”, LWT, 148, 111765, (2021); M. Barón-Yusty et al., “Encapsulated EVOO improves food safety and shelf life of refrigerated pre-cooked chicken nuggets”, Clean Technology, 4 (1), 53-66, (2022)].

[0034] In the first piece of evidence, W02004080205A1, the inventors add alpha-cyclodextrin, beta-cyclodextrin, gamma-cyclodextrin, combinations thereof, and modified derivatives thereof in the preparation of food products and intermediate food products to reduce acrylamide levels. This is because the amino acid asparagine is sequestered in the hydrophobic binding pocket of the cyclodextrin, preventing it from reacting with a reducing end. In other words, they use cyclodextrins as a food additive before the cooking process (boiling, baking, and frying).

[0035] This same treatment is carried out in the third evidence by Barón-Yusty et al., where they encapsulated extra virgin olive oil in alpha-cyclodextrins and added them to the breading product of chicken pieces, prior to the ultra-freezing stage and subsequent frying [“Encapsulated EVOO improves food safety and shelflife of refrigerated pre-cooked chicken nuggets”, Clean Technology, 4 (1), 53-66, (2022)].

[0036] Another highly effective approach was that of researchers AJ. Pérez-López et al., from the second evidence, where they encapsulated carvacrol (the major monoterpene of oregano essential oil) in beta-cyclodextrins using ultrasonic sonication complexation followed by spray-drying, and added it to frying oil. It proved effective in frying fresh potatoes using sunflower oil and extra virgin olive oil. Furthermore, a sensory analysis demonstrated that consumers did not reject the fries made with this modified oil [“Acrylamide content in French fries prepared with vegetable oils enriched with β-3-cyclodextrin or β-3-cyclodextrin-carvacrol complexes”, LWT, 148, 111765, (2021)].

[0037] However, this evidence presents several drawbacks that have hindered its practical application in industry. Ultrasonic equipment is expensive and generates heat in the mixture, which degrades certain organic compounds such as essential oils, resulting in lower acrylamide reduction efficiency. In fact, the acrylamide reduction achieved is entirely insufficient, as it does not fall below the European Union limit of 750 pg / kg.

[0038] Thus, according to the information published in the document by AJ. Pérez-López et al., the addition of p-cyclodextrins to frying oil resulted in a 15% reduction in acrylamide concentration, while the addition of carvacrol as an essential oil encapsulated in p-cyclodextrins to frying oils resulted in a 40% reduction in acrylamide concentration. For both modified oils, the concentration was above 750 pg / kg, exceeding the current European Union recommendation.On the other hand, the method of synthesizing the encapsulated additive using ultrasound technology requires a costly technology that is difficult to scale up industrially, as well as highly qualified personnel. Furthermore, the subsequent spray-drying stage has the disadvantage that, being a dehydration process, the percentage of water that can be reduced is lower compared to the method of the present invention based on lyophilization. Additionally, the application of the temperature required for spray drying can partially degrade the essential oil.

[0039] For the reasons stated above, the lack of studies carried out with food products rich in carbohydrates or oils enriched with bioactive compounds encapsulated in cyclodextrins in real situations means that both this and other methods of acrylamide reduction currently lack a globally known industrial application.

[0040] EXPLANATION OF THE INVENTION

[0041] The present invention proposes a vegetable oil enriched or enhanced with essential oils encapsulated in p-cyclodextrins, as well as a process for obtaining them, which enables the reduction of acrylamide concentration when frying carbohydrate-rich foods, such as potatoes (sliced ​​or fried) in a pan or fryer. This oil is applicable to restaurants and industrial plants, as detailed in the accompanying claims. These oils represent a significant improvement over the prior art.

[0042] According to the essence of the invention, in the claimed process the vegetable oil is enriched with an additive consisting of a host molecule and a bioactive material that is a major monoterpene of an essential oil, the additive being synthesized by coprecipitation followed by a freeze-drying step.

[0043] Thus, the vegetable oil with added ingredients for frying carbohydrate-rich foods obtained by the proposed procedure includes at least one additive consisting of an essential oil (thymol or eugenol) encapsulated by p-cyclodextrins, the concentration of essential oil encapsulated in the p-cyclodextrins in the vegetable oil with added ingredients being 1 g / L, so that in the frying of carbohydrate-rich foods at temperatures between 175°C and 190°C, the concentration of acrylamide present in the fried food is reduced by at least 77% compared to the acrylamide produced in frying processes with non-enriched vegetable oils.

[0044] Specifically, according to possible non-limiting embodiments of the invention, it relates to a vegetable oil additive in p-cyclodextrins with thymol encapsulated by the formation of an inclusion complex and subsequent drying by dehydration (lyophilization) and a vegetable oil additive in p-cyclodextrins with eugenol encapsulated by the formation of an inclusion complex and subsequent drying by dehydration.

[0045] The process for manufacturing vegetable oil enriched with an additive obtained by freeze-drying an inclusion complex includes the following steps:

[0046] preparation of a first solution of p-cyclodextrins with water by stirring;

[0047] preparation of a second solution by mixing thymol monoterpene or eugenol monoterpene in ethanol;

[0048] pouring the second solution drop by drop onto the first solution under agitation for the formation of the inclusion complex by coprecipitation;

[0049] Vacuum filtration of the previous solution yields an inclusion complex filtrate and a solid residue. Preferably, this filtration is carried out using filter paper with a pore size of 0.45 µm;

[0050] freezing the inclusion complex at at least -80°C for at least 24 hours; dehydrating the frozen inclusion complex by freeze-drying at a temperature of at least -45°C and under vacuum pressure for at least three days, obtaining an encapsulated additive; and

[0051] agitation of a vegetable oil with the encapsulated additive obtained in the previous stage to obtain an additive-enhanced vegetable oil, where the concentration of the additive-enhanced vegetable oil is 1 g of additive per liter of vegetable oil.

[0052] The main advantage of forming the inclusion complex through coprecipitation followed by dehydration via lyophilization as a synthesis method is the low cost and simplicity of the first stage, based on conventional stirring, compared to other methods such as those based on ultrasound, which require expensive equipment and highly qualified personnel. It is also important to highlight that this method is easily scalable and commonly used in industry for other purposes. Furthermore, since no heat is applied during the drying stage, the active ingredient (thymol and eugenol) does not undergo degradation, thus maintaining its physicochemical properties.

[0053] Freeze-drying (lyophilization) has the advantage of preserving the characteristics of heat-sensitive compounds because the process involves freezing the sample and then sublimating the water under vacuum, thus avoiding heating and degradation of heat-sensitive compounds such as essential oils. Furthermore, biological activity is better preserved due to minimal heat exposure, and it produces particles of uniform size and controlled morphology. The porous structure resulting from the sublimation process can improve rehydration and the controlled release of the encapsulated compound. Another advantage is its versatility in terms of formulation and its suitability for a wide range of compounds. Methods based on spray-drying were mentioned in the background section.While this method is fast and economical, it involves the loss of volatile compounds such as essential oils due to the high temperatures used during the process. This can lead to thermal degradation of some compounds due to heat exposure during spray-drying, resulting in products encapsulated using this method exhibiting lower biological activity and chemical stability during processing.

[0054] In the process of obtaining the additive vegetable oil, the additives are incorporated and homogenized into the vegetable oil preferably with a propeller agitator at 1200 W, for 5 minutes at a concentration of 1 g / L.

[0055] The advantages of adding the encapsulated ingredients to vegetable oil are as follows:

[0056] It can be applied to any vegetable oil, so it is not exclusive to one type of oil.

[0057] The encapsulation dose: oil allows for a reduction in the economic cost of the product and will be unique for each type of oil.

[0058] The homogenization method is very simple, already commercially available, and does not require highly qualified personnel to obtain the enriched frying oil.

[0059] Additive oils maintain their physicochemical properties.

[0060] Therefore, the present invention comprises obtaining vegetable frying oils for the reduction of acrylamide concentration in potatoes in flakes or sticks and cooked in a pan or fryer, on a laboratory or industrial scale, through the addition of an additive based on the encapsulation in p-cyclodextrins of the monoterpenes mayohtahos in thyme- Thymus vulgaris (thymol) and in cavo- Syzygium aromaticum (eugenol).

[0061] BRIEF DESCRIPTION OF THE FIGURES To complement the description being made and in order to help a better understanding of the characteristics of the invention, a set of figures is included as an integral part of said description, in which, for illustrative and non-limiting purposes, the following has been represented:

[0062] Figure 1 Diagram showing vegetable oils subject to the invention with the synthesized additives to reduce the concentration of achlamide in potato chips according to two preferred embodiments of the invention and with two alternative procedures that allow arguing the advantages of the present invention over them, where AV refers to 'Vegetable Oil' and IIACD to the additive with which it is enriched.

[0063] Figure 2.- Shows the synthesis method, inclusion complex plus freeze-drying, of the additive UACD-2 (P-cyclodextrins with encapsulated thymol) according to a first embodiment of the object of the invention.

[0064] Figure 3.- Shows the synthesis method, inclusion complex plus freeze-drying, of the additive UACD-3 (P-cyclodextrins with encapsulated eugenol) according to a second embodiment of the object of the invention.

[0065] Figure 4.- Shows an alternative synthesis method, based on obtaining an inclusion complex plus spray drying of the additive UACD-6 (P-cyclodextrins with encapsulated thymol).

[0066] Figure 5.- Shows an alternative synthesis method, based on obtaining an inclusion complex plus spray drying, of the additive UACD-7 (P-cyclodextrins with encapsulated eugenol).

[0067] Figure 6.- Reaction that takes place during the synthesis process of the additive with thymol according to the procedure of the present invention.

[0068] Figure 7.- Reaction that takes place during the synthesis process of the additive with eugenol, according to the procedure of the present invention.

[0069] Figure 8.- Schematic of the additive / enrichment process with the synthesized additives by means of inclusion complex and lyophilization to a vegetable oil and subsequent homogenization. Finally, the additive-enhanced vegetable oil (AV-UACD-) is shown.

[0070] Figure 9.- Morphology and surface determined by scanning electron microscopy (SEM) with magnifications of x250 (top row) and x5000 (bottom row) for the additives obtained according to the procedure of the invention and labelled as UACD-2 and UACD-3.

[0071] Figure 10. Thermogravimetric analysis (TGA) and its derivative (DTG) showing the mass loss with temperature for unencapsulated thymol. The data series represent: (solid line) the mass loss of thymol with temperature, (dashed line) the first derivative of the mass loss of thymol with temperature. The x-axis represents temperature in °C, the left y-axis mass in mg, and the right y-axis DTG in mg / s.

[0072] Figure 11. Thermogravimetric analysis (TGA) and its derivative (DTG) showing the mass loss with temperature for unencapsulated eugenol. The data series represent: (solid line) the mass loss of eugenol with temperature, (dashed line) the first derivative of the mass loss of eugenol with temperature. The x-axis represents temperature in °C, the left y-axis mass in mg, and the right y-axis DTG in mg / s.

[0073] Figure 12.- Thermogravimetric analysis (TGA) and its derivative (DTG) for sample UACD-2. The data series represent: (long dashes) is the TGA of additive UACD-2, while (solid line) is the DTG of additive UACD-2. The x-axis represents temperature in °C, the left y-axis represents mass in mg, and the right y-axis represents DTG in mg / s.

[0074] Figure 13.- Thermogravimetric analysis (TGA) and its derivative (DTG) for the UACD-3 sample. The data series represent: (long dashes) is the TGA of the UACD-3 additive, while (solid line) is the DTG of the UACD-3 additive. The abscissa axis represents the temperature in °C, the left ordinate axis represents the mass in mg, and the right ordinate axis represents the DTG in mg / s.

[0075] Figure 14.- Differential scanning calorimetry (DSC) for the UACD-2 and unencapsulated thymol samples. The data series represent: (solid line) is the heat flux for unencapsulated thymol, while (dashed line) is the heat flux for the UACD-2 additive. The x-axis represents the temperature in °C, while the y-axis represents the heat flux in mW.

[0076] Figure 15.- Differential scanning calorimetry (DSC) for the UACD-3 and unencapsulated eugenol samples. The data series represent: (solid line) is the heat flux for unencapsulated eugenol, while (dashed line) is the heat flux for the UACD-3 additive. The x-axis represents the temperature in °C, while the y-axis represents the heat flux in mW.

[0077] DETAILED EXPOSURE OF MODES OF REALIZATION

[0078] Based on the configuration examples shown in the figures, specific, non-limiting ways of realizing the configuration will be described.

[0079] According to a first embodiment of the invention illustrated in Figure 2, a first additive is prepared by dissolving 10.206 g of p-cyclodextrins in 30 mL of distilled water using magnetic stirring. This is the first solution. Separately, 1.352 g of the monoterpene thymol are dissolved in 5 mL of ethanol using magnetic stirring. This is the second solution. The second solution is added dropwise to the first solution on a magnetic stirrer, covered with aluminum foil, and magnetic stirring is maintained for 24 h. The solution is then vacuum-filtered using filter paper with a pore size of 0.45 mm. The solution is then stored in a freezer at -80°C for 24 h. Finally, the first additive is lyophilized at -45°C under vacuum for 3 days. This first additive is named UACD-2.

[0080] In a second embodiment of the invention, a second additive is prepared by dissolving 10.206 g of p-cyclodextrins in 30 mL of distilled water using magnetic stirring. This is the first solution. Separately, 1.478 g of the monoterpene eugenol is dissolved in 5 mL of ethanol using magnetic stirring. This is the second solution. The second solution is added dropwise to the first solution on a magnetic stirrer, covered with aluminum foil, and magnetic stirring is maintained for 24 h. The solution is then vacuum-filtered using filter paper with a 0.45 µm pore size. The resulting solution is then stored in a freezer at -80°C for 24 h. Finally, the second additive is lyophilized at -45°C under vacuum for 3 days. This second additive is named UACD-3.To demonstrate the improved results obtained using the procedure of the present invention, based on the formation of an inclusion complex followed by freeze-drying, compared to other alternative techniques disclosed in the prior art, a third additive is prepared. In this first solution, 10.206 g of p-cyclodextrins are dissolved by magnetic stirring in 30 mL of distilled water. Separately, 1.352 g of the monoterpene thymol are dissolved by magnetic stirring in 5 mL of ethanol. This is the second solution. On a magnetic stirrer, the second solution is added dropwise to the first solution, covered with aluminum foil, and magnetic stirring is maintained for 24 h.Subsequently, the solution is atomized using a mini spray dryer at an injection temperature of 120°C, 100% aspiration and a vacuum pressure of 20%, obtaining the encapsulated additive, which is assigned the label UACD-6.

[0081] This alternative atomization-based procedure was followed to prepare a fourth additive containing eugenol. For this, 10.206 g of p-cyclodextrins were dissolved by magnetic stirring in 30 mL of distilled water. This is the first solution. Separately, 1.478 g of the monoterpene eugenol were dissolved by magnetic stirring in 5 mL of ethanol. This is the second solution. On a magnetic stirrer, the second solution was added dropwise to the first solution, covered with aluminum foil, and magnetic stirring was maintained for 24 h. Subsequently, the solution was atomized using a mini-spray dryer at an injection temperature of 120°C, 100% aspiration, and a vacuum pressure of 20%, obtaining the encapsulated additive, which was assigned the label UACD-7.

[0082] Using these additives, a virgin olive oil was enriched, and a series of potato cooking experiments were conducted. The procedure for cooking French fries includes the following variables: cooking method, potato variety, type of oil, cut, temperature, and cooking time.

[0083] Example 1

[0084] In a practical example of frying using an embodiment of the present invention, 500 mL of commercial virgin olive oil are placed in a 26 cm forged aluminum frying pan and heated on an induction hob to 180°C. Once the operating temperature is reached, 50 g of commercial frozen potatoes are added and fried for 3 minutes. The excess oil is then removed with absorbent paper.

[0085] The same procedure is followed for the different oils, in accordance with the described embodiments of the present invention and the proposed alternative methods that yield inferior results. First, the oils are prepared by homogenizing 0.5 g of additive (UACD-2, UACD-3, UACD-6, and UACD-7) with 500 mL of virgin olive oil, as shown in Figure 8. The final concentration was 1 g of additive / 1 L of oil. Then, the oils are individually fried at 180°C for 3 minutes.

[0086] The quantification of acrylamide concentration in potato chips was performed using high-performance liquid chromatography coupled with a diode array detector (HPLC-DAD), following an extraction step. The extraction step consisted of placing 4 g of crushed and homogenized potato chips into a centrifuge tube with 20 mL of ultrapure water, vortexing for 10 minutes, and centrifuging for 15 minutes at 4500 rpm. Finally, the samples were filtered into a vial using a 0.45 µm PTFE filter. The HPLC conditions were as follows: C18 column, mobile phase composed of a 0.1% aqueous solution of formic acid (A) and acetonitrile (B) with a constant gradient of A = 99% and B = 1%, injected volume of 60 pL, flow rate of 0.7 mL / min, constant column temperature of 25°C, and a detection wavelength of 210 nm. The calibration curve is performed using a pure acrylamide standard.

[0087] Based on the data shown in Table 1 from the frying experiment with the different oils proposed in this invention, it can be concluded that a partial reduction of acrylamide concentration is achieved in ultra-frozen French fries cooked for 3 minutes. Following this example, the additive consisting of eugenol encapsulated by inclusion and freeze-drying in p-cyclodextrins can be considered the most effective, with a reduction of 97.6%. TABLE 1

[0088] Variation of acrylamide concentration for the different virgin olive vegetable oils with additives synthesized from encapsulation processes (AV-UACD-2: p-cyclodextrins with thymol encapsulated by inclusion complex and freeze-dried, AV-UACD-3: p-cyclodextrins with eugenol encapsulated by inclusion complex and freeze-dried, AV-UACD-6: p-cyclodextrins with thymol encapsulated by inclusion complex and spray-dried and AV-UACD-7: p-cyclodextrins with eugenol encapsulated by inclusion complex and spray-dried) compared to the vegetable oil without additives (AV) for a frying time of 3 minutes.

[0089] Sample [Acrylamide] (g / kg) % Reduction AV 615.14

[0090] AV-UACD-2 124.15 79.8

[0091] AV-UACD-3 14.52 97.6

[0092] AV-UACD-6 455,38 26,0

[0093] AV-UACD-7 423,85 31,1

[0094] Example 2

[0095] In a second practical example of frying using an embodiment of the present invention, 500 mL of commercial virgin olive oil are placed in a 26 cm forged aluminum frying pan and heated on an induction hob to 180°C. Once the working temperature is reached, 50 g of commercial frozen potatoes are added and fried for 5 minutes. The excess oil is then removed with absorbent paper.

[0096] The same procedure is followed for the different oils covered by the present invention. First, the oils are prepared by homogenizing 0.5 g of additive (UACD-2, UACD-3, UACD-6, and UACD-7) with 500 mL of virgin olive oil, as shown in Figure 9. The final concentration was 1 g of additive / 1 L of oil. Then, each oil is individually fried at 180°C for 5 minutes.

[0097] The quantification of acrylamide concentration in potato chips was performed using high-performance liquid chromatography coupled with diode array detection (HPLC-DAD), following an extraction step. The extraction step consisted of placing 4 g of crushed and homogenized potato chips into a centrifuge tube with 20 mL of ultrapure water, vortexing for 10 minutes, and centrifuging for 15 minutes at 4500 rpm. Finally, the samples were filtered into a vial using a 0.45 µm PTFE filter. The HPLC equipment conditions were as follows: C18 column, mobile phase composed of a 0.1% aqueous solution of formic acid (A) and acetonitrile (B) with a constant gradient of A = 99% and B = 1%, injected volume of 60 pL, flow rate of 0.7 mL / min, constant column temperature of 25°C, and detection wavelength of 210 nm. The calibration curve was performed using a pure acrylamide standard.

[0098] Based on the data shown in Table 2 of the frying experiment with the different oils proposed in this invention, it can be concluded that there is a considerable increase in acrylamide concentration in potatoes fried with oil without additives, and that a partial reduction is achieved in frozen potatoes fried for 5 minutes. Following this example, the additive consisting of thymol encapsulated by inclusion and freeze-drying in p-cyclodextrins can be considered the most effective, with a reduction of 92.3%. TABLE 2

[0099] Variation of acrylamide concentration for the different virgin olive vegetable oils with additives synthesized from encapsulation processes (AV-UACD-2: p-cyclodextrins with thymol encapsulated by inclusion complex and freeze-dried, AV-UACD-3: p-cyclodextrins with eugenol encapsulated by inclusion complex and freeze-dried, AV-UACD-6: p-cyclodextrins with thymol encapsulated by inclusion complex and spray-dried and AV-UACD-7: p-cyclodextrins with eugenol encapsulated by inclusion complex and spray-dried) compared to the vegetable oil without additives (AV) for a frying time of 5 minutes.

[0100] Sample [Acrylamide] (g / kg) % Reduction AV 1523.46

[0101] AV-UACD-2 117.68 92.3

[0102] AV-UACD-3 349,82 77,0

[0103] AV-UACD-6 1137.34 25.3

[0104] AV-UACD-7 1121,98 26,4

[0105] On the other hand, after the synthesis of the different additives that are the subject of the present invention UACD-2, UACD-3, a characterization of particles is carried out to know the influence of the encapsulation method, as well as the drying method on properties such as particle size, Z potential, morphology and thermal stability.

[0106] Analysis of particle size and zeta potential using dynamic light scattering (DLS).

[0107] First, it's important to note that a larger particle size results in lower physical stability, solubility, and bioavailability. Furthermore, its release will be slower due to the smaller surface area relative to volume compared to smaller molecules. It's also important to highlight that smaller particles tend to remain in suspension longer, making them more stable in suspension and thus improving the overall stability of the formulation.

[0108] Regarding the zeta potential, it's important to note that it measures the surface electrical charge of particles in a suspension and provides relevant information for understanding the suspension's stability. A higher zeta potential indicates greater electrostatic repulsion between particles, which generally leads to greater colloidal stability.

[0109] As can be seen in Table 3, the additives have particle sizes ranging from 371-622 nm, with UACD-3 having the smallest particle size (371 nm), which could indicate better solubility and bioavailability compared to the others.

[0110] Regarding the zeta potential, it should be noted that they are all negative, between -47.0 and -56.8 mV, with the UACD-3 additive having the most negative zeta potential (-56.8 mV), which indicates greater colloidal stability due to the greater electrostatic repulsion between the particles.

[0111] It can be concluded that, for the proposed essential oils, encapsulation using an inclusion complex followed by freeze-drying produces smaller and more uniform particles. It also achieves better dispersion and colloidal stability. This is due to the effective formation of the complex and the preservation of its structure during freeze-drying, as well as improved distribution of the essential oil and the protection provided by the cyclodextrins. However, additives encapsulated by physical mixing exhibit a lower surface charge, are less colloidally stable, and have a greater tendency to form aggregations, thus promoting particle growth.

[0112] TABLE 3

[0113] Particle size and Z potential of the UACD-2, UACD-3 additives prepared according to the object of the present invention.

[0114] Sample Particle size (nm) Zeta potential (mV)

[0115] UACD-2 594 -54.6

[0116] UACD-3 371 -56.8

[0117] Analysis of surface morphology and distribution using scanning electron microscopy (SEM).

[0118] Figure 9 shows the surface determined by scanning electron microscopy with magnifications of x250 (top row) and x5000 (bottom row) for the additives UACD-2 and UACD-3. As can be seen, the UACD-2 sample presents small and uniform particles, with a well-defined structure and little aggregation, indicating efficient encapsulation and stability of the essential oil thymol.

[0119] For those encapsulated with eugenol essential oil, it is important to note that, similar to what was obtained for the encapsulation of thymol, the additive UACD-3 presents small, uniform and stable particles, indicating an efficient encapsulation of eugenol.

[0120] It should be noted that the results are in agreement with the conclusions presented for particle size and zeta potential, showing how different encapsulation methods influence the physicochemical and morphological properties of the additives.

[0121] Analysis of thermal stability by thermogravimetric analysis with differential scanning calorimetry (TGA / DSC).

[0122] To complete the characterization of the proposed additives for the additive-enhanced vegetable oils of the invention, Figures 10 to 13 show the data obtained for the analysis of thermal stability by thermogravimetric analysis with differential scanning calorimetry.

[0123] Figures 10 and 11 show the mass loss with temperature for unencapsulated thymol (Figure 10) and eugenol (Figure 11). In the case of thymol, thermal degradation begins at 75°C, and by 175°C, no thymol is detectable, indicating 100% degradation. For eugenol, this occurs at 100°C and is complete at 210°C, demonstrating that this essential oil is more stable than thymol.

[0124] However, after an encapsulation process using the method proposed in this patent, both thymol and eugenol are protected by the p-cyclodextrin cavity, as can be seen in Figures 12 and 13. This indicates that both encapsulations work correctly, protecting the essential oil from thermal degradation, so that they will be stable at the temperature during frying processes.

[0125] Regarding differential scanning calorimetry (DSC) analysis, this technique involves measuring the heat difference by increasing the sample temperature, while the reference temperature is measured as a function of that temperature, providing information on whether an exothermic or endothermic process is occurring. As can be seen in Figures 14 and 15, thymol undergoes two endothermic processes (at 60°C and 170°C), while eugenol exhibits only one endothermic peak (at 210°C). It is worth noting that, at these temperatures, the encapsulated complexes do not exhibit these endothermic processes, demonstrating high thermal stability. This finding confirms the results obtained in the thermogravimetric analysis.

Claims

CLAIMS 1 a - Process for obtaining an additive-enhanced vegetable oil for frying carbohydrate-rich foods, comprising the following steps: preparation of a first solution of p-cyclodextrins with water by stirring; preparation of a second solution by mixing thymol monoterpene or eugenol monoterpene in ethanol; pouring the second solution drop by drop onto the first solution under agitation for the formation of the inclusion complex by coprecipitation; vacuum filtration of the previous solution, obtaining an inclusion complex filtrate and a solid residue; freezing the inclusion complex at at least -80°C for at least 24 hours; dehydrating the frozen inclusion complex by lyophilization at a temperature of at least -45°C and under vacuum pressure for at least three days, obtaining an encapsulated additive; and agitation of a vegetable oil with the encapsulated additive obtained in the previous stage to obtain an additive-enhanced vegetable oil, where the concentration of the additive-enhanced vegetable oil is 1 g of additive per liter of vegetable oil; so that in the frying of carbohydrate-rich foods at temperatures between 175°C and 190°C, the concentration of acrylamide present in the fried food is reduced by at least 77% compared to the acrylamide produced in frying processes with non-additive vegetable oils. 2 a - Process for obtaining an additive-enhanced vegetable oil, according to claim 1 a , characterized in that the first solution includes 10.206 g of p-cyclodextrins in 30 mL of water while the second solution includes 1.352 g of thymol monoterpene dissolved in 5 mL of ethanol. 3 a - Process for obtaining an additive-enhanced vegetable oil, according to claim 1 a, characterized in that it includes 10.206 g of p-cyclodextrins in 30 mL of water while the second solution includes 1.478 g of eugenol monoterpene dissolved in 5 mL of ethanol. 4 a - Process for obtaining an additive-enhanced vegetable oil, according to claim 1 a , characterized in that the agitation of the vegetable oil with the additive is carried out with a propeller agitator at 1200 W for 5 minutes.

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