Method for obtaining an emulgel and emulgel obtained using said method

Abstract

The present invention relates to a method for producing a clean label and healthy emulgel using mandarin bagasse as the only structuring agent, the mandarin bagasse being generated as a by-product of the juice manufacturing industry. The invention relates to a physical homogenisation process that improves the structuring properties of mandarin bagasse. The invention also relates to the emulgel obtained which is capable of substituting the solid fats commonly used in the food industry. This emulgel consists of an oil fraction formed by sunflower vegetable oil representing between 30% and 40% and an aqueous phase containing the mandarin bagasse in turn representing 6% of the emulgel. The properties and composition of this emulgel also allow foods formulated therefrom to be labelled as clean label products.

Description

[0001] PROCEDURE FOR OBTAINING AN EMULGEL AND EMULGEL OBTAINED BY SAID PROCEDURE.

[0002] OBJECT OF THE INVENTION

[0003] The present invention describes a process for obtaining an emulgel, which can be labeled as healthy or clean label, using mandarin pulp, a byproduct of the juice industry, as a structuring agent. The process for obtaining the emulgel includes steps to improve the structuring properties of the mandarin pulp through a physical homogenization treatment.

[0004] The present patent also covers the emulgel itself obtained by said procedure, which is capable of replacing solid fats, commonly used in the food industry, and which also allows foods formulated with these emulgels to be labelled as healthy or clean label.

[0005] Specifically, the procedure for obtaining the emulgel consists of structuring a liquid oil, such as sunflower oil, which has a high content of unsaturated fatty acids and, therefore, a high nutritional quality, using only the by-product, mandarin pomace, from the juice manufacturing industry, as a structuring agent.

[0006] To improve its emulsifying and stabilizing properties, this pomace undergoes a physical homogenization treatment before being incorporated into the emulgel. The resulting emulgel consists of an aqueous phase containing the homogenized mandarin pomace and an oil phase made up of sunflower oil. It can replace the solid fats commonly used in the food industry, which are characterized by a high content of saturated fatty acids with low nutritional value.

[0007] In addition to being healthy, the developed emulgel, unlike other emulsions and other types of structured oils, contains no additives; therefore, it is clean label and can be used for the formulation of clean label foods. BACKGROUND OF THE INVENTION

[0008] The use of solid fats is common in the food industry because they provide foods with desirable textural properties, a pleasant mouthfeel, structural integrity, and an extended shelf life. These properties make them widely used in the frying, confectionery, bread, and pastry industries, among others. However, excessive consumption of these fats, characterized by their high saturated fatty acid content, is linked to increased levels of LDL cholesterol in the blood and an increased risk of cardiovascular disease, obesity, type 2 diabetes, and metabolic syndrome, among other conditions.Replacing these solid fats with healthier liquid oils, consisting mainly of mono- and polyunsaturated fatty acids, represents a technological challenge for the food industry, since the textural, sensory and stability properties (both physical and oxidative) of food can be negatively affected.

[0009] To give vegetable oils, which are liquid at room temperature, properties similar to those of solid fats, they have traditionally been subjected to chemical reactions such as hydrogenation and isomerization. In these reactions, the unsaturated fatty acids that make up the liquid oils undergo chemical modifications, such as the addition of hydrogen atoms to the double bonds or the isomerization of C-S double bonds (those present in natural fatty acids) to trans bonds. This results in fats with a more solid consistency capable of mimicking the physicochemical and sensory properties of industrial solid fats. These methods have several drawbacks, including the generation of saturated and / or trans fatty acids, high cost, and the loss of nutritional properties in the oils.

[0010] An alternative to using solid fats and those obtained by chemical methods is the structuring of liquid oils to obtain systems with solid-like behavior. Oil structuring allows for the creation of network structures similar to those of a gel, with the mechanical properties of a solid. Its main advantage is that it does not alter the chemical structure of the unsaturated fatty acids that make up the liquid oils. Some examples of structured oils are oleogels, high internal phase emulsions, and emulgels. Oleogels are gelled structures composed mainly of oils (>90%) and one or more gelling agents, primarily additives. High internal phase emulsions are defined as emulsions with a concentration of more than 74% oil (internal phase) dispersed as droplets within a continuous phase, consisting of water and structuring agents.Emulgels are composed of oils, structuring agents, and water. Unlike other types of structured oils, emulgels contain a lower oil content and a higher proportion of water, yet they can still mimic the properties of solid fats, just like oleogels and high-internal-phase emulsions. Emulgels can lead to healthier food formulations (like other types of structured oils), and by increasing the water content, they reduce fat intake without compromising the sensory quality of the food.

[0011] Son conocidos los documentos de Círstea, N., Nour, V., Corbu, A. R., Muntean, C., & Codiná.G. G., 2023 [Reformulation of Bologna Sausage by Total Pork Backfat Replacement with an Emulsion Gel Based on Olive, Walnut, and Chia Oils, and Stabilized with Chitosan. Foods, 12(18), 3455]; Curtí, E., Federici, E., et al., 2018 [Structured emulsions as butter substitutes: effects on physicochemical and sensory attributes of shortbread cookies. Journal of the Science of Food and Agriculture, 98(10), 3836-3842]; Fontes-Candia, C., Strom, A., Lopez- Sanchez, P., Lopez-Rubio, A., & Martinez-Sanz, M., 2020 [Rheological and structural characterization of carrageenan emulsion gels. Algal Research, 47, 101873]; Freire, M., Cofrades, S., et al., 2018 [Emulsion gels containing n-3 fatty acids and condensed tannins designed as functional fat replacers. Food Research International, 113, 465-473]; Pintado, T., Herrero, A. M., et al., 2016 [Effects of emulsion gels containing bioactive compounds on sensorial, technological, and structural properties of frankfurters. Food Science and Technology International, 22(2), 132-145]; Poyato, C., Ansorena, D., Berasategi, I., Navarro-Blasco, í., & Astiasarán, I., 2014 [Optimization of a gelled emulsion intended to supply UJ-3 fatty acids into meat products by means of response surface methodology. Meat Science, 98(4), 615-621]; which disclose different types of emulsifiers used primarily to replace or reduce animal fat such as butter or pork fat in various products such as cookies, sausages, or other meat products.These emulsifiers have been developed using various structuring agents as emulsifiers, stabilizers, and / or gelling agents widely recognized and used by the food industry, such as soy or whey protein isolates, sodium alginate (E-401), carrageenan (E-407), sodium caseinate, bovine gelatin, pyrophosphate (E-450), polysorbate (E-433), or calcium sulfate (E-516). Some of these structuring agents are food additives, while others are not. However, none of the emulsifiers developed use food industry byproducts as the sole structuring agent. The present invention develops emulsifiers using a byproduct from the mandarin juice industry, previously subjected to a physical homogenization treatment, to improve its structuring properties.Obtaining these emulgels using this mandarin byproduct allows for both clean-label products and adding value to these industry byproducts. Mandarin pulp, subjected to the physical homogenization treatment, is a valuable source of antioxidant compounds, such as carotenoids, which are essential in preventing certain diseases, including cardiovascular disease, neurodegenerative processes, and cellular aging.

[0012] In the prior art, various methods for obtaining emulgels have been described. Freire, M., Cofrades, S., et al., in their article "Emulsion gels containing n-3 fatty acids and condensed tannins designed as functional fat replacers," Food Research International, 113, 465-473 (Freire et al., 2018), describe a method for preparing emulgels based on heat-induced gelation. First, they prepared emulsions with sodium caseinate, whey protein isolate, or soy protein isolate. Subsequently, these emulsions were gelled at 80°C by adding κ-carrageenan, gelatin, and transglutaminase. Poyato, C., Ansorena, D., Berasategi, I., Navarro-Blasco, í., & Astiasarán, I. in their article Optimization of a gelled emulsion intended to supply UJ-3 fatty acids into meat products by means of response surface methodology. Meat Science, 98(4), 615-621 (Poyato et al., 2014), Fontes-Candia, C., Strom, A., Lopez-Sanchez, P., López-Rubio, A., & Martinez-Sanz, M.In their article "Rheological and structural characterization of carrageenan emulsion gels," Algal Research, 47, 101873 (Fontes-Candia et al., 2020), and in their article "Emulsion gel enriched with a barley β3-glucan concentrate for reducing saturated fat in biscuits," Food Hydrocolloids, 145, 109163 (Sereti et al., 2023), Sereti et al. also produced emulgels by thermogelation at 70°C, 90°C, and 60°C, respectively. In contrast, the invention proposed herein is achieved using the cold gelation technique, as the emulsion is obtained at room temperature (20-25°C) and then refrigerated to complete the gelation process and thus obtain an emulgel.This cold process has certain advantages over heat-induced gelation, since, on the one hand, it prevents the degradation of the heat-labile antioxidant compounds present in the mandarin byproduct and, on the other hand, it prevents premature oxidation of the oil, thus preventing the formation of compounds harmful to health and extending the shelf life of the emulgel. The cold gelation process has been previously reported by Círstea, N., Nour, V., Corbu, AR, Muntean, C., & Codiná, GG in their article "Reformulation of Bologna Sausage by Total Pork Backfat Replacement with an Emulsion Gel Based on Olive, Walnut, and Chia Oils, and Stabilized with Chitosan." Foods, 12(18), 3455 (Círstea et al., 2023), and by Curtí, E., Federici, E., et al. in his article Structured emulsions as butter substitutes: effects on physicochemical and sensory attributes of shortbread cookies. Journal of the Science of Food and Agriculture, 98(10), 3836-3842 (Curtí et al., 2018) and by Pintado, T., Herrero, AM, et al. in their article "Effects of emulsion gels containing bioactive compounds on sensorial, technological, and structural properties of frankfurters." Food Science and Technology International, 22(2), 132-145 (Pintado et al., 2016). In these cases, the emulsifying and gelling agents were also obtained at room temperature and stored under refrigeration; however, these emulsifying and gelling agents were prepared using emulsifying and gelling agents such as soy protein isolate, chitosan, microbial transglutaminase, commercial preparations of vegetable fibers, and additives such as sodium alginate (E-401), pyrophosphate (E-450), or calcium sulfate (E-516). These emulsifying and gelling agents used (alone or in combination) to obtain emulsifying and gelling agents are, in some cases, food allergens and, in others, considered food additives. In the specific case of the commercial preparation of vegetable fibers used by Curtí, E.Federici, E., et al., in their article "Structured emulsions as butter substitutes: effects on physicochemical and sensory attributes of shortbread cookies," Journal of the Science of Food and Agriculture, 98(10), 3836-3842 (Curtí et al., 2018), described how these fibers underwent conditioning processes that eliminated a large portion of the compounds present in the original byproducts, such as bioactive compounds, and generated new residues. These ingredients and food additives make it difficult to achieve clean labeling for products formulated with the resulting emulsifiers. In contrast to these emulsifiers, the present invention uses only homogenized mandarin pulp, an industrial byproduct that does allow for clean labeling of products formulated with this emulsifier.

[0013] Patent document WO2023156691 A1, relating to the manufacturing process of a spreadable solid fat obtained from an emulsion, the resulting spreadable solid fat, and its use, discloses the manufacturing process of a spreadable solid fat from an emulsion, specifically a high internal phase emulsion with a lipid fraction exceeding 74%. This emulsion, which structures high-quality nutritional vegetable oils, is made with structuring agents considered food additives, such as hydroxypropyl methylcellulose (E-464), sodium alginate (E-401), and carrageenan (E-407). Therefore, the resulting spreadable solid fat would not qualify for clean labeling because it is formulated from an emulsion structured with additives, unlike the one developed in the present invention, which is an emulgel structured with homogenized mandarin pomace.

[0014] Martínez-Martí, J., Quiles, A., Moraga, G., Llorca, E., & Hernando, I., in their article "High Internal Phase Emulsions Preparation Using Citrus By-Products as Stabilizers," Foods, 11 (7), 994 (Martínez-Martí et al., 2022), prepared emulsions with 80% oil using citrus by-products as stabilizers. These by-products were dried and did not undergo any physical or chemical treatment. In the referenced article, a maximum of 1.25% by-product was used, and the resulting product did not achieve the consistency of an emulgel. In the present invention, the emulgel contains 40% oil, and the proportion of citrus by-product used is 6%. This results in greater utilization of the by-product and a reduction in the fat content of the emulgel.

[0015] Martínez-Martí, J., Panusková, K., et al., in their article "Using different physical treatments to modify the structure and improve the technofunctional properties of clementine by-products," Food Structure, 38, 100346 (Martinez-Marti et al., 2023), used mandarin by-products subjected to a homogenization treatment to prepare emulsions. The homogenization treatment used in that article differs from that used in the present invention. The homogenization protocol used in this invention includes a centrifugation step at a higher speed and for a longer duration than that used in the article.

[0016] In this regard, the article in question describes how fresh pomace undergoes a drying process to obtain powdered pomace. This dried powder is then homogenized. Therefore, the article argues that drying the mandarin pomace before homogenization results in the loss of its bioactive compounds (and antioxidant properties), meaning the final product lacks antioxidant properties.

[0017] As detailed below, in the present invention, fresh bagasse is homogenized directly without prior drying, thus ensuring the preservation of the bagasse's bioactive compounds with antioxidant properties, such as phenolic compounds. Therefore, the present invention yields emulgels with a lower oil content than those found in the literature, structured solely with bagasse, using a higher proportion of bagasse than those found in the literature. These emulgels are therefore healthier than existing ones and can replace solid fats used in the formulation of industrial foods. Foods formulated with these emulgels have antioxidant properties and can be labeled as clean label.

[0018] DESCRIPTION OF THE INVENTION

[0019] The procedure described below resolves the aforementioned problem, as it yields an emulgel of high nutritional quality. This is due both to its sunflower oil content, rich in unsaturated fatty acids, and to the presence of antioxidant compounds, such as carotenoids, components of the mandarin byproduct used as a structuring agent. This emulgel is healthy and clean label because it uses only mandarin pulp, which has undergone a physical conditioning process to enhance its structuring properties, as its structuring agent. Furthermore, this emulgel can replace industrial solid fats, which are rich in saturated fatty acids, allowing foods formulated with it to be labeled as clean label.

[0020] The procedure developed in the present invention requires, first, a conditioning or prior homogenization phase of the mandarin pomace, from the juice obtaining industry, by means of a physical homogenization process, and, a second phase of obtaining an emulgel made with sunflower oil, water and the previously conditioned, homogenized mandarin pomace.

[0021] The invention process therefore involves the following stages:

[0022] First phase of improving the structuring properties of the mandarin bagasse by-product through a physical homogenization treatment, which comprises the following stages:

[0023] - Addition of water to fresh mandarin pomace up to 96% moisture by weight, usually starting from a moisture content of 85% by weight of fresh mandarin pomace.

[0024] Homogenization of the mandarin pomace obtained in the previous phase at a speed of at least 5,800 rpm for at least 5 min using a blade agitator, preferably a food processor.

[0025] - Addition of 96° ethanol in a bagasse:ethanol ratio of 1:2 (v / v).

[0026] - Adjust pH to 7 by adding a NaOH solution, preferably with a NaOH solution concentration of 1 M.

[0027] Homogenization with a propeller stirrer at a speed of 1,010 rpm for at least 30 min.

[0028] Centrifugation at 12,000 xg for at least 15 min for the precipitation of the mandarin bagasse, so that it is subsequently possible to separate the mandarin bagasse from 96° ethanol and water.

[0029] Separation by decantation of 96° ethanol and water from the precipitated mandarin bagasse obtained in the previous stage.

[0030] Removal of the remaining ethanol in the precipitated mandarin bagasse in a hot air oven at a temperature of 60°C until a constant weight is obtained to obtain a dry mandarin bagasse.

[0031] - Crushing the dried mandarin pomace at 10,200 rpm for at least 1 min using a blade agitator, obtaining a homogenized mandarin pomace that retains its antioxidant bioactive compounds.

[0032] Second phase of obtaining an emulgel made from the homogenized mandarin pomace obtained in the previous set of stages, such that said phase comprises the following stages:

[0033] The homogenized mandarin pulp is dissolved in water to obtain the aqueous phase of the emulgel. The resulting emulgel contains 6% by weight of homogenized mandarin pulp relative to its total composition. The solution obtained in this stage will be the aqueous phase of the emulgel. This aqueous phase will represent between 60% (6% pulp and 54% water of the total emulgel) and 70% (6% pulp and 64% water of the total emulgel) of the emulgel.

[0034] - Stirring the aqueous phase obtained in the previous step for at least one hour at a speed of 500 rpm, preferably using a magnetic stirrer. Cooling the aqueous phase to a temperature of 4°C for at least one hour.

[0035] Homogenization of the aqueous phase at a speed of at least 8,000 rpm, preferably using a homogenizer.

[0036] - Addition to the aqueous phase of sunflower oil, where the sunflower oil content is between 30% and 40% of the total emulgel obtained.

[0037] Homogenization of the aqueous-oil phase mixture at a speed of at least 19,000 rpm for 2 min, obtaining an emulsion of homogeneous appearance.

[0038] Cooling the emulsion obtained in the previous stage to a temperature of 4°C for at least 12 h to obtain the emulgel.

[0039] In this regard, it is noteworthy that mandarin pomace, homogenized on its own and in a proportion of 6% (taking into account the total composition of the emulgel obtained) allows obtaining an emulgel with between 30% and 40% sunflower oil of the total weight of the emulgel (taking into account the total composition of the emulgel).

[0040] It is worth noting that the presence of the initial stage of adding water (or hydration) to the fresh bagasse allows obtaining a homogenized mandarin bagasse to be used in the preparation of an emulgel with a higher content of antioxidant bioactives compared to other known emulgels.

[0041] In other words, the addition of water allows the molecules with techno-functional properties that make up mandarin pomace—such as pectins, cellulose, hemicellulose, and proteins—to change their three-dimensional conformation, improving the pomace's water and oil retention capacity and structural properties. This step was not included in the available background information and is vital for obtaining an emulgel with distinct and advantageous properties compared to others already known.

[0042] Thus, the direct homogenization of fresh bagasse, without drying, ensures the preservation of its bioactive compounds, such as phenolic compounds and carotenoids, and therefore its antioxidant properties. In this way, the process of the present invention achieves: energy savings by eliminating the need for initial drying of the bagasse, and the preservation of bioactive compounds, such as the phenolic compounds and carotenoids in the bagasse, which gives the emulgel antioxidant properties.

[0043] The developed procedure offers several advantages. Firstly, it allows for the structuring of a vegetable oil, such as sunflower oil, with a high-quality lipid profile, using mandarin pulp byproduct. The use of homogenized mandarin pulp is economical and sustainable, since these industrial byproducts, generally used for animal feed or as biofuel and often discarded, have a relatively low cost compared to other emulsifiers. Furthermore, their use allows for the valorization of these byproducts within the context of a circular economy.

[0044] On the other hand, the procedure developed to prepare the emulgel does not require high temperatures, thus avoiding chemical modifications of the unsaturated fatty acids that make up the oil and the constituents of the pomace. In this regard, the ethanol removal step requires the application of a temperature of 60°C, which in no way destroys the antioxidant bioactive compounds of the homogenized mandarin pomace.

[0045] This process yields a high-quality emulgel, structured with homogenized mandarin pomace and containing between 30% and 40% sunflower oil by weight. This makes the emulgel rich in unsaturated fatty acids and gives it a high nutritional profile. The emulgel contains approximately 6% pomace by weight, and the sunflower oil ideally comprises 40% by weight. This higher oil percentage allows for a more plastic-like behavior, resulting in a more solid emulgel.

[0046] The bagasse used in the production of emulgels has a high content of antioxidant compounds such as carotenoids. Carotenoids are known for their antioxidant properties and other health benefits (eye protection, immune system support, promotion of cardiovascular health, support of skin health, and potential anti-cancer properties). Developing foods with carotenoid-rich ingredients can confer functional properties to these products, improve their nutritional quality, and provide specific benefits to consumers. It is also important to note that carotenoid absorption can be enhanced when consumed with healthy fats, as they are fat-soluble compounds.Therefore, combining ingredients rich in carotenoids, present in mandarin pulp, with healthy fats (present in sunflower oil), can maximize the absorption of these beneficial compounds in the body.

[0047] Consumers are increasingly demanding products with labels that are less additive-intensive. The use of homogenized mandarin pulp allows the resulting emulgel, as described in this invention, to be labelled as a clean label product.

[0048] It should be noted that the percentage of the various ingredients used to formulate the structured emulgel with homogenized mandarin pomace described in this invention is determined by the structural, textural, and sensory characteristics of the final product, which influence the stability and shelf life of the resulting emulgel. In this regard:

[0049] The amount of liquid sunflower oil retained (between 30% and 40% by weight) in the emulgel of the invention is what minimizes oil loss from the emulgel and, therefore, maximizes its physical stability, maintaining the emulgel's solid characteristics. An increase in the amount of oil results in greater oil loss and, consequently, a loss of physical stability. Conversely, a reduction in the amount of oil compromises the solidity of the resulting emulgels. Decreasing the amount of homogenized mandarin pomace (<6% by weight) in the resulting emulgel leads to greater oil loss, as the aqueous phase is unable to retain the oil present in the emulgel. Furthermore, the aqueous phase loses viscosity, which is essential for the gelation of the resulting emulgel.

[0050] An increase in the amount of homogenized mandarin pomace (>6% by weight) in the resulting emulgel does not allow complete solubilization of the pomace in the aqueous phase, and the emulgel becomes unstable during its production process.

[0051] The use of unhomogenized mandarin pomace does not allow the production of emulsils with solid fat characteristics at room temperature.

[0052] The innovative aspect of this invention lies in the use of mandarin pomace, conditioned through a physical homogenization treatment, as the sole structuring agent for obtaining an emulgel. The manufacturing process is carried out in the order and under the conditions detailed above to achieve a texture similar to that of a solid fat. The objective is to replace the use of solid fats with a high saturated fatty acid profile with vegetable oils that have a high nutritional quality lipid profile and are rich in unsaturated fatty acids.

[0053] Thus, the emulgel of the present invention offers particular physical properties characteristic of solid fats, making this product a suitable and healthy substitute for solid fats at room temperature.

[0054] DESCRIPTION OF THE FIGURES

[0055] To enrich the description that follows and facilitate understanding of the invention's features, examples of its embodiment are included. These examples are presented as an integral part of the description by means of a set of illustrative figures that represent, in an exemplary and non-restrictive manner, the following:

[0056] Figure 1 shows a macroscopic image of the structured emulgel with homogenized mandarin pomace obtained according to the described invention. This emulgel contains 6% homogenized mandarin pomace and 40% sunflower oil.

[0057] Figure 2 shows a macroscopic image of the homogenized mandarin bagasse.

[0058] Figure 3 shows a micrograph, obtained by optical microscopy, of the structured emulgel with homogenized mandarin pomace. The image was obtained using a magnification of 20X.

[0059] Figure 4 shows a macroscopic image of the structured emulgel with dried (non-homogenized) mandarin bagasse (6%) and 40% sunflower oil.

[0060] Figure 5 shows, as an example, a macroscopic image of an emulgel prepared with 6% homogenized mandarin pomace and an oil ratio of 50%, i.e., higher than that of the present invention.

[0061] Figure 6 shows, as an example, a macroscopic image of an emulgel prepared with 5% homogenized mandarin pomace and the same proportion of oil as the present invention.

[0062] Figure 7 shows, as an example, a macroscopic image of an emulgel prepared with 7% homogenized mandarin pomace and the same proportion of oil as the present invention.

[0063] Figure 8 shows a comparison between the macroscopic appearance of an emulgel made with 6% homogenized bagasse previously dried by hot air (A) and the macroscopic appearance of an emulgel made according to the present invention (B).

[0064] PREFERRED EMBODIMENT OF THE INVENTION

[0065] The final composition of the emulgel (expressed as a percentage by weight) according to the preferred embodiment of the invention, which has been structured with homogenized mandarin pomace according to the procedure described in the present invention, is presented in Table 1:

[0066] Table 1. Composition of the structured emulgel with homogenized mandarin pomace in percentage (%).

[0067] Ingredients %

[0068] Sunflower oil 40

[0069] Water 54

[0070] Homogenized mandarin pomace 6

[0071] It is noteworthy that the objective during the development of the invention was to maximize the amount of homogenized mandarin bagasse in order to valorize the maximum amount of this by-product and obtain a texture similar to that of solid fats with a high content of saturated fatty acids.

[0072] The following details the tests performed on the structured emulgel with homogenized mandarin bagasse obtained according to the described invention procedure.

[0073] Specifically, the macroscopic structure, microscopic structure, texture, and physical stability are detailed. The concentration values ​​of carotenoids, antioxidant compounds present in homogenized mandarin pulp, are also included.

[0074] Macroscopic structure of the structured emulgel with homogenized mandarin pomace

[0075] Figure 1 shows the structured emulgel made with homogenized mandarin pulp obtained according to the described invention. The emulgel has a compact and stable structure and a visual firmness similar to that of solid fats at room temperature, such as margarine. Figure 2 shows the homogenized mandarin pulp, which has been physically conditioned by homogenization and is used as a structuring agent.

[0076] Microscopic structure of the structured emulgel with homogenized mandarin pulp

[0077] Figure 3 shows the microstructure of the structured emulgel with homogenized mandarin pomace obtained according to the described invention. Optical microscopy (OM) was used to study its microscopic structure using a Nikon Eclipse 80i optical microscope (Nikon Co., Ltd., Tokyo, Japan) with an integrated FlexaCam C3 camera (Leica Camera AG, Wetzlar, Germany).

[0078] The sample was placed on a glass slide and observed at 20X, and the image was captured and stored at 1024 x 1024 pixels using LAS X microscope software (Leica Camera AG, Weztlar, Germany).

[0079] The micrograph (Figure 3) shows the arrangement of the fat globules in the emulgel, which form a dense and homogeneous matrix. The figure reveals a high degree of packing of the fat globules, indicative of good physical stability.

[0080] Texture study of structured emulgel with homogenized mandarin pomace. Texture evaluation was carried out using a back extrusion test with a TA.XT2 texture analyzer equipped with Texture Exponent software (Stable Micro Systems, Godaiming, UK). A flat compression disc with a diameter of 35 mm was inserted into a cylindrical vessel 50 mm in diameter and 75 mm high. The penetration distance was 25 mm and the compression rate was 1 mm / s.

[0081] Seventy grams of structured emulgel made with homogenized mandarin pulp were introduced into the cylindrical vessel. The emulgel had been previously tempered at 20°C for at least 1 hour. From the reverse extrusion test, a force-time curve was obtained, yielding values ​​for firmness (g), consistency (gs), cohesiveness (g), and viscosity index (gs). The values ​​obtained for the textural parameters of the structured emulgel made with homogenized mandarin pulp are shown in Table 2.

[0082] Table 2. Textural parameters obtained for the structured emulgel with homogenized mandarin bagasse obtained according to the described invention procedure:

[0083] Texture parameters

[0084] Firmness (g) 587 (42)

[0085] Consistency (gs) 12.817 (961)

[0086] Cohesiveness (g) -536 (3) Viscosity index (gs) -1.076 (121)

[0087] In Table 2, the figures in parentheses refer to the standard deviation of the measurements.

[0088] Texture is one of the most important parameters in industrial fats. In food formulation, the texture of the fat is crucial for its use, as it influences the final texture of the food and its sensory quality. Some of the solid fats used in the food industry have firmness values ​​ranging from 500 to 800 g. The texture values ​​obtained after the back extrusion test confirm that using homogenized mandarin pulp as the sole structuring agent of the proposed emulgel results in a final emulgel with a texture very similar to that of commercially available products. The emulgel developed as described in this invention could therefore be used in the formulation of healthy and clean-label foods.

[0089] Physical stability of the structured emulgel with homogenized mandarin pomace

[0090] The physical stability of the structured emulgel with mandarin pomace obtained according to the described invention was determined by measuring the oil loss from the emulgel by centrifugation. For this purpose, 1 g of the emulgel was weighed into a 1.5 mL Eppendorf tube. The sample was centrifuged in a 5415R centrifuge (Eppendorf, Hamburg, Germany) at 540 x g for 60 min at 20°C, and the oil released by the emulgel during centrifugation was removed. The oil loss was calculated according to Equation 1:

[0091] Oil loss (%) =((m2-m3)) / ((m2-mi)) x 100

[0092] (Equation 1)

[0093] Where r is the initial mass of the empty Eppendorf tube, m2 is the initial mass of the Eppendorf tube and the sample, and m3 is the mass of the Eppendorf tube and the sample after centrifugation and removal of the released oil.

[0094] The result of the physical stability determination by oil loss was 0.00289 ± 0.00053%. These results demonstrate high physical stability to centrifugation of the structured emulgel with homogenized mandarin pomace obtained according to the described invention. Therefore, the emulgel developed as described in the present invention is stable and can be used in the formulation of healthy and clean-label foods.

[0095] Concentration of carotenoids and phenolic compounds in homogenized mandarin pomace

[0096] The carotenoid content of homogenized mandarin pomace was determined spectrophotometrically at 450 nm, and the phenolic compound content at 765 nm. For carotenoid determination, 1 g of sample was extracted with 100 mL of a hexane:ethanol:acetone solution (50:25:25). A p-carotene in hexane calibration curve was prepared to calculate the carotenoid concentration of the homogenized mandarin pomace. For phenolic compound determination, a 1% HCl extraction solution in 96% ethanol was used. A gallic acid in 96% ethanol calibration curve was prepared to calculate the phenolic compound concentration of the homogenized mandarin pomace.

[0097] The result of the spectrophotometric determination of the carotenoid concentration of homogenized mandarin bagasse was 280 ± 22 mg of p-carotene per 100 g of homogenized mandarin bagasse (on a dry basis).

[0098] The result of the spectrophotometric determination of the concentration of phenolic compounds in homogenized mandarin bagasse was 158 ± 6 mg of gallic acid per 100 g of homogenized mandarin bagasse (on a dry basis).

[0099] The carotenoid and phenolic compound content of homogenized mandarin pulp confirms that it is an excellent source of these bioactive compounds, which have antioxidant properties and the capacity to act as provitamin A (in the case of carotenoids). Using homogenized mandarin pulp as a structuring agent to obtain an emulgel will also impart these antioxidant properties to it. Therefore, homogenized mandarin pulp can be used on its own as a structuring agent to obtain emulgels, but it also contributes antioxidant compounds to the emulgel, making it healthier than other structured emulsions found in the literature that use other ingredients and additives as structuring agents.

[0100] Concentration of carotenoids and phenolic compounds of the structured emulgel with homogenized mandarin pomace

[0101] The carotenoid content of the structured emulgel made with homogenized mandarin pulp was determined spectrophotometrically at 450 nm, and the phenolic compound content at 765 nm. For carotenoid determination, 1 g of sample was extracted with 100 mL of a hexane:ethanol:acetone solution (50:25:25). A p-carotene in hexane calibration curve was prepared to calculate the carotenoid concentration of the homogenized mandarin pulp. For phenolic compound determination, a 1% HCl extraction solution in 96% ethanol was used. A gallic acid in 96% ethanol calibration curve was prepared to calculate the phenolic compound concentration of the homogenized mandarin pulp.

[0102] The result of the spectrophotometric determination of the carotenoid concentration of the structured emulgel with 6% homogenized mandarin bagasse was 6.5 ± 0 mg of p-carotene per 100 g of structured emulgel with homogenized mandarin bagasse (dry basis).

[0103] The result of the spectrophotometric determination of the concentration of phenolic compounds in homogenized mandarin bagasse was 148 ± 0 mg of gallic acid per 100 g of structured emulgel with homogenized mandarin bagasse (on a dry basis).

[0104] Finally, with the aim of demonstrating the inventive effort and innovative character of the present invention, some examples of the preparation of emulgels from bagasse not subjected to the physical treatment of homogenization or with proportions of bagasse and oil different from those established in the present invention and which do not allow a stable emulgel to be obtained are detailed.

[0105] Specifically, it details: a structured emulgel with mandarin bagasse subjected to a conditioning treatment consisting of drying, a structured emulgel with 6% homogenized mandarin bagasse and 50% sunflower oil, a structured emulgel with 5% homogenized mandarin bagasse and 40% sunflower oil, and a structured emulgel with 7% homogenized mandarin bagasse and 40% sunflower oil.

[0106] Structured emulsifier with dried mandarin pulp (not homogenized)

[0107] The procedure for obtaining the structured emulgel with non-homogenized dried mandarin bagasse was as follows:

[0108] The following stages are involved in the experiment procedure:

[0109] Drying stage of mandarin pulp using hot air drying:

[0110] Drying of mandarin pomace at 60°C until constant weight in a hot air drying oven.

[0111] - Grinding the dried mandarin pulp at 10,200 rpm for 1 min using a food processor.

[0112] Step to obtain an emulgel made with dried mandarin pomace, water and sunflower oil:

[0113] A 6% by weight solution of the total composition of the emulgel obtained, made from mandarin pomace dried at 54% by weight of the total composition of the emulgel obtained, and water. The resulting solution will be the aqueous phase of the emulgel obtained and will represent 60% of the emulgel.

[0114] - Stirring the solution (aqueous phase) for 1 hour at a speed of 500 rpm using a magnetic stirrer plate.

[0115] Cooling the solution to 4°C for at least 1 h.

[0116] - Stirring the aqueous phase of the emulgel at 8,000 rpm using a homogenizer.

[0117] - Addition to the aqueous phase of 40% by weight, of the total composition of the emulgel obtained, of sunflower oil.

[0118] - Stirring the aqueous phase and the oil in a homogenizer at 19,000 rpm for 2 min to obtain an emulsion of homogeneous appearance.

[0119] Cooling the emulsion obtained at a temperature of 4°C for 12 h to obtain the emulgel.

[0120] The final composition of the structured emulgel with non-homogenized dried mandarin pomace was as follows (Table 3):

[0121] Table 3. Sample composition in percentage (%).

[0122] Ingredients %

[0123] Sunflower oil 40

[0124] Water 54

[0125] Dried mandarin pomace (not homogenized) 6

[0126] Figure 4 shows that the resulting emulsion lacks both the consistency and visual firmness of the structured emulgel obtained with homogenized mandarin pulp according to the described invention. This emulsion, obtained with dried (non-homogenized) mandarin pulp, is not suitable for replacing solid fats (at room temperature). Therefore, the homogenization treatment carried out to improve the structuring properties of the mandarin pulp is necessary to obtain an emulgel capable of replacing solid fats.

[0127] Thus, the test carried out to obtain a structured emulgel with dried (non-homogenized) mandarin bagasse allows us to verify that the procedure described in the invention, both for improving the structuring properties of the mandarin bagasse, and for obtaining an emulgel made with the homogenized mandarin bagasse and the percentages required therein, represents an innovative development that provides a surprising effect and is not the result of an obvious alternative for an expert in the area, based on the current available knowledge.

[0128] Structured emulsifier with 6% homogenized mandarin pomace and 50% sunflower oil

[0129] The final composition of the structured emulgel with 6% homogenized mandarin pomace and 50% sunflower oil was as follows (Table 4):

[0130] Table 4. Sample composition in percentage (%).

[0131] Ingredients %

[0132] Sunflower oil 50

[0133] Water 44

[0134] Homogenized mandarin pomace 6

[0135] Figure 5 shows that the resulting emulgel is not structured. It has a high proportion of free oil that was not incorporated into the emulsion during its preparation. This lack of structure prevents the emulgel from having a solid and stable consistency and from being used as a substitute for solid fats. Therefore, exceeding the 40% sunflower oil content proposed in this invention to obtain an emulgel with solid characteristics suitable as a substitute for solid fats is not appropriate.

[0136] Structured emulsifier with 5% homogenized mandarin pomace and 40% sunflower oil

[0137] The final composition of the structured emulgel with 5% homogenized mandarin pomace and 40% sunflower oil was as follows (Table 5):

[0138] Table 5. Sample composition in percentage (%).

[0139] Ingredients %

[0140] Sunflower oil 40

[0141] Water 55

[0142] Homogenized mandarin pomace 5

[0143] Figure 6 shows that, although the resulting emulgel is somewhat structured, it exhibits less consistency than the emulgel proposed in the present invention. While the emulgel obtained according to the described preparation procedure maintains a compact, single-block structure when removed from its container (Figure 1), the emulgel obtained with 5% homogenized mandarin pomace and 40% sunflower oil breaks into several blocks upon removal, making it difficult to handle.

[0144] Therefore, the use of 6% homogenized mandarin pomace has proven necessary to obtain an emulgel capable of replacing solid fats, and the use of a proportion less than 6% of homogenized pomace (such as 5% in this case) does not ensure obtaining an emulgel with the required characteristics.

[0145] Structured emulsifier with 7% homogenized mandarin pomace and 40% sunflower oil

[0146] The final composition of the structured emulgel with 7% homogenized mandarin pomace and 40% sunflower oil was as follows (Table 6): Table 6. Sample composition in percentage (%).

[0147] Ingredients %

[0148] Sunflower oil 40

[0149] Water 53

[0150] Homogenized mandarin pomace 7

[0151] Figure 7 shows that the resulting emulgel is unstructured and lacks consistency compared to the emulgel proposed in the present invention. While the emulgel obtained according to the described preparation procedure maintains a compact, single-block structure when removed from its container (Figure 1), the emulgel obtained with 7% homogenized mandarin pomace and 40% sunflower oil breaks down easily and exhibits syneresis. Therefore, the use of 6% homogenized mandarin pomace has proven essential for obtaining an emulgel capable of replacing solid fats, and using a proportion greater than 6% of homogenized pomace (such as the 7% in this case) does not guarantee obtaining an emulsion with the required characteristics.

[0152] On the other hand, and to demonstrate that the stages and proportions proposed in the present invention cannot be obviously deduced from what is disclosed in the article Martínez-Martí et al., (2023), Figure 8 shows a comparison between the macroscopic appearance of an emulgel (A) prepared according to what is disclosed in the article Using different physical treatments to modify the structure and improve the technofunctional properties of clementine by-products. Food Structure, 38, 100346 (Martinez-Marti et al., 2023) with 6% homogenized bagasse previously dried by hot air and the macroscopic appearance of an emulgel prepared according to the present invention (B).

[0153] Thus, it can be observed that the bagasse contained in the emulgel of Figure 8A does not have sufficient structuring character, while the emulgel of Figure 8B offers high consistency.

Claims

- Procedure for obtaining an emulgel comprising the following phases: - Addition of water to fresh mandarin pomace up to 96% moisture by weight. Homogenization of the mandarin pomace obtained in the previous phase at a speed of at least 5,800 rpm for at least 5 minutes using a blade agitator. - Addition of 96° ethanol in a bagasse:ethanol ratio of 1:2 (v / v). - Adjust pH to 7 by adding a NaOH solution. Homogenization with a propeller stirrer at a speed of 1,010 rpm for at least 30 min. Centrifugation at 12,000 xg for at least 15 min for the precipitation of the mandarin pomace. Separation by decantation of 96° ethanol and water from the precipitated mandarin bagasse obtained in the previous stage. Removal of the remaining ethanol in the precipitated mandarin bagasse in a hot air oven at a temperature of 60°C until a constant weight is obtained to obtain a dry mandarin bagasse. - Crushing the dried mandarin pomace at 10,200 rpm for at least 1 min using a blade agitator, obtaining a homogenized mandarin pomace that retains its antioxidant bioactive compounds. Dissolving the homogenized mandarin pomace in water to obtain the aqueous phase of the emulgel, so that the emulgel obtained has 6% by weight of homogenized mandarin pomace with respect to the total composition of the emulgel obtained. - Stirring the aqueous phase obtained in the previous stage for at least one hour at a speed of 500 rpm. Cooling the aqueous phase to a temperature of 4°C for at least one hour. Homogenization of the aqueous phase at a speed of at least 8,000 rpm. - Addition to the aqueous phase of sunflower oil, where the sunflower oil content is between 30% and 40% of the total emulgel. Homogenization of the aqueous-oil phase mixture at a speed of at least 19,000 rpm for 2 min, obtaining an emulsion of homogeneous appearance. Cooling the resulting emulsion to a temperature of 4°C for at least 12 h for obtaining the emulgel. Where the homogenized mandarin pomace is structured to the sunflower oil, obtaining an emulgel with a content of between 30% and 40% sunflower oil of the total weight of the emulgel, presenting the emulgel carotenoids and phenolic compounds.

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