Process for obtaining sustainable polymer film, plasticising film and related use

Abstract

The present invention aims to describe a process for producing sustainable polymer film reinforced with glutamic acid in commercial starch and pectin matrices. Through the incorporation of glutamic acid, biodegradable polymer films benefit from improved mechanical strength without compromising their natural degradation time in the environment. Furthermore, the present invention relates to a sustainable polymer film reinforced with glutamic acid, obtained by the aforementioned process, as well as the use thereof, most notably in packaging.

Description

PROCESS FOR OBTAINING SUSTAINABLE POLYMERIC FILM, PLASTICIZING FILM AND RELATED USES Field of the Invention

[0001] The present invention falls within the field of chemistry focused on plastic waste. Conventional plastics are known for their long lifespan and resistance to decomposition, leading to long-term environmental damage. The introduction of biodegradable polymers, as an alternative to synthetic plastics for food packaging, emerges as a promising solution. State of the Art

[0002] Conventional plastics, mainly used in food packaging, are known for their long lifespan and resistance to decomposition, which leads to significant environmental damage, particularly in the long term.

[0003] This raises concerns about the problem of plastic pollution, in line with global efforts to promote a circular economy and adopt more sustainable practices, particularly in the food packaging industry, a major user of this type of raw material.

[0004] The introduction of biodegradable polymers as an alternative to synthetic plastics for food packaging and similar products emerges as a promising solution. These polymers offer the advantage of degrading naturally over time, helping to reduce the accumulation of polymer waste and mitigate the adverse environmental impacts associated with conventional plastics.

[0005] A notable advancement in this field is the addition of glutamic acid during the production process of these films. Biodegradable polymers. This strategy aims not only to improve the mechanical and barrier properties of the films, but also to maintain the complete degradability of the materials after disposal. This is because, by incorporating glutamic acid, biodegradable polymer films become more likely to withstand mechanical stress and exhibit characteristics that are pleasing to the desired application, in addition to the ease, since it is a film produced exclusively from organic compounds, of decomposing naturally in the environment, promoting bioassimilation in the soil and reducing its overall toxicity.

[0006] This not only directly addresses the problem of plastic pollution, but also aligns with global efforts to promote a circular economy and adopt more sustainable practices in the food packaging and related industries.

[0007] In addition to the addition of glutamic acid in the production of biodegradable polymer films, there are other solutions to address the problem of pollution caused by plastic waste. Some of these solutions include: • Plastic recycling: Recycling is a common practice to reduce the amount of plastics discarded in landfills or the environment. However, the effectiveness of recycling depends on adequate infrastructure, community participation, and economic viability. Many types of plastics are difficult to recycle or require complex processes, which can limit their recyclability. • Bioplastics: In addition to biodegradable polymers, bioplastics are an alternative that utilizes materials Renewable organic materials, such as corn starch, sugarcane, or cellulose, instead of non-renewable resources like petroleum. While bioplastics have the potential to reduce dependence on non-renewable sources, they still face challenges in terms of cost, raw material availability, and performance compared to conventional plastics. • Reducing plastic use: A key approach to tackling plastic pollution is reducing the amount of plastic used. This can be achieved through consumer awareness, government incentives for reusable products, bans on single-use plastics, and incentives for more sustainable packaging design. However, changing habits and implementing effective policies can face cultural resistance, economic interests, and logistical challenges.

[0008] Limitations and shortcomings of existing solutions: • Inadequate infrastructure: Recycling and composting require specific infrastructure, such as recycling and composting facilities, which may not be available in all regions. This can limit the effectiveness of these solutions, especially in resource-limited areas. • Technical and economic difficulties: Recycling certain types of plastics can be technically challenging and economically unfeasible, especially when the plastics are contaminated or mixed with other materials. This can reduce the recycling rate and increase the amount of discarded plastics. • Availability and performance of alternative materials: Bioplastics and biodegradable polymers face challenges in terms of raw material availability, production cost, and performance compared to conventional plastics. Furthermore, the degradation of some biodegradable materials can release toxic waste or contribute to soil and water pollution.

[0009] Regarding the state of the art, for example, patent BR 112019013252-0, granted on August 22, 2023, entitled "CARBOHYDRATE-BASED POLYMERIC MATERIALS," can be cited. This patent refers to articles that include carbohydrate-based polymeric materials and methods for forming such articles. Such items may exhibit enhanced sustainability, biodegradability, increased resistance, and / or various other beneficial characteristics. However, films produced with starch, pectin, and glutamic acid have distinct characteristics from those mentioned in the aforementioned patent, which relies exclusively on carbohydrates to form the polymeric films. Glutamic acid is an amino acid; therefore, carbohydrates represent a different category of organic compounds.

[0010] Furthermore, Chinese patent CN1285662C, granted on September 14, 2005, entitled "NONTOXIC WHOLE-DEGRADABLE PLASTICS AND PROCESS FOR MAKING SAME," refers to a non-toxic, fully degradable plastic and its method of preparation. It is mainly made of starch, polyvinyl alcohol, vegetable protein powder, polyglutamic acid, xylitol, and glycerin. The particularity of the non-toxic, fully degradable plastic particles made through this invention makes the invention advantageous for its prolonged use. In this In the previous study, polyglutamic acid is mentioned as one of the components of the non-toxic polymer; however, there is no clear explanation of how it contributes to improving the material's properties. In contrast, in the present invention, glutamic acid is highlighted as a reinforcing material to improve both the mechanical and physicochemical properties of starch- and pectin-based films. This distinction is significant, since glutamic acid, being an amino acid, can contribute specifically to the characteristics of the films, while polyglutamic acid is a polymer composed of multiple glutamic acid units, which may result in different and possibly less specific properties for application in biodegradable starch- and pectin-based films.

[0011] Chinese patent application CN106496985A, filed on March 15, 2017, entitled “DEGRADABLE ENVIRONMENT-FRIENDLY MATERIAL FOR FOOD PACKAGING AND PREPARATION METHOD THEREOF,” refers to a degradable and environmentally friendly material for food packaging and a method for its preparation. The degradable and environmentally friendly material is prepared, by weight, with 20-30 parts pectin, 30-40 parts polylactic acid, 8-15 parts corn starch, 5-8 parts acanthopanacis bark, 2-4 parts dicranum scoparium, 1-5 parts luffa stem, 0.5-0.8 parts sodium stearate, 2-6 parts D-isoleucine, 4-8 parts ethyl acetate, and 0.5-0.9 parts chlorogenic acid. The aforementioned application relates to a degradable and environmentally friendly material for food packaging, which includes pectin, polylactic acid, corn starch, among other components. In the present invention, however, it addresses... The synthesis and characterization of starch, pectin, and glutamic acid-based films, with the purpose of improving their mechanical and physicochemical properties. A fundamental difference between the two studies is the composition of the materials, in addition to the preparation methods and the use of raw materials.

[0012] Korean patent KR102508277B1, granted on January 9, 2023, entitled “THERMOPLASTIC STARCH COMPOSITION MANUFACTURING, METHOD THEREOF AND USE THEREOF”, refers to a thermoplastic starch composition comprising starch, a plasticizer, a compatibilizer, a biodegradable polymer, and a reaction initiator. The compatibilizer, in this case, can be glutinic acid (also known as glutamate or 2-aminopentanedioic acid, an isomer of glutamic acid). Furthermore, by extruding a biodegradable composition in which the thermoplastic starch composition and the biodegradable polymer are uniformly mixed, a biodegradable film can be prepared. The prepared biodegradable film possesses excellent mechanical strength and low hygroscopic properties. Both glutamic and glutinic acids are naturally occurring and biodegradable.However, differences in their chemical structures can affect the physicochemical properties of the biofilm and the biodegradation efficiency of the polymeric films that contain them.

[0013] Furthermore, the scientific article “EDIBLE FILMS AND COATINGS: CONCEPT, APPLICATION AND USE IN THE POST-HARVEST OF FRUITS, VEGETABLES AND GREENS”, by BARBOZA, Henriqueta Talita Guimarães et al., published in 2022, addresses edible coatings where biopolymers emerge. as potential substitutes for petroleum-based packaging materials. Known as "green plastics" or bioplastics, they are derived from biodegradable polymers such as starches, cellulose, sodium alginate, among others, with numerous studies being conducted to investigate the ability of edible coatings to preserve the quality and extend the shelf life of fresh fruits and vegetables by regulating the metabolic activities of the fruits, in addition to the addition of active ingredients that interact with the product. The difference between the two studies is the main objective: while the present invention focuses on improving biodegradable films, the article is focused on the development of edible coatings. Furthermore, the materials used are also different.

[0014] Therefore, it is clear that no prior art document reveals or suggests a sustainable polymer film development process, nor a sustainable polymer film obtainable through the aforementioned process and its use.

[0015] Therefore, the need to develop sustainable alternatives for different types of products that require plastic packaging is undeniable.

[0016] Thus, the sustainable polymer film development process of the present invention solved the problems of the prior art, obtaining a sustainable polymer film composition reinforced with glutamic acid, which can be used by the packaging industries as an alternative to synthetic plastics. Brief Description of the Invention:

[0017] In order to not only directly address the problem of plastic pollution, but also to align with global efforts to promote a circular economy and adopt more sustainable practices in the food packaging industry, the present invention aims to describe a process for producing a sustainable polymeric film, reinforced with glutamic acid, in commercial starch and pectin matrices. This is because, by incorporating glutamic acid, biodegradable polymeric films become more likely to withstand mechanical stress and exhibit characteristics that are pleasing to the desired application, in addition to the ease, since it is a film produced exclusively from organic compounds, of decomposing naturally in the environment, promoting bioassimilation in the soil and reducing its overall toxicity.

[0018] Furthermore, the present invention relates to a sustainable polymeric film reinforced with glutamic acid, obtained by the aforementioned process, as well as to its use, most notably in packaging. Brief Description of the Figures:

[0019] Figure 1 presents the flowchart for the manufacture and characterization of the glutamic acid-free polymer film, referring to steps (c) to (g) of the process of the present invention.

[0020] Figure 2 presents the flowchart for the manufacture and characterization of the polymeric film with glutamic acid, referring to steps (a) to (g) of the process of the present invention.

[0021] Figure 3 shows a sample of films with and without AG, produced by the casting method, where A) represents the film without AG and B) the film with AG.

[0022] Figure 4 presents a graph showing the mechanical properties (deformation vs. engineering stress) of starch-based films with different pectin concentrations.

[0023] Figure 5 presents a graph comparing the model predictions with the observed values.

[0024] Figure 6 presents a graph with FTIR spectra of the starch-pectin film, without AG, and of the film with AG insertion.

[0025] Figure 7 presents a graph with FTIR spectra of glutamic acid and glutamate.

[0026] Figure 8 shows a micrograph of the polymer films during the melting process at A) ~25ºC; B) ~100ºC; C) ~150ºC; and D) 165ºC to 180ºC. Column 1: without fatty acids; Column 2: condition 4: pH 5, Pectin: 6 g, Glutamic acid: 1.25 g; Column 3: condition 10: pH 6, Pectin: 5 g, Glutamic acid: 1 g; Column 4: condition 6: pH 7, Pectin: 4 g, Glutamic acid: 1.25 g. 5x magnification.

[0027] Figure 9 shows differential scanning calorimetry thermograms of the films with and without AG.

[0028] Figure 10 shows the biodegradation of polymeric films – without AG (Samples 1, 2 and 3); condition 4: pH 5, Pectin: 6 g, Glutamic acid: 1.25 g (Samples 4, 5 and 6); condition 9: pH 6, Pectin: 5 g, Glutamic acid: 1 g (Samples 7, 8 and 9); and condition 6: pH 7, Pectin: 4 g, Glutamic acid: 1.25 g (Samples 10, 11 and 12): A) Before degradation; B) After 7 days; C) Experimental apparatus used in the assay showing the position of the samples on the wire mesh. and organic soil with a low clay content. Detailed Description of the Invention:

[0029] The present invention describes a process for developing a sustainable polymeric film reinforced with glutamic acid in commercial starch and pectin matrices, comprising the following steps: a) Dilute between 0.75g and 1.25g (w / v) of glutamic acid in deionized water under constant stirring (magnetic stirrer with heating) at ~200 rpm; b) Adjust the pH (5, 6 or 7) of the rotating solution with NaOH (8.3N) for the dissolution of the fatty acid; c) Add to the solution 10 g of starch, 4% (v / v) acetic acid solution and 80% glycerol; d) Add 1 to 6 g (w / v) of pectin to the solution under constant stirring at 800 rpm at 27°C; e) Stir the resulting solution until it reaches 80 ± 2°C, preferably 80°C for 2 hours; f) Dry the solution obtained in e) at room temperature without forced air circulation; e) Obtain a polymeric film.

[0030] This is because, for the formation of the starch-pectin blend without AG (steps (c) to (g) of the process), it is necessary to: dilute starch in deionized water in a 1:20 ratio, w / v; add 3 mL of vinegar and 4 mL of glycerol to the solution; and add different masses of pectin (between 1 and 6 g) to the beakers containing the mixture of starch, acetic acid, and glycerol, under magnetic stirring and at 27±2°C. After adding the pectin, it is necessary to: constantly stir the new solution (approximately 800 rpm) at 27±2°C until it reaches 80±3°C for 2 hours; carefully pipette the solutions into Petri dishes. with different pectin masses; and dry at room temperature (27±2°C) without forced air circulation. After drying, the films must be removed from the Petri dishes and analyzed for water content and tensile strength (TS) (Figure 1).

[0031] For the formation of the starch-pectin blend with AG (steps (a) to (g) of the process) (Figure 2), the process variables used are the pH of the solution (an important parameter to favor the dissolution of glutamic acid), which can vary between 5 and 7, the pectin concentration, which can vary between 4 and 6 g, and the glutamic acid concentration, which can vary between 0.75 and 1.25 g, based on the tensile strength limit (TSL) of the polymeric films (Table 1). In step (a), preferably 1.0 g of glutamic acid mass is added to a beaker containing 200 mL of deionized water under constant stirring at 200 rpm. In step (b), the pH of the solution is adjusted with NaOH, under constant rotation of the solution. The pH should preferably reach 6. Table 1 - Process conditions for the study of the mechanical properties of the polymeric film. Variables at the point level of the process: lower, central, upper (-1) (0) (+1) pH 5 6 7 Pectin (g) 4 5 6 Glutamic acid (g) 0.75 1.00 1.25

[0032] The choice of pectin concentration was based on the work of Chhatariya, Srinivasan, Choudhary and Begum (2022), the pH value and the concentration of glutamic acid. Through analysis, the aim was to understand the best dissolution of AG in water, since these parameters were not found in the literature for the production of polymeric films.

[0033] Each factor was varied at three levels for the 2 factorial design. 3+3 The method of central points was used with the coded variables: +1, 0, -1, totaling 11 trials. The results were obtained using the response surface methodology (RSM) through the STATISTICA® version 7.0 program. CHARACTERIZATION METHODS

[0034] The characterization of the polymeric films followed steps such as mechanical analysis (EQUILAM, WDW-100E), programmed for displacement / speed control of 0.5 mm / min. -1, 200mm target, with a 50N load cell. The polymer films were prepared according to ASTM D882 with dimensions of 80x15mm (length x width) and a thickness of 0.02mm.

[0035] In order to explain structural changes due to temperature variation of the constituent elements of the polymer film, the films were heated from 25 o C a 100 o C with a heating rate of 1 o C min -1 , out of 100 o C a 150 o C and 150 o C a 200 o C at 0.5 o C min -1 The images were captured every 60 seconds, with a 5x magnification. Four images were selected based on the main thermal events observed: at approximately 25 o C, 100 o C (first stage of degradation due to water loss), 150 o C and 180 oC, respective middle and end of the first stage of degradation), thermal (DSC - model Q20 – TAINSTRUMENTS). To determine the functional groups present in biodegradable films in the presence In the absence of glutamic acid, Fourier Transform Infrared Spectroscopy with attenuated total reflectance (FTIR-ATR) was performed (BRUKER, Tensor 27). The analysis was conducted in the spectral range between 4000 and 600 cm⁻¹. -1 A zinc selenide ATR accessory with a 45º penetration angle was used. To avoid possible interference, the polymer films were kept in a desiccator with silica gel until the time of analysis. For comparison purposes, the analysis was also performed, under the same conditions, for pure glutamic acid and sodium glutamate.

[0036] For the biodegradation test in soil with low clay content (samples of the biodegradable film were cut to 2 x 2 cm and placed on the soil using an aluminum screen as an apparatus).

[0037] After the natural organic soil, with a low clay content, was deposited on the polymer films, which were placed 2 cm deep, water was sprayed twice a day and the soil was maintained at a pH of 7.5 at 25±2. o C, URAr: 65±1%. After 7 days, the film samples were removed from the soil and photographed. BIOFILM PRODUCTION

[0038] The biopolymer production was carried out under six different conditions, without the fatty acid (FA), varying the pectin concentration (1 to 6 g), and with the FA, under 11 different conditions (altering the pH parameters, pectin concentration, and glutamic acid concentration) and reproducibility at the central point (see Table 2), according to the statistical design. After production, the polymer film samples were characterized regarding their mechanical properties. and physicochemical properties. Figure 3 illustrates the appearance of the biopolymers produced under conditions without AG and with AG. Preliminary mechanical properties

[0039] Khazaei, Esmaiili, and Emam-Djomeh (2016) state that the mechanical properties of films indicate their strength and ability to increase food integrity. Among the commonly studied mechanical properties, the tensile strength limit (TSL) is selected.

[0040] Understanding tensile strength (TS) is fundamental in biodegradable polymer films and plays a crucial role in their effectiveness and applicability in sustainable packaging, which is often used as a more environmentally friendly alternative to conventional plastic. Adequate TS ensures that these packages can withstand weight and transport conditions without breaking, guaranteeing product integrity and preventing waste.

[0041] Furthermore, when films reach the end of their useful life, it is important that they decompose safely and quickly. The tensile strength limit can influence how these materials fragment and degrade in the environment, according to the article CAZON, VELAZQUEZ, RAMIREZ, VAZQUEZ (2017), entitled “Polysaccharide-based films and coatings for food packaging: A review”, published in Food Hydrocolloids, and BRIASSOULIS and GIANNOULIS, (2018), entitled “Evaluation of the functionality of bio-based food packaging films”, published in the Journal Polymer Testing.

[0042] Among the raw materials that can be used, the most common are the polysaccharides starch and pectin, which They contain hydroxyl (-OH) and carboxyl (-COOH) functional groups. These functional groups form hydrogen bonds with each other, creating a three-dimensional network that helps bind the molecules in the film together. These hydrogen bonds contribute to the film's cohesion and mechanical strength.

[0043] However, research by Chhatariya, Srinivasan, Choudhary, and Begum (2022) shows that starch concentration (greater or less than 10g) does not significantly alter the mechanical strength of starch-pectin-based polymer films. Conversely, pectin concentration can alter moisture content (approximately 25%), tensile strength (approximately 11%), and solubility in alcohol and water (approximately 33%).

[0044] Thus, in the present invention, the starch concentration was kept constant (10 g) and the pectin concentration was varied (1 to 6 g) to understand its influence on the tensile strength limit (TSL). After drying, the films were mechanically treated, and the results are shown in Figure 4.

[0045] According to the results obtained, the increase in pectin concentration was proportional to the increase in LRT; however, the values ​​are still low. Therefore, in order to improve LRT, the combination of glutamic acid with the starch-pectin blend, based on the preliminary study, aimed to improve this property. However, glutamic acid is more soluble in water in its ionic state, that is, as the glutamate ion.

[0046] Therefore, dissolving AG in NaOH (8.3N) results in the conversion of the acid to its ionic form, which may allow the formation of reactive functional groups that They bind to starch and pectin, creating a polymer network with better mechanical resistance and more suitable for applications requiring greater durability. Based on the above, the main factors studied for the LRT (Lower Resistance Threshold) of polymer films with the addition of glutamic acid will be demonstrated below. LRT OPTIMIZATION

[0047] Table 2 shows the result of the 2 factorial design. 3+3 and the mechanical strength results according to each test performed. Observing the LRT values, it is noted that the variation was from 4.115 MPa to 6.346 MPa. Low LRT values, between 0.09 and 0.27 MPa, were shown in the work of Kang, et al. (2005), entitled “Combination of gamma irradiation and CaCl immersion for a pectin-based biodegradable film”, published in Carbohydrate Polymers, in pectin-polyvinyl alcohol-glycerol films, combined with gamma irradiation and immersion in CaCl2.

[0048] The addition of glutamic acid and adjustment of the pH of the solutions resulted in better LRT values ​​than without glutamic acid (Table 2). This denotes the effect of FA enhancement on the starch-pectin blend.

[0049] When comparing the pectin concentration in 5 g with (approximately 5.26 MPa) and without GA (1.83 MPa – see Figure 4, inserted for the different pectin concentrations), the LRT was increased more than 3x. Among the conditions studied, the pH value (7) and higher glutamic acid concentration (1.25 g) were most relevant to increasing the tensile strength limit (6.346 MPa - condition 6).

[0050] Conversely, when the concentration of glutamic acid decreased and the concentration of pectin increased, Maintaining the pH value (7), the LRT (4.115 MPa) showed a less expressive value when compared to all other results, but still superior to the values ​​of 3.05 MPa, 0.59 MPa and 1.80 MPa obtained by the respective articles Zolek-Tryznowska and Kaluz (2021), entitled “The Influence of Starch Origin on the Properties of Starch Films: Packaging Performance”, published in the Journal Materials, Susmitha, et al. (2021), entitled “Development and characterization of corn starch-gelatin based edible films incorporated with mango and pineapple for active packaging”, published in the Journal Food Bioscience and Chhatariya, Srinivasan, Choudhary and Begum (2022), entitled “Corn starch biofilm reinforced with orange peel powder: Characterization of physicochemical and mechanical properties”, published in Materials Today.

[0051] This demonstrates that the addition of fatty acids (FA) to the starch-pectin blend contributed to improving the tensile strength of the biopolymer. It has been shown that a lower amount of FA and a higher amount of pectin (condition 4) can interfere with the tensile strength of the material, which can be explained by the agglomeration of particles due to the higher pectin content, resulting in a weakening of the mechanical properties, as observed by Ali et al. (2019), Sganzerla et al. (2020), Zolek-Tryznowska and Kaluz (2021), and Chhatariya, Srinivasan, Choudhary, and Begum (2022). Table 2 - Results of the tensile strength limit of the biofilms using a 2² factorial design. 3+3

[0052] Based on statistical analysis using STATISTICA 7.0 software, the results in the table show a close relationship between the values ​​and a significant correlation between the positive and negative deviations, demonstrating a statistically favorable and high-quality model fit (See Figure 5). This shows that the model can be an accurate representation of the events studied, and may have some underlying pattern in the behavior of the data captured by the model. The residuals (difference between the observed values ​​and the values ​​predicted by the model) can explain most of the data variation.

[0053] The influences of pH, pectin concentration, and fatty acid concentration on the mechanical properties of biofilms were verified through analysis of variance (ANOVA) (Table 3). Table 3 - ANOVA results for the tensile strength limit (TSL) variable of polymeric films. Tensile Strength Limit (TSL / MPa) Source of SS DL MS Fcalculated Ftabulated R Variation Regression 2.87 6 0.48 43.64 6.16 98.46 Residual 0.045 4 0.011 - - Lack of fit 0.042 2 0.021 14.00 19.00 Pure Error 0.003 2 0.0015 - - Total 19.77 10 - -

[0054] With these data, the significance of the regression and lack of fit can be obtained with 95% confidence (p ≤ 0.05), using the F-test for the studied design. The analysis of variance (ANOVA) showed that the model was statistically significant and adjusted to the experimental values, since the MQR / MQr ratio (calculated F) was ~7x greater than the tabulated value of F0.95;6.4 (6,16) and the MQfaj / MQep ratio was ~25% less than the F value. 0,95;2,2 (19.00). The coefficient of determination (R 2 The coefficient of variation (CV) was 0.9846, indicating that the model explained approximately 99% of the variation in the observed data.

[0055] Thus, since the coefficient of determination was close to 1.0, it is stated that the model is well-fitted and can be used to predict the mechanical strength value for the variables studied. Equations X, Y, and Z (below) describe the proposed coded models for the respective process conditions: X = pH and pectin concentration; Y = pH and fatty acid concentration; and Z = pectin concentration and fatty acid concentration. LRT = 5.13 + 0.18 * pH - 0.36 * pectin - 0.21 * pH * pectin Equation XLRT = 5.13 + 0.18 * pH + 0.29 * AG + 0.24 * pH * AG Equation YLRT = 5.13 - 0.36 * pectin + 0.30 * AG + 0.27 * pectin * AG Equation PHYSICAL-CHEMICAL ANALYSES

[0056] Table 4 shows the values ​​of the physicochemical parameters analyzed: residual water content, index of Swelling, solubility, TVA, thickness, color, and opacity are important factors in understanding whether the produced biopolymer is suitable for food packaging applications. Table 4 - Physicochemical properties of biodegradable polymer films. Residual Water Content (%) With (9) Color Residual water content

[0057] The analysis of residual water content refers to the amount of moisture that remains after the processing or storage of polymer films. In the present invention, the films, before and after the insertion of the AG, had more than 90% of free water removed in the drying process, leaving 6% to 7% residual water.

[0058] The water content was measured by the gravimetric method, in which the drying of the polymeric film was monitored at 27^2ºC until the mass became constant (14 days). In this method, the Petri dish used to deposit the film, after solubilization of the starch-pectin and starch-pectin-glutamic acid, was weighed on an analytical balance (10- 4 g) and the mass was recorded. Subsequently, the balance with the Petri dish was tared and the polymer film solution was placed on the dish to identify the mass of the solution. After three days, the polymer film began to form on the Petri dish, which was weighed again and the value recorded. This process was repeated on the 7th, 11th, and 14th days.

[0059] In food packaging, the presence of water can affect product quality and shelf life. Polymeric films with low residual water content and high resistance to moisture penetration are essential to maintain product integrity and prevent degradation upon contact with the product. The article by Pineros-Hernandez, Medina-Jaramillo, Lopez-Cordoba, and Goyane (2017), entitled “Edible cassava starch films carrying rosemary antioxidant extracts for potential use as active food packaging,” published in Food Hydrocolloids, describes that edible cassava starch films containing rosemary antioxidant extract for active packaging had approximately 20% residual water. Solubility and Swelling Index

[0060] The solubility of the polymer films was determined by the percentage of material that dissolved after 24 hours of immersion in water. To do this, sections of the polymer films measuring 4x4 cm were placed in beakers containing 50 mL of deionized water and gently stirred at 27±2ºC for 24 h. After this period, the films... Non-soluble samples were vacuum filtered and subsequently dried in a forced-air oven at 70±2ºC for 24 h to determine the weight of the dry matter that did not dissolve in water. Three replicates were obtained for each sample.

[0061] For both moisture content (T%) and water solubility (S%), the calculations were in accordance with Equation A, where T% = water content in percentage; S% = solubility in percentage; Mi = mass before drying; Mf = mass after drying. 00 (A)

[0062] The swelling index assessment was conducted on polymeric films with and without the addition of glutamic acid.

[0063] Knowledge of the swelling index or absorption index is important for evaluating the ability of the polymer film to absorb liquids. In food packaging, it is essential that the polymer film acts as an effective barrier against moisture, oils, and other liquids that could compromise the quality and safety of the product.

[0064] The swelling index helps to evaluate the barrier performance of the film. Therefore, the analysis was performed on polymeric films with and without AG.

[0065] With AG, films were used in the best (condition 6) and worst (condition 4) response to LRT and at the central point. In this analysis, 3 samples of the polymeric film in each condition were prepared in rectangular pieces measuring 2.5 x 2 cm. The fragmented films were placed in Petri dishes and inserted into a desiccator containing silica gel (previously dehydrated) for 24 h. After, the films were removed from the desiccator, weighed (10 -4 g) and the Values ​​were recorded. In Petri dishes properly identified according to the corresponding sample, 20 mL of NaCl solution (0.9% w / v) were added. The dishes were left to rest, following the defined time intervals (1, 10, 30, and 60 min). At the end of each interval, the samples were weighed and the resulting values ​​recorded. To determine the swelling index, the calculation according to Equation B was used, where II% = swelling index in percentage; Mi = mass of the membrane after swelling at times 1, 10, 30, and 60 min; Ms = mass of the dry membrane at time 0 (zero). 1 00 (B)

[0066] Several conditions of statistical experimental design were used in order to analyze whether changes in the concentration of fatty acids (FA) and / or pectin and in the pH could influence the results. In films produced with lower pectin concentration and higher FA concentration, at neutral pH (pH 7, - condition 6), there was greater water absorption than in films with the same pH but higher pectin concentration and lower FA concentration (pH 7 – condition 4).

[0067] After the experiments, it was possible to demonstrate that not only can more protonated media influence the water absorption capacity, but also the size of the empty spaces, the degree of compaction between molecules, and the free volume can influence the diffusion rate in polymer films.

[0068] Pectin forms gels in aqueous media and, as observed by the present invention, the diffusion rate of water through these gels was influenced by the pectin content, since a higher concentration conferred greater Resistance to water penetration. This factor is positive, since the film that showed a higher LRT may be more susceptible to degradation, as hydrophilicity aids in this process.

[0069] The water solubility of biodegradable films may be closely related to the presence and nature of hydrophilic groups in the raw material used. In the present invention, it was observed that polymeric films produced without the addition of glutamic acid (GA) and those with its incorporation, while maintaining high mechanical strength (condition 6), showed solubilities around 73%.

[0070] These results are congruent with the research by Tien et al. (2023), entitled “Biodegradable films from dragon fruit (Hylocereus polyrhizus) peel pectin and potato starches crosslinked with glutaraldehyde”, published in Food packaging and self-life, in which polymeric films, derived from dragon fruit peel and subjected to different treatments in potato starch as a starch source, demonstrated similar solubility values, ranging between 68% and 87%.

[0071] However, a notable highlight was the observation of high solubility at condition 4, reaching approximately 93%. This is similar to the work of Matta and Bertola (2020), entitled “Development and characterization of high methoxyl pectin film by using isomalt as plasticizer”, published in the Journal of Food Processing and Preservation, which reported 100% solubility in pectin films with high methoxyl content using isomalt as a plasticizer. These results suggest that pH 7, used during the production of some of the polymeric films, It played a key role in increasing solubility. The proximity of this pH to the pH value of water made the films more susceptible to the action of water, and the lower mechanical resistance presented by these films facilitated their dissolution.

[0072] Interestingly, the presence of carboxyl groups (-COOH) in the AG did not show a significant effect on solubility at pH 7. On the other hand, the solubility of the films was reduced when exposed to pH 6 under condition 9, reaching approximately 57%.

[0073] These observations suggest that a pH close to that of water may increase solubility, while a lower pH minimizes this effect. However, it is noted that the amount of AG had little impact on solubility, as evidenced by observing conditions 4 (0.75 g) and 6 (1.25 g).

[0074] With regard to pH, it is important to note that glutamic acid has carboxylic acid (-COOH) and amine (-NH2) functional groups, giving it the properties of an amino acid. Variations in pH value can affect the ionization of the functional groups present in glutamic acid, resulting in different charged forms.

[0075] Ionization of the carboxylic group can lead to the formation of a carboxylate ion (COO-) and a hydrogen ion (H+), which affects the overall charge of the molecule and, consequently, its chemical interactions and physical properties. Therefore, the solubility results indicate that the pH value can be crucial in dissolving the films in water.

[0076] The study conducted by Pobudkowska and Domańska (2014), entitled “Study of pH-dependent drug solubility in water,” published in the Journal Chemical Industry & Chemical Engineering Quarterly, examined the water solubility profile of five drugs in relation to pH, finding that the solubility of these compounds is directly influenced by the level of acidity or alkalinity. Each drug analyzed revealed a specific solubility pattern, with a general increase observed as the pH increased.

[0077] In another approach, the study by Sogias, Khutoryanskiy, and Williams (2010), entitled “Exploring the Factors Affecting the Solubility of Chitosan in Water,” published in the Journal Macro-Molecular Chemistry and Physics, investigated the solubility of chitosan in water, highlighting an expansion of this property over a wider range of pH values. These findings reinforce the correlation between pH and solubility, corroborating the results presented in the present invention.

[0078] In the overall context, the results highlight the crucial importance of precise pH control during the formulation of polymer films, an essential consideration to ensure desirable properties such as moisture resistance and adequate solubility.

[0079] The analysis of solubility and swelling properties highlights the intricate relationship between a polymer and its solvent. The hydrophilicity of the biodegradable polymer, as highlighted here, emerges as a critical factor that facilitates not only solubility but also the swelling of the material.

[0080] The present invention demonstrates the importance of understanding the affinity between polymer and solvent, which is influenced by various elements, from chemical structure to environmental conditions. Therefore, physical properties are crucial for guiding the development of polymeric materials with specific characteristics, providing significant advances in the practical application of these materials in various fields. Water vapor transmission rate (WVTR)

[0081] The TVA test was based on the gravimetric method described in ASTM E96-80, with modifications such as replacing the kit suggested by the standard with a Petri dish.

[0082] Before and after the insertion of glutamic acid, the films were placed on Petri dishes and then in a desiccator containing a saturated 40% (w / v) NaCl solution for 72 hours. Afterwards, the films were properly prepared for the water vapor transmission rate (WVTR) test. Within each Petri dish, the biodegradable polymeric film covered an area of ​​10 cm². 2 10 g of CaCl2 were added. Subsequently, the films were individually fixed to Petri dishes using film strips.

[0083] The assemblies formed by the Petri dish, polymeric film, CaCl2, and parafilm were weighed at the beginning of the analysis, marking the initial time. These assemblies were then placed inside a desiccator containing dehydrated silica gel to maintain the system's water balance. The films were weighed at specific times: 24, 48, 72, and 96 h; at each time point, the mass values ​​obtained were... annotated, enabling the calculation of the water vapor transmission rate of biodegradable polymer films.

[0084] In addition to the main samples, a control kit was prepared without the polymer films. This control kit served as a baseline for comparison throughout the experiment.

[0085] To determine the TVA, the calculation was used according to Equation C, where: GM = mass gain (g); t = total analysis time (h); A = permeation area of ​​the polymeric film (cm²). 2 ):

[0086] The results of the water vapor transmission rate (WVTR) analysis for the films, with and without AG, indicated that the addition of AG did not have a significant effect on the water vapor permeability properties of the films.

[0087] Comparing the films with AG under different conditions (4, 6, and 9) with the film without AG, it is observed that the film with AG, under condition 4, showed a slightly higher water vapor transmission rate than the film without AG (approximately 20%). On the other hand, the films with AG, under conditions 6 and 9, showed slightly lower water vapor transmission rates than the film under condition 4. This indicates that, under these conditions, the addition and / or quantity of AG contributed little to improving the moisture barrier of the films.

[0088] However, it is important to emphasize that TVA (Transmissible Water Value) is not the only factor to be considered in evaluating the moisture barrier properties of a material. Other factors, such as morphological structure and chemical composition, also play a role. The biopolymer also plays an important role in this aspect. Thickness and opacity

[0089] The thickness of packaging films, such as those made of polyethylene, plays a crucial role in their physical and chemical properties. Generally, thickness values ​​are associated with the permeability, mechanical strength, and transparency of the films, according to the article by Abdullah and Talip (2014), entitled “Characterization of a new biodegradable edible film made from salep glucomannan”, published in Carbohydrate Polymers. Therefore, the results obtained by the present invention suggest that films with AG can exhibit permeability properties similar to those of the reference films, while maintaining an adequate thickness (approximately 0.16 mm) for packaging applications.

[0090] Analysis of the thickness of biopolymer films, with and without glutamic acid (GA), revealed consistent results, with small variations observed between the different films. Films without GA had an average thickness of 0.15 mm, while films with GA, under conditions 4, 6, and 9, had average thicknesses of 0.17 mm, 0.16 mm, and 0.16 mm, respectively. These variations in thickness can be attributed to the nature of the materials and the film production process. Comparing these results with values ​​found in the literature, it is observed that the thickness of the films obtained in the development of the present invention is within the typical range reported for biodegradable films. Previous studies have shown that the thickness of these films can vary from 0.1 mm for different types of polymers to 0.3-0.4 mm in the case of films made with According to the article by Garcia et al. (2009), entitled "A comparison between the physico-chemical properties of tuber and cereal starches," published in Food Research International, these differences in film thickness are mainly influenced by the amount of film-forming solution applied to the Petri dishes during the manufacturing process.

[0091] To determine the thickness of the polymer films under conditions without AG, best LRT, worst LRT, and center point, a Mitutoyo digital micrometer (São Paulo, Brazil) was used, with a measuring range of 0-25 mm and a precision of 0.001 mm. The average thickness of each film was obtained from measurements at five different points.

[0092] Assessing opacity is essential when considering biodegradable films for food packaging, as it directly influences the material's ability to protect products from light. Films with higher opacity can be particularly useful for preserving the quality of lipid-rich foods, which are sensitive to photodegradation (ASSIS, 2021). The opacity of polymeric films varies, with low-opacity films being transparent, while high-opacity films are considered opaque, according to the article by Almeida et al. (2013), entitled "Physical, chemical and barrier properties in films formed by a blend of bacterial cellulose and potato starch", published in Polímeros Ciência e Tecnologia.

[0093] The opacity of the films was evaluated using a UV / Visible spectrophotometer (model KASVI K37). To obtain a comprehensive understanding of whether there would be any alteration in the To determine the opacity values ​​of the polymeric films, analyses were performed by scanning wavelengths between 20 nm (UV region) and 700 nm (visible region). For this, the films were cut into 4 cm x 1 cm rectangles and placed directly into the quartz cuvette of the equipment, using an empty cuvette of the same material as a reference. As the scanning results maintained the same opacity at virtually all wavelengths, it was decided to keep the absorbance for the measurements at 600 nm. The results were presented as the ratio between absorbance and film thickness, as defined by ASTM D1746, reflecting the films' ability to absorb light.

[0094] Opacity results showed that the films without glutamic acid (GA) were 4.15 mm thick. -1, indicating low opacity and therefore greater transparency. On the other hand, films with added AG showed higher values, indicating greater opacity and lower transparency. Notably, the film with AG (6) had the highest opacity value, at 9.82 mm -1 , suggesting that this formulation may be the most effective at blocking light passage. These results may be important for selecting the most suitable formulation, depending on the transparency and light barrier requirements for the desired application.

[0095] Comparing with the studies by Gomes (2022), entitled “Characterization of cellulose acetate film incorporated with cellulose nanocrystals and fruit salad aroma”, published in The Journal of Engineering and Exact Sciences and Amaral (2019), entitled “Biodegradable material based on cassava starch (Manihot esculenta) for application in food preservation”, published in the Proceedings of the 15th o The results of the Brazilian Polymer Congress (15 CBPOL) found an increase in the opacity of films with the addition of different additives, and are consistent. Gomes (2022) observed a significant increase in opacity with the addition of aroma and cellulose nanocrystals, with a value of 7.58 mm. -1 Amaral (2019) also found an increase in opacity in a cassava starch-based biopolymer, with a value of 6.93 mm -1 These results highlight the influence of additives on film opacity, indicating that the composition of the polymer matrix and other added materials, such as lipids and proteins, play a relevant role in film formation and transparency. Film opacity can be adjusted by the concentration and type of material used in its composition (KOWALZCKYK; BARANIAK, 2011). Color

[0096] The determination of color is an important characteristic of food packaging films, according to the article by Cao et al. (2023), entitled “Colorimetric and antioxidant films based on biodegradable polymers and black nightshade (Solanum nigrum L.) extract for visually monitoring Cyclina sinensis freshness”, published in Food Chemistry: X, in aspects ranging from consumer acceptance (MATTA and BERTOLA, 2020) to food safety and quality control. It is an important tool to ensure that these materials meet the aesthetic, functional, and regulatory requirements in their applications.

[0097] For color measurement, the surface of the polymer film samples was analyzed using a colorimeter (BRASEQ, Colorflex EZ) in the HunterLab system against a color. White (L* = 97.75, a* = −0.49, b* = 1.96) was used as the standard background. The equipment recorded the spectrum of the reflected light to determine the parameters L* (luminosity), a* and b* (chromatic coordinates); a* and b* indicate the directions of the colors, being the direction of red (+a*), direction of green (-a*), direction of yellow (+b*) and direction of blue (-b*). From the parameters it was possible to determine the chromaticity (C*) (Equation D) and the hue angle (H). o ) (Equation E) which indicate respectively the intensity and hue of the color. At least three measurements were taken on each side of the sample:

[0098] In the present invention, the chromaticity results a* and b*, all polymeric films, with and without AG, tended towards a greenish (-a*) and yellowish (+b*) tone. The a* and b* values ​​close to zero indicate a grayish coloration, according to the color scale, which corroborates the appearance of the polymeric films produced.

[0099] The brightness value, which ranges from white (100) to black (0), showed a slight decrease after the insertion of the AG, indicating that under these conditions the films were slightly darker compared to films without AG.

[0100] The chroma index (*C) indicated more grayish colors and lower color saturation under the studied conditions, while the Hue angle (*H) values ​​showed that after the insertion of AG into the polymer films, the hue of the films was close to yellow (90 o ) and the tonality of the films without AG became more orange. However, all the films obtained were in the same quadrant according to with the color definition scale. The results were similar to those observed in the work of Tien et al. (2023). ANALYSIS OF FUNCTIONAL GROUPS (FTIR-ATR)

[0101] In order to determine if there was variation in the functional groups, the films with and without glutamic acid were analyzed and the results are shown in Figure 6.

[0102] The FTIR spectra of the AG-free polymer film showed bands around ~3300 cm⁻¹. -1 (O-H elongation), ~2900 cm -1 (CH of alkyl groups) and in the region around ~1000cm -1 (CO elongation), which corroborates the work of Pineros-Hernandez, Medina-Jaramillo, Lopez-Cordoba and Goyanes (2017) on edible cassava starch films and with Chhatariya, Srinivasan, Choudhary, Begum (2022) on corn starch films reinforced with orange peel powder. Variations in approximately 1750 cm -1These changes can be attributed to the stretching vibration of methyl esterification of the carbonyl group (C=O) of pectin, as observed by Bai et al. (2023) in starch-pectin films and by Pereira, Vieira, Vicente and Cruz (2021), in the article entitled “Development and characterization of pectin films with Salicornia ramosissima: Biodegradation in soil and seawater”, published in Polymers (Basel). Since the functional groups of starch and pectin are similar, many of the bands may overlap and / or shift some peaks compared to the isolated analysis of the pure elements. The band at ~1400 cm⁻¹ -1 This shows the binding of glycerol with starch-pectin-water, according to the article by Zhang and Han (2006), entitled “Plasticization of pea starch films with monosaccharides and polyols”, published in Food Science.

[0103] The FTIR spectra of the films with and without AG show that there were significant changes after the insertion of AG into the starch-pectin blend, mainly in the broadest band due to hydrogen-bonded groups, which appeared at its most intense point at ~3300 cm⁻¹. -1 (ZHANG and HAN, 2006). In this region (~3300 cm -1 ), films with AG showed changes due to the stretching of OH and NH bonds sensitive to H bonding and confirm the presence of ion-hydrophilic / hydrophobic interactions, according to the article by Dhal, Singh and Talukdar (2022), entitled “Volumetric, viscometric and spectroscopic studies of molecular interactions of glutamic acid with potassium sorbate and sodium benzoate in aqueous medium at T = 293.15 - 313.15 K”, published in the Journal of Molecular Analysis.

[0104] Detailed (dotted) evaluation of spectra between approximately 3000 cm⁻¹ -1 2000 cm -1showed important differences in the broad absorption band that may represent the complex free-wave stretching vibrations of sodium glutamate (Figure 7).

[0105] Glutamate spectra exhibit characteristic bands at approximately 1500 cm⁻¹. -1 at 1300 cm -1 Changes in bands in these regions (1500 cm) -1 at 1400 cm -1 These changes can be attributed to the symmetric and asymmetric stretching of the CO bonds in the carboxylate ion, while the band at approximately 1300 cm⁻¹ -1 This likely occurred due to CN elongation, according to the article by Castro and Cassela (2016), entitled “Direct determination of sorbitol and sodium glutamate by attenuated total reflectance Fourier transform infrared spectroscopy (ATRFTIR) in the thermostabilizer employed in the production of yellow-fever vaccine”, published in Talanta.

[0106] Therefore, through the analysis of the functional groups present in pure sodium glutamate and glutamic acid (Figure 7), it is verified that the polymeric films produced in the present invention compare more favorably with pure glutamic acid than with the conversion of pure glutamate to sodium glutamate. MORPHOLOGICAL AND THERMAL ANALYSES Optical microscopy

[0107] Optical microscopy was used to understand the morphology and visible differences of biodegradable polymer films produced by casting with and without the addition of glutamic acid using temperature variation over time (Figure 8).

[0108] From 25 o C a 100 o C (Figure 8), under all conditions studied, it was not possible to observe any modification in the polymeric films in relation to the change in color or in the ordered structure of the films with increasing temperature. At approximately 150 oC (Figure 8), all films showed color changes, but the film without AG (Figure 8) showed greater degradation due to increased temperature compared to the other films.

[0109] In Figure 8, under all conditions, the polymer films are completely degraded: the films without AG at approximately 179 o C, the worst LRT (condition 4) at approximately 165 o C, at the central point (condition 9) at approximately 175 o C and at the best LRT (condition 6), it occurred at approximately 182 o C. Among the conditions studied, Superior thermal stability was consistent with the increase in LRT. Thermal properties

[0110] According to the DSC curves (Figure 9), four peaks were observed, three endothermic and one exothermic. The polymeric films with and without AG showed rapid mass loss, represented by the endothermic peak, at approximately 100 oC. This first event may be related to the evaporation process of residual water bound to the polymeric matrix of the films. Vaporization of some of the starch and pectin may also occur due to the hydroxyl groups present in these elements.

[0111] The second endothermic peak was observed at 187 o C (without AG) and 193 o C (with AG – condition 9). These peaks indicate that the melting temperature may be related to the breakdown of some of the starch and pectin chains. This degradation region corroborates that observed in the microscopy analyses (Figure 8).

[0112] The present invention demonstrates that the thermostability of the film was improved after the incorporation of glutamic acid, and that in this film there is a third degradation event at 248 oC, not observed for the film without AG. The higher degradation temperature of the film with AG may be associated with crosslinking, which promotes the strengthening of the three-dimensional network of the starch-pectin blend, in addition to the formation of crystalline regions after the incorporation of glutamic acid.

[0113] The fourth event, which corresponds to the exothermic peak at approximately 300 o C indicates degradation by decomposition related to the breakdown of pectin chains. This behavior was observed by Siqueira et al. (2022), in the article entitled “Pequi mesocarp: a new source of pectin to produce biodegradable film for application as food packaging”, published in Food Science and Technology, in pequi mesocarp films at 262 oC and by Nisar et al. (2018), in the article entitled “Characterization of citrus pectin films integrated with clove bud essential oil: Physical, thermal, barrier, antioxidant and antibacterial properties”, published in the International Journal of Biological Macromolecules, in citrus pectin films incorporated with clove essential oil at approximately 235 o C. Biodegradation test in soil

[0114] Polymer films under different processing conditions were analyzed at 7 and 15 days after being buried in organic soil with a low clay content. The degree of degradation of the films after 7 days (Figure 10) shows that there was a significant loss of approximately 60% of the structure, and after 15 days this loss was almost 100%, since upon unearthing the films, they were no longer in the soil or had disintegrated upon handling, therefore they are not shown in Figure 10.

[0115] This suggests that the films, under all conditions analyzed, were effectively decomposed by microorganisms present in the organic soil. In general, microorganisms responsible for this process are bacteria and fungi of the genera *Acidovorax facilis*, *Aspergillus fumigatus*, *Comamonas* sp., *Pseudomonas lemoignei*, and *Variovorax paradoxus*, according to the article by Shah, Hasan, Hameed, and Ahmed (2008), entitled “Biological degradation of plastics: A A comprehensive review, published in Biotechnology Advances, revealed that in the present invention, the weighing process was impossible due to the loss of structural integrity of the polymer films.

[0116] According to the European Standard EN 13432 (2000), decomposition must occur within 6 months for packaging to be considered biodegradable.

[0117] Studies by Pereira, Vieira, Vicente, and Cruz (2021) on pectin films with Salicornia ramosissima showed greater degradation in 21 days. Jamarillo et al. (2016) showed that, in cassava starch-glycerol films with yerba mate concentrations, the first signs of degradation appeared in 6 days and complete biodegradability in two weeks. Susmitha et al. (2021) showed that, in edible films based on gelatin and corn starch incorporated with mango and pineapple, degradation in almost 50% of the films occurred after 15 days; however, these authors observed that increasing the concentration of pure mango, mango with peel, and pineapple pulp increased microbial activity in the films.The same behavior was observed by Nouraddini, Esmaiili and Mohtarami (2018), in the article entitled “Development and characterization of edible films based on eggplant flour and corn starch”, published in the International Journal of Biological Macromolecules, with the incorporation of eggplant flour providing an improvement in the degradation of corn starch films.

[0118] Previous results corroborate the speed and effectiveness of biodegradation with those obtained by the present invention. Thus, biodegradable films Products incorporated with glutamic acid show promise for use in food packaging.

[0119] The present invention is defined herein in terms of its preferred embodiment. Nevertheless, a person skilled in the art is perfectly capable of observing that modifications may be made to the information described herein, such modifications still being covered by the same scope of the subject matter described and claimed.

Claims

1 / 2 CLAIMS 1. PROCESS for obtaining a sustainable polymeric film characterized by comprising glutamic acid (GA) in starch and pectin matrices and the following steps: a) Dilute between 0.75g and 1.25g (w / v) of glutamic acid in deionized water under constant stirring (magnetic stirrer with heating) at ~200 rpm; b) Adjust the pH (5, 6 or 7) of the solution under constant stirring with NaOH (8.3N) for GA dissolution; c) Add to the solution 10 g of starch, 4% (v / v) acetic acid solution and 4 mL of glycerol; d) Add 1 to 6 g (w / v) of pectin to the solution under constant stirring at 800 rpm at 27ºC; e) Stir the resulting solution until it reaches 80± 2°C, preferably 80ºC, for 2 hours; f) Dry the solution obtained in e) at room temperature without forced air circulation; e) Obtain a polymeric film. 2.PROCESS according to claim 1 characterized by step (a) the mass of glutamic acid, preferably 1.0 g mass (w / v), being added to a beaker containing 200 mL of deionized water under constant stirring at 200 rpm.

3. PROCESS according to claim 1 characterized by step (b) the pH of the solution being 6.

4. PROCESS according to claim 1 characterized by step (c) starch being added to the solution in a 1:20 w / v ratio, followed by 3 mL of 4% (v / v) acetic acid and 4 mL of glycerol. 2 / 2 5. PROCESS, according to claim 1, characterized by step (d) occurring under constant agitation of 800 rpm.

6. PROCESS, according to claim 1, characterized by step (f) the ambient temperature being between 25ºC and 29ºC, preferably 27ºC.

7. PLASTICIZING FILM, characterized by being obtained by the process described in claims 1 to 6 and exhibiting moisture barrier properties, maintaining an adequate thickness, between 0.15 mm and 0.17 mm, preferably 0.16 mm.

8. FILM, according to claim 7, characterized in that, for mechanical properties, the polymeric films are prepared with dimensions of 80x15 mm (length x width) and a thickness of 0.02 mm, with a displacement / speed control of 0.5 mm / min. -1 9. FILM, according to claims 7 and 8, characterized by having a residual water content of 6.1^3, a swelling index range of 280.4^5 to 372.4^5, a solubility of 57.8^1 to 93.5^5, and a density of 3.41 x 10 -94.08 x 10 -9 g / h.cm 2 TVA, 8.52 and 9.82 mm -1 of opacity, and color with ^H from 82^3 to 88^3 and C from 9^1 to 12^1.

10. FILM, according to claim 9, characterized by a tensile strength limit (TSL) ranging from 4,115 to 6,346 MPa.

11. USE OF THE SUSTAINABLE POLYMERIC FILM, as defined in claims 7 to 10, characterized by being a plasticizer, for application in packaging, preferably food packaging.

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