Method for obtaining intelligent and active packaging film and packaging film obtained by the method

Abstract

The present invention relates to a method (100) for obtaining multifunctional alginate-based packaging films that are sensitive to pH changes in the environment, have barrier properties against UV and

Description

[0001] DESCRIPTION METHOD FOR OBTAINING INTELLIGENT AND ACTIVE PACKAGING FILM AND PACKAGING FILM OBTAINED BY THE METHOD Technical Field The present invention relates to a method for obtaining multifunctional alginate- based packaging films that are sensitive to pH changes in the environment, have barrier properties against UV and visible light, have antioxidant and antimicrobial properties; and to a packaging film obtained by the method. Background of the Invention Food packaging plays an important role in the preservation and transportation of foodstuffs without affecting their flavour or quality. It protects the contents from toxins and moisture; enables food products to be protected against physical damage, external contamination and spoilage; and helps to maintain their shape and quality. Until now, emerging packaging innovations have primarily been limited to the development of, for example, barrier materials (new polymers, composite and multilayer materials) or materials created for marketing purposes. "Active and intelligent packaging" technology, which has emerged in recent years and attracted a great deal of attention in the food industry, is a creative food packaging application that combines active and intelligent properties in packaging in order to improve the safety and quality of packaged foods, as well as to monitor quality changes in food by detecting external and internal conditions of packaged foods. Such systems comprise components that monitor the condition of the packaged food or environment thereof and provide the consumer with accurate information about the environmental conditions in which the product is present during transportation and storage. For this purpose, there are studies on the use of temperature, humidity, pH change and gas level (O2and CO2) indicators as an integral part of the package or as separate components placed inside the package. While systems are being developed in intelligent food packaging technologies in order to monitor products and to provide quality information during the storage of packaged foods, new additives are being tested in active food packaging methods in order to slow down the oxidation of packaged foods and to prevent the growth of harmful bacteria, yeasts and moulds so as to help to maintain the quality of foods and to extend their shelf life. Various types of biopolymers such as polysaccharides, lipids and proteins have started to be used in order to solve environmental problems caused by non- biodegradable synthetic packaging waste and to develop high value functional packaging materials by using new active and intelligent packaging technologies. Among polysaccharides, alginate obtained from marine brown algae has been widely applied in the production of various edible coatings due to its biocompatibility, biodegradability, antibacterial properties, edibility and exceptional film-forming properties. In the presence of polyvalent cations such as calcium ions, alginate gels easily and becomes indissoluble due to the formation of a cross-linked structure. Another biopolymer widely used in coating and film production is protein-based gelatine. Gelatine is characterized by excellent coating properties, physical properties that are reversible with temperature, good barrier properties and antioxidant activities. Blending is an effective way to improve the performance of films. In general, when the two components used for blending are compatible, the blended films may form a homogeneous structure and may perform better than the individual components. In a limited number of studies, the production of composite films by blending alginate and gelatine in different ratios has been studied. However, a film comprising a natural dye (curcumin-turmeric) that is sensitive to pH changes in the environment and has barrier properties against UV and visible light, and a natural essential oil (olive leaf extract) with antioxidant and antimicrobial properties, based on a blend of alginate and gelatin biopolymers, which can instantly notify product quality and safety as well as effectively extend the shelf life of the packaged product, has not been developed. For this reason, in order to overcome the above-mentioned deficiencies, there is a need for a method for obtaining multifunctional alginate-based packaging films that are sensitive to pH changes in the environment; have barrier properties against UV and visible light; have antioxidant and antimicrobial properties; and to a packaging film obtained by the method. The Turkish patent document no. TR2021 / 003745, an application included in the state of the art, discloses an antibacterial edible food packaging containing olive leaf extract, curcumin and chitosan additives. In the said invention, it is aimed to prevent packaging with carcinogenic effects and toxicity that is widely used today by producing intelligent food packaging by benefiting from the high anti-bacterial properties of curcumin and olive leaf extract. Films were prepared by preparing gelatine, chitosan, curcumin stock solutions and combining them with olive leaf extract. Three groups of food packaging were produced accordingly. The 25G-25C- KZ package which showed the best properties was selected and sent to the laboratory by giving raw chicken and raw chicken wrapped in cling film as reference. The prepared new generation anti-bacterial packaging has been shown to extend the shelf life of food through scientific results obtained by examining the properties of mould, fungi and bacteria on food; and can be consumed along with food as no toxic chemicals are used in its preparation. Summary of the Invention An object of the present invention is to realize an alginate and gelatine based packaging film which can be used for food packaging; has active abilities; can change colour depending on pH changes in the environment; has barrier properties against UV and visible light; has antioxidant and antimicrobial functions; is thermally and chemically stable; has water barrier properties; has a thin, flexible structure; and a method for obtaining the packaging film. Another object of the present invention is to realize a packaging film, which combines the ability to be effective in increasing the quality and safety as well as the shelf life of the packaged product in food, cosmetic and pharmaceutical packaging, and which is also biodegradable; and an obtaining method thereof. Detailed Description of the Invention “Method for Obtaining Intelligent and Active Packaging Film and Packaging Film Obtained by the Method” realized to fulfil the objectives of the present invention is shown in the figures attached, in which: . Figure 1 is the flow diagram of the inventive method. Figure 2 is the UV−Visible region absorbance− wavelength graphs for the a) CR and OLE b) AL films. Figure 3 shows a) the appearance of the films , and b) the light transmittance (Transmittance %)− wavelength graphs of AL films in the UV-Visible region. Figure 4 is the UV-Visible Region absorption spectrum of curcumin solution [0.01% CR (aqueous-aq.)] between the wavelength range of 200 nm−800 nm at different pHs. Figure 5 shows the chemical changes in the curcumin molecule based on the pH of the environment. Figure 6 is the UV-Visible Region absorption spectra of films coded AL20 and AL22 at different pHs and their images. Figure 7 is the Elastic Modulus (E′) and tan delta values of AL film (control group not comprising CR and OLE) between the range of 0℃−60℃. Figure 8 is the Elastic Modulus (E′) and tan delta values of films coded AL11 (1.0 mL 0.1% CR and 1.0 mL OLE) and AL22 (2.0 mL 0.1% CR and 2.0 mL OLE), for example between the temperature range of 0℃−60℃. Figure 9 is the temperature -E′ (Elastic Modulus) curves of AL films between the range of 20℃−60℃. Figure 10 is the temperature-stiffness % curves of AL films between the range of 20℃−60℃. Figure 11 is the swelling rates of AL films at pH=3.0 and pH=7.0 in the water at the 30thand 60thminutes. The component illustrated in the figures are individually numbered, where the numbers refer to the following: 100.Method A method (100) for obtaining an inventive packaging film which can be used as food / cosmetic / drug packaging; has the ability to change colour on pH changes occurring based on spoilage in the environment; combines antioxidant and antimicrobial properties that will play an active role in delaying the spoilage of food / cosmetics / drugs and the ability to be effective in increasing the quality and safety as well as the shelf life; and is also biodegradable comprises the steps of: - preparing a sodium alginate (Na Alginate) solution (101); - preparing a CaCl2solution used as cross-linker (102); - preparing a gelatine solution (103); - preparing a curcumin (turmeric) (CR) solution (104); - obtaining a film mixture by mixing a sodium alginate solution and a gelatine solution (105); - obtaining a packaging film by adding a CaCl2, curcumin and olive leaf extract (OLE) to a film mixture (106). In the step of preparing a sodium alginate (Na Alginate) solution (101) of the inventive method for obtaining packaging film (100), sodium alginate is mixed with pure water at 40−45℃ in a mechanical mixer (Ultra Thorax) at 20000−21000 rpm (round per minute) for 20−25 minutes in order to obtain 1000−2000 mL solution of 2.0−4.0%. The prepared solution is stored in a labelled beaker with a lid. In the step of preparing a CaCl2 solution used as a crosslinker (102) of the inventive method (100) for obtaining packaging film (100), a 0.5−1.0% of CaCl2w:v (weight:volume) (aq.) solution is prepared by using CaCl2.2H2O. In the step of preparing a gelatine solution (103) of the inventive method for obtaining packaging film (100), gelatine is mixed with pure water at 40−45℃ in a mechanical mixer at 500−550 rpm for 120−130 minutes in order to obtain a solution of 5.0−10.0%. The prepared solution is stored in a closed flask. In the step of preparing a curcumin (turmeric) (CR) solution (104) of the inventive method for obtaining packaging film (100), a 75−150 mL of 1.0 M acetic acid (aq) is mixed with a 425−850 mL of technical ethanol of 98%. Then, a 0.5−1.0 g of curcumin is added to the solvent mixture prepared with acetic acid and ethyl alcohol. A 0.1% of curcumin stock solution is prepared by mixing it at 40−45℃, at 500−550 rpm for 30−35 minutes. The prepared stock solution is stored in the dark in a flask wrapped with aluminium foil. In the step of obtaining a film mixture by mixing sodium alginate solution and gelatine solution (105) of the inventive method for obtaining packaging film (100), a 50−25 mL of 2.0−4.0% of Na alginate solution and a 20−10 mL of 5.0−10.0% of gelatine solution are obtained and put into a beaker in such a way that the masses of Na alginate and gelatine are equal. The Na alginate and gelatine solutions taken into the beaker are mixed in a magnetic mixer at 1000−1200 rpm for 30−35 minutes at 60−70 ℃ in order to obtain the film mixture. A 0.8−0.4 mL of glycerine (d=1.26 g.mL-1) is added to the film mixture as a compatibilizer. In the step of obtaining a packaging film by adding CaCl2 (aq), curcumin and olive leaf extract (OLE) to the film mixture (106) of the inventive method for obtaining packaging film (100), a 2.0−1.0 mL of 0.5−1.0% of CaCl2 (aq), and a 1.0−2.0 mL of 0.1% of curcumin solution are respectively added to the film mixture and mixing is carried out for 30−40 minutes at 500−550 rpm at 60−70 ℃. Then, mixing is performed respectively for 30 minutes / 60 minutes / 90 minutes at 500−550 rpm at 60−70℃ after 1.0 / 2.0 / 3.0 mL of olive leaf extract (OLE, d=1.12 g.mL-1measured by pycnometer in the laboratory) is added to the film mixtures separately, in order to ensure homogeneous distribution of the oil phase in the film mixture. Control groups not comprising olive leaf extract (OLE) are also prepared in a similar way. In an ultrasonicator (CY-500 Optic Ultrasonic Homogenizer, Ivymen System) operating at 50 kHz, 500 W, and 70-80% amplitude with a 5.5:0.0 pulse ratio, the probe of the apparatus with a 5.6 mm diameter and 60 mm length is immersed in the film mixture at a depth of 70 mm and ultrasonicated at 25-30°C for 20-25 minutes; the coarse emulsion is then converted into a nanoemulsion by means of ultrasonic emulsification. Control groups (AL, AL10, AL20) are also prepared in a similar way. The mass % composition, pH, conductivity, dynamic viscosity and density values of the film forming nanemulsions are given in Table 1. The pH values of the nanoemulsions were observed in the range of 7.77−4.83, and as the amount of CR and OLE in the mixtures increased, the pH values of the emulsions slightly decreased below 7.0. Table 1. Composition (% by mass), pH, conductivity, dynamic viscosity and density values of AL nanoemulsions (AL: Na alginate; GE: gelatine; CR: Curcumin; OLE: Olive Leaf Extract))1yti)1-,)%ss%e )y ss )ss )ssti0.0s1 L v± oc0. )l2ania %a ait ssi0±m.1 Cm remRmEmcunevci ,s ( 0Cy b(yly Cy L Oy d.nm maytis± Gb(b(b(o Ceia S nmne pHm(y(D D 0.007 0.90 0.000 0.00 7.00 4.63 2.13 1.018 0.007 0.90 0.001 0.00 7.00 4.57 2.11 1.017 0.007 0.90 0.001 1.60 7.77 3.60 2.08 1.018 0.007 0.90 0.001 3.20 7.71 4.08 1.95 1.021 0.007 0.90 0.001 4.80 6.55 4.21 2.09 1.032 0.007 0.90 0.003 0.00 5.58 3.55 1.98 1.010 0.007 0.90 0.003 1.60 4.83 4.07 2.01 1.016 0.007 0.90 0.003 3.20 6.58 4.01 1.85 1.020 0.007 0.90 0.003 4.80 5.93 4.79 1.86 1.020 The film mixture converted into nanoemulsion is tared and poured into plastic petri plates (2R=11.5cm) and left for gelling in the drying oven at +39−42℃ for seven days. The dried films are stored in the refrigerator at +4℃ with closed lid. Compositions, mass and diameter values of the prepared sodium alginate (AL) film samples are given in Table 2. Table 2. Compositions, mass and diameter values of AL films (AL: Na alginate; GE: Gelatine; CR: Curcumin; OLE: Olive Leaf Extract) 2.0% 5.0% AL, GE Wet Dried Dried (w / v, (w / v, 0.1% 1.0% film film film Film aq.) aq.) CR OLE CaCl2 Glycerine mass mass diameter sample (mL) (mL) (mL) (mL) (mL) (mL) (g) (g) (cm) AL 50 20 0.0 0.0 1.0 0.8 70.0 2.93 11.5 AL10 50 20 1.0 0.0 1.0 0.8 70.0 2.89 11.5 AL11 50 20 1.0 1.0 1.0 0.8 70.0 3.29 11.5 AL12 50 20 1.0 2.0 1.0 0.8 70.0 3.69 11.5 AL13 50 20 1.0 3.0 1.0 0.8 70.0 4.07 11.5 AL20 50 20 2.0 0.0 1.0 0.8 70.0 2.65 11.5 AL21 50 20 2.0 1.0 1.0 0.8 70.0 2.94 11.5 AL22 50 20 2.0 2.0 1.0 0.8 70.0 3.48 11.5 AL23 50 20 2.0 3.0 1.0 0.8 70.0 3.84 11.5 Physical characterizations of the obtained AL films were realized. All film samples exhibited homogeneous surfaces without visible bubbles or cracks. Furthermore, the samples were removed from the plastic petri plates without tearing and showed easy to use properties. This situation means that the recipes applied for the preparation of the samples were successful in forming films that were neither sticky nor brittle. The thicknesses and densities of the obtained films are determined. The homogeneity and thickness of the film-forming emulsion affects the drying process, which may cause differences in the film structure. Therefore, the density, viscosity and uniform distribution of the film mixture on the poured surface enables the film thickness to be controlled, which is crucial for the physical and barrier properties of the dried films. The thicknesses of the AL films given in Table 3 were determined by taking measurements from 5 different regions and averaging these measurements. The average film thickness was measured as 0.28 mm for the control group and there was no significant change (p<0.05) with the addition of CR and OLE. Film thicknesses varied between 0.37 and 0.24 mm. Table 3. Thickness measurements of AL films in five different regions and their average thickness Measureme Measureme Measure Measure Measure Average Film sample nt 1 nt 2 ment 3 ment 4 ment 5 (mm) (mm) (mm) (mm) (mm) (mm) AL 0.26 0.27 0.26 0.26 0.340.28±0.02AL10 0.21 0.21 0.27 0.38 0.300.27±0.06AL11 0.28 0.3 0.29 0.3 0.310.30±0.02AL12 0.28 0.29 0.28 0.33 0.390.31±0.02AL13 0.38 0.35 0.40 0.32 0.390.37±0.03AL20 0.36 0.21 0.39 0.20 0.350.30±0.08AL21 0.27 0.24 0.27 0.25 0.270.26±0.01AL22 0.31 0.28 0.28 0.29 0.270.29±0.02AL23 0.23 0.21 0.24 0.30 0.230.24±0.05 Addition of 1.0, 2.0 and 3.0 mL of OLE to mixtures comprising 1.0 mL of 0.1% CR (aq) solution increased the film thickness by 0.02, 0.03 and 0.09 mm compared to the film from the AL control group. This increase is coherent with the gradual increase in the nanoemulsion density depending on the increasing amount of OLE. On the other hand, the film thicknesses of AL21, AL22 and AL23, which comprise 1.0, 2.0 and 3.0 mL of OLE and to which 2.0 mL of 0.1% CR (aq.) solution was added, were respectively measured as 0.26, 0.29 and 0.24 mm; these values do not show significant difference from the control group. Table 4. Mass, size and density values of AL films in dried form Dried film Dried Dried thickness film film Dried film (average of five Film Dries film mass diamete surface measurements) volume density Sample (g) r (cm) area (cm2) (cm) (cm3) (g.cm−3) AL 2.930 11.5 103.91 0.0278 2.89 1.01 AL10 2.890 11.5 103.91 0.0274 2.85 1.02 AL11 3.290 11.5 103.91 0.0296 3.08 1.07 AL12 3.690 11.5 103.91 0.0314 3.26 1.13 AL13 4.070 11.5 103.91 0.0368 3.82 1.06 AL20 2.650 11.5 103.91 0.0302 3.14 0.84 AL21 2.940 11.5 103.91 0.0260 2.70 1.09 AL22 3.480 11.5 103.91 0.0286 2.97 1.17 AL23 3.840 11.5 103.91 0.0242 2.51 1.53 The density values of dried AL films comprising CR and OLE given in Table 4 vary between 1.06 and 1.53 g.cm-3. The fact that the water-based films show a slightly higher density than the density of water indicates that air bubbles can be successfully removed from the film-forming nanoemulsions. The examination of the colorimetric and optical properties of AL films has been realized. The optical properties of the films are directly related to their UV-Visible spectra, light transmittance (T) and opacity, compositions, surface properties and the distribution of the components forming the structure within the film. Therefore, optical properties provide important information about the structure of the films. The colour properties of AL films found by colorimetric measurement are shown in Table 5. The AL control group has the highest lightness / illuminance (L*) value (85.50). CR has a natural yellow-orange colour having a low negative a* value and a high positive b* value. The inclusion of curcumin leads to composites having an intense orange colour. The L* values of AL10 and AL20 which respectively comprise only 1.0 mL and 2.0 mL of 0.1% CR (aq.) were measured as 81.00 and 76.35. With the increase of OLE content, L* values decreased, while redness (a*) and yellowness (b*) values increased, which showed that the films appeared reddish yellow after the addition of OLE. Table 5. Colorimetrically measured L*, a*, b* and ^E* values of AL film samples Sample L*average^L* a*average^a* b*average^b* ^E* White Paper 91.98±0.03 1.63±0.06 −4.43±0.04 The light absorption properties of AL films in the UV and visible region were examined. The light transmission of the films against ultraviolet (UV) and visible light was determined by using a UV-Visible spectrophotometer (SOIF UV−5100 UV / VIS 200−1000 nm, Shanghai Metash Instruments, China) in absorption (A) mode at selected wavelengths (800−200 nm) according to the method described by Bonilla and Sobral. The films were cut into 10 × 40 mm samples and placed directly on the inner wall of the sample cell of the spectrometer. Zero adjustment between the range of 800−200 nm with the empty sample cell and then the measurement of the samples was realized. The absorbance-wavelength in the UV-Visible Region graphs of 0.1% of CR solution (pH 8.5) and pure OLE are given in Figure 2(a), and of AL films comprising increasing amounts of CR and OLE and the AL control group are given in Figure 2(b). Curcumin solution showed a strong and intense absorption band at 430 nm and a shoulder-shaped absorption band at 480 nm in the visible region depending on the presence of phenolic groups. The shoulder given by the CR (aq.) solution in the UV region at 292 nm emerges depending on the transition between keto−enol forms in alkaline environment. As confirmed by the UV-Visible spectrum, curcumin absorbs UV-Visible light efficiently. This observation is in accordance with the literature data. In the UV-Visible spectrum of OLE, three peaks are observed in the UV region at 322 nm (Band I), in the visible region at 422 (Band II) and at 492 nm (Band III). The fact that these bands belong to the main phenolic compounds of OLE can be suggested on the basis of previous data. Band I belongs to oleuropein which is the most abundant compound in olive leaves and hydroxytyrosol which is its precursor. Band II and Band III relate to luteolin-7-O-glucoside and apigenin-7-O-glucoside and verbascoside which are flavone compounds mainly present in olive leaf extract. As seen in Figure 2 (b), while the light absorption value of the AL control group (CR=0; OLE=0) was very low in the visible region, the absorption gradually increased as it moved towards the UV region and reached the maximum UV light absorption value at 240 nm, giving a shoulder at 280 nm. On the other hand, a significant change in the UV absorption capacity of the films was observed upon addition of CR and OLE to the film samples. The light absorption values below 600 nm of AL11, AL12, AL13, AL21, AL22 and AL23 comprising CR and OLE started to increase rapidly compared to the control group. Four bands at 380 nm (400−340 nm, UVA1), 312 nm (340−315 nm, UVA2), 280 nm (280−315 nm, UVB) and 240 nm (230−280 nm, UVC) were observed in all samples. The intensity of these bands was higher in AL21, AL22 and AL23 comprising 2.0 mL of 0.01% of CR, and the UV barrier properties progressively improved with increasing curcumin content depending on the presence of phenolic compounds that enable the absorption of UV radiation. The results are in accordance with the previous findings. The light transmittance and opacity of AL films in the visible region were examined. The absorption values of the film samples were measured at ^ = 600 nm in order to determine the opacity of them. Each sample tested 3 times. The opacity value for each film was calculated by using the following equation: Opacity value = (-log10 T600) / x ..........(1) In equation (1), T600 is the visible light transmittance value at 600 nm and x is the film thickness (mm). The opacity values of AL films are given in Table 6. Table 6 shows that the opacity value of AL films at 600 nm increases depending on the increase in CR and OLE concentrations. The opacities of AL11, AL12 and AL13 films comprising 1.0 mL of 0.1% of CR and increasing amounts of OLE have increased between 46.5% and 134% compared to the opacity value of the AL control group. The opacity values of AL21, AL22 and AL23 comprising 2.0 mL of 0.1% of CR and increasing amounts of OLE have increased by 147% to 255%. The increase in opacity depends on the presence of CR as well as the light scattering properties of the oil phase distributed in the alginate matrix. Table 6. Light transmittance and opacity of AL films at 600 nm Average Opacity Film thickness value* sample Absorbance T% T (xaveragemm) (mm−1) AL 0.16 68.60 0.6860 0.28 0.58 AL11 0.42 38.00 0.3800 0.31 1.36 AL12 0.33 46.80 0.4680 0.39 0.85 AL13 0.51 30.70 0.3070 0.39 1.32 AL21 0.62 24.20 0.2420 0.27 2.28 AL22 0.39 41.20 0.4120 0.27 1.43 AL23 0.47 33.60 0.3360 0.23 2.06 *Opacity Value = (−log10 T600) / The effects of the inclusion of CR and OLE on the light transmittance of the films are shown in Figure 3. The films comprising CR and OLE exhibited excellent UV barrier properties which could protect food from light-induced oxidative degradation in the UV range of 200−400 nm when compared to the AL control group. Furthermore, the UV barrier properties of the films progressively increased with increasing CR and OLE content depending on the presence of phenolic compounds having UV radiation absorption properties. The light transmittance (T%) of films comprising CR and OLE in the visible region (400-700 nm) also significantly reduced compared to the AL control group. The T% values decreased from 69% to 24% at 600 nm with increasing CR and OLE concentration, which shows that CR and OLE have a good compatibility with the alginate matrix. The colour change of AL films depending on pH was examined by UV-Visible Spectrometer and colorimeter. UV-Visible absorption spectra of 0.01% of CR (aq.) solution at different pHs were recorded in order to verify the pH indicator property of curcumin. The images and UV-Visible absorption spectra of curcumin solutions at different pHs are given in Figure 4. As the pH values increased from 3.0 to 11.0, it is observed that the colour of curcumin changed noticeably from light yellow to orange-red. The colour of CR is yellow (light to dark) at pH 3.0, 5.0, 7.0 and reddish brown at pH 9.0 and 11.0. These changes are caused by the reversible structural transformation of CR at different pH, the respective scheme is shown in Figure 5. The keto form of CR is predominant in acidic and neutral environments, and the enol form is predominant at pH values above 8.0. Curcumin is stable under acidic pH conditions; this stability is attributed to the presence of a conjugated diene structure. When pH is 8.0 and higher, the easy reaction of phenolic hydroxyl group with OH- for forming phenoxide anion causes colour change (Figure 5). Table 7. Maximum absorption values of turmeric (CR) solution at pH 3.0, 5.0, 7.0, 9.0 and 11.0 and the respective wavelength Wavelength Absorption Wavelength Absorption pH ( ^) (nm) (relative) ( ^) (nm) (relative) 3 430 1.300 300 2.470 5 430 1.520 300 2.610 7 430 1.970 292 2.040 9 292 1.880 426 4.210 480 3.160 11 292 1.860 426 4.210 In the absorption spectrum of curcumin, at pH 3.0, 5.0 and 7.0 under acidic and neutral conditions, the maximum absorption emerged at 430 nm in the visible region. The respective data are shown in Table 7. The peak at 430 nm is attributed to a combination of electron excitation of the π-π* and n→n^ transitions of the carbonyl groups of CR. An evident change occurred in the UV-Visible absorption spectrum of curcumin at pH 9.0 and 11.0. In the visible region, the peak at 430 nm shifted to 426 nm and at 480 nm a shoulder formation with high absorption intensity was observed. The shoulder at 480 nm depends on the CR losing its protons under alkaline condition. In alkaline environment, the peak observed at 426 nm relates to the conversion of the keto form into the enol form. Curcumin solution peaked at 300 nm in the UV region at pH 3.0 and 5.0, this peak took the form of a shoulder by shifting to 292 nm at pH 7.0-9.0-11.0. This shift is attributed to the degradation products of curcumin. UV-Visible region absorption spectra at different pHs and colorimetric measurements of films coded AL20 and AL22 were realized. In order to evaluate the pH sensing function of the films, AL20 (0.1% CR: 2.0 mL; OLE: 0 mL) and AL22 (0.1% CR: 2.0 mL; OLE: 2.0 mL) buffer solutions with pH 3.0, 5.0, 7.0, 9.0 and 11.0 were sprayed on the film surface and UV-Visible spectrometer measurements were realized after the films were dried. UV visible absorption spectra of the films at different pHs are given in Figure 6 and absorption values at 422 nm and 354 nm wavelength are given in Table 8. As seen in Figure 6 and Table 8, the absorption-wavelength graph of AL22 comprising 2.0 mL of 0.1% of CR and 2.0 mL of OLE at pH 3.0, 5.0, 7.0, 9.0 and 11.0 showed an evident change compared to the respective graph of AL20 comprising only 2.0 mL of 0.1% of CR solution. The shoulder at 322 nm in the OLE-specific UV region and the peak at 422 nm in the visible region are observed. In addition to the change in the UV-Visible light absorption behaviour of CR at different pHs, it is understood that OLE preserves its structure intact in acidic and alkaline environments. Table 8. Absorption values of AL 20 and AL22 at 422 nm and 354 nm wavelength at different pHs Absorption (relative) Absorption (relative) Film ( ^= ^ ^ ^ nm) ( ^= ^ ^ ^ nm) The colour change in colorimetric measurements of the films coded AL22 and AL23 at different pHs and the obtained colour parameters are listed in Table 9. L* and b* values of AL22 and AL23 films at pH 3.0-7.0 are high and their colours are close to yellow. When the pH increased from 7.0 to 9.0, there was a sudden increase in the a* value of AL22 from 12.25 to 14.52 and the a* value of AL23 from 9.41 to 14.53, which shows a strong shift to red under basic conditions. Furthermore, with the increase in alkalinity from pH 9.0 to pH 11.0, redness increased in both samples. Table 9. Colorimetric measurement results of AL22 and AL23 at different pHs Sample L* a* b* ΔE AL22 46.93±0.93 20.35±0.74 34.78±1.11 59.91±^0.09 AL22(pH3) 66.20^±^0.05 12.74^±^0.01 42.83^±^0.01 51.22^±^0.02 AL22(pH5) 56.65^±^0.05 10.25^±^0.01 41.61^±^0.01 56.71^±^0.02 AL22(pH7) 68.23^±^0.02 12.25^±^0.01 38.30^±^0.11 46.30^±^0.05 AL22(pH9) 55.94^±^0.02 14.52^±^0.15 30.20^±^0.09 48.76^±^0.11 AL22 (pH11) 56.81^±^0.09 16.99^±^0.10 23.58^±^0.08 43.21^±^0.12 AL23 40.59±2.63 19.74±2.70 27.43±3.26 61.00±4.98 AL23(pH=3.0) 76.97±1.01 7.94±0.62 34.97±0.23 38.58±1.21 AL23(pH=5.0) 54.93±2.76 14.71±0.87 37.74±1.31 54.47±3.18 AL23(pH=7.0) 67.36±0.01 9.41±0.06 44.17±0.28 51.16±0.29 AL23(pH=9.0) 63.01±0.92 14.53±0.64 35.89±2.01 45.69±2.45 AL23(pH=11.0) 62.98 ±1.97 15.12±0.17 48.58±3.61 58.17±4.11 Antioxidant properties of AL films were examined. Total phenolic content, DPPH radical and ABTS radical were used for this. Different antioxidant tests represent different action systems. DPPH radical scavenging activity is attributed to the hydrogen donating ability of the test compounds. ABTS method, which is more effective than DPPH radical for lipophilic and hydrophilic antioxidants, was used in order to measure total antioxidant capacity. The total phenolic content of the films was determined by using the Folin-Ciocalteu method with some modifications. The total phenolic content of AL films as gallic acid equivalent (GAE) is summarized in Table 10. The total phenolic compound content of the AL control group, which is 7.37 mg GAE / g film, relates to the presence of polyphenolic compounds in the structure of alginate located in the film matrix. Table 10. Total phenolic content of AL films as gallic acid equivalent (GAE) Aborbance76-1C= c x Vfilm extract / Sample cGAE (mg.L ) 0 mfilm (mgGAE / g film) AL 0.1147 241.60±0.02 7.48±0.02 AL11 0.4499 912.00±0.02 29.80±0.02 AL12 0.5102 1032.60±0.02 32.78±0.02 AL13 0.5514 1115.00±0.02 35.40±0.02 AL21 0.5276 1067.40±0.02 33.89±0.02 AL22 0.6436 1299.40±0.02 40.86±0.02 AL23 0.7717 1555.60±0.02 50.51±0.02 The antioxidant activity of the films increased significantly with the addition of curcumin and olive leaf extract. When the contribution of curcumin to total phenolic content was examined: the total phenolic content of AL11 comprising one millilitre of 0.1% of CR (aq.) and 1.0 mL of OLE was calculated as 29.80 mg GAE / g film, and the total phenolic content of AL21 comprising two millilitres of 0.1% of CR (aq.) and 1.0 mL of OLE was calculated as 33.89 mg GAE / g film. Similarly, while the total phenolic content of AL12 and AL13 comprising 1.0 mL of 0.1% of CR (aq.) and 2.0 and 3.0 mL of OLE was respectively 32.78 and 35.40 mg GAE / g film, the total phenolic content of AL22 and AL23 comprising two millilitres of 0.1% of CR (aq.) and 2.0 and 3.0 mL of OLE increased to 40.86 and 50.51 mg GAE / g film by increasing 4.4-4.7 times. On the other hand, when the contribution of OLE to the total phenolic content was examined: the total phenolic content of AL21, AL22 and AL23 comprising 1.0, 2.0 and 3.0 mL of OLE together with, for example, two millilitres of 0.1% of CR (aq.) increased both compared to the control group and among themselves as the amount of OLE increased. The total phenolic content of AL21, AL22 and AL23 calculated as GAE respectively increased 4.5, 5.5 and 6.8 times to 33.89, 32.78 and 35.40 mg GAE / g film compared to the AL control group. As a result, as the amounts of CR and OLE increase in the composition of AL films, the total phenolic content of the film samples increases at a rate of 300-575% by CR and OLE showing a synergistic effect. The antioxidant activity of the film samples was evaluated by simple and quick DPPH free radical scavenging test. Table 11. DPPH scavenging activity values of AL film samples Sample AL AL10 AL20 AL11 AL12 AL13 AL21 AL22 AL23 DPPH 48.4 164.5 676.1 864.7 836.0 581.9 881.1 scavenging 89.93 88.18 5 9 3 5 8 1 1 activity (%) DPPH scavenging 4.8 9.0 8.8 16.5 67.6 86.5 83.6 58.2 88.1 activity / film mass (%.g−1) DPPH free radical scavenging activity values of AL film samples are seen in Table 11. DPPH free radical scavenging activity values are coherent with the increase in total phenolic content observed as parallel to the increase in the amounts of CR and OLE in the film structure. The DPPH scavenging activity of AL control group was measured as 4.8 %.g-1. Previous studies have shown that sodium alginate and gelatine exhibit some antioxidant activity. The DPPH scavenging activities of AL13 (1.0 mL CR and 3.0 mL OLE) and AL23 (2.0 mL CR and 3.0 mL OLE) have peaked respectively at 86.5 %.g-1and 88.1 %.g-1by increasing approximately 18-fold compared to the AL control group. ABTS (2,2-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) free radical scavenging activity of the film samples was determined. ABTS Free Radical Scavenging Activity values of AL film samples in Trolox equivalent are summarized in Table 12. The ABTS free radical scavenging activity in Trolox equivalents of AL10 and AL20 comprising respectively 1.0 mL and 2.0 mL of 0.1% CR (aq.) solution prepared in order to determine the contribution of only the addition of CR to the free radical scavenging activity showed an increase of 6.5% and 28.5% compared to the control group. When increasing volumes of OLE were added, a great increase in antioxidant activity was observed compared to AL10 and AL20. Table 12. ABTS free radical scavenging activity of AL film samples µMolar Trolox equivalent / g film Sample AL AL10 AL11 AL12 AL13 AL20 AL21 AL22 AL23 Concentratio 3.47 3.69 5.25 6.17 6.74 4.45 5.69 6.07 7.98 n (µmol.L-1) Concentratio n (µmol.L-1.g-1346. 368.94 525.49 617.15 674.20 445.30 569.48 607.30 798.19 film) Increase %- 6.50 51.60 78.10 94.60 28.50 64.30 75.30 130.30 For example, the ABTS free radical scavenging activity of AL21, AL22 and AL23 comprising 1.0, 2.0, 3.0 mL of OLE in addition to 2.0 mL of CR (aq.) solution increased as the amount of OLE in the film composition increased and showed a significant increase in antioxidant activity of 64.3%, 75.3% and 130.3%, respectively, compared to both the control group AL and AL20 films comprising only CR (aq.). The antioxidant capacity is positively related to the total phenolic content in the films. In summary, the addition of curcumin and tea leaf extract significantly increased the antioxidant capacity of alginate-gelatine films, the highest antioxidant capacity was observed in AL23 film comprising 2.0 mL CR (aq.) and 3.0 mL OLE. The antimicrobial properties of AL films were also examined. Coagulase positive staphylococci count, total coliform bacteria count (cfu / g - colony-forming unit per gram), Pseudomonas aeruginosa detection and count (cfu / g), Listeria monocytogenes screening (cfu / 25g) and yeast and mould count tests, which are standard tests for materials and articles in contact with food, were applied to films coded AL, AL11, AL12, AL13, AL21, AL22 and AL23 and the results are given in Table 13. When the analysis results were examined, no coagulase positive staphylococcus, coliform bacteria, Pseudomonas aeruginosa, Listeria monocytogenes and yeast / mould formation, which are common foodborne pathogenic bacteria, were detected in any of the samples, including the control group, independent of the amount of CR and OLE comprised in the film samples. The antibacterial and antifungal effect observed in the control group was associated with the presence of calcium chloride in the structure. Table 13. Antimicrobial test results of AL, AL11, AL12, AL13, AL21, AL22 and AL23 Coagulase Total positive coliform Pseudomonas Listeria 1 staphyloc bacteria aeruginosa monocytogenes occi count count detection and screening Yeast and mould Sample (cfu / g) (cfu / g) count (cfu / g) (cfu / 25g) formation AL <100* <10** <100* Not detected Not detected AL11 <100* <10** <100* Not detected Not detected AL12 <100* <10** <100* Not detected Not detected AL13 <100* <10** <100* Not detected Not detected AL21 <100* <10** <100* Not detected Not detected AL22 <100* <10** <100* Not detected Not detected AL23 <100* <10** <100* Not detected Not detected The dynamic mechanical properties of AL films were examined. The elastic modulus (E′) variation and tan delta values drawn on log scale against linear temperature scale for AL, AL11 and AL22 between the temperature range from 0℃ to 60℃ are respectively shown in Figure 7 and Figure 8. As summarised in Figure 8, Figure 9, Figure 10 and Table 14 and 15, in addition to glycerol and CaCl2, the E′ values of AL11 comprising 1.0 mL 0.1% CR (aq.) and 1.0 mL OLE were measured in the Pa range of 1.5x109-2.5x108at 0-36℃, and the minimum E′ value was found as 3.78x107 Pa at Tg=37℃. The E′ values of Al22 comprising 2.0 mL 0.1% CR (aq.) and 2.0 mL OLE were measured in the Pa range of 5.4-2.7x108at 0- 45℃, and the minimum E′ value was found as 1.05x107Pa at Tg=46℃. In addition to the decrease in E′ values and tan delta values of AL films with the addition of OLE, the elastic storage modulus values and tan delta values of the films obtained by adding increasing amounts of OLE as well as CR to the alginate-gelatine matrix were found to be in the same order with the values given in the literature for films that can be used as food packaging. Table 14. E′ values of AL, AL11 and AL22 in the range 0℃-60℃ Temperature (℃) 0 5 10 14 20 25 30 35 40 45 50 55 59 AL E′ (MPa) 17342 16225 13604 10233 4332 971 427 1109 976 1250 872 1481 2535 AL11 E′ (MPa) 1468 724 499 330 203 289 163 86 244 173 255 176 198 AL22 E′ (MPa) 540 570 499 293 478 354 523 418 231 272 202 265 352 Table 15. Tan ^ values of AL, AL11 and AL22 in the range 0℃ - 60℃ Temperature (℃) 0 5 10 14 20 25 30 35 40 45 50 55 59 AL tan ^ 0.19 0.19 0.22 0.31 0.47 2.58 3.21 1.01 1.05 1.35 0.41 0.12 0.35 AL11 tan ^0.07 0.19 0.33 0.42 0.28 0.36 0.10 0.33 0.23 0.48 0.21 0.37 0.04 AL22 tan ^ 0.14 0.20 0.14 0.31 0.65 0.33 0.09 0.32 0.67 1.00 0.60 0.17 0.12 The swelling behaviour and dissolution behaviour of AL films in aqueous environment were examined. Buffer solutions with pH 3.0 and 7.0 were used for swelling (S) measurements at different pHs. The film samples were cut into 10 x 20 mm pieces, weighed in tared petri plates (mfirst), 2.0 mL of buffer solution was dripped on them and kept for 60 minutes at room temperature, the excess of the solution phase on the sample was removed with filter paper and weighed (mlast). The swelling% values of AL films at pH 3.0 and 7.0 at the 30thand 60thminutes are given in Table 16 and Figure 11. At pH 3.0, the swelling value of the AL control group in water at the 30thand 60thminutes is respectively 9.2% and 12.8%. The water swelling values of the samples coded AL12 (1.0 mL CR and 2.0 mL OLE), AL13 (1.0 mL CR and 3.0 mL OLE), AL22 (2.0 mL CR and 2.0 mL OLE) and AL23 (2.0 mL CR and 3.0 mL OLE), to which increasing amounts of OLE were added to the alginate-gelatine matrix with CR, were measured in the range of 4.0- 8.3% at the 30thminute and in the range of 2.7-12.1% at the 60thminute. At pH 7.0, the swelling values of AL12 (1.0 mL CR and 2.0 mL OLE), AL13 (1.0 mL CR and 3.0 mL OLE), to which increasing amounts of OLE were added to the alginate- gelatine matrix with CR, were 31.3% and 18.4% at the 60thminute. While no significant change was observed in samples AL22 (2.0 mL CR and 2.0 mL OLE) and AL23 (2.0 mL CR and 3.0 mL OLE) at the 30thminute compared to pH 3.0, swelling rates reached the order of 23-24%, especially at the 60thminute. However, these values are also lower than the values found for the control group. Table 16. Swelling rates of AL films in buffer solutions with pH 3.0 and pH 7.0 at the 30thand 60thminutes pH=3.0 pH=7.0 Swelling% Swelling% Swelling% Swelling% Sample (30 min) (60 min) (30 min) (60 min) AL 9.2 12.8 7.4 27.9 AL10 12.5 9.5 11.0 25.9 AL12 4.0 2.7 13.0 31.3 AL13 4.8 3.8 7.8 18.4 AL20 10.3 15.8 5.9 24.0 AL22 8.3 12.1 4.3 22.7 AL23 5.5 4.8 8.7 23.6 In summary, film samples show no significant swelling (3.0-12.0%) in water at pH 3.0 at the 60thminute and show swelling in the order of 20-25% at pH 7.0 in a neutral environment. On the other hand, it can be said that the addition of OLE to the structure decreased the swelling property both at pH 3.0 and pH 7.0 compared to the control group. This situation is related to the fact that the structure gains a more hydrophobic property depending on the presence of OLE droplets in the dense network formed by cross-linking of alginate polymer chains with Ca+2 ions. The solubility of AL films at different pHs was examined. After the final wet weighing at the end of the swelling experiment in water at different pHs (pH 3.0 and 7.0), 2.0 mL of buffer solution was added to the samples again and kept for 24 hours. Each film sample was dried with the petri plate in a drying oven at 45-50°C for 24 hours and the final dried matter content (mdried) was determined by weighing. The results are summarised in Table 17. Table 17. Dissolution rates of AL films in buffer solutions with pH 3.0 and pH 7.0 pH=3.0 pH=7.0 Sample Mass loss % (24 hours) Mass loss % (24 hours) AL 0.1 0.3 AL12 0.0 0.4 AL13 0.3 0.4 AL22 0.1 0.6 AL23 0.4 0.4 According to the mass measurements made after keeping at pH 3.0 for 24 hours and then drying at 50℃ in a drying oven for 24 hours, the mass loss of AL13 and AL23 comprising 3.0 mL OLE with 1 or 2.0 mL of CR was found to be 0.3 and 0.4%. In a similar experiment conducted at pH 7.0, mass losses of water solubility values in AL12, AL13, AL22 and AL23, in other words water solubility experimental groups, were calculated in the order of 0.4-0.6%. As seen, AL films have a very high resistance to dissolution in water. This increase in the water resistance of AL films is due to the cross-linking of alginate polymer chains with Ca+2 ions forming a denser network that prevents the alginate from leaving the film. This dense network also prevents OLE droplets from leaving the film. Water vapor permeability of AL films was examined. Water vapor permeability (WVP) is one of the most important properties of films that will be used as food packaging. This is an important parameter to consider when deciding on the type of packaging for a particular food product. Water vapour transmission rate and water vapor permeability values of AL film samples calculated in the water vapor permeability test are given in Table 18. The low WVP of the film will help to reduce or prevent moisture exchange between the food and the surrounding environment. Water vapor permeability (WVP) test was performed according to ASTM E96-00 (ASTM.2004) with some modifications. Eppendorf tubes (V=1.5 mL) were filled with anhydrous silica (0% RHc), the opening (2R=9.47 mm) was tightly sealed with film sample and weighed (Wi). A 100 mL of saturated NaCl (aq.) solution (75% RHd) was added to a desiccator, tubes were placed vertically in the desiccator. Experiments were performed at 20°C. As the relative humidity (RHc) inside the tubes is lower than outside, the water vapour transmission was determined from the weight gain of the tubes. The weights of the tubes at the 3rd, 6thand 9thday were recorded by measuring with an electronic balance (Wt) and plotted as a function of time. The slope of each curve ( ^m / ^t. g H2O.s−1) was obtained by linear regression. Water Vapor Transmission Rate (WVTR) and accordingly Water Vapor Permeability (WVP) values were calculated by equations numbered (2) and (3) by dividing the calculated slope by the permeability surface area (A, m2) of the film samples: Water Vapor Transmission Rate: WVTR= Slope / A (g H2O. s−1.m−2) ....... (2)Water Vapor Permeability: WVP= WVTR / [PV H2Ox (RHd− RHc) xd] (g H2O.Pa−1.s −1.m −1 ) ……….. (3)Herein shows: PV H2O = Saturation water vapor pressure (2339.27 Pa at 20°C) at the ambient temperature (20°C) wherein the test was performed; RHd- RHc= Relative humidity gradient across the film - expressed as a fraction (0.75); A = Water vapor permeability area of the film (m2) and daverage= Film thickness (m) which is the average of five measurements. The Water Vapor Transmission Rate (WVTR) and Water Vapor Permeability (WVP) of alginate film samples mainly depend on their chemical structure and morphology. The water vapor transmission rate of Al films to which OLE was added at increasing rates had decreased, and accordingly, WVP values appeared lower on the 3rd, 6thand 9thdays compared to the AL control group. For example, the water vapor permeability values of AL21, AL22 and AL23 comprising 1.0, 2.0 and 3.0 mL of OLE with 2.0 mL of 0.1% CR (aq.) were calculated as 2.28x10−2, 1.85 x10−2and 2.32x10−2g H2O.Pa−1.s−1.m−1on the 3rdday, respectively, decreasing by 8-25-6% compared to AL. Although there is no direct proportion between the WVP values of the films, it is seen that the water vapor transmission rate and water vapor permeability of AL21 to which a minimum of 1.0 mL OLE is added decreases with the increase in the amount of OLE due to the non-uniform distribution of OLE which is the oil phase in the film matrix. AL22 to which 2.0 mL OLE was added had the lowest water vapor permeability on the 3rdday. The cage structure formed by alginate-gelatine chains with Ca+2ions seems to reduce the water vapor transmission of OLE droplets trapped therein. Table 18. Water vapor transmission rate and water vapor permeability values of AL film samples at 3rd, 6thand 9thday The present invention also relates to safe active food packaging films which change colour instantaneously depending on the change of pH value upon degradation of fresh and / or processed foods, food supplements, cosmetic products and others that are sensitive to pH changes in the environment by means of the colour changing property of turmeric added to the structure in different mixture ratios; protect the product against UV and visible light by means of barrier property thereof by means of the UV and visible light absorbing property of turmeric; delay the oxidation of the products packaged by the synergistic interaction of alginate, turmeric and olive leaf extract; prevent bacterial growth; preserve the distinctive taste / smell and colour of the food / cosmetic product / the like; are thermally stable; have very low water dissolution and water vapour permeability; are suitable for packaging; are cost- efficient; and can easily be applied to industrial production processes; and will be effective in increasing shelf life as well as quality and safety. Within these basic concepts; it is possible to develop various embodiments of the inventive “Method (100) for Obtaining Intelligent and Active Packaging Film and Packaging Film Obtained by the Method (100)”; the invention cannot be limited to examples disclosed herein and it is essentially according to claims.

[0002] 

Claims

CLAIMS 1. A method (100) for obtaining a packaging film which can be used as food / cosmetic / drug packaging; has the ability to change colour on pH changes occurring due to spoilage in the environment; combines antioxidant and antimicrobial properties that will play an active role in delaying the spoilage of food / cosmetics / drugs and the ability to be effective in increasing the quality and safety as well as the shelf life; and which is also biodegradable characterized by comprising the steps of; - preparing a sodium alginate solution (101); - preparing a CaCl2 solution used as cross-linker (102); - preparing a gelatine solution (103); - preparing a curcumin solution (104); - obtaining a film mixture by mixing a sodium alginate solution and a gelatine solution (105); - obtaining the a film by adding CaCl2, curcumin and olive leaf extract to a film mixture (106).

2. A method (100) according to Claim 1; characterized in that in the step of preparing a sodium alginate (Na Alginate) solution (101), sodium alginate is mixed with pure water at 40-45℃ in a mechanical mixer at 20000-21000 rpm for 20-25 minutes in order to obtain 1000-2000 mL solution of 2.0-4.0%.

3. A method (100) according to Claim 1 or 2; characterized in that in the step of preparing a CaCl2solution used as a crosslinker (102), a 0.5−1.0% of CaCl2w:v (aq.) solution is prepared by using CaCl2.2H2O.

14. A method (100) according to any one of the preceding claims; characterized in that in the step of preparing a gelatine solution (103), gelatine is mixed with pure water at 40−45℃ in a mechanical mixer at 500−550 rpm for 120−130 minutes in order to obtain a solution of 5.0−10.0%.

5. A method (100) according to any one of the preceding claims; characterized in that in the step of preparing curcumin (turmeric) (CR) solution (104), a 75−150 mL of 1.0 M acetic acid (aq.) is mixed with 425−850 mL of technical ethanol of 98%; and then, a 0.5−1.0 g of curcumin is added to the dissolver mixture prepared with acetic acid and ethyl alcohol; and a 0.1% of curcumin stock solution is prepared by mixing it at 40−45℃, at 500−550 rpm for 30−35 minutes.

6. A system (1) according to any one of the preceding claims; characterized in that in the step of obtaining the film mixture by mixing sodium alginate solution and gelatine solution (105), a 50−25 mL of 2.0−4.0% of Na alginate solution and a 20−10 mL of 5.0−10.0% of gelatine solution are obtained and put into a beaker in such a way that the masses of Na alginate and gelatine are equal; and the Na alginate and gelatine solutions taken into the beaker are mixed in a magnetic mixer at 1000−1200 rpm for 30−35 minutes at 60−70 ℃ in order to obtain the film mixture.

7. A method (100) according to Claim 6; characterized in that in the step of obtaining a film mixture by mixing sodium alginate solution and gelatine solution (105), a 0.8−0.4 mL of glycerine is added to the film mixture as a compatibilizer.

8. A method (100) according to any one of the preceding claims; characterized in that in the step of obtaining a packaging film by adding CaCl2, curcumin and olive leaf extract (OLE) to the film mixture (106), a 2.0−1.0 mL of 0.5−1.0% of CaCl2 (aq) and a 1.0−2.0 mL of 0.1% of curcumin are respectively added to the film mixture and mixing is carried out for 30−40 minutes at 500−550 rpm at 60−70 ℃ after each added chemical.

29. A method (100) according to Claim 8; characterized in that in the step of obtaining a packaging film by adding CaCl2, curcumin and olive leaf extract (OLE) to the film mixture (106), mixing is performed respectively for 30 minutes / 60 minutes / 90 minutes at 500−550 rpm at 60−70℃ after 1.0 / 2.0 / 3.0 mL of olive leaf extract is added to the film mixtures separately, in order to ensure homogeneous distribution of the oil phase in the film mixture.

10. A method (100) according to Claim 8 or 9; characterized in that in the step of obtaining a packaging film by means of adding CaCl2, curcumin and olive leaf extract (OLE) to the film mixture (106), the probe of apparatus is dipped into the film mixture in an ultrasonicator at 25−30℃; and the coarse emulsion is converted into nanoemulsion via ultrasonic emulsification by applying ultrasonication for 20−25 minutes.

11. A method (100) according to Claim 8 to 10; characterized in that in the step of obtaining a packaging film by means of adding CaCl2, curcumin and olive leaf extract (OLE) to the film mixture (106), the film mixture converted into nanoemulsion is poured into petri plates and left for gelling in the drying oven at +39−42℃ for seven days; and the dried films are stored in the refrigerator at +4℃ with closed lid.

12. Safe active food packaging films which are obtained by following the above-mentioned method (100) steps; change colour instantaneously depending on the change of pH value upon degradation of fresh and / or processed foods, food supplements, cosmetic products and others that are sensitive to pH changes in the environment by means of the colour changing property of turmeric added to the structure in different mixture ratios; protect the product against UV and visible light by means of barrier property thereof by means of the UV and visible light absorbing property of turmeric; delay the oxidation of the products packaged by the synergistic interaction of alginate, turmeric and olive leaf extract; prevent bacterial growth; preserve the distinctive taste / smell and colour of the food / cosmetic 3product / the like; are thermally stable; have very low water dissolution and water vapour permeability; are suitable for packaging; are cost-efficient; and can easily be applied to industrial production processes; and finds effective use in increasing shelf life as well as quality and safety. 4

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