Detection system for amine in food

Abstract

The invention relates to a novel detection system of amine compounds for monitoring food storage conditions.

Description

Technical Field

[0001] The present invention relates to a novel detection system for amine compounds, particularly biogenic amines (ABs), for monitoring food storage conditions. Background Art

[0002] Some smart packaging technologies or intelligent packaging are able to provide an indication of the storage conditions and / or quality of the food contained in the package. Unfortunately, while these technologies can be crucial in assessing the characteristics of food, they are strongly opposed by the large retail industry, who are concerned that consumers will not purchase products with negligible changes, thereby resulting in large amounts of food waste.

[0003] ABs are important nitrogen-containing compounds, mainly formed by decarboxylation of amino acids or amination and transamination of aldehydes and ketones. In food and beverages, biogenic amines are mainly formed by decarboxylation of amino acids by microorganisms. Therefore, the total amount and type of amines in food packaging depends largely on the type of food, the presence of microorganisms and the storage state of the food (Yesim et al., Biogenic Amines in Food: Analysis, Occurrence and Toxicity, 2019, pp.1-17).

[0004] ABs can be found in many products, such as meat, vegetables, fish products, dairy products, wine and fermented products. For example, even after heat treatment, the latter may contain different amounts of different amines. In addition, some products, such as mackerel and non-mackerel (e.g., sardines, salmon, swordfish, anchovies, herring), cheese, meat products and beverages, may contain high levels of bioactive amines, i.e., harmful to consumers, and are therefore considered risk foods (Ingars Reinholds et al., Foods 2020, 9 (1), 93). For example, many biogenic amines can be formed in the muscle tissue of fish. One of them is histamine, which is formed by decarboxylation of the amino acid histidine. This occurs through the action of enzymes, such as histidine decarboxylases produced or released by some bacteria, such as Escherichia coli, Vibrio, Proteus, Klebsiella, Clostridium, Salmonella and Shigella (Masashi Kanki et al., Appl Environ Microbiol. 2007 Mar; 73 (5): 1467-1473). In this regard, Regulation (EC) No. 2073 / 2005 identifies red-fleshed fish, such as tuna, mackerel, sardines, herring and mahi-mahi, as fish with the greatest risk of histidine. The presence of histamine can also be detected in fish families not mentioned in the regulation (e.g. white-fleshed fish, such as amberjack) if stored improperly for long periods of time. In addition to histamine, protein degradation also produces other biogenic amines, such as cadaverine and putrescine, which have a synergistic or reinforcing effect with histamine and give the altered product an unpleasant odor. However, the toxic effect is maintained only by histamine. It is noted that fresh fish does not contain histamine or the concentration is less than 10 mg / kg. Therefore, the increase in concentration is due to the following factors:

[0005] 1. Use raw materials that are no longer fresh,

[0006] 2. Time / temperature abuse,

[0007] 3. The use of enzymatic ripening processes (proteolysis) in the production of processed foods (e.g., pickled anchovies) leads to the formation of free histidine in the product, further promoting histamine production.

[0008] In particular, the effect of temperature on AB formation in fish is crucial. In fact, AB formation occurs at moderate and high temperatures, with histamine formation being highest at a temperature of 37.8 °C. In contrast, storage of products at low temperatures is detrimental to amine formation; if fish products are stored at 0 °C, they contain lower amounts of histamine for up to 18 days, and if they are stored at 10 °C, they have concentrations as high as 1 g / Kg after only 5 days. According to EC Regulation 2073 / 05, 100 mg / kg of histamine in fishery products rich in histidine (e.g., scombroids) represents a potentially toxic level.

[0009] Likewise in cheese, the availability of amino acids, as well as pH and salinity, favor the formation of AB. However, in this case, the values ​​found are lower than those considered toxic, but are able to significantly modify the sensory characteristics of the food. Therefore, the problem of the presence of amines in dairy products should not be underestimated.

[0010] Cadaverine can be used to monitor changes in white and red meat (Vinci G., Control. 2002; 13: 519-524), while tyramine can only be used for red meat. In chicken, the increase in amines occurs earlier and faster than in beef (Alessandroni L. et al., Food Chem. 2022; 371: 131134), so the storage of this meat is more critical. The increase in total AB content is also temperature-dependent. In fact, storage of meat at temperatures below 4°C can reduce the formation of AB (Maria Schirone et al., Foods 2022 Mar; 11 (6): 788). The increase in putrescine, cadaverine and histamine levels in pork also appears to be significantly correlated with the concentration of total volatile basic nitrogen (TVB-N). In fresh beef that was vacuum-packed and stored at 1°C for 120 days, significant levels of amine formation were observed starting from the 20th day of storage. In salami and soppressta from southern Italy, the most abundant amine was tyramine (up to 500 mg / Kg), followed by putrescine and cadaverine, 2-phenylethylamine was found in very low levels, and histamine was only present in some soppressta samples (50 mg / Kg).

[0011] Considering that AB can be ingested from a variety of dietary sources, the sum of amines ingested by consumers can easily exceed the safe level. Therefore, when assessing the risks associated with amine intake, it is not the individual amines but their sum that should be considered (AgataDurak-Dados et al., J Vet Res. 2020 Jun; 64(2): 281-288).

[0012] Therefore, it is clear that there is a need to provide new detection systems for amine compounds to monitor the storage state of food. In this case, the evolved amines from the earliest degradation processes in foods of animal and plant origin can be used to indicate that the foods are improperly stored or handled before they spoil, so that they can be consumed in a short time, minimizing food waste and protecting consumer health. In this case, it is also important to monitor the total amines generated by the degradation process.

[0013] Several systems for detecting the storage state of food are described in the literature. For example, patent application CA 2621754A1 describes a CO2 sensor based on a polar polymer matrix, which contains a variety of indicators, including pH-sensitive dyes and lipophilic metal ion cationic complexes. These receptors form soluble ion pairs in polar polymer matrices (e.g., ethylcellulose, methylcellulose, and aminocellulose). In this case, the material is processed from a solution containing a toxic solvent (e.g., methanol).

[0014] Danchuck et al., Analytical and Bioanalytical Chemistry (2020); 412: 4023-4036, discusses the study of Severin et al., Chem. Commun. (2011); 47: 9639-9641, which focuses on the use of coumarin derivatives prepared by formylation of 7-(N,N-dimethylamino)-4-hydroxycoumarin. In this case, the modification of the hydroxycoumarin allows the molecule to react with amines in a buffered aqueous solution to form enamines. The reaction for some amines showed a color change in the system, which was clearly visible to the naked eye because the molecule absorbed visible light up to 500nm. When added to polymethyl methacrylate (PMMA) stored in chloroform solution, the formylated hydroxycoumarin also showed different color changes for different amines and gas phase ammonia. PMMA is a polymer used for decorative purposes because of its high optical transparency, but it has been treated at least once with formylated hydroxycoumarin in chloroform. However, the processes and materials used are not compatible with use in food packaging, as the solvent (chloroform) required to make the film is highly toxic, teratogenic and suspected to be carcinogenic. The PMMA used also does not appear to be suitable for food, nor is the new formylated compound, as there is no information on its toxicity properties and possible use as contact material.

[0015] Hongqi Li et al. ("Coumarin-Derived Fluorescent Chemosensors," Advances in Chemical Sensors (2012)) reviewed a paper by Richard J. Ansell et al., Org. Biomol. Chem. (2009); 7(6): 1211-1220 on the polymerization of 6-styrylcoumarin-4-carboxylic acid (SCC) and 6-vinylcoumarin-4-carboxylic acid (VCC) into "molecularly imprinted polymers" (MIPs) precisely polymerized around a (+)-ephedrine molecule. This polymerization process of SCC and VCC derivatives allows the creation of specific pores with the shape of the ephedrine molecule. This property means that, due to the nature of the MIP, the system can only interact with the molecule used for the synthesis, namely the (+)-ephedrine enantiomer. In fact, the system does not even react with the (-)-ephedrine enantiomer, which is structurally identical to the enantiomer used, only with a different spatial arrangement of some bonds, let alone with other amines. Likewise, the response of the system is clearly visible both colorimetrically and with the naked eye, since the emission spectrum of the polymer shows a peak in the green spectral region. In principle, the process can be applied to single biogenic amines, but the polymerization of 6-styrylcoumarin-4-carboxylic acid (SCC) and 6-vinylcoumarin-4-carboxylic acid as well as molecular imprinting are rather complex processes that are incompatible with food packaging, since they involve the use of several toxic and potentially carcinogenic compounds and solvents. In fact, there are no toxicity studies of the new coumarin-based polymers. Moreover, the extreme selectivity of MIPs does not allow their use for the detection of total biogenic amines, which is crucial to enable the system to detect the storage state of different protein matrices (e.g., meat, fish, and cheese).

[0016] Therefore, it is clear from the analysis of the existing literature that the systems proposed so far are based on the use of compounds that prevent their use in packaging due to issues associated with potential toxicity. Furthermore, all systems have been developed for colorimetric detection visible to the naked eye. This approach has failed as it has been shown to lead to increased food waste. Summary of the invention

[0017] The object of the present invention is to provide a product capable of solving the above-mentioned problem of early detection of food spoilage in an innovative and original way by detecting the total amines produced by a system that is compatible with food packaging (i.e. non-toxic and biocompatible) and that is not detectable to the human eye without the use of appropriate instruments. For this purpose, a sensor for amine detection is introduced into the packaging, intended to detect the degradation process based on an optical reaction that is not visible to the naked eye, i.e. a non-colorimetric method, preferably a fluorescent method.

[0018] Another object of the present invention is to provide a system comprising a detection sensor consisting of a polymer matrix, a chemical receptor and a simple readout device that can be monitored only by internal personnel.

[0019] The sensor is part of the packaging itself and has a negligible impact on its cost. Furthermore, the sensor is inherently able to track the packaging to the end of its life. Therefore, the status of a single package can be comprehensively monitored throughout the supply chain.

[0020] Both the polymer matrix and the receptor are "food grade," meaning they can be used as food contact materials.

[0021] In the manufacture of this system, non-toxic solvents or molecules are used, and only molecules and solvents approved for use in the food industry in accordance with regulations and rules are used. Therefore, the components of this system are safe and suitable for contact with food and do not pose a risk to human health or alter the safety or quality of food.

[0022] The selected polymers meet requirements such as the absence of toxic substances or pollutants, chemical stability and food compatibility. They follow regulations and guidelines such as those of the Italian National Unified Agency (UNI) or the European Food Safety Authority (EFSA) to ensure safety and compliance with food standards.

[0023] The device used to detect the condition of the sensor consists of a monochromatic light source whose emission is compatible with the absorption spectrum of the chemical receptor only after interaction with the food degradation product. The wavelength selected must not be absorbed by other materials, including the polymer matrix, the receptors that have not interacted with the food degradation product, the food itself, and those materials generated by the degradation of the food.

[0024] The above main objects are achieved by a sensor according to claim 1, its use for detecting total amines in food according to claim 10, a method for manufacturing a sensor according to claims 11 and 12, a food container comprising a sensor according to claim 13, and a detection system according to claim 14. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 : Absorption spectra of maltol (black, solid line) and coumarin (grey, dashed line) in PLA (left, panel a) and CA (right, panel b).

[0026] Figure 2 : Absorption spectra of coumarin before (black solid line) and after (grey dashed line) interaction with amines.

[0027] Figure 3: Photoluminescence spectra of PLA (Fig. a) and PS (Fig. b, c, and d) films containing coumarin (a, b), maltol (c), and kojic acid (d) before (black solid line) and after (gray dashed line) interaction with amines in the gas phase.

[0028] Figure 4 : Infrared spectra of PLA films before and after interaction with amines. DETAILED DESCRIPTION

[0029] Unless otherwise defined, all technical terms, symbols and other scientific terms used herein are intended to have the meanings commonly understood by those skilled in the art to which the invention belongs. In some cases, terms with commonly understood meanings are defined herein for clarity and / or ease of reference; therefore, such definitions contained herein should not be interpreted as indicating a substantial difference from the general understanding of the art.

[0030] The terms "about" and "approximately" herein refer to the range of experimental errors that may occur in the measurements.

[0031] The terms "comprising," "having," "including," and "comprising" are to be construed as open-ended terms (i.e., meaning "including but not limited to") and are to be considered as providing support for also the terms "consisting essentially of," "consisting essentially of," "consisting of," or "consisting of."

[0032] The terms "consisting essentially of" and "essentially composed of" are to be interpreted as semi-closed terms, meaning that other ingredients that materially affect the basic and novel characteristics of the invention are not included (thus, optional excipients may be included).

[0033] The terms "consisting of," "composed of," are to be construed as closed terms.

[0034] The term "food grade" means that the material can be used as food contact according to national and international regulations.

[0035] Detailed description of the invention

[0036] The present invention aims to provide a non-colorimetric optical sensor for detecting the presence of total biogenic amines, consisting of a food-grade polymer matrix having dispersed therein molecules containing one or more pyrones (receptors) that are not chemically bound to the matrix.

[0037] In a preferred embodiment, the sensor according to the invention is fluorescent and invisible to the naked eye, ie non-colorimetric.

[0038] Advantageously, molecules containing one or more pyrones are able to change their optical properties (absorption spectrum and fluorescence) upon selective interaction with the amine groups of amines formed during food degradation. Thus, the sensor detects all discovered amines and is non-specific.

[0039] In particular, the receptors used are associated with light absorption phenomena below 400 nm, depending on the structure of the molecules (receptors) used.

[0040] This property makes it possible to detect the presence of biogenic amines using simple instrumentation through changes in the absorbance and / or fluorescence spectra of the receptors, which are invisible to the naked eye and therefore to the consumer.

[0041] The detection of amine compounds is essential for monitoring the condition of food (meat, fish, cheese and processed products in general, including alcoholic and non-alcoholic beverages).

[0042] In a preferred embodiment, the polymer matrix is ​​selected for its food compatibility, chemical resistance, thermal stability and other properties that make it suitable for use in a food environment. Preferably, the polymer material is selected from polystyrene (PS), polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polylactic acid (PLA) or mixtures thereof. Thus, the polymer used is only "food grade" and does not exhibit any specific polar properties that may cause interaction between the matrix and a primarily water-based food.

[0043] In another preferred embodiment, the sensor according to the present invention is capable of detecting the presence of total amine concentrations between 500 micrograms per kilogram and 10 grams per kilogram in the packaging atmosphere or under ambient conditions, thereby detecting the occurrence of the degradation process once it is triggered, thereby facilitating food industry operators to implement avoidance / disposal / shortening of shelf life measures to protect consumer health while minimizing food waste.

[0044] In another preferred embodiment, the polymer matrix is ​​in the form of a film (preferably 100 nm to 500 μm thick), fiber, film, sheet, foam, granule or powder compatible with the specific application.

[0045] Preferably, the receptor containing one or more pyrone that can be used in the present invention is selected from coumarin, maltol, ethyl maltol, chromone or kojic acid, and flavonoids, which are usually extracted from natural materials without chemical treatment. Pyrone is a molecule composed of a six-membered heterocyclic ring containing an oxygen atom and a ketone functional group.

[0046] Examples of commercially available pyrone-containing molecules that can be used in the present invention include coumarin (1-benzopyran-2-one), maltol (3-hydroxy-2-methyl-4H-pyran-4-one) and its derivatives, such as ethyl maltol (2-ethyl-3-hydroxy-pyran-4-one), chromone (1,4-benzopyrone), kojic acid (5-hydroxy-2-(hydroxymethyl)-4H-pyran-4-one) and / or flavonoids.

[0047] The receptors are dispersed in the polymer matrix and are not chemically bound, thus not changing their properties and thus affecting their use in food packaging according to current regulations.

[0048] The pyrone containing molecules are non-toxic at the concentrations used (1-20% w / w).The sensors are of variable and suitable size to control the total amount of receptors present.

[0049] Another object of the present invention is to detect total amines in food using sensors, only by optical methods (absorption or fluorescence) that are not detectable by the human eye, i.e. not providing a colorimetric reaction (fluorescence emission with a characteristic color or absorption in the visible spectrum).

[0050] A further object of the present invention is represented by a method for manufacturing a sensor according to the present invention, comprising:

[0051] - mixing the polymeric material and the molecule containing one or more pyranones in a food grade solvent, preferably in accordance with Regulation 2009 / 32 / EC, Regulation (EC) 1935 / 2004 and Regulation (EC) 10 / 201 (more preferably in a solvent selected from water, ethyl acetate, ethanol, acetone, hexane, methyl ethyl ketone, diethyl ether, methyl acetate, propanol and butanol), depending on the polymer matrix and pyrone used;

[0052] - depositing the resulting solution on a substrate (e.g. greaseproof paper, Teflon, glass, packaging film), preferably by techniques such as drop coating, spin coating and dip coating;

[0053] - evaporating the solvent, preferably at room temperature, to form a thin film;

[0054] - extracting the remaining solvent by one or more water washes and one or more vacuum treatments;

[0055] - Optionally, removing the film from the substrate.

[0056] The concentration of the polymer is preferably 30-50 g / L, while the molecules containing one or more pyrones have a preferred concentration between 1 and 20% by weight, based on the weight of the polymer.

[0057] All processes are preferably carried out under ambient conditions (pressure and temperature).

[0058] Preferably, the thin film has a thickness between 100 nm and 500 μm.

[0059] In one embodiment, the sensor can be made from a polymer melt by extrusion and subsequent deformation. In this case, the manufacturing includes:

[0060] - mixing a polymer material (powder, granules or other physical form) with a pyrone-containing molecule (powder, granules or other physical form) at room temperature or above the melting and / or glass transition temperature of the polymer material;

[0061] - homogenizing the resulting mixture;

[0062] - melting / softening the polymer matrix containing the receptor (molecule containing one or more pyranone(s);

[0063] - forming films, including structured films, such as films formed from fiber bundles, preferably by industrial techniques including extrusion, calendaring, lamination, film casting, film blowing, blow molding, thermoforming, spinning, electrospinning, molding, rotational forming, additive manufacturing and foaming.

[0064] Another object of the invention is a food container comprising the sensor of the invention.

[0065] The sensor may be in the form of a "tag" inside the package, visible or invisible to the naked eye, or the package itself (film, food tray, absorbent pad) may be formed with a polymer molecule mixture containing one or more pyrones. The sensor inherently follows the end of life of the package.

[0066] The sensor functions (i) in contact with the food, (ii) on the bottom of the tray in contact with the resulting liquid, and (iii) even when not in contact with the food, by interacting with volatile amines in the gas phase.

[0067] Another object of the present invention is a system for detecting total amines in food, comprising a sensor according to the present invention, a monochromatic light source having an emission wavelength corresponding to the absorption of receptor molecules after interaction with amines, and a non-dispersive detector (photodiode, photoresistor, photodetector, etc.) that filters the radiation incident on the sensor using a suitable optical system (filters and lenses).

[0068] The monochromatic light source must be compatible with the absorption spectrum of the chemical receptors after interaction with the food degradation products and be able to excite their fluorescence. Preferably, it must not be absorbed by other materials, including the polymer matrix, the receptors that have not interacted with the food degradation products, the food, and the products resulting from the degradation of the food degradation products.

[0069] The following examples are intended to further illustrate the present invention, but are not intended to limit the present invention.

[0070] Example

[0071] Material

[0072] Example 1

[0073] 10 g of PS was mixed with 1 g of maltol and dissolved in hexane. The solution was coated on Teflon-coated paper and allowed to dry. The resulting film was peeled off the substrate and bonded to the food packaging and formed a "label" visible from the outside. When irradiated with a strong light source at 405 nm, the label will emit specific radiation only when it interacts with biogenic amines produced by food degradation. The emission is collected and recorded by a detection system consisting of a photodiode and an optical filter.

[0074] Example 2

[0075] 100 g of PS was premixed with 10 g of coumarin and fed into an extruder. The extrusion process softened the polymer and homogenized the mixture. The extrudate was filmized to form an amine-sensitive film that can be used as food packaging. Alternatively, the extrudate can be made into a tray or label with the same properties. Testing was performed as described in Example 1.

[0076] method

[0077] Reading of the sensor can be accomplished by various methods based on fluorescence and absorption of light by the pyrone-containing molecules.

[0078] In absorption measurements, a beam of white light (200-1100 nm) is used to illuminate the receptor-loaded polymer matrix, which is then sent to a non-dispersive detector that can quantify the material's absorption. This value is then correlated with the values ​​before and after the receptor and previously detected amine react.

[0079] In fluorescence measurement, a high intensity monochromatic light beam is used to illuminate the polymer matrix containing the receptors to excite the fluorescence of the receptors. The fluorescence can then be measured using a non-dispersive detector such as a photodiode or photoresistor coupled to an optical filter system that detects only the presence / absence and intensity of the fluorescence. The light emitted by the sample and any reflected light is filtered through a dichroic or color filter system to ensure that the detector works and avoid false readings.

[0080] result

[0081] UV-Vis and FT-IR spectroscopy analysis showed that the sensor of the present invention has a clear response to amine groups.

[0082] Figure 1UV-Vis analysis of some of the tested materials is shown. In the left spectrum, PLA is loaded with maltol (black, solid line) and coumarin (grey, dashed line), and in the right spectrum, cellulose acetate is loaded with the same receptors. The absorption band below 250 nm indicates the polymer matrix, while the receptors absorb at wavelengths between 250-350 nm. In fact, these films appear completely transparent.

[0083] The absorption bands mean that, in order to excite the fluorescence signal of the molecules that have not reacted with the amines in the polymer matrix, an intense light source with a wavelength below 350 nm is required for both molecules in both polymer matrices. This behavior is characteristic of many of the pyrones covered by the present invention.

[0084] To illustrate the changes that occur during exposure to amines, Figure 2 The absorption spectra of a concentrated coumarin solution before (solid black line) and after (dashed grey line) interaction with an amine are shown. It can be seen that the coumarin molecules absorb at longer wavelengths after reaction with the amine. This allows:

[0085] - The response to the presence of amines is also monitored by intensity measurement of the absorbed radiation.

[0086] - Excitation of fluorescence of pyrone-containing molecules by light sources with wavelengths greater than 350 nm interacting with one or more ABs.

[0087] In this case, fluorescence is excited only when the pyrone-containing molecules interact with the amine.

[0088] Therefore, the presence of the fluorescent signal indicates the presence of amines in the food and the start of the degradation process.

[0089] Figure 3 The responses of some polymer sensors loaded with coumarin, maltol and kojic acid and exposed to amine vapor are shown. It can be seen how the emission spectrum, which initially peaked at a wavelength below the analyzed spectral range (black line), is altered to consist of colorless emission light, but which extends across the entire visible spectrum, making it impossible to decipher by the naked eye (grey dashed line).

[0090] It should be noted that the absorption shift of amines allows the fluorescence of the material to be measured using sources with wavelengths greater than 400 nm only after interaction with the amines.

[0091] The fluorescence can then be excited using any source with a wavelength less than 350 nm (before and after interaction with the amine) or using a longer wavelength source. In the latter case, a separate fluorescence signal that may be present only after the interaction between the pyrone-containing molecule and the amine indicates that an interaction has occurred.

[0092] Figure 4The infrared spectrum of a PLA polymer matrix is ​​shown. In this single case, the polymer disrupts the mechanism of polymer chain participation in amine recognition by either a β-elimination or nucleophilic substitution mechanism. This allows for a more efficient exposure of the receptor to the amine. In fact, the spectrum of PLA exposed to amines shows a strong affinity for amines in the range of 3000 to 3800 cm -1 There are amplified bands associated with the presence of amine groups. In addition, in the spectrum of the material collected after exposure to amines, there are amplified bands at approximately 1640 and 1535 cm -1 Two bands at are clearly visible, which are characteristic of amide groups formed during polymer chain scission.

Claims

1. A non-colorimetric optical detection sensor for detecting total amines in food, the sensor being composed of a food-grade polymer matrix, wherein molecules containing one or more pyrones are dispersed in the polymer matrix and are not chemically bound to the polymer matrix.

2. The sensor according to claim 1, characterized in that The sensor is a fluorescent type sensor that is invisible to the naked eye.

3. A sensor according to claim 1 or 2, which is capable of emitting fluorescence only after interaction with one or more amines, said fluorescence being unobservable without a suitable readout instrument.

4. The sensor according to any one of the preceding claims, characterized in that The food is protein, preferably meat, fish, cheese, processed products or alcoholic and non-alcoholic beverages.

5. The sensor according to any one of the preceding claims, characterized in that The food-grade polymer matrix is ​​composed of a non-polar polymer material selected from polystyrene (PS), polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET) and polylactic acid (PLA) or a mixture thereof.

6. A sensor according to any one of the preceding claims, characterised in that The sensor detects the concentration of total amines in the food that are compatible with the establishment of degradation processes, preferably between 500 micrograms per kilogram and 10 grams per kilogram.

7. A sensor according to any one of the preceding claims, characterised in that The polymer matrix is ​​in the form of a film, fiber, sheet, foam, granule or powder.

8. The sensor according to any one of the preceding claims, characterized in that The molecule containing one or more pyrones is selected from coumarins, maltol and its derivatives, chromones, kojic acid and / or biologically derived flavonoids and is suitable for food packaging according to applicable regulations.

9. The sensor according to any one of the preceding claims, characterized in that The sensor is in the form of a label within the package or forms the package itself.

10. Use of a sensor according to any one of the preceding claims for detecting total amines in food by an optical method which is non-colorimetric and not observable by the human eye.

11. A method for manufacturing a sensor according to any one of claims 1 to 9, comprising: - mixing the polymer material and the molecule containing one or more pyranones in a food grade solvent, preferably, the food grade solvent is selected from water, ethyl acetate, ethanol, acetone, hexane, methyl ethyl ketone, diethyl ether, methyl acetate, propanol and butanol; - depositing the resulting solution on a substrate, preferably by a technique selected from drop coating, spin coating and dip coating; - evaporation of the solvent to form a film; - extracting the remaining solvent by one or more water washes or one or more vacuum treatments; - Optionally, removing said film from said substrate.

12. A method for manufacturing a sensor according to any one of claims 1 to 9, comprising: - mixing a polymeric material with a molecule containing one or more pyrones at room temperature or a temperature above the melting and / or glass transition temperature of the polymeric material; - homogenizing the resulting mixture; - melting or softening the polymer matrix containing the molecules; - forming a film, preferably by a technique selected from extrusion, calendering, lamination, film casting, film blowing, blow molding, thermoforming, spinning, electrospinning, molding, rotational forming, additive manufacturing and foaming.

13. A food container comprising a sensor according to any one of claims 1 to 9, wherein the sensor operates when in contact with a vapor, liquid or solid containing one or more amines.

14. A system for detecting total amines in food, comprising the sensor according to any one of claims 1 to 9, a monochromatic light source and a non-dispersive detector.

15. The system according to claim 14, characterized in that The non-dispersive detector is selected from a photodiode, a photoresistor, a photomultiplier tube, or a photodetector coupled to a suitable optical system including a filtering system for radiation incident on the sensor.

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