Detection system for amines in food

Abstract

The present invention relates to a novel detection system for amine compounds for monitoring the storage state of food products.

Description

[Technical Field]

[0001] The present invention relates to a novel detection system for amine compounds, particularly biogenic amines (ABs), for monitoring the storage state of food products. [Background technology]

[0002] Some smart packaging technologies or smart packaging are able to provide an indication of the storage state and / or quality of the food contained in said packaging. Unfortunately, however important these technologies may be for assessing the properties of food, they are strongly opposed by large retailers who fear that consumers will not purchase products that are subject to only slight deterioration changes, resulting in large amounts of food waste.

[0003] ABs are important nitrogen compounds produced primarily by the decarboxylation of amino acids and the amination and transamination of aldehydes and ketones. In foods and beverages, biogenic amines are largely produced by the decarboxylation of amino acids, which is primarily mediated by microorganisms. Therefore, the total amount and type of amines in food packaging strongly depend on the type of food, the microorganisms present, and the storage conditions of said food (Yesim Oezogul et al., Biogenic Amines in Food: Analysis, Occurrence and Toxicity, 2019, pp. 1-17).

[0004] ABs can be found in many products, including meat, vegetables, fish products, dairy products, wine, and fermented products. For example, the latter can contain varying amounts of different amines, even after heat treatment. Furthermore, some products, such as mackerel and other fish (e.g., sardines, salmon, swordfish, anchovies, and herring), cheese, meat products, and beverages, are considered hazardous foods because they may contain high levels of biologically active amines, which are harmful to consumers (Ingars Reinholds et al., Foods 2020, 9(1), 93). For example, numerous biogenic amines can be produced in fish muscle tissue. One of these is histamine, which is produced by decarboxylation of the amino acid histidine. This occurs through the action of enzymes such as histidine decarboxylase, which are produced or released by certain bacteria, including 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 species, such as tuna, mackerel, sardines, herring, and mahi-mahi, as fish most at risk due to the presence of histidine. The presence of histamine can also be detected in fish species not listed in the regulation (e.g., whitefish such as amberjack) if stored improperly for long periods. In addition to histamine, other biogenic amines, such as cadaverine and putrescine, are also produced by protein degradation, which have synergistic or potentiating effects with histamine and contribute to the unpleasant odors of spoiled products. However, the toxicity is only maintained by histamine. Note that fresh fish contains no histamine or has a concentration below 10 mg / kg. Therefore, the increased concentration is due to: 1. Use of ingredients that are no longer fresh, 2. Time / temperature misuse, 3. The use of enzymatic ripening processes (proteolysis) in the production of processed foods (e.g., salted anchovies) generates free histidine in the product, further promoting histamine production.

[0005] The effect of temperature on AB formation in fish is particularly important. Indeed, AB formation occurs at both moderate and high temperatures, with histamine formation being highest at 37.8°C. Conversely, storing products at low temperatures is unfavorable for amine formation. When fish products are stored at 0°C, the histamine content is low for up to 18 days, but when stored at 10°C, concentrations of 1 g / kg are reached after just 5 days. According to EC Regulation 2073 / 05, 100 mg / kg of histamine in histidine-rich seafood, such as mackerel, corresponds to a potentially toxic level.

[0006] In cheese, too, the availability of amino acids, together with pH and salt concentration, favors the formation of AB. However, in this case, although the detected values are below those considered toxic, they can significantly alter the organic properties of the food. Therefore, the problem of the presence of amines in dairy products should not be underestimated.

[0007] Cadaverine can be used to monitor spoilage in both white and red meat (Vinci G., Control. 2002;13:519-524), whereas tyramine can only be used in red meat. Storage of chicken meat is more critical because amines increase more rapidly in chicken than in beef (Alessandroni L. et al., Food Chem. 2022;371 :131134). The increase in total AB content is also temperature-dependent. In fact, storing meat below 4°C can suppress AB formation (Maria Schirone et al., Foods 2022 Mar;11 (6):788). Increased concentrations of putrescine, cadaverine, and histamine in pork also appear to be significantly correlated with the concentration of total volatile basic nitrogen (TVB-N). When fresh beef 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 soppressata from southern Italy, the most abundant amine was tyramine (up to 500 mg / kg), followed by putrescine and cadaverine, with 2-phenylethylamine present in very small amounts, and histamine only detected in some soppressata samples (50 mg / kg).

[0008] Considering that ABs can be ingested in the diet from various sources, the total amount of amines ingested by consumers can easily exceed safe levels, and therefore it is the sum of amines, rather than individual amines, that should be considered when assessing the risks associated with amine intake (Agata Durak-Dados et al., J Vet Res. 2020 Jun;64(2):281-288).

[0009] Therefore, it is clear that there is a need to provide a new detection system for amine compounds to monitor the food preservation status. In this context, the occurrence of amines in foods of animal and plant origin, which originate from the earliest decomposition processes, can indicate poor storage or handling even before the food spoils, allowing the food to be consumed quickly, minimizing food waste and protecting consumer health. From this perspective, it is also important to monitor the total amines produced by the decomposition process.

[0010] Several systems for detecting the storage status of food have been described in the literature. For example, patent application CA 2621754 A1 describes a CO2 sensor based on a polar polymer matrix containing multiple indicators, including pH-sensitive dyes and lipophilic metal ion-cation complexes. These receptors form soluble ion pairs in polar polymer matrices such as ethyl cellulose, methyl cellulose, or aminocellulose. In this case, these materials are removed from solution and treated with a toxic solvent such as methanol.

[0011] A review article by Danchuck et al. in Analytical and Bioanalytical Chemistry (2020);412: 4023-4036 discusses a study by Severin et al. in Chem. Commun. (2011);47: 9639-9641, which focused on the use of coumarin derivatives prepared by formylation of 7-(N,N-dimethylamino)-4-hydroxycoumarin. Modification of the hydroxycoumarin in this case allows the molecule to react with amines in buffered aqueous solutions to form enamines. Upon reaction with certain amines, the molecule absorbs visible light up to 500 nm, resulting in a color change in the system that is clearly visible to the naked eye. Formylated hydroxycoumarin also exhibits different color changes in response to different amines and vapor-phase ammonia when incorporated into polymethyl methacrylate (PMMA) precipitated from a chloroform solution. PMMA, a polymer used for decorative purposes due to its high optical transparency, is treated at least once with formylated hydroxycoumarin in chloroform. However, the process and materials used are not suitable for use in food packaging because the solvent required to make the film (chloroform) is highly toxic, teratogenic, and suspected to be carcinogenic. The PMMA used also does not appear to be suitable for food use, and no information is available on the toxicity properties of the new formylated compounds or their potential use as contact materials.

[0012] Hongqi Li et al. ("Coumarin-Derived Fluorescent Chemosensors," Advances in Chemical Sensors (2012)") review a paper by Richard J. Ansell et al., Org. Biomol. Chem. (2009); 7(6): 1211-1220, which describes the polymerization of 6-styrylcoumarin-4-carboxylic acid (SCC) and 6-vinylcoumarin-4-carboxylic acid (VCC) to form "molecularly imprinted polymers" (MIPs) precisely polymerized around the (+)-ephedrine molecule. This polymerization process of SCC and VCC derivatives allows the creation of specific pores that retain the shape of the ephedrine molecule. This property means that the MIPs can only interact with the molecule used to synthesize them, i.e., the enantiomer of (+)-ephedrine. In fact, this system does not react with other amines, nor even with the (-)-ephedrine enantiomer, which is structurally identical to the used enantiomer except for the spatial arrangement of some bonds. Again, the reaction of the system can be clearly confirmed colorimetrically and with the naked eye, as the emission spectrum of the polymer exhibits a peak in the green spectral region. In principle, this process can be applied to individual biogenic amines. However, the polymerization of 6-styrylcoumarin-4-carboxylic acid (SCC) and 6-vinylcoumarin-4-carboxylic acid, as well as molecular imprinting, are quite complex processes, and these processes involve the use of several toxic and potentially carcinogenic compounds and solvents, making them incompatible with food packaging. In fact, there are no studies on the toxicity of the new coumarin-based polymers. Furthermore, the extreme selectivity of MIPs precludes their use for the detection of total biogenic amines, which is essential for enabling systems to detect the preservation status of various protein matrices, such as meat, fish, and cheese.

[0013] Therefore, analyzing the existing literature, it is clear that currently proposed systems are based on the use of chemical compounds that cannot be used in packaging due to potential toxicity issues. Furthermore, all systems have been developed based on colorimetric detection visible to the naked eye. Therefore, it is already clear that this approach is not a solution, as it has been shown to lead to increased food waste. Summary of the Invention [Problem to be solved by the invention]

[0014] The object of the present invention is to provide a product that solves in an innovative and original way the above-mentioned problem of early detection of food deterioration through the detection of the total amines produced by a system that is compatible with food packaging, i.e., a non-toxic, biocompatible system and that is undetectable by the human eye without the use of appropriate equipment. For this purpose, a sensor for detecting amines is introduced into the packaging, which is based on an optical reaction that is invisible to the naked eye, i.e., non-colorimetric, preferably non-fluorescent, with the aim of detecting the degradation process.

[0015] Another object of the present invention is to provide a system that includes a detection sensor consisting of a polymer matrix and a chemical receptor, and a simple readout device that can be monitored only by an insider.

[0016] The sensors are part of the packaging itself and have a negligible impact on cost. Furthermore, the sensors inherently track the expiration date of the packaging. Thus, the status of each individual package can be comprehensively monitored throughout the supply chain.

[0017] Both the polymer matrix and the receptor are "food grade", ie, suitable for use in food contact applications.

[0018] The system is manufactured without the use of toxic solvents or molecules, and only molecules and solvents that comply with regulations and specifications approved for use in the food industry, making the system components safe and suitable for contact with food without posing risks to human health or altering the safety or quality of food.

[0019] The polymers selected must meet requirements such as the absence of harmful substances and pollutants, chemical stability, and food compatibility, and are in accordance with regulations and guidelines from the Italian National Unitary Agency (UNI) and the European Food Safety Authority (EFSA) to ensure safety and food compliance.

[0020] The device used to detect the state of the sensor consists of a monochromatic light source with emission that matches the absorption spectrum of the chemical receptor only after interaction with food degradation products. The wavelength selected must not be absorbed by other substances, including the polymer matrix, the receptor not interacting with food degradation products, the food itself, or those resulting from food degradation. [Means for solving the problem]

[0021] The above-mentioned main object is achieved by a sensor according to claim 1, by its use for detecting total amines in food according to claim 10, by a method for manufacturing a sensor according to claims 11 and 12, by a food container comprising a sensor according to claim 13, and by a detection system according to claim 14. [Brief explanation of the drawings]

[0022] [Figure 1] Figure 1 shows the absorption spectra of maltol (black, solid line) and coumarin (gray, dashed line) in PLA (left, panel a) and CA (right, panel b). [Figure 2] Figure 2 shows the absorption spectra of coumarin before (solid black line) and after (dashed grey line) interaction with amines. [Figure 3]Figure 3 shows the photoluminescence spectra of PLA (panel a) and PS (panels b, c, d) films containing coumarin (a, b), maltol (c), and kojic acid (d) before (solid black line) and after (dashed gray line) interaction with amines in the gas phase. [Figure 4] Figure 4 shows the infrared spectra of the PLA film before and after interaction with amines.

[0023] definition Unless otherwise defined, all technical terms, notations, and other scientific terms used herein are intended to have the meaning commonly understood by one of ordinary skill in the art to which this disclosure pertains. In some cases, terms having a commonly understood meaning are defined herein for clarity and / or ready reference, and the inclusion of such definitions herein should not be construed as representing a substantial departure from what is commonly understood in the art.

[0024] As used herein, the terms "approximately" and "about" refer to the range of experimental error that can occur in a measurement.

[0025] The terms "comprising," "having," "including," and "containing" are to be construed as open-ended terms (i.e., meaning "including, but not limited to") and are to be deemed to support terms such as "consist essentially of," "consisting essentially of," "consist of," or "consisting of."

[0026] The terms "consist essentially of" and "consisting essentially of" are to be interpreted as semi-closed phrases, meaning that no other ingredients are included that materially affect the basic and novel characteristics of the invention (thus, optional excipients may be included).

[0027] The terms "consists of" and "consisting of" are to be construed as closed terms.

[0028] The term "food grade" means that the material can be used as a food contact material in accordance with national and international regulations. DETAILED DESCRIPTION OF THE INVENTION

[0029] It is an object of the present invention to provide a non-colorimetric optical sensor for detecting the presence of total biogenic amines, which consists of a food-grade polymer matrix having dispersed therein molecules containing one or more pyrones (receptors) that are not chemically bound to the matrix.

[0030] In a preferred embodiment, the sensor according to the invention is a fluorometric, non-visible sensor, ie not colorimetric.

[0031] Advantageously, the pyrone or pyrone-containing molecules can change their optical properties (absorption spectrum and fluorescence) by selectively interacting with the amine groups of amines formed during food decomposition, thus making the sensor non-specific and detecting all amines generated.

[0032] In particular, the receptors used are associated with a phenomenon of light absorption below 400 nm due to the structure of the molecule (receptor) used.

[0033] This property allows simple devices to detect the presence of biogenic amines by changes in the absorption and / or fluorescence spectra of the receptor, changes that are invisible to the naked eye and therefore not noticeable to the consumer.

[0034] The detection of amine compounds is essential for monitoring the condition of food products (meat, fish, cheese, and processed products in general, including alcoholic and non-alcoholic beverages).

[0035] In a preferred embodiment, the polymer matrix is selected for its food compatibility, chemical resistance, thermal stability, and other properties 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 a mixture thereof. Therefore, the polymers used are exclusively "food grade" and do not exhibit specific polar properties that may cause interactions between the matrix and primarily water-based foods.

[0036] In another preferred embodiment, the sensor according to the invention is capable of detecting the presence of concentrations of total amines between 500 μg per kg and 10 g per kg in the packaging atmosphere or under ambient conditions in order to detect the onset of degradation processes as soon as they are triggered, in a way that facilitates the implementation of avoidance / disposal / shortening measures by food business operators in order to protect consumer health while minimizing food waste.

[0037] 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, pellet or powder adapted to the particular application.

[0038] Preferably, the receptor containing one or more pyrones that can be used in the present invention is selected from coumarin, maltol, ethyl maltol, chromone or kojic acid, and flavonoids, which are generally extracted from natural sources and have not been chemically treated. Pyrones are molecules consisting of a six-membered heterocycle containing an oxygen atom and a ketone functional group.

[0039] 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.

[0040] The receptor is dispersed in the polymer matrix and is not chemically bound, so it does not alter its properties and does not affect its use in food packaging according to current regulations.

[0041] The pyrone-containing molecules are non-toxic at the concentrations used (1-20% w / w).The sensor has a variable size suitable for controlling the total amount of receptor present.

[0042] Another object of the present invention is represented by the use of a sensor that detects total amines in food solely by optical methods (absorption or fluorescence) that are not detectable by the human eye, i.e., do not result in a colorimetric response (fluorescence emission with a characteristic color or absorption in the visible spectrum).

[0043] A further object of the present invention is to provide a method for producing a method for manufacturing a semiconductor device comprising the steps of: - mixing a polymeric material with a molecule comprising one or more pyrones in a food-grade solvent, preferably in accordance with Regulation 2009 / 32 / EC, Regulation (EC) no. 1935 / 2004 and Regulation (EC) no. 10 / 201, depending on the polymer matrix and the pyrone used (more preferably in a solvent selected from water, ethyl acetate, ethanol, acetone, hexane, ethyl methyl ketone, diethyl ether, methyl acetate, propanol and butanol); - depositing the resulting solution onto a substrate (e.g. greaseproof paper, Teflon, glass, packaging film), preferably by techniques such as drop casting, spin coating and dip coating; - allowing the solvent to evaporate, preferably at room temperature, to form a film; - extracting the remaining solvent by one or more washes in water or one or more vacuum treatments; - optionally removing the film from the substrate. The present invention is represented by a method for manufacturing a sensor according to the present invention, which comprises:

[0044] The concentration of the polymer is preferably 30 to 50 g / L, and the concentration of the molecule containing one or more pyrones is preferably 1 to 20 wt % based on the weight of the polymer.

[0045] All steps are preferably carried out under ambient conditions (pressure and temperature).

[0046] Preferably, the film has a thickness between 100 nm and 500 μm.

[0047] In one embodiment, the sensor can be manufactured from a polymer melt by extrusion followed by deformation, where the manufacturing comprises the following steps: - mixing a polymeric material (powder, pellets or other physical form) with said pyrone(s)-containing molecule(s) (powder, pellets or other physical form) at room temperature or above the melting temperature and / or glass transition temperature of said polymeric material; homogenizing the mixture obtained; - melting / softening the polymer matrix containing the receptor (a molecule containing a pyrone or pyrones); forming films, including structured films such as those formed from fiber bundles, preferably by industrial techniques such as extrusion, calendaring, lamination, film casting, film blowing, blow molding, thermoforming, spinning, electrospinning, molding, rotoforming, additive manufacturing, foaming, etc. Includes:

[0048] Another object of the invention is a food container comprising a sensor according to the invention.

[0049] The sensor may be in the form of a "label" inside the packaging, visible or invisible to the naked eye, or the packaging itself (film, food tray, absorbent pad) may be made of a polymer molecule mixture containing one or more pyrones. The sensor is essentially functional for the life of the packaging.

[0050] The sensor functions by interacting with volatile amines in the gas phase (i) when in contact with food, (ii) on the bottom of the tray in contact with the generated liquid, and (iii) even when not in contact with food.

[0051] Another object of the present invention is a system for detecting total amines in food, comprising a sensor according to the invention, a monochromatic light source having an emission wavelength corresponding to the absorption of said receptor molecule after interaction with said amines, and a non-dispersive detector (photodiode, photoresistor, photodetector, etc.) using appropriate optics (filters and lenses) to filter the emitted light incident on said sensor.

[0052] The monochromatic light source must match the absorption spectrum of the chemical receptor after interaction with the food degradation products and be able to excite its fluorescence, which preferably should not be absorbed by other materials, including the polymer matrix, the receptor that has not interacted with the food degradation products, the food, and products resulting from the degradation of the food degradation products.

[0053] The following examples are intended to further illustrate, but not limit, the present invention. [Example]

[0054] material

[0055] Example 1 Ten grams of PS is mixed with 1 gram of maltol and dissolved in hexane. The resulting solution is applied to Teflon-coated paper and allowed to dry. The resulting film is peeled from the substrate and adhered to food packaging to form a "label" that is visible from the outside. When illuminated with a powerful 405 nm light source, the label emits a specific emitted light only upon interaction with biogenic amines resulting from food degradation. This emission is collected and recorded by a detection system consisting of a photodiode and optical filters.

[0056] Example 2 100 g of PS is premixed with 10 g of coumarin and fed into an extruder. The extrusion process softens the polymer and homogenizes the mixture. The extrudate is filmed to form an amine-sensitive film that can function as a food packaging. Alternatively, the extrudate can be made into trays or labels with the same properties. Detection is performed as described in Example 1.

[0057] method The sensor can be read in a variety of ways based on fluorescence and light absorption by pyrone-containing molecules.

[0058] In the absorption measurement, the polymer matrix loaded with the receptor is irradiated with white light (200-1100 nm) and then directed to a non-dispersive detector that can quantify the absorption of the material, resulting in a value that correlates with the receptor value before and after reaction with the previously detected amines.

[0059] In fluorescence measurements, the polymer matrix containing the receptor is irradiated with high-intensity monochromatic light to excite the receptor's fluorescence. Fluorescence can then be measured using a non-dispersive detector, such as a photodiode or photoresistor, coupled with an optical filter system that can detect only the presence and intensity of fluorescence. Light emitted from the sample and any reflected light source is filtered through an interference or color filter system to ensure the detector is functional and prevent erroneous measurements.

[0060] result UV-Vis and FT-IR spectroscopy demonstrate a clear response of the sensor of the present invention to amine groups.

[0061] Figure 1 shows the UV-Vis analysis of some test materials. The spectrum on the left is for PLA loaded with maltol (black, solid line) and coumarin (gray, dashed line), while the spectrum on the right is for cellulose acetate loaded with the same receptors. The absorption band below 250 nm is due to the polymer matrix, while the receptor absorbs at wavelengths between 250 and 350 nm. In fact, the tested films appear completely transparent.

[0062] The absorption bands suggest that for both molecules in both polymer matrices, an intense light source at wavelengths below 350 nm is required to stimulate the fluorescence signal of the molecules that have not reacted with the amines in the polymer matrix, a behavior characteristic of many of the pyrones of interest in this invention.

[0063] To illustrate the changes that occur during exposure to amines, Figure 2 shows the absorption spectra of a concentrated coumarin solution before (solid black line) and after (dashed grey line) interaction with amines. It can be seen that the coumarin molecule absorbs at longer wavelengths after reacting with the amine. This allows us to: - Monitoring the response to the presence of amines also by measuring the intensity of the absorbed radiation. - stimulating the fluorescence of the pyrone-containing molecule interacting with one or more ABs with said light source at wavelengths longer than 350 nm.

[0064] In this case, the fluorescence is excited only when the pyrone-containing molecule interacts with the amine.

[0065] The presence of such a fluorescent signal therefore indicates the presence of amines and the initiation of the degradation process in the food.

[0066] Figure 3 shows the response of several polymeric sensors loaded with coumarin, maltol, and kojic acid exposed to amine vapors. It can be seen how the emission spectrum (black line) changes, initially peaking at wavelengths lower than the analyzed spectral range, and consisting of non-colored emission, which is not visible to the naked eye because it is spread across the entire visible spectrum (gray dashed line).

[0067] Note that the absorption shift of the amine allows fluorescence measurement of the material using a light source at wavelengths longer than 400 nm only after interaction with the amine.

[0068] Fluorescence can then be stimulated with any light source of wavelength less than 350 nm (before or after interaction with the amine) or with a light source of higher wavelength, in which case the presence of a discrete fluorescent signal, only possible after interaction of the pyrone-containing molecule with the amine, indicates that the interaction has occurred.

[0069] Figure 4 shows the infrared spectrum of a PLA polymer matrix. In this single case, the polymer participates in the amine recognition mechanism by cleaving the polymer chain via a β-elimination or nucleophilic substitution mechanism. This allows the receptor to be more effectively exposed to amines. Indeed, the spectrum of amine-exposed PLA reveals a band between 3000 and 3800 cm associated with the presence of amine groups. -1 Furthermore, a broadened band at approximately 1640 cm is observed, which is characteristic of the amide group formed upon polymer chain cleavage. -1 and 1535cm -1 Two bands at 1000 kJ / cm are clearly visible in the spectrum of material taken after exposure to the amine.

Claims

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

2. 2. The sensor of claim 1, wherein the sensor is a fluorometric type sensor that is invisible to the naked eye.

3. 3. The sensor according to claim 1 or 2, characterized in that the sensor is capable of fluorescing only after interaction with an amine or amines, and said fluorescence is not noticeable without an appropriate reading device.

4. Sensor according to any one of claims 1 to 3, characterized in that the food is a proteinaceous food, preferably meat, fish, cheese, processed products or alcoholic and non-alcoholic drinks.

5. 5. The sensor according to claim 1, wherein the food-grade polymer matrix consists of a non-polar polymer material selected from polystyrene (PS), polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polylactic acid (PLA) or mixtures thereof.

6. 6. The sensor according to any one of claims 1 to 5, characterized in that the sensor detects the concentration of total amines in foodstuffs compatible with the establishment of a degradation process, said concentration preferably being between 500 μg per kg and 10 g per kg.

7. The sensor according to any one of claims 1 to 6, characterized in that the polymer matrix is in the form of a film, fiber, sheet, foam, pellet or powder.

8. 8. The sensor according to claim 1, wherein the pyrone or pyrone-containing molecules are selected from coumarin, maltol and its derivatives, chromone, kojic acid and / or biologically derived flavonoids, and are suitable for use in food packaging in accordance with applicable regulations.

9. A sensor according to any one of claims 1 to 8, characterized in that the sensor is in the form of a label inside a package or forms the package itself.

10. Use of the sensor according to any one of claims 1 to 9 for detecting total amines in food by an optical method that is not colorimetric but is not noticeable to the human eye.

11. A method for producing the sensor according to any one of claims 1 to 9, comprising the steps of: - mixing the polymeric material with the pyrone or pyrone-containing molecules in a food-grade solvent, preferably selected from water, ethyl acetate, ethanol, acetone, hexane, ethyl methyl ketone, diethyl ether, methyl acetate, propanol and butanol; - depositing the resulting solution onto a substrate, preferably by a technique selected from drop casting, spin coating and dip coating; - evaporating the solvent to form a film; - removing the remaining solvent by one or more washes in water or one or more vacuum treatments; - optionally removing the film from the substrate. A method comprising:

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

13. 10. A food container comprising the sensor of any one of claims 1 to 9, wherein the sensor operates in contact with a vapor, liquid, or solid comprising an amine or 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. 15. The system of claim 14, wherein 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 filter system for the emitted light incident on the sensor.

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