Improved method for determining an atmospheric composition in a storage environment for respiring products

Abstract

Method for controlling an atmospheric composition in a substantially wholly closed storage environment (100) configured to preserve respiring products, such as vegetables and / or fruit, which method comprises the following steps of: measuring a gas pressure inside the storage environment (100); feeding in an inert gas on the basis of the measured gas pressure until the gas pressure inside the storage environment (100) reaches a predetermined threshold value; measuring one or more gas concentrations of the atmospheric composition inside the storage environment (100); determining a metabolic coefficient of the atmospheric composition inside the storage environment (100) on the basis of the fed-in inert gas and the measured one or more gas concentrations.

Description

[0001] Improved method for determining an atmospheric composition in a storage environment for respiring products

[0002] Field of the invention

[0003] The invention relates to a method for determining an atmospheric composition in an at least partially closed storage environment.

[0004] Proper preservation of respiring products such as fruit, vegetables and plants is important. It is known to preserve such products at a low temperature, for instance of down to about 0°C, in combination with a reduced Oj and increased COj partial pressure. This technique is referred to as Controlled Atmosphere, abbreviated to CA. In use of CA the composition of the atmosphere in a storage space is kept precisely within predetermined threshold values. This allows for a decrease in the respiration rate of the respiring products and an increase in the shelf life thereof. The optimal atmospheric composition is of crucial importance here. Too low an Oj partial pressure may for instance induce a fermentation process in the respiring product. The aerobic respiration of the respiring product switches to an anaerobic respiration here, wherein glucose will be converted into carbon dioxide and alcohol. This results in unpleasant flavours of for instance ethanol upon consumption and in preservation disorders, such as the product turning brown or even nuclear degradation. Too high a COj partial pressure may also result in flavour or preservation defects. For this reason the O2 and CO2 partial pressure is kept at a safe and stable value in commercial refrigeration chambers.

[0005] Conventional CA makes use of static threshold values which are recommended as optimal storage conditions. Research has however shown that the optimal storage concentrations depend on the biological variability of the respiring products and may differ considerably from the predetermined recommended optimal storage conditions.

[0006] Adaptive CA, abbreviated to ACA, storage systems can adjust the atmospheric gas composition on the basis of the actual physiological state of the respiring product as a function of the batch and the time, so that variations resulting from factors such as geographical location, cultivar, mutant, orchard effects, harvesting date and storage duration can be taken into consideration.

[0007] In ACA storage the respiring product is preserved in an atmosphere with the lowest possible oxygen content tolerated by the respiring product. In practice a product response signal which is generated under such conditions is used to monitor the so-called hypoxia. On one hand, there is a monitoring system that uses chlorophyll fluorescence as product response signal. On the other, the measuring of an ethanol production is used as product response signal. Chlorophyll fluorescence has the drawback that it is a process which is not practically feasible in an automated control system. Furthermore, only the signal from a small sample of the fruit, typically 6 pieces of fruit, is measured in order to measure the chlorophyll fluorescence. There is a high risk that this signal is not representative of all the fruit in the storage space. Measuring the ethanol production is unreliable due to possible interaction of the measuring equipment with gases such as ethylene, which may be present. Ethanol is also highly soluble in the juice of the fruit, due to which systems that measure ethanol in the gas phase in the storage space do not generate a signal until a very late stage, and the fruit is already damaged. Measuring ethanol in the fruit juice is in turn timeconsuming, harmful and expensive since pieces of fruit must repeatedly be removed from the storage space - in which space a low oxygen concentration already prevails - and then be analysed in a laboratory.

[0008] Both methods have been compared to respiration measurements. The Oz concentration which was designated as the beginning of the hypoxia by the chlorophyll fluorescence or ethanol measurement has here been found to coincide with the O2 concentration which is indicated as the beginning of the hypoxia on the basis of respiration measurements.

[0009] Determining the respiration frequency or respiration rate can be achieved by measuring the change in the O2 and / or CO2 concentration in the atmosphere around the respiring products. A ratio between the O2 absorption and the CO2 production is then determined. A measure for this ratio is the so-called Respiration Coefficient (RQ). This measure is defined as the ratio of the CO2 formed by the respiring product and the O2 consumed. The measuring of the respiration frequency in storage spaces has been found to be impractical. In this context measuring of the respiration frequency is used synonymously with the term detecting respiration. Practical external factors, such as the size and shape of the storage space, leaks, climatic conditions, stacking pattern, storage of gases in the fruit, thus prevent a precise determination of RQ. This makes accurate monitoring difficult in practice.

[0010] EP2816890B1 describes a method for controlling the atmosphere in a closable space, wherein the method comprises of directly detecting the respiration of the respiring products. In order to obviate said drawbacks however, the space need be closed to external influences during detection of the respiration. It is essential here for the space to have a leak-tightness of less than 0.2 cm2per 100 m3during detection of the respiration. Such spaces are expensive and difficult to manufacture. It is furthermore still essential according to the method of EP2816890B1 for the storage space to be brought to a considerably higher pressure than the surrounding area.

[0011] In practice the application of the above stated monitoring systems has been found to be sub-optimal, particularly due to the high standards set for the storage space and the sensitivity of the monitoring systems to pressure differences and external influences. Summary of the invention

[0012] Embodiments of the invention have the object of providing a method which allows an atmospheric composition in a storage environment for preserving respiring products to be determined in improved manner.

[0013] According to a first aspect, the invention provides for this purpose a method for determining an atmospheric composition in an at least partially closed storage environment configured to preserve respiring products, such as vegetables and / or fruit, which method comprises the following steps of:

[0014] - measuring a gas pressure inside the storage environment;

[0015] - feeding in an inert gas on the basis of the measured gas pressure until the gas pressure inside the storage environment reaches a predetermined threshold value;

[0016] - measuring one or more gas concentrations of the atmospheric composition inside the storage environment;

[0017] - determining a change in the atmospheric composition inside the storage environment on the basis of the fed-in inert gas and the measured one or more gas concentrations.

[0018] The advantage of the invention is based on the insight that an equilibrium between the fed-in gas and gas leaks is found by feeding in inert gas to a threshold value on the basis of the gas pressure measured in the storage space. This is because, according to the gas law, no pressure increase will take place if a volume of gas is still increasing in the storage space. When the pressure in the storage environment increases, this indicates the physical property of the whole volume of the storage space being taken up by gas, further insertion of gas must consequently result in a pressure increase. In the inevitable practical event of a leak being present in the storage environment gas will escape from the storage environment and realize a corresponding pressure drop in the space. Infeed of inert gas until the gas pressure in the storage environment reaches a predetermined threshold value enables a reliable observation of the change in the atmospheric composition to be carried out. This observation can be carried out practically independently of the properties of the storage environment, such as a leak- tightness. A storage environment which does not comply with strict hermetic properties, for instance 0.2 cm2per 100 m3, can thus for instance still be used.

[0019] The method preferably comprises of measuring an atmospheric pressure outside the storage environment, wherein the predetermined threshold value lies a maximum of 20 Pa above the measured atmospheric pressure, preferably a maximum of 15 Pa, more preferably a maximum of 10 Pa. This allows further external influences, such as pressure fluctuations due to weather conditions, to be taken into account when determining the metabolic coefficient of the atmospheric composition.

[0020] The method preferably further comprises of measuring a flow rate of the fed-in inert gas, wherein determining the metabolic coefficient of the atmospheric composition inside the storage environment further comprises of determining the change in the atmospheric composition on the basis of the flow rate of the fed-in inert gas. The flow rate is preferably measured volumetrically.

[0021] The inert gas is preferably nitrogen gas.

[0022] The method of determining the metabolic coefficient preferably further comprises of determining a respiration quotient, RQ. The respiration quotient, RQ, more preferably comprises a ratio of a rate of a COz gas production relative to a rate of an O2 gas consumption. The respiration quotient preferably further comprises a change in a ratio between the rate of a CO2 gas production relative to a rate of an O2 gas consumption. The method preferably further comprises of controlling the atmospheric composition inside the storage environment on the basis of the determined change in the atmospheric composition and the fed-in inert gas.

[0023] The storage environment preferably remains open to external influences during determining of the metabolic coefficient of the atmospheric composition.

[0024] The inert gas is preferably fed into the storage space in continuous manner during determining of the metabolic coefficient of the atmospheric composition.

[0025] The method preferably further comprises an initialization phase wherein, during the initialization phase, the method further comprises of bringing the infeed of the inert gas into mass balance relative to a leakage gas flow leaking from the storage space on the basis of the measured gas pressure.

[0026] According to a second aspect, the invention provides an assembly for storing respiring products, the assembly comprising an at least partially closed storage environment configured to store respiring products, a pressure measuring device configured to measure a gas pressure inside the storage environment, a gas infeed device configured to feed an inert gas into the storage space, at least one gas concentration measuring device configured to measure one or more gas concentrations of the atmospheric composition inside the storage environment, and a control device, which control device is configured to control the gas infeed device on the basis of the measured gas pressure until the gas pressure inside the storage environment reaches a predetermined threshold value and is configured to determine a change in the atmospheric composition inside the storage environment on the basis of the fed-in inert gas and the measured one or more gas concentrations.

[0027] According to a third aspect, the invention provides a computer program product comprising instructions which, when the program is run by a computer, make the computer perform the above stated method.

[0028] According to a fourth aspect, the invention provides a control device for use with an assembly as described above, which control device comprises a computer on which the computer program product as described above is stored. Brief description of the figures

[0029] The above stated and other advantageous features and objects of the invention will become more apparent, and the invention better understood, on the basis of the following detailed description when read in combination with the accompanying drawings, in which:

[0030] Figure 1 shows schematically a storage environment in which respiring products are preserved according to an exemplary embodiment.

[0031] Detailed embodiments

[0032] The following detailed description relates to determined specific embodiments. The teaching hereof can however be applied in different ways. The same or similar elements are designated in the drawings with the same reference numerals.

[0033] The present invention will be described with reference to specific embodiments. The invention is however not limited thereto, but solely by the claims.

[0034] As used here, the singular forms “a” and “the” comprise both the singular and plural references, unless clearly indicated otherwise by the context.

[0035] The terms “comprising”, “comprises” and “composed of’ as used here are synonymous with “including”. The terms “comprising”, “comprises” and “composed of’ when referring to stated components, elements or method steps also comprise embodiments which “consist of’ the components, elements or method steps.

[0036] The terms first, second, third and so on are further used in the description and in the claims to distinguish between similar elements and not necessarily to describe a sequential or chronological order, unless this is specified. It will be apparent that the thus used terms are mutually interchangeable under appropriate circumstances and that the embodiments of the invention described here can operate in an order other than described or illustrated here.

[0037] Reference in this specification to “one embodiment”, “an embodiment”, “some aspects”, “an aspect” or “one aspect” means that a determined feature, structure or characteristic described with reference to the embodiment or aspect is included in at least one embodiment of the present invention. The manifestations of the sentences “in one embodiment”, “in an embodiment”, “some aspects”, “an aspect” or “one aspect” in different places in this specification thus do not necessarily all refer to the same embodiment or aspects. As will be apparent to a skilled person in this field, the specific features, structures or characteristics can further be combined in any suitable manner in one or more embodiments or aspects. Although some embodiments or aspects described here comprise some but no other features which are included in other embodiments or aspects, combinations of features of different embodiments or aspects are further intended to fall within the context of the invention and to form different embodiments or aspects, as would be apparent to the skilled person. In the appended claims all features of the claimed embodiments or aspects can for instance be used in any combination.

[0038] The same or similar elements are designated in the drawing with the same reference numerals. Figure 1 shows a storage environment 100 which is configured to preserve respiring products. Figure 1 further shows an assembly comprising a pressure measuring device 110A configured to measure a gas pressure inside the storage environment 100, a gas infeed device 120 configured to feed an inert gas into storage space 100, at least one gas concentration measuring device 131, 132 configured to measure one or more gas concentrations of the atmospheric composition inside storage environment 100, and a control device 140. The assembly and the storage environment are configured to store or preserve respiring products. Typical examples of respiring products, also referred to as breathing products, are vegetables and fruit. The terms “vegetables” and “fruit” are used interchangeably throughout the application. Figure 1 shows apples for the purpose of illustration. It will however be apparent that the storage environment is not limited to apples and that storage environment 100 can be utilized for other types of fruit, such as pears, bananas or strawberries, or vegetables. During storage, fruit and vegetables absorb oxygen, Oj, and emit carbon dioxide, COj. Prolonged preservation of vegetables and fruit amounts to preventing ripening and maturation so that flavour and quality are preserved, as was already elucidated at length in the description introduction. By modifying the gas conditions in storage environment 100 the breathing, also referred to as respiration, of vegetables and fruit can be inhibited to great extent. Oxygen is an essential component in the respiration. In order to inhibit the respiration the oxygen content in storage environment 100 is reduced. This reduces the fruit respiration and allows the fruit quality to be preserved. The carbon dioxide concentration is generally also permitted to rise, this contributing to quality preservation. As described above however, an optimal atmospheric composition inside storage environment 100 is of crucial importance here. Too low an Oj partial pressure, possibly in combination with too high a partial COj pressure, may for instance induce a fermentation process in the respiring product. The aerobic respiration of the vegetable or fruit switches to an anaerobic respiration here, wherein glucose will be converted into carbon dioxide and alcohol. This results in unpleasant flavours of for instance ethanol upon consumption and in preservation disorders, such as the product turning brown or even nuclear degradation. For this reason the O2 and CO2 partial pressure in storage environment 100 is kept at a safe and stable value. As described above however, determining the correct respiration values is highly complex and susceptible to external influences in practice.

[0039] According to a first aspect, a method is provided for determining an atmospheric composition in the storage environment 100. Storage environment 100 is at least partially closed off from an outside environment. It will be apparent that storage environment 100 is at least temporarily accessible for loading and unloading of fruit and vegetables, for instance via a closable door. Storage environment 100 may be insulated, for instance when it is desirable to preserve vegetables and fruit at a low temperature and to optimally preserve the coolness in storage environment 100 in this way. A leak-tightness of storage environment 100 is further preferably as low as possible, for instance 1 cm2per 100 m3, in order to limit loss of gas from storage environment 100. It is however not essential for storage environment 100 to comply with such highly stringent leak-tightness requirements since the method allows almost any loss of gas from storage environment 100 to be taken into account in ingenious manner, as will be further elucidated below. This is because any storage environment 100 will have one or more gas leaks along which gas is able to escape from the storage environment. This is indicated in figure 1 with reference letter L.

[0040] According to the method, a gas pressure inside storage environment 100 is measured. For this purpose one or more pressure measuring devices 110A are provided, these measuring a gas pressure in storage environment 100. Further also provided is a gas infeed device 120 which allows an inert gas to be fed into storage environment 100. A plurality of gas infeed devices can also be provided, for instance when it is desirable to feed different types of gas into storage environment 100. The gas infeed device 120 is configured to feed gas into storage environment 110 on the basis of the gas pressure measured by the pressure measuring device 110 A. The gas infeed device 120 feeds in gas until a predetermined threshold value is reached.

[0041] One or more gas concentrations of the atmospheric composition inside the storage environment are measured before, during or after infeed of the inert gas. One or more gas concentration measuring devices 131, 132 are provided for this purpose. A first gas concentration measuring device 131 can for instance measure the concentration of oxygen. A second gas concentration measuring device 132 can for instance measure the concentration of carbon dioxide. A metabolic coefficient of the atmospheric composition inside storage environment 100 is then determined on the basis of the fed-in inert gas and the measured one or more gas concentrations. The metabolic coefficient is preferably determined as a result of a calculation on the basis of the measured gas concentrations of one or more gases Ci in the storage space with i = 1, .... n, as shown in formula [1].

[0042] MC = f(Ci) [1]

[0043] The advantage hereof is based on the insight that an equilibrium between the fed-in gas and gas leaks L is found with the infeed of inert gas to a threshold value on the basis of the gas pressure measured in storage space 100. This is because, according to the well-known gas law, no pressure increase will take place if a volume of gas is still increasing in the storage space 100. In this context the volume is determined by the closed storage space 100. When the pressure in storage environment 100 increases, this indicates the physical property of the whole volume of storage space 100 being taken up by gas, for instance a combination of oxygen gas, carbon dioxide gas and nitrogen. According to the well-known gas laws, the further infeed of gas then must result in a pressure increase inside storage space 100. In the inevitable practical event of a leak L being present in storage environment 100, gas will escape from storage environment 100. Because the oxygen content in the area outside the storage environment is typically about 1%, in known monitoring systems this leak L will result in an excessively high detection of the oxygen content inside storage space 100 and thus in an overestimation of the respiration quotient RQ. The leak further also has the result that the pressure in storage environment 100 drops. Feeding in inert gas until the gas pressure in the storage environment reaches a predetermined threshold value enables a reliable observation of the change in the atmospheric composition to be performed in each case. This observation can be carried out practically independently of the properties of the storage environment, such as a leak-tightness. A storage environment 100 which does not comply with strict hermetic properties, for instance 0.2 cm2per 100 m3, can thus for instance still be used. Determining the metabolic coefficient preferably further comprises of determining a change in a ratio between the measured one or more gas concentrations. Use can be made here of both a onetime measurement of the concentration of the gases, but also of repeated measurements of the gas concentrations, which allows the production and / or consumption rates of these gases to be calculated and to be used to determine the metabolic coefficient.

[0044] According to an exemplary embodiment, the metabolic coefficient comprises a respiration quotient, RQ, wherein determining of the metabolic coefficient is performed on the basis of a COz production rate, rcoi, and the O2 consumption rate, ro2, of respiring products, preferably according to formula [2] :

[0045] According to a further exemplary embodiment, the metabolic coefficient comprises a respiration rate, R, wherein use is made of the CO2 production rate, rco2, of the respiring products, preferably according to formula [3]:

[0046] R=f(.cco2)= rco2[3] Alternatively or in combination, the metabolic coefficient can be determined on the basis of at least one or more of the following gas concentrations: ethylene, ethanol, acetaldehyde, methanol, ethyl acetate, acetone, 1-propanol, 2-butanone, propylene, propionaldehyde, methyl alcohol, acetone, 2- propanol, 2-methyl-2-butanone, 2-methyl-2-butenal, ethyl acetate, propane, 2-ethoxy-2-methyl-l- propanol, 2-methyl-amylene hydrate, 2-pentanone, pentanal, furan, 2-ethyl-l -butanol, 3-methyl-l- butanol, 2-methyl-methyl isobutyl ketone, 2-pentenal, (e)-furan, tetrahydro-2, 2,5, 5 -tetramethylmethyl isovalerate, 3-hexanone, 2-hexanone, hexanal, 2-hexenal, (e)-2-hexenal, (e)-2-hexen-l-ol, (z)-l -hexanol, styrene, 2-heptanone, heptanal, 2-ethyl-2-heptanone, 4-methyl-5-hepten-2-one, 6- methyl-(2r,5s)-2-methyl-5-(prop-l-en-2-yl)-2-vinyl tetrahydrofuranl,3-cyclohexadiene, 1-methyl- 4-(l-methylethyl)-o-cymene, d-limonene, eucalyptol, 3-carene.gamma.-terpinene, trans-linalool oxide (furanoid), benzaldehyde, 4-methyl-benzoic acid, methyl ester, linalool, nonanal, citral, 1- .alpha.-terpineol, cyclohexanone, 2-methyl-5-(l-methylethenyl)-, trans-decanal, 3 -cyclohexene- 1- acetaldehyde, .alfa.,4-dimethyl-2,6-octadiene-l-ol, 3,7-dimethyl-, (z)-ethylbutanoate, butyl acetate, hexanal, 2-methylbutyl acetate, butyl propionate, geraniol, eugenoln 5,9-undecadien-2-one, 6,10- dimethyl-(e), ethyl propionate, propyl acetate, methyl 2-methyl butanoate, 2-methylpropyl acetate, amyl acetate, 3-hexanol, 2-methyl- 1 -butanol, (e)-2hexenal, (z) -2 -pentenyl acetate, 1-pentanol, hexyl acetate, 5-hexenyl acetate, (e)-2-hexenyl acetate, 6-methyl-5-hepten-l-one, 1-hexanol, (e)-3- hexen-l-ol, heptyl acetate, (z)-3-hexen-l-ol, (e)-2-hexen-l-ol, (e)-5-hexen-l-ol, (e)-3-hexen-l-ol, acetic acid, 6-methyl-5-hepten-2-ol.

[0047] It has been found in practice that the longer fruit and vegetables are preserved inside the storage environment 100, the smaller the changes in atmospheric composition inside storage environment 100 become, enabling a period between two determinations of the atmospheric composition inside storage environment 100 to be increased. The inert gas is preferably fed into the storage space 100 in continuous manner during determining of the metabolic coefficient of the atmospheric composition. The gas pressure always remains below the predetermined threshold value here so that an equilibrium between the fed-in gas and the leaking gas is created. The equilibrium is preferably realized during an initialization phase wherein, during the initialization phase, the method further comprises of bringing the infeed of the inert gas into mass balance relative to a leakage gas flow leaking from the storage space on the basis of the measured gas pressure.

[0048] It is further advantageous for an atmospheric pressure outside the storage environment 100 to be measured, for instance using a pressure measuring device 110B which is located outside storage environment 100. Measuring of the atmospheric pressure outside storage environment 100 allows further external influences, such as pressure fluctuations due to weather conditions and an altitude of storage environment 100 relative to sea level, to be taken into account when determining the metabolic coefficient of the atmospheric composition. The predetermined threshold value lies a maximum of 20 Pa above the measured atmospheric pressure here, preferably a maximum of 15 Pa, more preferably a maximum of 10 Pa.

[0049] The method can further comprise of controlling the atmospheric composition inside storage environment 100 on the basis of the determined changes in atmospheric composition and the fed-in inert gas. Oxygen gas or carbon dioxide gas can thus for instance be added on the basis of the determined change when the oxygen content inside storage environment 100 is found to be below or above a minimum value for the fruit or vegetable. Determining the atmospheric composition in improved manner thus further also allows an improved control of the atmospheric composition inside storage environment 100 to be carried out, whereby fruit and vegetables can be preserved for longer.

[0050] The method preferably further comprises of measuring a flow rate of the fed-in inert gas, wherein determining the metabolic coefficient of the atmospheric composition inside the storage environment further comprises of determining the change in the atmospheric composition on the basis of the flow rate of the fed-in inert gas. The flow rate is preferably measured volumetrically.

[0051] In contrast to known monitoring systems, such as described in NL2008346, during determining of the metabolic coefficient of the atmospheric composition the storage environment 100 can remain relatively open to external influences, or external systems, such as a pressure compensation system, which compensate for the effect of external influences such as pressure differences are not needed. This makes the storage environments 100 simpler to manufacture and inexpensive.

[0052] The skilled person will appreciate on the basis of the above description that the invention can be embodied in different ways and on the basis of different principles. The invention is not limited here to the above described embodiments. The above described embodiments and the figures are purely illustrative and serve only to increase understanding of the invention. The invention will not therefore be limited to the embodiments described herein, but is defined in the claims.

Claims

Claims1. Method for determining an atmospheric composition in an at least partially closed storage environment configured to preserve respiring products, such as vegetables and / or fruit, which method comprises the following steps of:- measuring a gas pressure inside the storage environment;- feeding in an inert gas on the basis of the measured gas pressure until the gas pressure inside the storage environment reaches a predetermined threshold value;- measuring one or more gas concentrations in the atmospheric composition inside the storage environment;- determining a metabolic coefficient of the atmospheric composition inside the storage environment on the basis of the fed-in inert gas and the measured one or more gas concentrations.

2. Method according to the foregoing claim, further comprising of measuring an atmospheric pressure outside the storage environment, wherein the predetermined threshold value lies a maximum of 20 Pa above the measured atmospheric pressure, preferably a maximum of 15 Pa, more preferably a maximum of 10 Pa.

3. Method according to any one of the foregoing claims, further comprising of measuring a flow rate of the fed-in inert gas, wherein determining the metabolic coefficient of the atmospheric composition inside the storage environment further comprises of determining the change in the atmospheric composition on the basis of the flow rate of the fed-in inert gas.

4. Method according to any one of the foregoing claims, wherein the inert gas is nitrogen gas.

5. Method according to any one of the foregoing claims, wherein determining of the metabolic coefficient further comprises of determining a respiration quotient, RQ.

6. Method according to the foregoing claim, wherein the respiration quotient, RQ, comprises a ratio of a rate of a COz gas production relative to a rate of an O2 gas consumption.

7. Method according to any one of the claims 5-6, wherein the respiration quotient further comprises a change in a ratio between the rate of a CO2 gas production relative to a rate ofan Oj gas consumption.

8. Method according to any one of the foregoing claims, further comprising of controlling the atmospheric composition inside the storage environment on the basis of the determined metabolic coefficient of the atmospheric composition and the fed-in inert gas.

9. Method according to any one of the foregoing claims, wherein the storage environment remains open to external influences during determining of the metabolic coefficient of the atmospheric composition.

10. Method according to any one of the foregoing claims, wherein the inert gas is fed into the storage space in continuous manner during determining of the metabolic coefficient of the atmospheric composition.

11. Method according to any one of the foregoing claims, wherein the method further comprises an initialization phase wherein, during the initialization phase, the method further comprises of bringing the infeed of the inert gas into mass balance relative to a leakage gas flow leaking from the storage space on the basis of the measured gas pressure.1 . Assembly for storing respiring products, the assembly comprising an at least partially closed storage environment configured to store respiring products, a pressure measuring device configured to measure a gas pressure inside the storage environment, a gas infeed device configured to feed an inert gas into the storage space, at least one gas concentration measuring device configured to measure one or more gas concentrations of the atmospheric composition inside the storage environment, and a control device, which control device is configured to control the gas infeed device on the basis of the measured gas pressure until the gas pressure inside the storage environment reaches a predetermined threshold value and is configured to determine a metabolic coefficient of the atmospheric composition inside the storage environment on the basis of the fed-in inert gas and the measured one or more gas concentrations.

13. Computer program product comprising instructions which, when the program is run by a computer, make the computer perform the method according to any one of the claims 1-11.

14. Control device for use with an assembly according to claim 12, which control device comprises a computer on which the computer program product according to claim 13 is stored.

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