Method for preserving a packaged food product

Abstract

The present invention relates to a method for preserving packaged food products to destroy vegetative B. cereus and spores thereof, as well as packaged food products which are kept in a refrigerator.

Description

[0001] Method for preserving a packaged food product

[0002] FIELD

[0003] The present invention relates to a method to preserve packaged food products and to packaged food products prepared thereby.

[0004] BACKGROUND

[0005] In today's fast-paced society, Refrigerated Processed Foods of Extended Durability (REPFEDs) have gained popularity due to the time constraints faced by people. These REPFEDs inherently contain bacteria, such as Bacillus cereus, Listeria monocytogenes, faecal streptococci, and Clostridium botulinum, and spores thereof, which pose significant health risks to consumers. Therefore, the bacterial load and spores in REPFEDs have to be reduced or eliminated. While various conservation methods exist, their effectiveness in killing these strains and their spores is limited. One commonly used conservation technique is sterilization, typically applied to REPFEDs with a pH value above 4.5. This method involves subjecting the food to intense heating at temperatures around 121.1°C-140°C for approximately 20 to 40 minutes in an autoclave. Although vegetative bacteria and their spores are destroyed during this process, the overall quality of the food is hugely compromised. Foods that have undergone sterilization are commonly known as canned foods with a long shelf life up to a few years. Another widely recognized method is pasteurization, specifically for REFPEDs with a pH value up to 4.5. During pasteurization, REPFEDs undergo brief heating to about 70 to 90°C to eliminate vegetative bacteria while minimizing molecular and structural changes of the REPFEDs. For REPFEDs with a pH above 4.5, an acid or additive is used to lower the pH to 4.5 or less prior to the pasteurization process. Despite pasteurization's effectiveness in eliminating some vegetative bacteria such as Listeria monocytogenes and faecal streptococci, it has been observed that certain other vegetative bacteria such as Bacillus cereus and Clostridium botulinum are capable of surviving this treatment. Furthermore, spores are known to be more resilient to heat, including those of Bacillus cereus and Clostridium botulinum, and can survive the pasteurization process. In refrigerated environments, these spores can germinate and multiply, albeit with restricted growth potential, thus limiting the overall storage life of pasteurized REPFEDs to just a few days. More specific, the psychrotrophic Bacillus cereus, is widely distributed in nature (ICMSF. 1996. Microorganisms in Foods 5. Characteristics of Microbial Pathogens.). Consequently, it is considered a potential contaminant in REPFEDs. As a result, thermal processes used for conserving refrigerator-stable foods need to address the elimination of psychrotrophic Bacillus cereus spores, which are more resistant to heat than, for instance, the spores of non-proteolytic Clostridium botulinum. Therefore, there is a need for new methods to further improve the microbial safety and storage stability of REFPEDs while minimizing the degradation of the taste and nutrients of REPFEDs. SUMMARY

[0006] The present invention is concerns a method for preserving packaged food products to safeguard them from bacteria, in particular from spore-forming bacteria, such as at least from Bacillus cereus and optionally further from Listeria monocytogenes, faecal streptococci, and psychrotropic Clostridium botulinum and spores thereof, to improve their storage stability and to minimize the reduction of the organoleptic properties of preserved packaged food products such as REPFEDs. By extending the refrigerated shelf life of preserved packaged food products to weeks, months or years, manufacturers can more efficiently and economically supply their products to local and export markets through the distribution and storage chains. The shelflife of the food product is not limited by the amount of colony forming unit or growth of bacteria but it depends on oiganoleptic properties of the food product itself.

[0007] Accordingly, in a first aspect, the present invention relates to a method for preserving a packaged food product comprising: a) pressure heating the packaged food product to 110 to 125 degrees Celsius; b) maintaining the packaged heated food product between 10 to 60 seconds at 110 to 125 degrees Celsius; c) cooling down the packaged heated food product to 0 to 12 degrees Celsius in less than 15 minutes.

[0008] In a particular embodiment, the food product is a Refrigerated Processed Foods of Extended Durability (REPFED) product.

[0009] In a particular embodiment, the food product or at least a portion thereof has pH of at least 4.6.

[0010] In a particular embodiment, higher than atmospheric pressure is applied externally onto the packaged food product during at least a portion of step a) and / or step b), preferably wherein the externally applied pressure is between 0.1 and 1.0 bar (1X104-1X105Pa) higher than the pressure within the packaged food product, preferably between 0.2 and 0.7 bar (2xl04-7xl04Pa), such as between 0.1 and 0.3 bar (IxlO4- 3xl04Pa), e.g., about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, or 0.7 bar, higher than the pressure within the packaged food product, more preferably wherein the externally applied pressure is between 0.15 and 0.25 bar (1.5-2.5xl04Pa) higher than the pressure within the packaged food product. It shall be understood that to heat the food product within the package to temperatures prescribed in step a) and / or step b), the pressure within the package can be expected to build up to values higher than atmospheric pressure, in particular to values higher than 1.0 bar. By means of an example and without limitation, temperature of 112°C of the food product within the package may correspond to pressure within the package of about 1.53 bar. The externally applied pressure, which is higher than the internal pressure within the package, will thus act to counterbalance the built-up internal pressure, inter alia preventing deformations and failures of the package, such as micro leaks especially at seams between different materials, bloated out packages, etc. In a particular embodiment, before step a) a food product is packaged and prior to packing, the food product is preheated, in particular under atmospheric pressure, to a temperature between 50°C and 75 °C, more preferably between 55 °C and 70 °C, and most preferably between 60 °C and 65 °C.

[0011] In a particular embodiment, before step a) a food product is packaged and prior to packing, optionally before and / or during the optional preheating, the food product is deaerated.

[0012] In a particular embodiment, a pressure magnetron or autoclave is used for pressure heating the packaged food product.

[0013] In a particular embodiment, a pressure magnetron, or autoclave, or ohmic heating is used for preheating the food product.

[0014] In a particular embodiment, to maintain the packaged heated food product at 110 to 125 degrees Celsius, the packaged heated food product is immersed in water.

[0015] In a particular embodiment, in step c) nitrogen gas (N2) or cold air or cold water or ice is used to cool down the packaged heated food product.

[0016] In a particular embodiment, the food product has been packaged under protective atmosphere, optionally under nitrogen gas (N2) atmosphere, preferably wherein the amount of oxygen in the headspace of the package is less than 1 percent by volume.

[0017] Accordingly, in a further aspect, the present invention relates to a packaged food product obtainable or obtained by the method as disclosed herein.

[0018] In a particular embodiment, the food product is a Refrigerated Processed Foods of Extended Durability (REPFED) product.

[0019] In a particular embodiment, at temperature between 0 °C and 12 °C the packaged food product is free of at least vegetative Bacillus cereus and optionally free of Listeria monocytogenes and / or faecal streptococci and / or psychrotropic Clostridium botulinum and the spores of said bacteria are at least fatally injured such that the spores can no longer grow out vegetatively into the respective bacteria.

[0020] In a particular embodiment, the packaged food product is free of vegetative psychrotrophic Bacillus cereus and the spores thereof are at least fatally injured.

[0021] In a particular embodiment, the food product is free of preservatives.

[0022] BRIEF DESCRIPTION OF THE FIGURES

[0023] The following description of the figures of specific embodiments of the invention are merely exemplary in nature and is not intended to limit the present teachings, their application or uses. FIG 1 illustrates a radar chart of sensory results for red cabbage treated with three different methods. Method 1 (dark gray), method 2 (gray) and method 3 (light gray). Values are mean on scale from 0- 100% for each sensorial aspect. n=10.

[0024] DESCRIPTION OF EMBODIMENTS

[0025] Before the present products, compositions, uses and methods of the invention are described, it is to be understood that this invention is not limited to particular products, compositions, uses and methods or combinations described, since such products, compositions, uses and methods and combinations may, of course, vary. It is also to be understood that the terminology used herein is not intended to be limiting, since the scope of the present invention will be limited only by the appended claims.

[0026] As used herein, the singular forms "a", "an", and "the" include both singular and plural referents unless the context clearly dictates otherwise.

[0027] The terms "comprising", "comprises" and "comprised of as used herein are synonymous with "including", "includes" or "containing", "contains", and are inclusive or open-ended and do not exclude additional, non-recited members, elements or method steps. It will be appreciated that the terms "comprising", "comprises" and "comprised of as used herein comprise the terms "consisting of, "consists" and "consists of.

[0028] The recitation of numerical ranges by endpoints includes all numbers and fractions subsumed within the respective ranges, as well as the recited endpoints.

[0029] The term "about" or “approximately” as used herein when referring to a measurable value such as a parameter, an amount, a temporal duration, and the like, is meant to encompass variations of + / -10% or less, preferably + / -5% or less, more preferably + / -1% or less, and still more preferably + / -0.1% or less of and from the specified value, insofar such variations are appropriate to perform the disclosed invention. It is to be understood that the value to which the modifier "about" or “approximately” refers is itself also specifically, and preferably, disclosed.

[0030] Whereas the terms “one or more” or “at least one”, such as one or more or at least one member(s) of a group of members, is clear per se, by means of further exemplification, the term encompasses inter aha a reference to any one of said members, or to any two or more of said members, such as, e.g., any >3, >4, >5, >6 or >7 etc. of said members, and up to all said members.

[0031] All references cited in the present specification are hereby incorporated by reference in their entirety. In particular, the teachings of all references herein specifically referred to are incorporated by reference. Unless otherwise defined, all terms used in disclosing the invention, including technical and scientific terms, have the meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. By means of further guidance, term definitions are included to better appreciate the teaching of the present invention.

[0032] In the following passages, different aspects and embodiments of the invention are defined in more detail. Each aspect and embodiment so defined may be combined with any other aspect or aspects and embodiment or embodiments unless clearly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features indicated as being preferred or advantageous.

[0033] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to a person skilled in the art from this disclosure, in one or more embodiments. Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the appended claims, any of the claimed embodiments can be used in any combination.

[0034] As corroborated by the experimental section, which illustrates certain representative embodiments of the present invention, the inventors provide advantageous applications of a method to preserve packaged food products such as REPFEDs, offering a notable advantage in significantly extending the shelf life of packaged food products while retaining or minimally reducing their quality and taste. By applying the method, the shelf life of preserved packaged food products can be extended from a short span of days to several weeks, months or even up to a year. This innovative approach eliminates the need for preservatives, making it a highly advantageous method for long-term food preservation. The method effectively eliminates pathogenic microorganisms, including vegetative Bacillus cereus and optionally vegetative Listeria monocytogenes and faecal streptococci and Clostridium botulinum and at least incapacitates the spores of said bacteria, preventing their transition into active vegetative bacteria, and therefore ensures the microbial safety of the packaged food products and significantly reduces the risk of foodbome illnesses associated with these harmful microorganisms. Additionally, the method promotes sustainability by minimizing food loss, maximizing food utilization and resource management.

[0035] An aspect of the invention thus provides a method for preserving a packaged food product comprising: a) pressure heating the packaged food product to 110 to 125 degrees Celsius; b) maintaining the packaged heated food product for 10 to 60 seconds at 110 to 125 degrees Celsius; c) cooling down the packaged heated food product to 0 to 12 degrees Celsius in less than 15 minutes.

[0036] The method according to the invention enables the preservation and conservation of packaged food products without addition of preservatives, and vegetative Bacillus cereus and optionally Listeria monocytogenes, faecal streptococci, and Clostridium botulinum and spores thereof are killed or the spores of said bacteria are at least fatally injured.

[0037] As used herein, the terms “preservation”, “preserving”, “preserve” generally refer to a set of techniques and methods employed to extend the shelf life and maintain the quality, safety, and freshness of packaged food products over a period. The preservation methods generally aim to reduce the growth of spoilage-causing microorganisms, enzymatic reactions, and chemical changes that can lead to food deterioration, loss of nutritional value, or the presence of harmful bacteria.

[0038] As used herein, the terms “conservation”, “conserving”, “conserve” generally refer to a comprehensive set of processes and techniques aimed at minimizing food waste, optimizing resource utilization, and promoting sustainability throughout the food supply chain. The concept of “conservation”, “conserving”, “conserve” encompasses various measures, including but not limited to food storage and food processing.

[0039] In a certain embodiment, the food product is a Refrigerated Processed Foods of Extended Durability (REPFED) product.

[0040] As used herein, the term “fatally injured” refers to spores that are not dead but damaged to a degree that they are incapable of germinating in a food product which is kept at maximum 10 degrees Celsius, preferably at maximum 4 degrees Celsius. In embodiments, the spores of said bacteria are at least fatally injured such that the spores can no longer grow out vegetatively into the respective bacteria in a food product which is kept at maximum 12 degrees Celsius, preferably at maximum 10 degrees Celsius, more preferably at maximum 4 degrees Celsius .

[0041] In a certain embodiment, the food product or at least a portion thereof has pH of at least 4.6, more preferably of 4.6 to 7.0, such as 5.0 to 7.0, and most preferably of 4.6 to 6.0, such as 5.0 to 6.0.

[0042] In a certain embodiment, higher than atmospheric pressure is applied externally onto the packaged food product during at least a portion of step a) and / or step b). For example, higher than atmospheric pressure may be applied onto the packaged food product only during step a) but not during step b). In another example, higher than atmospheric pressure may be applied onto the packaged food product during both step a) and step b). For example, higher than atmospheric pressure may be applied onto the packaged food product during the entire step a), or for at least 50%, at least 60%, at least 70%, at least 80%, or at least 90% of the duration of step a). Independently, higher than atmospheric pressure may be applied onto the packaged food product during the entire step b), or for at least 50%, at least 60%, at least 70%, at least 80%, or at least 90% of the duration of step b).

[0043] In a certain embodiment, the externally applied pressure is between 0.1 and 1.0 bar (1X104-1X105Pa) higher than the pressure within the packaged food product, preferably between 0.2 and 0.7 bar (2xl04- 7xl04Pa), such as between 0.1 and 0.3 bar (1X104-3X104Pa), e.g., about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, or 0.7 bar higher than the pressure within the packaged food product, more preferably wherein the externally applied pressure is between 0. 15 and 0.25 bar (1 ,5-2.5xl04Pa) higher than the pressure within the packaged food product.

[0044] In a certain embodiment, the packaged food product is immersed in water during pressure heating and the temperature of the water can be elevated during pressure heating.

[0045] As used herein, the term “pressure heating” refers to a process involving the application of an external pressure to a food product within its packaging, wherein the external pressure is higher than atmospheric pressure, whereby the temperature of the food product within the package is elevated to temperatures above 100°C while the package is subjects to an external pressure.

[0046] In a certain embodiment, before step a) a food product is packaged and prior to packing, the food product is preheated under atmospheric pressure to a temperature between 50 and 75 degrees Celsius, more preferably between 55 and 70 degrees Celsius and most preferably between 60 and 65 degrees Celsius. Hence, an embodiment of the method comprises, prior to step a), preheating the food product under atmospheric pressure to a temperature between 50 and 75 degrees Celsius and packing the food product to provide the packaged food product. The preheating temperature may be preferably between 55 and 70 degrees Celsius and most preferably between 60 and 65 degrees.

[0047] In a certain embodiment, before step a) a food product is packaged and prior to packing the food product is deaerated. Hence an embodiment of the method comprises, prior to step a), deaerating the food product. Optionally, where the food product is also preheated, deaeration may be performed before and / or during preheating, such as preferably during preheating. The food product can be mixed during preheating to speed up the deaeration. In certain embodiments, when preheating is performed using ohmic heating, the food product is preferably deareated before the preheating in order to ensure that the product to be preheated contains substantially no air bubbles which can interfere with the ohmic heating process.

[0048] As used herein, the terms “deaerated”, “deaeration”, and “deaerating” refers to the process wherein air present in the food product is removed. Several processes to deaerate the food product exist such as, but not limited to, heating the food product to lower the solubility of gases. In a certain embodiment, deaeration is performed under atmospheric pressure by heating the food product to a temperature between 50°C and 75 °C, more preferably between 55 °C and 70 °C and most preferably between 60 °C and 65 °C. In case the food product is non-homogeneous containing a liquid portion with solid food pieces distributed / present therein, the air can be expected to be first removed form the liquid portion and afterwards from the pieces.

[0049] In a certain embodiment, during the packaging procedure of a food product, the food product is positioned in an open container or receptacle, such as a tray or a cup. Subsequently, a lid or cover sheet or film is applied or attached onto the container, covering, such as in particular hermetically covering, the open side of the container. The resulting packaged food product includes a distinct headspace that exists between the surface of the food product and the lid, sheet, or fdm; in other words the headspace corresponds to that part of the enclosure within the sealed container or receptacle which is not occupied by the food product. To enhance preservation and quality, it is preferred that the headspace is filled with nitrogen gas or CO2.

[0050] As used herein, the term “packaging” generally refers to sealable bags and open containers or receptacles, such as a tray or a cup that can be sealed with a lid, sheet, or film. The packaging can be manufactured from one or more materials, preferably heat-resistant and pressure resistant materials, for example but without limitation, from metals such as aluminium, glass, and plastics, such as polypropylene (PP), low-density polyethylene (LDPE), high-density polyethylene (HDPE), polystyrene (PS), and polyethylene terephthalate (PET). The open containers or receptacle can be made from different material than the lid, sheet, or film. To seal the containers or receptacles, different types of a lid, sheet, or film can be employed, which ensure product integrity and prevent contamination. Such lids, sheets, or films can be designed to be peelable for easy opening or may require a separate tool like a knife or scissors for opening the packaging. Certain examples for lids, sheets, or films are stretch lids, sheets, or films, heat-seal lids, sheets, or films that are used to cover the open surface of the containers or receptacles.

[0051] In step a), the packaged food product is heated to a temperature between 110 and 125 degrees Celsius, preferably to a temperature between 110 and 120 degrees Celsius, or between 111 and 120 degrees Celsius, more preferably to a temperature between 110 and 117 degrees Celsius, or between 111 and 117 degrees Celsius, more preferably to a temperature between 110 and 115 degrees Celsius, or between 111 and 115 degrees Celsius, even more preferably to a temperature between 112 to 120 degrees Celsius, or between 112 to 117 degrees Celsius, or between 112 to 115 degrees Celsius with pressure heating.

[0052] In an exemplary embodiment, the method for preserving a packaged food product comprises: a) pressure heating the packaged food product to 111 to 125 degrees Celsius; b) maintaining the packaged heated food product between 10 to 60 seconds at 111 to 125 degrees Celsius; c) cooling down the packaged heated food product to 0 to 12 degrees Celsius in less than 2 hours.

[0053] The duration required to heat a packaged food product can vary and depend on various factors, including the initial temperature of the food product prior to pressure heating it, the dimensions of the packaged food product, the composition of the food product, and the packaging material utilized.

[0054] In a certain embodiment, a pressure magnetron or autoclave is used for pressure heating and optionally for preheating the packaged food product. Common radio wave frequency emitted by state of the art magnetrons is 2450MHz or 915MHz. In step b), the temperature of the packaged heated food product is maintained at 110 to 125 degrees Celsius, preferably at a temperature between 110 and 120 degrees Celsius, or between 111 and 120 degrees Celsius, more preferably at a temperature between 110 and 117 degrees Celsius, or between 111 and 117 degrees Celsius, more preferably at a temperature between 110 and 115 degrees Celsius, or between 111 and 115 degrees Celsius, even more preferably to a temperature between 112 to 120 degrees Celsius, or between 112 and 117 degrees Celsius, for 10 to 60 seconds, for 10 to 55 seconds, for 10 to 50 seconds, for 10 to 45 seconds, preferably for 10 to 40 seconds, more preferably for 10 to 35 seconds, more preferably for 10 to 30 seconds, , for 15 to 60 seconds, for 15 to 55 seconds, for 15 to 50 seconds, for 15 to 45 seconds, preferably for 15 to 40 seconds, more preferably for 15 to 35 seconds, more preferably for 15 to 30 seconds. To maintain the temperature of the packaged heated food product, the packaged heated food product can be, at least partially or preferably completely, immersed in water at temperatures specified above. By immersing the packaged heated food product in water within a pressurised environment, the occurrence of burnt edges and cold spots can be minimized or eliminated altogether.

[0055] In an exemplary embodiment, the method for preserving a packaged food product comprises: a) pressure heating the packaged food product to 110 to 125 degrees Celsius; b) maintaining the packaged heated food product between 10 to 55 seconds at 110 to 125 degrees Celsius; c) cooling down the packaged heated food product to 0 to 12 degrees Celsius in less than 2 hours.

[0056] In an exemplary embodiment, the method for preserving a packaged food product comprises: a) pressure heating the packaged food product to 111 to 125 degrees Celsius; b) maintaining the packaged heated food product between 10 to 55 seconds at 111 to 125 degrees Celsius; c) cooling down the packaged heated food product to 0 to 12 degrees Celsius in less than 2 hours.

[0057] In an exemplary embodiment, the method for preserving a packaged food product comprises: a) pressure heating the packaged food product to 110 to 125 degrees Celsius; b) maintaining the packaged heated food product between 10 to 50 seconds at 110 to 125 degrees Celsius; c) cooling down the packaged heated food product to 0 to 12 degrees Celsius in less than 2 hours.

[0058] In an exemplary embodiment, the method for preserving a packaged food product comprises: a) pressure heating the packaged food product to 111 to 125 degrees Celsius; b) maintaining the packaged heated food product between 10 to 50 seconds at 111 to 125 degrees Celsius; c) cooling down the packaged heated food product to 0 to 12 degrees Celsius in less than 2 hours.

[0059] In an exemplary embodiment, the method for preserving a packaged food product comprises: a) pressure heating the packaged food product to 110 to 125 degrees Celsius; b) maintaining the packaged heated food product between 10 to 45 seconds at 110 to 125 degrees Celsius; c) cooling down the packaged heated food product to 0 to 12 degrees Celsius in less than 2 hours.

[0060] In an exemplary embodiment, the method for preserving a packaged food product comprises: a) pressure heating the packaged food product to 111 to 125 degrees Celsius; b) maintaining the packaged heated food product between 10 to 45 seconds at 111 to 125 degrees Celsius; c) cooling down the packaged heated food product to 0 to 12 degrees Celsius in less than 2 hours.

[0061] In a certain embodiment, to maintain the temperature of the packaged heated food product, at temperatures specified above, the packaged heated food product is immersed in water in the pressure magnetron kept at pressures between 0.1 and 1.0 bar (1X104-1X105Pa) higher than the pressure within the packaged food product, preferably between 0.2 and 0.7 bar (2xl04-7xl04Pa), such as between 0.1 and 0.3 bar (1X104-3X104Pa), e.g., about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, or 0.7 bar higher than the pressure within the packaged food product. By means of example and without limitation, to heat and maintain a food product at a temperature between 110 and 117 degrees Celsius the pressure within the packaged heated food product may be between 1.2 and 1.8 bar, at a temperature between 110 and 115 degree Celsius the pressure within the packaged heated food product may be between 1.2 and 1.6 bar, and at a temperature of 112 degrees Celsius the pressure within the packaged heated food product may be around 1.5 bar.

[0062] To track the temperature and pressure of the food product during pressure heating and maintaining the temperature, a temperature and pressure data logger may be used. The data logger can be placed inside a packaged food product and will record the temperature and pressure conditions throughout the pressure heating and maintenance of the temperature of the food product to ensure that the food product was heated to the desired temperature and the temperature was maintained for the desired time. It shall be understood that once the process has been optimised and tested for a particular type of food product and type of packaging, the process can be operated at industrial volumes using the optimised settings even without including a temperature and pressure data logger within the package. Optionally, a temperature and pressure data logger may be included in a minor subset of treated packages for quality control purposes.

[0063] In step c), the packaged heated food product is cooled down to 0 to 12 degrees Celsius in less than 2 hours, preferably in less than 75 minutes, more preferably in less than 60 minutes, more preferably in less than 20 minutes, more preferably in less than 19 minutes, more preferably in less than 18 minutes, more preferably in less than 17 minutes, more preferably in less than 16 minutes, even more preferably in less than 15 minutes, or in an increasing order of preference in less than 14 minutes, in less than 13 minutes, in less than 12 minutes, in less than 11 minutes, in less than 10 minutes, in less than 9 minutes, in less than 8 minutes, in less than 7 minutes, in less than 6 minutes, in less than 5 minutes, in less than 4 minutes, in less than 3 minutes, in less than 2 minutes, or in less than 1 minute. Accordingly, the temperature of the packaged heated food product is reduced from the starting temperature of 110-125 degrees Celsius to the resulting temperature of 0-12 degrees Celsius within the recited amount of time.

[0064] In an exemplary embodiment, the method for preserving a packaged food product comprises: a) pressure heating the packaged food product to 110 to 125 degrees Celsius; b) maintaining the packaged heated food product between 10 to 60 seconds at 110 to 125 degrees Celsius; c) cooling down the packaged heated food product to 0 to 12 degrees Celsius in less than 20 minutes.

[0065] In an exemplary embodiment, the method for preserving a packaged food product comprises: a) pressure heating the packaged food product to 110 to 125 degrees Celsius; b) maintaining the packaged heated food product between 10 to 60 seconds at 110 to 125 degrees Celsius; c) cooling down the packaged heated food product to 0 to 12 degrees Celsius in less than 19 minutes.

[0066] In an exemplary embodiment, the method for preserving a packaged food product comprises: a) pressure heating the packaged food product to 110 to 125 degrees Celsius; b) maintaining the packaged heated food product between 10 to 60 seconds at 110 to 125 degrees Celsius; c) cooling down the packaged heated food product to 0 to 12 degrees Celsius in less than 18 minutes.

[0067] In an exemplary embodiment, the method for preserving a packaged food product comprises: a) pressure heating the packaged food product to 110 to 125 degrees Celsius; b) maintaining the packaged heated food product between 10 to 60 seconds at 110 to 125 degrees Celsius; c) cooling down the packaged heated food product to 0 to 12 degrees Celsius in less than 17 minutes.

[0068] In an exemplary embodiment, the method for preserving a packaged food product comprises: a) pressure heating the packaged food product to 110 to 125 degrees Celsius; b) maintaining the packaged heated food product between 10 to 60 seconds at 110 to 125 degrees Celsius; c) cooling down the packaged heated food product to 0 to 12 degrees Celsius in less than 16 minutes.

[0069] In an exemplary embodiment, the method for preserving a packaged food product comprises: a) pressure heating the packaged food product to 110 to 125 degrees Celsius; b) maintaining the packaged heated food product between 10 to 60 seconds at 110 to 125 degrees Celsius; c) cooling down the packaged heated food product to 0 to 12 degrees Celsius in less than 15 minutes.

[0070] In an exemplary embodiment, the method for preserving a packaged food product comprises: a) pressure heating the packaged food product to 110 to 125 degrees Celsius; b) maintaining the packaged heated food product between 10 to 60 seconds at 110 to 125 degrees Celsius; c) cooling down the packaged heated food product to 0 to 12 degrees Celsius in less than 14 minutes.

[0071] In an exemplary embodiment, the method for preserving a packaged food product comprises: a) pressure heating the packaged food product to 110 to 125 degrees Celsius; b) maintaining the packaged heated food product between 10 to 60 seconds at 110 to 125 degrees Celsius; c) cooling down the packaged heated food product to 0 to 12 degrees Celsius in less than 13 minutes.

[0072] In an exemplary embodiment, the method for preserving a packaged food product comprises: a) pressure heating the packaged food product to 110 to 125 degrees Celsius; b) maintaining the packaged heated food product between 10 to 60 seconds at 110 to 125 degrees Celsius; c) cooling down the packaged heated food product to 0 to 12 degrees Celsius in less than 12 minutes. In an exemplary embodiment, the method for preserving a packaged food product comprises: a) pressure heating the packaged food product to 110 to 125 degrees Celsius; b) maintaining the packaged heated food product between 10 to 60 seconds at 110 to 125 degrees Celsius; c) cooling down the packaged heated food product to 0 to 12 degrees Celsius in less than 11 minutes.

[0073] In an exemplary embodiment, the method for preserving a packaged food product comprises: a) pressure heating the packaged food product to 110 to 125 degrees Celsius; b) maintaining the packaged heated food product between 10 to 60 seconds at 110 to 125 degrees Celsius; c) cooling down the packaged heated food product to 0 to 12 degrees Celsius in less than 10 minutes. In a certain embodiment, in step c) nitrogen gas (N2) or cold air or cold water or ice is used to cool down the packaged heated food product. Hence, the method may comprise cooling down the packaged heated food product using nitrogen gas (N2) or cold air or cold water or ice.

[0074] In the context of the present invention, the term "nitrogen gas (N2)" is generally utilized as a cooling medium due to its excellent heat transfer properties. The nitrogen gas absorbs heat energy from the food product through convection, conduction, and direct contact. This heat exchange causes the food product's temperature to decrease rapidly, thereby facilitating efficient and uniform cooling. In a certain embodiment, the temperature of the nitrogen gas can range between -15 and 10 degrees Celsius, preferably between -10 and 5 degrees Celsius, more preferably between -5 and 0 degrees Celsius.

[0075] In the context of the present invention, the term "cold air" refers to air that is cooler in temperature compared to the temperature of the food product. Cold air may encompass air that has been chilled or cooled through various means, such as refrigeration systems, air conditioning units, or other cooling mechanisms. The temperature range associated with cold air may vary depending on the food product that needs to be cooled, but it generally implies a temperature lower than the food product or ambient or desired operating temperature. In a certain embodiment, the temperature of cold air can range between -15 and 10 degrees Celsius, preferably between -10 and 5 degrees Celsius, more preferably between -5 and 0 degrees Celsius.

[0076] In the context of the present invention, the term "ice" refers to the solid state of water that occurs when water molecules freeze and form a rigid crystalline structure. Ice is typically characterized by its lower temperature and distinct solid form. It is commonly formed when the temperature of water reaches or falls below its freezing point, resulting in the transformation of liquid water into solid ice. In a certain embodiment, the temperature of ice can range between -15 and 0 degrees Celsius, preferably between -10 and 0 degrees Celsius, more preferably between -5 and 0 degrees Celsius.

[0077] In the context of the present invention, the term "ice water" in the present patent application refers to a mixture of ice and liquid water. It is created by combining ice with water, resulting in a solution or mixture that includes both solid ice and liquid water phases. Ice water generally has a lower overall temperature of the mixture compared to pure liquid water, as the presence of ice acts as a cooling agent. In a certain embodiment, the temperature of ice water is around 0 to 1 degree Celsius.

[0078] In a certain embodiment, the food product has been packaged under protective atmospheric pressure, optionally under nitrogen gas (N2) atmosphere, preferably wherein the amount of oxygen in the headspace of the packaged food product is less than 1 percent. Hence, in a certain embodiment, the method comprises, prior to step a), packing a food product under protective atmospheric pressure, optionally under nitrogen gas (N2) atmosphere. In case nitrogen gas (N2) is used during packing of the food product, N2 is applied over the surface of the food product, N2 is caught in the headspace between the surface of the food product and the lid of the container. Preferably, N2 is applied before the application or attachment of the lid on the container or receptacle to close the packaging.

[0079] In a certain embodiment, after deaeration and before sealing the packaging, the food product is placed under vacuum to eliminate remaining air and oxygen within the food product. Additionally, there is an optional step wherein N2 is introduced after vacuuming the food product but prior to sealing the packaging. N2 is then caught or trapped in the headspace between the surface of the food product and the lid of the container and replaces the air that would have normally filled the headspace. Preferably, N2 is applied before the application or attachment of the lid on the container or receptacle to close the packaging.

[0080] In a further aspect, the present invention relates to a packaged food product obtainable or obtained by the method described herein.

[0081] These packaged food products have an extended refrigerated shelf life of at least about 3 months at a storage temperature of about 0 to 12 degrees Celsius, preferably about 0 to 6 degrees Celsius, more preferably about 0 to 4 degrees Celsius. Preferably, the extended refrigerated shelf life is at least about six months, more preferably at least about 12 months. The present invention allows for at least a doubling of the extended refrigerated shelf life of a food product compared with the corresponding product produced by standard processing technologies, such as pasteurisation.

[0082] In a particular embodiment, the food product is a Refrigerated Processed Foods of Extended Durability (REPFED) product.

[0083] In the context of the present invention, the term “food product” refers to a food product of plant, animal or fungal origin intended for dietary consumption, such as for instance and without limitation fruits, vegetables, sprouts, fish, meat, eggs, dairy, cheeses, bread, beer, wine, cider, rice, baked goods, cooking oils, dips, spreads, pasta, noodles, processed food products, unprocessed food products, high-moisture food products and REPFEDs. In certain embodiments the term does not include single low-moisture food products (LMFs) which are food products with a water activity below that which is required for the growth of microorganisms. LMFs are naturally low in moisture or are produced from high-moisture food products (HMFs) through drying or dehydration processes. Typically, LMFs exhibit a water activity level of 0.85 or below, such as cereals, grains, dried protein products, spices, dried herbs (including teas), nuts, confections, snacks, dried fruits, dried vegetables, and seeds.

[0084] As used herein, the term “Refrigerated Processed Foods of Extended Durability (REPFEDs)” , also known as “ready meals”, “minimally processed refrigerated foods”, “new generation refrigerated foods”, “chilled foods”, “extended shelf life refrigerated foods”, “sous-vide” are used in the broadest sense and generally refers to a diverse group of food products which are stored refrigerated (e.g., in a fridge or a refrigerated shelf) at maximum 12 degrees Celsius, preferably at maximum 10 degrees Celsius, more preferably at maximum 4 degrees Celsius.

[0085] In a particular embodiment, at temperature between 0 °C and 12 °C, preferably at temperature between 0 °C and 10 degrees Celsius, more preferably at temperature between 0 °C and 4 degrees Celsius the food product is at least free of vegetative Bacillus cereus (B. cereus) and optionally Listeria monocytogenes and faecal streptococci and Clostridium botulinum and the spores of said bacteria are at least fatally injured such that the spores can no longer grow out vegetatively into the respective bacteria. In embodiments, at temperature between 0 °C and 12 °C, preferably at temperature between 0 °C and 10 degrees Celsius, more preferably at temperature between 0 °C and 4 degrees Celsius the food product is at least free of vegetative Bacillus cereus (B. cereus) and optionally Listeria monocytogenes and faecal streptococci and Clostridium botulinum and the spores of said bacteria are at least fatally injured such that the spores can no longer grow out vegetatively into the respective bacteria at said temperature.

[0086] In a particular embodiment, the packaged food product is free of vegetative Bacillus cereus and the psychrotrophic spores thereof are at least fatally injured. In embodiments, the packaged food product is free of vegetative Bacillus cereus and the psychrotrophic spores thereof are at least fatally injured such that the spores can no longer grow out vegetatively into the respective bacteria in a food product which is kept at maximum 12 degrees Celsius, preferably at maximum 10 degrees Celsius, more preferably at maximum 4 degrees Celsius. In the context of the present invention, the term "vegetative" generally refers to the state in which bacteria actively growing and reproducing. It indicates the bacteria's active metabolic state, wherein they possess the ability to maintain essential cellular functions such as nutrient absorption and metabolism. As used herein, the term “free of vegetative bacteria” refers to a condition in which a food product is completely devoid, i.e., for practical purposes <3.0, preferably <2.0, more preferably <1.0 colony forming unit (CFU) per gram of the food product, of actively growing and reproducing bacteria to which it is referred. As used herein, the term “free of vegetative psychrotrophic Bacillus ce eus" refers to a condition in which a food product is completely devoid, i.e., for practical purposes <3.0, preferably <2.0, more preferably <1.0 colony forming unit (CFU) per gram of the food product of actively growing and reproducing psychrotrophic Bacillus cereus. It is indicated by the absence or eradication of psychrotrophic Bacillus cereus that are in their metabolically active state, including those involved in essential biological processes such as nutrient uptake, metabolism, and proliferation.

[0087] To test if a food product is free of vegetative psychrotrophic Bacillus cereus, the food product can be plated on a medium to grow the psychrotrophic Bacillus cereus present in the food product. Typically, psychrotrophic Bacillus cereus can be grown on an agar plate and will multiply after 4-5 days at 22 degrees Celsius under aerobic conditions. The vegetative bacteria can then be quantified.

[0088] In the context of the present patent application, the term "spores" refers to specialized structures formed by certain microorganisms, such as bacteria, as a means of survival and reproduction. These spores are inactive vegetative cells that serve as a dormant and resistant form that allows the bacteria to withstand unfavorable environmental conditions, such as extreme temperatures, desiccation, or exposure to chemicals or radiation. The spores originate from spore-forming bacteria, which are capable of forming and releasing spores during their life cycle. Spores can persist in the food product even under conditions that inhibit the growth or survival of vegetative bacteria and have the potential to germinate and give rise to vegetative bacteria under suitable conditions

[0089] To test if a food product is free of spores or the spores are fatally injured, the food product can be added to a medium to grow the psychrotrophic Bacillus cereus present in the food product. Typically, spores of psychrotrophic Bacillus cereus can be grown on a mannitol egg yolk polymyxin agar and will grow out and multiply after 24-48 hours at 30 degrees Celsius under aerobic conditions. Optionally, the food product can be subjected to 80 degrees Celsius for 10 minutes to activate spores before addition of the food product to the agar. The spores can then be quantified.

[0090] In a particular embodiment, the food product is free of preservatives, that is no preservatives are externally added to the product by the manufacturer.

[0091] As used herein, the term “preservatives” generally refers to chemical substances used to prevent or retard spoilage, including for example but without limitation acids, sorbic acid , sorbate (E200-E203), alcohols, benzoic acid and benzoate (E210-E219), butylated hydroxyanisole (BHA), butylated hydroxyl toluene (BHT), tert-butylhydroquinone (TBHQ), sulphite (E221-E228), nitrite (E249-E250), nitrate (E251-E252), propionates (E281-E283), Nisin (E234), Natamycin (235), Hexamethylene tetramine (E239), Dimethyl decarbonate (E242), Ethyl lauroyl arginate (E243), Propionic acid (E280), Boric acid (E284), Sodium tetraborate (285), Lysozyme (El 105), etc.

[0092] While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as follows in the spirit and scope of the appended claims.

[0093] The herein disclosed aspects and embodiments of the invention are further supported by the following non-limiting examples. EXAMPLES

[0094] Example 1

[0095] Bacillus cereus strains isolated from REFPEDs and categorized into phylogenic groups II and VI, were specifically chosen due to their capability to grow in low-temperature environments (below 10 degrees Celsius). Table 1 provides an overview of various B. cereus strains documented in the literature. The table includes the minimum, mean, and maximum values of the Dgo or D95 values (denoted with an asterisk) for each strain group, as reported by the respective sources.

[0096] Number of D90 of DPS* in minutes Growth strains

[0097] Group minimal mean Maximal z °C Source

[0098] II or VI

[0099] 6 1.6 4.4 7.3 - <10 Wijnands et al., (2005)

[0100] 6 0.8 1.2 150 - 4-5 Choma et al., (2000)

[0101] 26 0.7 1.8 3.3 - 6-9 Choma et al., (2000)

[0102] 13 0.7 4.8 7.7 12.4 6 Luu-Thi et al., (2014)

[0103] 2 2.6 7.7 12.8 9.4 8 Luu-Thi et al., (2014)

[0104] 1 - 4.7 - 10.2 8 Luu-Thi et al., (2014)

[0105] 28 29.0 128.5 817 - 7 Carlin et al., (2006)

[0106] 8 48.0 69.5 99 4 Carlin et al., (2006)

[0107] 13 42.0 105 396 - 7 Carlin et al., (2006)

[0108] 2* 3.0 9.9 16.8 - 4-7 Dongmin Kim. (2021)

[0109] 1* 15.9 17.9 20.8 9.5 8-10 Daelman (2013)

[0110] 1* 4.0 5.2 7.6 9.5 8-10 Daelman (2013)

[0111] 1* - 6.6 - - 4 Samapundo et al., (2014a)

[0112] 5* 3.3 33.2 90.9 9.3 9 Samapundo et al., (201 Ib+c)

[0113] 5* 0.5 9.9 26.6 9.3 9 Samapundo et al., (201 Ib+c)

[0114] 14 4.6 - 14.0 - 7-9 Dufrenne et al., (1994)

[0115] 11 2.2 4.1 9.2 - <7 Dufrenne et al., (1995)

[0116] 1 - >100 - - <7 Dufrenne et al., (1995)

[0117] 32 1.4 6.2 21.2 - 8 Valero et al., (2002)

[0118] Table 1. Heat resistance psychrotrophic B. cereus strains from group II or VI, isolated from chilled ready to eat meals. Example 2

[0119] Multiple strains were chosen from literature, taking into consideration their heat resistance. Table 2 displays the Dss, D90, and D95 values of each selected strain from the literature, along with their capacity to grow in low-temperature conditions. FF140 and FF67 strains were identified as suitable strains based on their high heat resistance, as indicated by their D95 value. Despite NVH1105-98 demonstrating significant heat resistance in the literature (evidenced by its D90 value), subsequent testing revealed that it lacked the expected heat resistance and, consequently, was excluded from consideration for the invention.

[0120] Origin Heat resistance Psychrotrophic Reference

[0121] Strain number character

[0122] FF119b Chicken D90 6.6 min Growth at 7°C Samapundo et al., (2014a)

[0123] (RTE) and weak 4°C

[0124] FF140 Bechamel Dss = 293.3 min Growth at >6°C Samapundo et al., (2011c) sauce D90 = 90.9 min

[0125] D95 = 26.6 min z = 9.6°C

[0126] FF355 Carrot Dss = 58.8 min Growth at >7°C Daelman (2013)

[0127] (RTE) D90 = 17.9 min

[0128] D95 = 5.2 min z = 9.5°C

[0129] FF67 Cooked Dss = 37.3 min Growth at >6°C Samapundo et al., (2011c) pasta D90 = 24.4 min

[0130] D95 = 4.1 min z = 10.4°C

[0131] LMG18989* Pasteurized D90 = 3 min Growth at 4°C Dongmin Kim et al., milk and 7°C (2021)

[0132] NVH1105-98 Steak sauce D9o = 817 min Growth at 7°C Carlin et al., (2006)

[0133] NS115 Spruce tree - Growth at 7°C Hallaksela et al., (1991)

[0134] NC7401 Food - Growth at 7°C Takeno et al., (2012) poisoning

[0135] Table 2. Origin, heat resistance, and psychrotrophic character of the eight selected B. cereus strains.

[0136] Example 3

[0137] Brain heart infusion (BHI) medium was inoculated with (104 CFU / g) spores of B. cereus from FF140 and FF67 strains and different pH values were set (pH 5.6, 5.8 and 6.0). Samples containing spores of B. cereus from FF140 and FF67 were placed in a metal or stainless steel tube and stored overnight between 0 degrees Celsius and 2 degrees Celsius to avoid germination of the spores. Samples were treated according to method according to certain embodiments of the present invention. The samples were heated to 105 or 112 degrees Celsius. After reaching the desired temperature, the temperature of each sample was maintained at that temperature for 10 or 30 seconds. The samples were then cooled to either directly 10 degrees Celsius within 20 minutes in ice or a blast chiller (Alpeninox, ABP0201). or to 30 degrees Celsius for 2 hours, and subsequently to 10 degrees Celsius. Spores of B. cereus were counted at inoculation of BHI and after the method according to certain embodiments of the invention for each sample. An inoculated non-heat treated sample was included as a blank for each pH. All analyses were performed in duplicate.

[0138] B. cereus spore count B. cereus spore count

[0139] _.X1i i a, , First cooled till 30 C for 2h, than cooled

[0140] Directly cooled 10 C after heating

[0141] (log CFU / g)* Reduction (log CFU / g)* Reduction

[0142] J'11PpH .mCBefore (A) After (B) (A-B) Before (A) After (B) (A-B) no 5.6 no 4.22 4.22 0.00 4.22 4.22 0.00

[0143] 112 10 4.22 3.17 1.05 4.22 2.30 1.92

[0144] 105 30 4.22 2.60 1.62 4.22 3.62 0.60

[0145] 112 30 4.22 <1 3.22 4.22 <1 3.22 no 5.8 no 4.28 4.28 0.00 4.28 4.28 0.00

[0146] 112 10 4.28 1.30 2.98 4.28 2.24 2.04

[0147] 105 30 4.28 3.62 0.66 4.28 3.74 0.55

[0148] 112 30 4.28 <1 3.28 4.28 <1 3.28 no 6.0 no 4.15 4.15 0.00 4.15 4.15 0.00

[0149] 112 10 4.15 1.91 2.25 4.15 1.54 2.62

[0150] 105 30 4.15 3.80 0.35 4.15 3.57 0.59

[0151] 112 30 4.15 <1 3.15 4.15 <1 3.15

[0152] Table 3. Effect of cooling treatment on a high inoculum level of B. cereus spores in Brain heart infusion (BHI) to demonstrate the extent of reduction.

[0153] According to the data presented in Table 3, the population of vegetative bacteria and spores of B. cereus was significantly reduced when the sample was pressure heated to 112 degrees Celsius and held for either 10 or 30 seconds. On the contrary, pressure heating the sample to 105 degrees Celsius and maintaining the temperature for 30 seconds was found to be insufficient in effectively reducing the number of vegetative bacteria and spores of B. cereus. Moreover, the duration of the cooling period was found to have an impact on decreasing the number of vegetative bacteria and spores of B. cereus, particularly for samples pressure heated to 112 degrees Celsius for a shorter duration (10 seconds). However, the effect of direct cooling within 20 minutes to 10 degrees Celsius or initially cooling to 30 degrees Celsius and then to 10 degrees Celsius, is similar for samples pressure heated to 112 degrees Celsius for 30 seconds. Additionally, for samples pressure heated to 105 degrees Celsius, direct cooling to 10 degrees Celsius within 20 minutes was found to be more effective in reducing the population of vegetative bacteria and spores of B. cereus compared to longer cooling treatments.

[0154] Example 4

[0155] Brain heart infusion (BHI) medium was inoculated with (104 CFU / g) spores of B. cereus from FF140 and FF67 strains and different pH values were set (pH 5.6, 5.8 and 6.0). Samples containing spores of B. cereus from FF140 and FF67 were placed in a metal or stainless steel tube and stored overnight between 0 degrees Celsius and 2 degrees Celsius to avoid germination of the spores. Samples were treated according to method according to certain embodiments of the present invention. The samples were pressure heated to 105 or 112 degrees Celsius. After reaching the desired temperature, the temperature of each sample was maintained at 10 or 30 seconds. The samples were than cooled to directly 10 degrees Celsius on ice or a blast chiller (Alpeninox, ABP0201). The samples were stored at 10 degrees Celsius for 30 days and 90 days. Spores of B. cereus were counted for each sample at inoculation of BHI, after application of invented method, after 30 days at 10 degrees Celsius and after 90 days at 10 degrees Celsius.

[0156] B. cereus spore count

[0157] Directly c

[0158] (log CFU /

[0159] Temp. „ Time Before heat After heat After 30 days at After 90 days at

[0160] (C) P (s) treatment treatment 10 (C) 10 (C) no 5.6 no 4.22 4.22 3.52 3.79

[0161] 112 10 4.22 3.17 <1 <1

[0162] 105 30 4.22 2.60 <1 <1.8

[0163] 112 30 4.22 <1 <1 <1 no 5.8 no 4.28 4.28 3.18 3.23

[0164] 112 10 4.28 1.30 <1 <1

[0165] 105 30 4.28 3.62 1.83 1.39

[0166] 112 30 4.28 <1 <1 <1 no 6.0 no 4.15 4.15 5.10 3.88

[0167] 112 10 4.15 1.91 <1 <1

[0168] 105 30 4.15 3.80 1.30 1.39

[0169] 112 30 4.15 <1 <1 <1

[0170] Table 4. spore count of B. cereus spores in BHI at different time points.

[0171] Based on the data provided in Table 4, it is evidenced that samples subjected to a heating treatment at 105 degrees Celsius and subsequently cooled to 10 degrees Celsius within 20 minutes exhibited a reduction in the number of vegetative bacteria and spores of B. cereus immediately after treatment. After storing the samples for 30 days at 10 degrees Celsius, there was a further decrease in the population of these spores. However, after 90 days of storage at 10 degrees Celsius, there was an increase in the number of spores of B. cereus. This indicates that the spores were able to germinate into vegetative bacteria of B. cereus, which, in turn, were capable of producing spores again. In contrast, for samples heated to 112 degrees Celsius for 10 seconds, no such increase in spore count was observed after 90 days. This suggests that the spores that were damaged during the heating were unable to survive, indicating that they were irreversibly injured (fatally) and eventually died over time. For samples heated to 112 degrees Celsius for 30 seconds, the spore count for B. cereus was reduced to less than 1 colonyforming unit per gram (CFU / g) following the method according to certain embodiments of the invention. After storing these samples for 30 days and 90 days at 10 degrees Celsius, the spore count remained below 1 CFU / g for B. cereus. This demonstrates that the spores were effectively eliminated during the treatment and were unable to germinate during storage at 10 degrees Celsius. Example 5

[0172] To evaluate the impact of the method according to the invention, the quality and taste of red cabbage were tested. The red cabbage was treated using three different methods: • Method 1 (method according to the invention): The red cabbage was pressure heated to 112 degrees Celsius for 30 seconds and then cooled down to 10 degrees Celsius within 20 minutes.

[0173] • Method 2: The red cabbage was pasteurized by heating to 90 degrees Celsius for 10 minutes.

[0174] • Method 3: The red cabbage was sterilized using a typical sterilization process, by pressure heating to 121 degrees Celsius for about 15 minutes and cooling down to about 40 degrees Celsius within 30 minutes.

[0175] Based on the data provided in Figure 1, it is evident that the red cabbage treated with the method according to the invention either maintains or minimally reduces the quality and taste of the food. The red cabbage treated with method 1 (dark grey) exhibited higher odour intensity, fresher aroma, brighter colour, better texture, more intense flavour, and fresher taste compared to the cabbage treated with methods 2 (gray) and 3 (light gray). Furthermore, Figure 1 shows that the red cabbage treated with method 1 is less salty, bitter, and sour, and has a lighter colour. Unlike the red cabbage treated with methods 2 and 3, the cabbage treated with method 1 is not overcooked.

Claims

CLAIMS1. Method for preserving a packaged food product comprising: a) pressure heating the packaged food product to 110 to 125 degrees Celsius; b) maintaining the packaged heated food product between 10 to 60 seconds at 110 to 125 degrees Celsius; c) cooling down the packaged heated food product to 0 to 12 degrees Celsius in less than 15 minutes.

2. The method according to claim 1, wherein the food product is a Refrigerated Processed Foods of Extended Durability (REPFED) product.

3. The method according to any of the previous claims, wherein the food product or at least a portion thereof has a pH of at least 4.6.

4. The method according to any of the previous claims, wherein higher than atmospheric pressure is applied externally onto the packaged food product during at least a portion of step a) and / or step b), preferably wherein the externally applied pressure is between 0.1 and 1.0 bar (lx 104-lxl05Pa) higher than the pressure within the packaged food product, preferably between 0.2 and 0.7 bar (2xl04-7xl04Pa), such as between 0.1 and 0.3 bar (1X104-3X104Pa).

5. The method according to any of the previous claims, wherein before step a) a food product is packaged and prior to packing, the food product is preheated under atmospheric pressure to a temperature between 50 °C and 75 °C, more preferably between 55 °C and 70 °C and most preferably between 60 °C and 65 °C.

6. The method according to any of the previous claims, wherein before step a) a food product is packaged and prior to packing, optionally before and / or during preheating the food product is deaerated.

7. The method according to any of the previous claims, wherein a pressure magnetron or autoclave is used for pressure heating and optionally for preheating the packaged food product.

8. The method according to any of the previous claims, wherein to maintain the packaged heated food product at 110 to 125 degrees Celsius, the packaged heated food product is immersed in water.

9. The method according to any of the previous claims, wherein in step c) nitrogen gas (N2) or cold air or cold water or ice is used to cool down the packaged heated food product.

10. The method according to any of the previous claims, wherein the food product has been packaged under protective atmosphere, optionally under nitrogen gas (N2) atmosphere, preferably wherein the amount of oxygen in the headspace of the package is less than 1 percent.

11. A packaged food product obtainable or obtained by the method according to any of the previous claims.

12. The packaged food product according to claim 11, wherein the food product is a Refrigerated Processed Foods of Extended Durability (REPFED) product.

13. The packaged food product according to claim 11 or 12, wherein at a temperature between 0 °C and12 °C the food product is at least free of vegetative Bacillus cereus and optionally Listeria monocytogenes and / or faecal streptococci and / or Clostridium botulinum and the spores of said bacteria are at least fatally injured such that the spores can no longer grow out vegetatively into the respective bacteria.

14. The packaged food product according to any of the claims 11 to 13, wherein the packaged food product is free of vegetative psychrotrofic Bacillus cereus and the spores thereof are at least fatally injured.

15. The packaged food product according to any of the previous claims 11 to 14, wherein the food product is free of preservatives.

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