How to store fresh food

Abstract

The present invention relates to a new process for preserving fresh produce, particularly fresh fruits and vegetables, by applying an alkaline solution and then an acidic solution onto the fresh produce.

Description

Technical Field

[0001] The present invention relates to the technical field of food preservation, and particularly to the preservation of fresh fruits and vegetables such as fruits, vegetables, and herbs.

Background Art

[0002] Food preservation involves preventing the growth of undesirable microorganisms, delaying oxidation, and suppressing and / or reversing processes that lead to visible deterioration such as the browning reaction of fresh cut fruits and vegetables, especially fresh fruits, vegetables, herbs, etc. Many processes for food preservation are known and can include various food preservation methods. In many processes, the properties such as the appearance and taste of processed foods are fundamentally changed. In contrast to such processes, it is often desired to extend the shelf life while making the food more durable and maintaining the properties such as flavor, texture, aroma, visual appearance, etc. as much as possible. Furthermore, in many known processes, they are only suitable for one or selected measures for food preservation such as preventing browning or delaying oxidation, and are not suitable for suppressing microorganisms such as bacteria and yeast, or vice versa. In particular, for the preservation of fresh fruits and vegetables such as fresh fruits, fresh vegetables, and fresh herbs, there is a desire to provide a preservation process that can simultaneously solve the most relevant aspects of preservation, namely delaying oxidation, anti-browning treatment, and suppressing or reducing microorganisms such as bacteria, fungi, and / or yeast. The undesirable browning of fresh fruits and vegetables occurs due to oxidation and enzymatic reactions (also called enzymatic browning), and may also occur due to discoloration caused by tissue damage after preservation treatment.

[0003] A method for preserving fresh produce, particularly cut fruits and vegetables, is described in European Patent Application Publication No. 3338563, which uses an aqueous solution containing potassium carbonate and at least one source of ascorbate ions and / or isoascorbate ions in a specific molar ratio in the range of 1.00:0.95 to 1.00:0.50 to prevent browning. By applying the solution, which is a mixture of all components, to fresh produce, the fresh produce is preserved and the shelf life of processed produce is extended. The mixture is not used to prevent microbial deterioration but has antioxidant and anti-browning properties.

[0004] Korean Registered Patent No. 101848788 describes the processing of fruit, which includes a fruit preparation step, a disinfection step, a step of cutting or removing parts of the fruit depending on the type of fruit, a pretreatment step of removing the peel, a washing step of washing the pretreated fruit by immersing it in a soaking solution, and a step of dehydrating the washed fruit. Specifically, the disinfection step includes applying 200 ppm chlorine, and the washing step includes applying a mixed aqueous solution containing ascorbic acid and sodium bicarbonate.

[0005] U.S. Patent Application Publication No. 2012 / 0045555 describes a process for preserving fresh cut fruit by applying a fresh fruit preservation solution comprising water, ascorbic acid, calcium ascorbate, carbohydrates, sodium chloride, magnesium chloride, potassium bicarbonate, and malic acid.

[0006] International Publication No. 94 / 12041 describes a process for keeping the cut surface of a fruit or vegetable fresh and preserving its natural appearance, the process of which involves absorbing sodium ions and / or potassium ions, calcium ions, and chloride ions from the cut produce. This includes immersion for a short time in a dilute aqueous solution containing ascorbic acid or ascorbate ions (or their isomers or derivatives), citric acid or citrate ions, or malic acid or malate ions (or their isomers or derivatives).

[0007] Regarding the application of metal ascorbates or combinations of ascorbic acid and metal salts in the treatment of fruits, vegetables, and other foods for the reduction of microbial contamination, prevention of discoloration, and preservation, this is disclosed in Japanese Patent Publication No. 06-181684, European Patent Application Publication No. 0141875, and International Publication No. 00 / 30460, and requires that the solution consist of ascorbic acid or a salt thereof, sodium carbonate or potassium carbonate, and citric acid or a salt thereof, sulfite or bisulfite compound, each present in an amount of 10% to 40%. The solutions described therein contain all components as a single mixture.

[0008] U.S. Patent Application No. 2012 / 045555 relates to a preservative for fresh fruit, particularly for reducing oxidation of the exposed cut surface of fruit. The preservative comprises a single mixture of ascorbic acid, calcium ascorbate, carbohydrates, sodium chloride, magnesium chloride, potassium bicarbonate, and malic acid.

[0009] Korean Published Patent No. 2013-0141017 describes a liquid composition for preventing browning of fruits, the composition comprising 1.5 wt% vitamin C, 0.3 wt% potassium carbonate, and 98.2 wt% water, resulting in a potassium cation to ascorbate anion molar ratio of 1:1.96, and the components exist as a single mixture.

[0010] Therefore, the latest technologies primarily offer methods for preserving fresh produce by applying a single preservation solution to fresh produce in one step. Known one-step preservation mixtures may contain ascorbic acid and / or isoascorbic acid, often in combination with carbonates or bicarbonates. Such compositions are particularly suitable for preventing oxidation and browning of fresh produce, but are not very suitable for preventing microbial deterioration. Even if such known and described preservatives have an effect in preventing microbial deterioration, their disinfectant properties are weak, and buffering effects or side reactions occurring in the mixture may inhibit strong antimicrobial effects. Furthermore, combining active ingredients in a single solution to simultaneously exhibit multiple very different effects, such as antimicrobial, antioxidant, and anti-browning effects, presents problems in preparing a suitable and effective formulation. In addition, as a solution to protect fresh produce from microbial deterioration, active disinfectants or antibacterial compounds, such as chlorine-based disinfectants, which may be harmful and are not approved for use in food preservation worldwide, are sometimes used. Such strong disinfectants are very often unacceptable to consumers. Furthermore, it is necessary to avoid undesirable residues that could affect the taste of the food after processing. Known preservative compositions do not address antimicrobial properties in their process and only provide the composition of the final solution. Typically, food is disinfected with a common disinfectant and then treated with an ascorbate solution.

[0011] Food preservation methods using two or more separate processing steps with two or more different preservation solutions are known, for example, in International Publication No. 2013 / 079903, European Patent Application Publication No. 1574135, U.S. Patent No. 6,500,476, and U.S. Patent No. 5,919,507.

[0012] International Publication No. 2013 / 079903 provides a method for protecting against enzymatic browning using a solution of calcium ascorbate and an enzyme inhibitor, which is an acidulant capable of lowering the pH to 4 or less. The method described therein may include an optional first step of pre-dipping fruits and vegetables in a solution containing a chelating agent.

[0013] European Patent Application Publication No. 1574135 describes a two-step preservation process in which a first acidic solution with a pH of 1.5 to 4.5 is applied to fruits and vegetables to reduce microbial concentration, and then a second anti-browning treatment is performed by applying a solution with a pH of 7 to 9 containing a chelating agent and an antioxidant.

[0014] International Publication No. 2013 / 079903 does not provide a treatment to suppress or mitigate microbial deterioration, while European Patent Application Publication No. 1574135 uses an acidic solution to suppress microorganisms. Such acid treatments have an undesirable effect on the taste of the treated agricultural products and their antimicrobial effect is insufficient. Furthermore, both methods require the use of chelating agents, which are undesirable for food regulatory reasons, and their permissibility in food processing is very limited in the European Union.

[0015] U.S. Patent No. 6,500,476 describes a three-step preservation procedure comprising: a first step of reducing microorganisms by contacting mushrooms with a high-pH alkaline solution of 10.5–11.5; a second neutralization step with a neutralization buffer of organic acids and their salts; and a third step of anti-browning treatment with antioxidants, calcium sources, and chelating agents. Therein, the first alkaline solution is preferably prepared with carbonates and bicarbonates. The second neutralization solution is substantially free of erythorbic acid and sodium erythorbate. The third anti-browning solution contains sodium erythorbate, erythorbic acid, ascorbic acid, or calcium ascorbate (or L-cysteine) as a browning inhibitor. Therefore, it is necessary to add washing and neutralization steps before the anti-browning treatment.

[0016] Similarly, U.S. Patent No. 5,919,507 describes a method of preserving mushrooms with a high pH alkaline solution of 9.5 to 11.0 to reduce microorganisms, employing a two-step process. The second step involves washing and neutralizing the mushrooms treated with a pH neutralizing solution containing erythorbic acid and sodium erythorbate in a specific ratio of 1:4. Similar to U.S. Patent No. 6,500,476, the two-step process described in U.S. Patent No. 5,919,507 preferably uses carbonates and bicarbonates in the preparation of the alkaline solution, and preferably adds EDTA as a chelating agent to the second neutralizing and anti-browning solution.

[0017] As described above, the use of anti-browning chelating agents is not very desirable, especially in the processing of fresh produce, due to regulatory constraints. Furthermore, the inventors of this invention have found that antimicrobial treatment with solutions with a pH of 11.5 or lower, as described in U.S. Patent No. 6,500,476 and U.S. Patent No. 5,919,507, yields only limited antimicrobial effects. In these prior art documents, even if a good total microbial plate count is obtained, products with a high total microbial count also enter the market, so this has limited significance regarding the shelf life of the product. In column 2, lines 62-66 of U.S. Patent No. 5,919,507, it is explained that high-alkaline preservative treatment has limitations regarding the upper pH limit, and that the exposure time to the solution must be carefully controlled to optimize bacterial destruction while avoiding chemical damage to cell tissue due to excessive exposure to extremely high pH.

[0018] The invention described herein provides a two-step procedure that achieves both anti-browning / antioxidant and microbial inhibition, while being more effective and cost-effective in terms of labor. Furthermore, the present invention can provide a preservation process that does not have the negative aspects of common disinfectants, such as physical deterioration of fruits and vegetables after treatment or deterioration of the properties of the product after treatment, and is not subject to the regulatory limitations of common anti-browning chelating agents. Surprisingly, the inventors of the present invention have further found that the novel process described herein makes it possible to apply an alkaline solution with antimicrobial effects at a pH value higher than 11.5 to fresh fruits and vegetables without causing deterioration or chemical damage to the fruits and vegetables after treatment, as can be expected from the teachings of U.S. Patent No. 5,919,507. In particular, the method of the present invention can avoid undesirable browning due to discoloration caused by cell tissue damage after preservation treatment. [Overview of the project] [Problems that the invention aims to solve]

[0019] With increasing transportation distances, schools, cafeterias, and fast-food restaurants need to provide and preserve convenient food products, especially fresh, pre-cut produce, requiring extended shelf life and quality retention. However, due to insufficient antimicrobial pretreatment, extending shelf life is limited by microbial contamination. Extending shelf life and preservation to combat deterioration involves protecting fresh produce from visual and tactile degradation such as oxidation, shrinkage, and undesirable browning. Therefore, there is a need for improved and effective antimicrobial treatment methods that can extend the shelf life of fresh produce without unacceptably altering its structure, taste, or appearance.

[0020] The present invention aims to provide an improved method for preserving fresh produce. In particular, it is necessary to control microbial contamination while avoiding undesirable effects on appearance, taste, and texture, such as undesirable browning reactions due to oxidation or discoloration caused by tissue damage after preservation treatment, changes in structure and crunchiness, residues that affect taste, and similar changes. Further, it is desirable to provide an effective preservation process that combines the two most important preservation aspects in the processing of fresh produce, achieving highly effective antimicrobial treatment and anti-browning / antioxidant treatment simultaneously. Such a preservation process must avoid undesirable browning due to discoloration caused by tissue damage after preservation treatment. In other words, a particular objective of the present invention relates to providing a novel, highly efficient food preservation process that balances a high alkaline pH for achieving highly efficient antimicrobial activity with avoiding undesirable deterioration of texture and structure, such as etching, chemical damage, and discoloration (browning) of the produce after treatment.

[0021] This process needs to be easy to apply and effectively reduce costs and labor. Furthermore, it needs to be suitable for circumventing regulatory restrictions, particularly by being able to prevent browning without the use of chelating agents. In a special embodiment, this new process should provide a highly effective preservation method that is highly effective against microbial degradation by yeast as well as bacteria. [Means for solving the problem]

[0022] The present invention solves this problem by providing a new method for preserving fresh fruits and vegetables, which, as described in detail herein, involves applying two different solutions in a two-step procedure. This new process can improve the performance related to antimicrobial contamination, such as activity against bacteria and yeast, while maintaining texture, crunchiness, taste, and visual appearance, and can extend the quality retention period. It has been shown that the food treated by the process according to the claims reduces yeast, bacteria, and fungi by up to 3 log. At the same time, the sensory properties are also greatly improved compared to general process technologies. Surprisingly, this new process can not only suppress the undesirable browning effect of fresh fruits and vegetables, but also reverse the browning to some extent, especially when applied to fresh fruits and vegetables such as cut fruits, vegetables, and herbs. Thus, it has been found surprisingly that this new process can provide a very effective preservation method that can avoid the undesirable browning due to discoloration caused by tissue damage after preservation treatment. The solutions applied in the new process are specially designed to perform specific functions in order to maximize the effect, and like many other single solutions, can obtain multiple effects simultaneously. Furthermore, this new process results in no deterioration, such as precipitation of active compounds, etc., and the preservation solution can be used more effectively and safely, and can be stably stored over a long period of time.

Brief Description of the Drawings

[0023] [Figure 1] Figure 1 shows the microbial counts of the comparative preservation solution and the solution according to the present invention on days 0, 3, and 6. [Figure 2] Figure 2 shows the microbial counts of the comparative preservation solution and the solution according to the present invention on day 6. [Figure 3] Figure 3 shows the visual evaluations (anti-browning evaluations) of the comparative preservation solution and the solution according to the present invention on days 0, 3, and 6.

Modes for Carrying Out the Invention

[0024] The present invention relates to a method for preserving fresh food, particularly fresh fruits and vegetables, the method comprising (a) Preparing a solution (1) which is an alkaline solution with a pH value of 10.0 or more; (b) Preparing an aqueous solution (2) containing 0.5 w / w% to 25 w / w% of ascorbic acid ions and / or isoascorbic acid ions; (c) Applying the solution (1) to fresh food; (d) Subsequently applying the solution (2) to the same fresh food. The fresh food according to the present invention is preferably fresh fruits and vegetables.

[0025] The solution (1) is an alkaline solution with a pH of 10.0 or more, preferably 10.5 or more, more preferably 10.9 or more, still more preferably 11.0 or more, still more preferably 11.5 or more, and most preferably 12.0 or more. Most preferably, the pH of the alkaline solution (1) is greater than 11.0, preferably greater than 11.5, and most preferably 12.0 or more. The alkaline solution (1) needs to be an effective composition for sterilizing the treated fresh food, particularly fresh fruits and vegetables, preventing further microbial contamination, delaying the growth of microorganisms, and reducing microbial contamination on fresh food to a certain extent. The alkaline solution (1) is preferably effective against one or more selected from the group of bacteria, yeasts, and fungi, and particularly preferably effective against at least bacteria and yeasts. It has been found that sufficient activity against yeasts can be obtained by applying an alkaline solution with a pH greater than 11.0, preferably greater than 11.5, and most preferably 12.0 or more.

[0026] In the meaning of the present invention, the pH value of the solution is measured using an electrochemical measurement of the pH value and a general laboratory pH meter for aqueous solutions at room temperature (20°C ± 5°C).

[0027] Suitable alkaline compounds for preparing the alkaline solution (1) can be selected from alkali metal salts, alkaline earth metal salts, or mixtures thereof. Preferred alkali metal salts or alkaline earth metal salts used to prepare solution (1) are salts of sodium, potassium, calcium, and magnesium, or mixtures thereof. More preferably, sodium salts or potassium salts, or mixtures thereof, are used. Preferably, hydroxides, carbonates, and bicarbonates are used to prepare solution (1).

[0028] Among alkaline compounds, hydroxides are preferred, and sodium hydroxide and potassium hydroxide, in particular, are the strongest bases among alkali metal hydroxides, and are the most stable and soluble bases. By using strong bases, the invasion of microorganisms into processed foods can be minimized due to their high antimicrobial and bactericidal properties.

[0029] In a preferred embodiment of the present invention, solution (1) comprises at least one hydroxide selected from the group consisting of calcium hydroxide, sodium hydroxide, potassium hydroxide, or a mixture thereof, preferably sodium hydroxide, potassium hydroxide, or a mixture thereof. The alkaline solution (1) may also comprise a mixture of at least one hydroxide and one or more carbonates, but in a preferred embodiment, solution (1) does not contain carbonate compounds.

[0030] It is preferable that at least one hydroxide in solution (1) is used at a concentration of at least 0.01 w / w%, preferably at least 0.1 w / w%, more preferably at least 0.5 w / w%, and most preferably at least 1.0 w / w%.

[0031] The upper limit of the concentration of at least one hydroxide in solution (1) is preferably 5.0 w / w%, more preferably 4.0 w / w%, even more preferably 3.0 w / w%, and most preferably 2.0 w / w%.

[0032] In a more preferred embodiment, solution (1) contains at least one hydroxide at a concentration of 0.01 w / w% to 5.0 w / w%, preferably 0.1 w / w% to 4.0 w / w%, more preferably 0.5 w / w% to 3.0 w / w%, and most preferably 1.0 w / w% to 2.0 w / w%. Depending on the specific process conditions, the composition of solution (2), and the food to be processed, an appropriate range can be selected from the lower and upper limits.

[0033] These concentration ranges and limits allow for a sufficient reduction in microbial growth in processed foods without causing irreversible damage or deterioration of taste.

[0034] The selected concentration range provides a good balance between preservative activity and protection of the treated food against deterioration of texture and sensation.

[0035] The solutions used in the methods of the present invention preferably do not contain potentially harmful and aggressive disinfectants, and more preferably do not include a disinfection step that uses such undesirable disinfectants. Disinfectants that are undesirable and should be avoided include, in particular, chlorine-based disinfectants, such as sodium chlorite and other salts of chlorite, hypochlorite, hypochlorous acid, and chlorine dioxide, but also peroxyacetic acid, quaternary ammonium compounds, ethyl alcohol, isopropyl alcohol, formaldehyde, and hydrogen peroxide. Such undesirable disinfectants can be harmful to food and consumers. The solutions used in the present invention preferably do not contain these compounds.

[0036] Solution (2) contains 0.5 w / w% to 25.0 w / w% ascorbate ions and / or isoascorbate ions.

[0037] Preferably, solution (2) contains at least 0.5 w / w%, at least 0.75 w / w%, at least 1.0 w / w%, at least 1.5 w / w%, at least 0.75 w / w%, and at least 2.0 w / w% ascorbic acid ions and / or isoascorbic acid ions.

[0038] The upper limit of the concentration of ascorbate ions and / or isoascorbate ions in solution (2) is 25.0 w / w%, preferably 24.0 w / w%, 23.0 w / w%, 22.0 w / w%, 21.0 w / w%, 20.0 w / w%, 19.0 w / w%, 18.0 w / w%, 17.0 w / w%, 16.0 w / w%, 15.0 w / w%, 14.0 w / w%, 13.0 w / w%, 12.0 w / w%, 11.0 w / w%, 10.0 w / w%, 9.0 w / w%, 8.0 w / w%, 7.0 w / w%, and 6.0 w / w%.

[0039] More preferably, solution (2) contains 1.0 w / w% to 15.0 w / w%, more preferably 1.5 w / w% to 10 w / w%, and most preferably 2.0 w / w% to 6.0 w / w% of ascorbic acid ions and / or isoascorbic acid ions.

[0040] Depending on the specific process conditions, the composition of solution (1), and the food being processed, an appropriate range can be selected from the lower and upper limits.

[0041] Ascorbate ions and / or isoascorbate ions can, in principle, be derived from ascorbic acid and isoascorbic acid. Preferably, salts of ascorbic acid and / or isoascorbic acid are used in the preparation of the solutions of the present invention, for example, preferably alkali metal salts or alkaline earth metal salts of ascorbic acid or isoascorbic acid, or mixtures thereof. Preferred salts are selected from calcium ascorbate, calcium isoascorbate, potassium ascorbate, potassium isoascorbate, sodium ascorbate, sodium isoascorbate, magnesium ascorbate, magnesium isoascorbate, and mixtures thereof. It is particularly preferable to use potassium ascorbate, potassium isoascorbate, sodium ascorbate, sodium isoascorbate, or mixtures thereof. In particular, these alkali metals and alkaline earth metals cannot be biochemically synthesized in the human body and are therefore essential nutrients for organisms to perform the functions necessary for maintaining their life. Thus, the use of these ascorbates and / or isoascorbicates is beneficial. Furthermore, acerola can be used as an ascorbic acid ion or other suitable source of ascorbic acid (vitamin C).

[0042] Furthermore, derivatives of ascorbic acid and / or isoascorbic acid, such as ascorbic acid esters or ascorbic acid ethers, particularly ascorbyl palmitate or ethyl ascorbate ether, can also be used.

[0043] The preferred pH value of solution (2) is 8.0 or less, preferably 7.5 or less, more preferably 7.0 or less, even more preferably 6.5 or less, even more preferably 6.0 or less, even more preferably 5.5 or less, even more preferably 5.0 or less, even more preferably 4.5 or less, even more preferably 4.0 or less, and most preferably 3.0 to 5.0.

[0044] Solution (2) affects the neutralization of alkaline solutions, halting alkaline activity and impacting the food after treatment. However, at the same time, solution (2) exhibits anti-browning / antioxidant properties without degrading the sensory and visual characteristics of the treated produce.

[0045] In certain embodiments of the present invention, the presence of a chelating agent, such as EDTA, in either solution (1) and / or (2) is excluded and is not necessary to achieve the desired effect.

[0046] Solutions (1) and (2) are generally aqueous solutions. Therefore, they use water as the solvent. In the sense of this invention, water includes drinking water publicly supplied by local governments and drinking water privately supplied by food businesses themselves.

[0047] Furthermore, additional solvents other than water may be used, provided they are water-miscible and suitable as food additives. Examples include solvents approved under government regulations, such as the German Zusatzstoff-Zulassungsverordnung (ZZulV) by the Lebensmittel-und Futtermittelgesetzbuch (LFGB), or classified as GRAS (Generally Recognized as Safe) food substances by the FDA. Such additional solvents include glycerol and propylene glycol, which are completely miscible with water.

[0048] Solution (1) and solution (2) can each be applied independently by spraying, spraying, sprinkling, dipping, immersion, or a combination thereof, which corresponds to steps (c) and (d) of the method described above.

[0049] In this invention, the term "spraying" refers to any technical process by which an aerosol is generated and applied to fresh produce being preserved. This may be done by a pump-type spraying system or a propulsion-type spraying system. The droplet size of solution (1) or solution (2) is not limited to any size range, but is preferably minute in size.

[0050] In this invention, the term "spraying" refers to any technical process in which drops and / or droplets of solution (1) or solution (2) are sprayed onto a material such as fresh produce by a spraying system.

[0051] In this invention, the term "dousing" refers to any technical process of dousing or pouring solution (1) or solution (2) onto a material such as fresh produce.

[0052] The technical process known as spraying, dispensing, or sprinkling can be applied to, but is not limited to, fresh produce placed on grids, trays, or conveyor belts.

[0053] The terms “dipping” and “immersion” according to the present invention relate to any technical process such that at least a portion, preferably the entire surface, of a material such as fresh produce is covered at least temporarily in a reservoir of solution (1) or solution (2), or that fresh food such as fresh produce is floated on the surface of solution (1) or solution (2).

[0054] Furthermore, any other means suitable for covering the surface of fresh produce, such as fresh fruits and vegetables, that are preserved in solution (1) or solution (2) can be applied in the method according to the present invention.

[0055] Preferably, solution (1) and / or solution (2) are applied independently for at least 5 seconds. The application time may vary depending on solution (1) and solution (2), and / or the processed food. Preferably, solution (1) and / or solution (2) are applied independently for at least 60 seconds.

[0056] The time between applying solution (1) and applying solution (2) is preferably not more than 1 hour, more preferably not more than 30 minutes, and most preferably between 30 seconds and 10 minutes. On the other hand, the invasion of microorganisms in fresh food decreases the longer solution (1) remains on the fresh food without applying solution (2). On the other hand, fresh food may be etched or saponified, leaving unpleasant residues on the food after treatment. This can also cause undesirable browning in fresh food, especially fresh fruits and vegetables. These side effects can be eliminated or suppressed by applying solution (2) which neutralizes solution (1).

[0057] The ascorbate-containing solution (2) removes residues from the hydroxide solution (1) through neutralization. Furthermore, it forms derivatives of vitamin C with the remaining sodium and / or potassium ions derived from the hydroxide solution (1). This neutralization process leaves only harmless substances in the food, such as sodium ascorbate and ascorbic acid, both of which are widely accepted and used food additives. Solution (2) further prevents browning, strengthens the structure, and, surprisingly, can even reverse the potential browning reaction induced by applying solution (1) to food, especially fresh produce. Applying only the ascorbate solution (2) can improve the color of food and prevent discoloration, but without pretreatment with solution (1), solution (2) alone cannot achieve a logarithmic reduction of bacteria. Internal research and literature indicate that using only fruit acids (pH 2.4) does not lead to a logarithmic reduction of bacteria. Acids also leave a sour taste in the fresh produce to be consumed, so it is preferable to avoid such acidification and maintain the natural taste of the food.

[0058] Preferably, solution (2) is applied for at least 5 seconds, the time of which may vary depending on the food and the amount and composition of solution (1) applied to the same fresh food. This minimum application time ensures a comprehensive antimicrobial effect by solution (1).

[0059] It is preferable that no additional washing or neutralization steps are applied between the treatment with solution (1) and the treatment with solution (2) of the present invention. In other words, a two-step treatment is desirable.

[0060] The duration of application of solution (1) can be extended by adding ascorbate ions / isoascorbate ions to solution (1), as will be described in more detail later, and by subsequent use of solution (2).

[0061] The composition of solution (2), which contains ascorbate ions and / or isoascorbate ions, is controlled to have a sufficiently high ascorbate / isoascorbate concentration to neutralize all the hydroxides in solution (1). Neutralization leads to the acidity problem of the ascorbate solution and / or isoascorbate solution.

[0062] Optionally, solution (1) and / or solution (2) according to the present invention further comprises one or more excipients suitable for use in food, especially fresh produce, selected from the group consisting of antifouling agents, binders, colorants, flavorings, lubricants, preservatives, sweeteners, and in particular substances approved in the German Zusatzstoff-Zulassungsverordnung (ZZulV) by the Lebensmittel-und Futtermittelgesetzbuch (LFGB) or classified as GRAS (Generally Recognized as Safe) food substances by the FDA. Further excipients can shorten or lengthen the application time of the solution, or enhance the microbial reduction effect.

[0063] In a preferred embodiment of the present invention, solution (1) and / or solution (2) comprises one or more excipients in less than 30 wt%, more preferably less than 20 wt%, even more preferably less than 10 wt%, and most preferably more than 5 wt% of excipients.

[0064] In a further embodiment, solution (1) may further contain ascorbate ions and / or isoascorbate ions. The buffering effect of the small amount of ascorbate ions and / or isoascorbate ions already added to the alkaline solution (1) remarkably slows down the etching and browning process of fresh foods, particularly fresh produce, without changing the pH of solution (1). The alkaline solution (1) further containing ascorbate ions and / or isoascorbate ions was expected to etch fresh foods, particularly fresh produce, in the same amount of time as when using solution (1) without ascorbate ions and / or isoascorbate ions. Since the application time of the alkaline aqueous solution (1) may exceed the sterilization period, the unexpected delay in etching significantly improves the suitability of the process.

[0065] In the embodiment, when ascorbate ions and / or isoascorbate ions are added to the alkaline solution (1), it is preferable that the solution (1) contains ascorbate ions and / or isoascorbate ions at a concentration of 0.1 w / w% to 10.0 w / w%.

[0066] In such embodiments, solution (1) preferably contains at least 0.2 w / w%, at least 0.3 w / w%, at least 0.4 w / w%, at least 0.5 w / w%, at least 0.75 w / w%, at least 1.0 w / w%, at least 1.5 w / w%, at least 2.0 w / w%, at least 2.5 w / w%, at least 3.0 w / w%, at least 3.5 w / w%, at least 4.0 w / w%, at least 4.5 w / w%, at least 5.0 w / w%, at least 5.5 w / w%, at least 6.0 w / w%, at least 6.5 w / w%, at least 7.0 w / w%, at least 7.5 w / w%, at least 8.0 w / w%, at least 8.5 w / w%, at least 9.0 w / w%, and at least 9.5 w / w% of ascorbic acid ions and / or isoascorbic acid ions.

[0067] In such embodiments, the upper limit of the concentration of ascorbate ions and / or isoascorbate ions in solution (1) is 10.0 w / w%, preferably 9.5 w / w%, 9.0 w / w%, 8.5 w / w%, 8.0 w / w%, 7.5 w / w%, 7.0 w / w%, 6.5 w / w%, 6.0 w / w%, 5.5 w / w%, 5.0 w / w%, 4.5 w / w%, 4.0 w / w%, 3.5 w / w%, 3.0 w / w%, 2.5 w / w%, 2.0 w / w%, 1.5 w / w%, or 1.0 w / w%.

[0068] More preferably, when ascorbate ions and / or isoascorbate ions are added to the alkaline solution (1), it is preferable that the solution (1) contains ascorbate ions and / or isoascorbate ions at a concentration of 0.5 w / w% to 5.0 w / w%, and more preferably 1.0 w / w% to 2.0 w / w%.

[0069] Depending on the specific process conditions, the composition of solution (1), and the food being processed, an appropriate range can be selected from the lower and upper limits.

[0070] In a preferred embodiment, ascorbate ions and / or isoascorbate ions are added to solution (1) until the pH of solution (1) reaches 10.0 or higher, more preferably 11.0 or higher, and most preferably 12.0 or higher.

[0071] As described above, generally, the process conditions, composition, and concentration of solutions (1) and (2) of the present invention can be selected and controlled within the scope claimed in the patent claims in order to obtain the desired effect. For example, when using solution (1) with a high pH value, for example, a pH of 12.0 or higher, the concentration of ascorbate ions / isoascorbate ions in solution (2) must be selected to achieve the desired neutralization. When using an alkaline solution (1) with a pH of 12.0 or higher and no ascorbate ions / isoascorbate ions are added to solution (1), the lower limit of the concentration of ascorbate ions and / or isoascorbate ions in solution (2) is preferably at least 0.75 w / w%, at least 1.0 w / w%, at least 1.5 w / w%, at least 0.75 w / w%, and at least 2.0 w / w%. However, in embodiments in which the alkaline solution (1) also contains ascorbate ions / isoascorbate ions, the concentration of ascorbate ions and / or isoascorbate ions in solution (2) can be selected from the entire range defined herein, i.e., 0.5 w / w% to 25 w / w%.

[0072] It is desirable that the pH values ​​of solution (1) and solution (2) be selected in a mutually dependent manner. It is preferable that solution (2) has a low pH (acidic) sufficient to reverse the pH of the food after treatment with alkaline solution (1) to a neutral pH or lower. If the food after treatment cannot be sufficiently neutralized or acidified with solution (2), and the food after preservation treatment maintains an alkaline pH higher than, for example, 8.0, it may lead to undesirable deterioration such as discoloration or browning of the food due to tissue damage. Therefore, it is preferable that the pH of solutions (1) and (2) be controlled so that the pH does not become alkaline during or after the step of treatment with solution (2), and that the pH is preferably 8.0 or less, preferably 7.5 or less, more preferably 7.0 or less, even more preferably 6.5 or less, even more preferably 5.5 or less, even more preferably 5.0 or less, even more preferably 4.5 or less, even more preferably 4.0 or less, and most preferably between 3.0 and 5.0.

[0073] The food preservation method of the present invention, particularly for fresh produce, is preferably carried out at room temperature / standard conditions. In any case, the temperatures of solution (1) and / or solution (2) must be controlled so as not to exceed their boiling points, in order to avoid boiling or heating of the fresh food being processed, particularly fresh produce, or deterioration due to other temperatures. The temperature of the coating solution is preferably 50.0°C or lower, more preferably 40.0°C or lower, even more preferably 30.0°C or lower, and most preferably room temperature (20°C ± 5°C). It is also possible to use chilled fresh food, particularly chilled fresh produce, and process it at a temperature of 20°C or lower, but the solution must be avoided from freezing.

[0074] Temperatures below the boiling point are preferred because the water retention of food, especially fresh produce, does not destroy the structure of the food after treatment. On the other hand, depending on the temperature, proteins and / or vitamins contained in fresh food, especially produce, may be denatured or destroyed at high temperatures, which may reduce the nutritional value of the food after treatment. Furthermore, for example, apples and nectarines may lose their crisp texture at high temperatures, so even lower temperatures, such as 40°C to 50°C or lower, are preferred. It is generally known that temperatures of 20°C, especially around or below 20°C, have little effect on the structure of food, especially fresh produce, with respect to alkaline and acidic treatments. Furthermore, lower treatment temperatures, especially in solution (2) as well as solution (1), can slow down etching, browning reactions, and structural deterioration, thus allowing for longer treatment periods. Longer treatment times can further reduce microbial invasion without adversely affecting the structure of fresh food, especially fresh produce.

[0075] It is known that alkaline solutions are used to treat fruits and vegetables. However, known alkaline treatments are intended for chemical peeling of fruits and vegetables, and are usually carried out under extremely high concentrations of alkaline compounds and under steam or high temperatures. In contrast, the method of the present invention is not used and is unsuitable for such alkaline / chemical peeling processes. This method has different treatment conditions, such as low temperature and low alkali concentration.

[0076] In the process of the present invention, the alkaline solution (1) and the acidic solution (2) neutralize each other, thus eliminating the need for a final washing step. This offers a clear procedural advantage in terms of saving time and resources.

[0077] The processes for preserving foods, particularly fresh produce, as described herein may further include one or more steps (e) selected from drying, sieving, centrifugation, air blowing, draining, packaging or candying, and combinations thereof.

[0078] In the sense of the present invention, the term “food” may refer to any food that is easily oxidized. “Food” includes processed foods such as cut, sliced, or peeled vegetables and fruits. The present invention relates particularly to fresh foods, and more specifically to fresh produce. However, the methods of the present invention may also be applied to dried or semi-dried produce.

[0079] In the sense of this invention, fresh produce refers to fresh foods such as vegetables, fruits, and herbs. In the sense of this invention, fresh foods refer to foods that have not been processed by chemical or physical preservation measures (especially chemical preservation methods excluded above, or preservation methods using heat or steam). In the sense of this invention, fresh foods that belong to the fungi taxonomically, such as champignons, wood ear mushrooms, porcinos, chantellet mushrooms, and other fungi, are interpreted as being included in the term "vegetables."

[0080] In the sense of the present invention, the term "fresh produce" in particular includes fresh fruits and vegetables. Such fresh produce is mainly grown on farms, but is not limited to that.

[0081] In the sense of the present invention, the term "fresh produce" further includes produce in its harvested state, or in a state that has been peeled, sliced, cut, or subjected to means such as slicing, shredding, cutting, or peeling to reduce the size of the produce or to make it bite-sized. Herbs may be in a cut state.

[0082] In a preferred embodiment, a method for preserving food, particularly fresh produce, is applied to fresh cut produce. Fresh cut produce is especially susceptible to etching and / or browning. This cut produce is particularly protected by treating it with solution (1) and solution (2) according to the process of the present invention.

[0083] The fresh fruits and / or fresh cut fruits preserved by the method of the present invention can be selected from the group of fresh fruits consisting of apples, avocados, rhubarb, melons, pineapples, cherries, strawberries, nectarines, peaches, kiwis, lemons, oranges, apricots, coconuts, grapes, or dragon fruit. Fresh produce and / or fresh cut produce selected from the group of fresh vegetables may be selected from the group consisting of pears, potatoes, carrots, lettuce, leeks, onions, turnips, kale, mushrooms, garlic, bell peppers, tomatoes, fennel, asparagus, green beans, peas, broccoli, cauliflower, Brussels sprouts, cabbage, celery, chard, corn, endive, leafy greens, okra, chilies, beetroot, turnips, ginger, radishes, squash, zucchini, pumpkins, artichokes, sweet potatoes, ginger, turmeric, eggplant or zucchini, and fungi (as defined above). Fresh produce and / or fresh cut produce selected from a group of fresh herbs can be chosen from basil, parsley, mint, dill, sage, rosemary, thyme, coriander, fennel, chamomile, lemongrass, oregano, chives, or watercress.

[0084] The method for preserving fresh cut produce is preferably applied to fresh cut produce selected from fruits such as apples, rhubarb, melons, pineapples, coconuts, strawberries, grapes, or kiwis; fresh cut produce selected from vegetables such as carrots, tomatoes, bell peppers, zucchini, leafy greens, mushrooms, and eggplants; and fresh cut produce selected from herbs including basil, parsley, mint, coriander, and chives.

[0085] The method for preserving fresh cut produce according to the present invention is preferably applied to apples, melons, pineapples, strawberries, coconuts, grapes, and leafy vegetables.

[0086] The present invention further relates to a combination of solid composition (1) and solid composition (2) that are ready to dissolve in a suitable solvent, preferably water or a mixture of water and another water-miscible solvent as defined above, in order to provide solution (1) and / or solution (2) as defined herein. Alternatively, the present invention relates to a ready-to-use combination of solution (1) and (2) for carrying out the processes described herein.

[0087] Further aspects of the present invention relate to a combination of parts kits (parts kit products), a) The solution (1) defined above, b) A solution (2) defined above, and a solution containing the above in a specific separation configuration, and optionally containing one or more c) Instructions for use and / or d) A container for holding parts that are treated like boxes or bags, for example, made of plastic, or other suitable containers such as tubes, falcons, cuvettes, bottles, syringes, dispensers, fils, etc., made of plastic, glass, or other suitable materials, or disposable devices for carrying out the process of the present invention, e) Optionally, a container for packaging and / or storing the parts to be processed or the parts after processing.

[0088] In a further embodiment, the present invention relates to a combination of parts kits (parts kit products), a) Compounds for preparing solution (1) as defined above, especially salts, b) A solution (2) containing the compounds for preparation as defined above, particularly salts, in a specific separation configuration, c) Optionally, a solvent defined above for dissolving the compound for solution (1) and solution (2), d) Instructions for use and / or e) Containers capable of dissolving compounds a) and / or b) to prepare solutions (1) and (2), such as tubes, falcons, cuvettes, bottles, fils, etc., made of plastic, glass, or other suitable materials, and / or f) A container for holding parts that are treated like boxes or bags, for example, made of plastic, or other suitable containers such as tubes, falcons, cuvettes, bottles, syringes, dispensers, fils, etc., made of plastic, glass, or other suitable materials, or disposable devices for carrying out the process of the present invention, g) optionally including a container for packaging and / or storing the parts being processed or the parts after processing.

[0089] This embodiment is preferable because, when the solvent for preparing solution (1) and solution (2) is water, that solvent does not need to be included in the parts kit.

[0090] The instructions for use may include, in particular, instructions regarding the preparation of solutions (1) and (2), as well as instructions regarding the processing conditions for fresh food.

[0091] The parts kits described herein are intended for use in methods for preserving fresh foods, particularly fresh produce. [Examples]

[0092] The present invention will be further described below with reference to examples, but will not be limited thereto.

[0093] A. Microbial logarithmic reduction test and sensory evaluation The logarithmic reduction of microorganisms can be measured under the following test conditions. I. Prepare the (solid) agar plate according to the instructions (adjust the pH value with NaOH or HCl as needed). 1. VRBD-Agar: 41.5 g / l in distilled water, sterilized at 118°C for 15 minutes. 2.YGC-Agar: 40.2g / l distilled water, sterile 121°C, 15 minutes. 3. LB-Agar 10g / l of tryptone 5g / l NaCl 5g / l yeast extract 2.5 g / l glucose 15g / l agar pH 7.5 Distilled water, sterilized at 121°C for 21 minutes. II. Weigh the product (fruit / vegetable), add the desired amount of liquid medium, and stir with a pestle until a homogeneous mixture is obtained. Since the titer is directly determined by the cfu / g product, it is easiest to use 1 ml per gram of product. If there is not enough liquid, increase the amount of medium. However, adjust the titer appropriately. III. Preparation of serial dilutions (0, 1, 2, 3... times dilution, depending on the expected bioburden) IV. Plate the contents of a 1.5 ml reaction tube (e.g.) onto a (solid) agar plate by transferring 100 μl of the measured homogeneous mixture of the test sample (e.g., fruit / vegetable) onto the agar surface. If intestinal bacteria are detected, a fresh VRBD-Agar solution should be prepared by pouring it on top (at a temperature between 45°C and 50°C) to create an anaerobic layer to promote the fermentation process. V. After 18-24 hours (BD) / 48 hours (LB) / (3-)7 days (YGC) at 37°C, and at room temperature (LB, YGC), the colony-forming units (CFU / ml) per 1 ml are measured to determine the titer. LB represents the total number of neutrophils and aerobic bacteria, VRBD represents the number of enterobacteria, and YGC represents the total number of fungi. In YGC, it is necessary to visually distinguish between yeast and fungi. In the case of VRBD, surface colonies are ignored. Purple colonies in the agar suggest acid production, while light-colored colonies do not produce acid.

[0094] The test is based on official procedures for assessing bacterial contamination. The temperature of the culture medium used for total bacterial count differs from that used for LB and YGC (room temperature, not 25°C).

[0095] Example A-1: ​​Control A pineapple slice that had not been treated for 5 days was used as a control. →Five days later, significant proliferation of bacteria, yeast, and fungi, along with sensory deterioration, was detected.

[0096] Comparative Example A-2: Treatment with ascorbic acid solution (pH 2.4) Pineapple slices similar to those used in Example A-1 were treated by coating them with a 6 w / w% ascorbic acid solution (pH 2.4). → Significant proliferation of bacteria, yeast, and fungi, along with slight sensory deterioration, were detected.

[0097] Comparative Example A-3: Treatment with 0.4 ppm ClO2 solution Pineapple slices similar to those used in Example A-1 were treated by coating them with a 0.4 ppm ClO2 solution (6 w / v%). This index corresponds to the permissible value set forth in the German Union's Drinking Water Regulations (TrinkwV) and is commonly used as a disinfectant. →Bacterial, yeast, and fungal growth decreased by 0.5 log, but sensory deterioration was detected after 5 days.

[0098] Comparative Example A-4: Treatment with 80 ppm peroxyacetic acid solution Pineapple slices similar to those in Example A-1 were treated by coating them with an 80 ppm peroxyacetic acid solution. This index corresponds to the permissible limit set by the U.S. FDA for washing fresh produce and is commonly used as a disinfectant in its application area. →Bacterial, yeast, and fungal growth decreased by 1 log, but sensory deterioration was detected after 5 days.

[0099] Comparative Example A-5: Treatment with 1% (w / w) sodium hydroxide solution Pineapple slices similar to those in Example A-1 were treated by coating them with a 1% (w / w) sodium hydroxide solution (corresponding to solution (1) of the present invention). →Bacterial, yeast, and fungal growth decreased by 1-2 log, but significant sensory deterioration was detected after 5 days.

[0100] Comparative Example A-6: Treatment with 0.4 ppm ClO2 solution followed by treatment with ascorbic acid solution (pH 2.4) Pineapple slices similar to those in Example A-1 were treated by coating them with a 0.4 ppm ClO2 solution (6 w / v%), and then a 6 w / w% ascorbic acid solution (pH 2.4) (corresponding to solution (2) of the present invention) was applied to the same test material. →Bacterial, yeast, and fungal growth decreased by 0.5 log, but slight sensory deterioration was detected after 5 days.

[0101] Comparative Example A-7: Treatment with 80 ppm peroxyacetic acid solution followed by treatment with ascorbic acid solution (pH 2.4) Pineapple slices similar to those in Example A-1 were treated by coating them with an 80 ppm peroxyacetic acid solution, and then a 6 w / w% ascorbic acid solution (pH 2.4) (corresponding to solution (2) of the present invention) was applied to the same test material. →Bacterial, yeast, and fungal growth decreased by 1 log, but slight sensory deterioration was detected after 5 days.

[0102] Example A-8: Treatment with 1% (w / w) sodium hydroxide solution [Solution (1)] followed by treatment with ascorbic acid solution (pH 2.4) [Solution (2)] Pineapple slices similar to those used in Example A-1 were treated by first coating the test material with a 1% (w / w) sodium hydroxide solution (corresponding to solution (1) of the present invention), and then coating the same test material with a 6 w / w% ascorbic acid solution (pH 2.4) (corresponding to solution (2) of the present invention). →Bacterial, yeast, and fungal growth decreased by 2 log, and superior sensory characteristics were detected for up to 8 days.

[0103] The reverse effect of discolored fresh produce Comparative Example B-1.1: Treatment of onions with a 1% (w / w) sodium hydroxide solution [Solution (1)]. When a 1% (w / w) sodium hydroxide solution (corresponding to solution (1) of the present invention) was applied to onion slices, they immediately discolored and remained discolored throughout the entire 14-day storage period.

[0104] Example B-1.2: Treatment of onions with 1% (w / w) sodium hydroxide solution [Solution (1)] followed by treatment with ascorbic acid solution (pH 2.4) [Solution (2)]. The test material was treated with the hydroxide solution (1) according to Example B-1.1, and immediately thereafter, a 6 w / w% ascorbic acid solution (2) (pH 2.4) [Solution (2)] was applied to the same test material. Surprisingly, not only did the discoloration stop, but the test material also returned to an appearance similar to that before the hydroxide treatment. This appearance was maintained for a 14-day storage period.

[0105] Comparative Example B-2.1: Treatment of apple slices with a 1% (w / w) sodium hydroxide solution [Solution (1)]. When a 1% (w / w) sodium hydroxide solution (corresponding to solution (1) of the present invention) was applied to apple slices, significant discoloration occurred within 1-2 minutes, and the discoloration persisted throughout the entire 21-day storage period.

[0106] Comparative Example B-2.2: Treatment of apple slices with ascorbate solution (pH 2.4) [Solution (2)] When a 6 w / w% ascorbate solution (pH 2.4) [corresponding to solution (2) of the present invention] was applied to apple slices, discoloration was suppressed in some apples, but discoloration occurred in others.

[0107] Example B-2.3: Treatment of apple slices with 1% (w / w) sodium hydroxide solution [Solution (1)], followed by treatment with ascorbic acid solution (pH 2.4) [Solution (2)]. The test material was treated in the same manner as in Example B-2.1, and immediately thereafter, a 6 w / w% ascorbic acid solution (2) (pH 2.4) [Solution (2)] was applied to the same test material. Discoloration was prevented more effectively. This appearance was maintained for a storage period of 21 days. The sodium ions in the sodium hydroxide solution significantly improved the anti-browning effect, allowing for more effective prevention of discoloration.

[0108] The results are shown in Table 1 below. [Table 1]

[0109] B. Comparative Tests Comparative experiments (Table 1) were conducted with the compositions described in the prior art U.S. Patent No. 6,500,476 and U.S. Patent No. 5,919,507, demonstrating the improvements and remarkable effects that can be achieved by the novel method of the present invention as claimed (Tables 2 and 3). Test conditions Storage: 5°C~8°C Packaging type: Plastic tray Size of one slice: very thin slices, machine-cut Exam period: 6 days

[0110] Fresh cut carrots were treated with different test solutions and evaluated in terms of their logarithmic reduction, as described in Example A above.

[0111] Furthermore, the visual appearance of the treated test specimens was examined by visual evaluation, and the anti-browning rate was determined using the following formula. 100 - (Number of browned test pieces / Total number of test pieces) × 100 = Anti-browning rate [%].

[0112] Here, the anti-browning rate (%) indicates the percentage of test specimens that did not brown. In other words, there is a correlation between a higher anti-browning rate and higher anti-browning performance.

[0113] Figures 1, 2, and 3 further illustrate the results shown in Tables 1 to 3 below.

[0114] [Table 2]

[0115] [Table 3]

[0116] [Table 4]

[0117] Analysis of the results Figures 1, 2, and 3 show the results for the 0-6 day test period.

[0118] Microbial evaluation The prior art solutions (U.S. Patent No. 6,500,476 and U.S. Patent No. 5,919,507, Test Solutions 2 and 3 in Table 1) all showed a higher microbial load of intestinal bacteria over a 6-day test period compared to the ("FF") test solutions (Test Solutions 4-9) according to the present invention.

[0119] Table 1 further shows that the microbial loads of the prior art solutions (U.S. Patent No. 6,500,476 and U.S. Patent No. 5,919,507, Test Solutions 2 and 3 in Table 1) are similar to, or even worse than, that of simple washing with water (control).

[0120] Comparing test solutions 4 and 7, it can be seen that a higher pH value results in a higher antimicrobial effect.

[0121] Test solution 8 further confirms the correlation with pH value. Comparative test solution 3 is almost identical to test solution 8 according to the present invention, but when comparative test solution 3 was used, the results regarding microorganisms were significantly worse. From this, it can be said that the high pH value of solution 8 is an important factor.

[0122] The results are shown in Figures 1 and 2. Figure 1 compares the results on day 0, day 3, and day 6, while Figure 2 shows the final result on day 6. The superiority of the preservation treatment according to the present invention is particularly clear from the final result in Figure 2.

[0123] Visual evaluation Here again, most of the test solutions according to the present invention ("FF" samples) were superior to the test solutions according to the prior art (U.S. Patent No. 6,500,476 and U.S. Patent No. 5,919,507, test solutions 2 and 3 in Table 1).

[0124] Test solution 5 is an example of the present invention in which solutions (1) and (2) have concentrations of the active ingredient encompassing the lower limit concentration of the present invention as defined herein, and have a significantly higher pH value (pH 12) compared to the prior art solutions (U.S. Patent No. 6,500,476 and U.S. Patent No. 5,919,507, Test solutions 2 and 3 in Table 1). This example of the present invention provides excellent antimicrobial effect by increasing the pH, yet it is still possible to maintain an acceptable anti-browning rate, which is still better than the results achieved with the prior art solution (Test solution 3) according to U.S. Patent No. 5,919,507.

[0125] Overall, the prior art solution (Test Solution 3) according to U.S. Patent No. 5,919,507 did not yield good visual results and performed even worse than the water control (Test Solution 1 in Table 1).

[0126] The results of the visual evaluation are shown in Figure 3, comparing the results for day 0, day 3, and day 6.

Claims

1. A method for preserving fresh food, consisting of the following steps: (a) A step of preparing an aqueous solution (1) which is an alkaline solution with a pH value greater than 11.5 and contains at least one hydroxide from sodium hydroxide and potassium hydroxide, (b) A step of preparing an aqueous solution (2) containing 0.5 w / w% to 25 w / w% ascorbate ions and / or isoascorbate ions, (c) The step of applying the aqueous solution (1) to fresh food, (d) A subsequent step of applying the aqueous solution (2) to the same fresh food, Methods for preserving fresh foods, including [specific examples of preservation methods].

2. A method for preserving fresh food, comprising the following steps: (a) A step of preparing an aqueous solution (1) which is an alkaline solution with a pH value greater than 11.5, (b) A step of preparing an aqueous solution (2) containing 0.5 w / w% to 25 w / w% ascorbate ions and / or isoascorbate ions, (c) The step of applying the aqueous solution (1) to fresh food, (d) A subsequent step of applying the aqueous solution (2) to the same fresh food, Includes, The aqueous solution (1) further contains 0.1 w / w% to 10.0 w / w% of ascorbic acid ions and / or isoascorbic acid ions, a method for preserving fresh food.

3. The method according to claim 1 or 2, wherein the aqueous solution (1) is an alkaline solution having a pH value of 12.0 or higher.

4. The method according to any one of claims 1 to 3, wherein the aqueous solution (1) contains at least one hydroxide having a concentration of 0.01 w / w% to 5 w / w%.

5. The method according to claim 1, wherein the aqueous solution (1) further comprises 0.1 w / w% to 10 w / w% ascorbic acid ions or isoascorbic acid ions.

6. The method according to any one of claims 1 to 5, wherein the pH value of the aqueous solution (2) is 3.0 to 5.

0.

7. The method according to any one of claims 1 to 6, wherein the temperatures of the aqueous solution (1) and the aqueous solution (2) are 30°C or lower.

8. The method according to any one of claims 1 to 7, wherein the aqueous solution (1) and / or the aqueous solution (2) further comprises one or more excipients suitable for use in food.

9. The method according to any one of claims 1 to 8, wherein the aqueous solution (1) and / or the aqueous solution (2) are applied for at least 5 seconds.

10. The method according to any one of claims 1 to 9, wherein the time between the application of the aqueous solution (1) and the application of the aqueous solution (2) does not exceed one hour.

11. The method according to any one of claims 1 to 10, wherein the aqueous solution (1) and / or the aqueous solution (2) are applied to fresh food by spraying, scattering, sprinkling, dipping, immersion, or a combination thereof.

12. The method according to any one of claims 1 to 11, further comprising step (e) drying, sieving, centrifugal separation, air blowing, draining, packaging or candying, and a combination thereof.

13. The method according to any one of claims 1 to 12, wherein no additional washing or neutralization step is applied between the application of the aqueous solution (1) and the application of the aqueous solution (2).

14. The method according to any one of claims 1 to 13, without using a chelating agent.

15. The method according to any one of claims 1 to 14, wherein the fresh food is selected from the group consisting of fresh fruits, fresh vegetables, and fresh herbs.

16. (a) Compounds, particularly salts, for preparing the aqueous solution (1) or the aqueous solution (1) as defined in any one of claims 1 to 15, (b) A fresh food preservation parts kit product comprising, in a separated location, the aqueous solution (2) or a compound, particularly a salt, for preparing the aqueous solution (2) as defined in any one of claims 1 to 15.

17. Use of the parts kit according to claim 16 for preserving fresh food.

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