JP3773841B2 - Pretreatment method for frozen storage of fresh food, apparatus therefor, and frozen storage method - Google Patents

Description

【００５０】
又、上記本発明方法の解凍後の生エビ（試料Ａ５）とそのドリップ（試料Ａ５Ｄ）と、比較例における解凍後の生エビ（試料Ｂ５）とそのドリップ（試料Ｂ５Ｄ）の各生菌数の測定値の結果は、表−２及び表−３の通りである。尚、生菌数の測定は、前述の通りである。
【００５１】
【表２】

【００５２】
【表３】

【００５３】
上記表−１から明らかな様に、本発明におけるオゾン水洗浄試料（試料Ａ）の生菌数は、無洗浄のブランク材（試料Ｃ）に比して、約１／６に低下しており、又、比較例として上げた真水（水道水）洗浄試料（試料Ｂ）と比べても約１／３に低下している。この事から、オゾン水洗浄処理を施す事は、その後の保存工程に有効である事が理解される。特に、この試験は、比較例においても細菌の繁殖の抑制される冷凍保存されたものであり、従来の冷凍保存物に比しても、細菌の繁殖が著しく抑制されている事が窺える。
【００５４】
又、上記表−２から明らかな様に、本発明方法により処理された試料（試料Ａ５）の解凍後の生菌数は、真水洗浄と真水氷の被覆層を形成された比較試料（試料Ｂ５）の解凍後の生菌数に比して約１／４弱に低下している。同様に、そのドリップも、本発明方法によるもの（試料Ａ５Ｄ）の生菌数は比較例のもの（試料Ｂ５Ｄ）に比して約１／２に低下している。尚、上記試験は、短期間（３時間）で且つ細菌の繁殖が抑制される冷凍保存における試験であるが、長期保存の場合や冷蔵保存の場合には、その差異は一層顕著になるものと推定される。
【００５５】
【発明の効果】
以上説明した如く、本発明によると、オゾン水の氷点以下の低温下で冷凍された冷凍生鮮食品をオゾン水中に浸漬する事により、該冷凍生鮮食品の表面にオゾン氷を生成させてオゾン氷被覆層を形成する様にしており、しかも、このオゾン氷は、冷凍下では、保存温度と初期濃度にもよるが、少なくとも数ケ月、長ければ１年以上も有効なオゾン濃度を保持する事が可能となるので、生鮮食品の品質を維持しつつ長期保存が可能となる。
【００５６】
又、前記生鮮食品を冷凍する前に、殺菌作用を有するオゾン水洗浄しておく事により、事前殺菌がなされるので、生鮮食品の変質防止に一層の効果が期待できる。特にオゾン水製造装置として電解式オゾン水製造装置を用いると、陰極側にアルカリ水が生成し、このアルカリ水自体も殺菌作用を有するものであるから、このアルカリ水を用いて生鮮食品の事前洗浄を行う事も可能であり、この場合には、オゾン水生成量の低減化と設備費及び運転コストの低減を図る事が可能となる。又、事前洗浄を、オゾン水とアルカリ水とを併用可能とする事により、オゾン氷被覆層形成に多量のオゾン水が消費される場合にはアルカリ水による事前洗浄を強化してオゾン水による洗浄負荷を軽減する等の設備の運転負荷に自由度を持たせる事も可能となる。
【００５７】
更に、オゾン氷被覆形成用のオゾン水槽内のオゾン水を電解式オゾン水製造装置の陽極側流路に還流させる事により、オゾン水濃度を一層高める事も可能となると共に、水資源の有効利用にも寄与する事になる。
【００５８】
又、本発明の設備は、極めて簡便な構造のものであるから、遠洋漁業の漁船に搭載しておけば、収穫した魚類に、その場でオゾン氷被覆層を形成して冷凍保存する事が可能となるので、出漁期間が長期にわたる場合でも、魚類の新鮮さを失う事なく持ち帰る事が可能となるので、大型漁船による長期間の遠洋漁業を可能にする等の、漁業自体に与える効果も大なるものが期待させる。
【図面の簡単な説明】
【図１】本発明に係る生鮮食品の保存処理工程図である。
【図２】本発明に係る生鮮食品の保存処理装置の第１実施例を示すフロー図である。
【図３】本発明に係る生鮮食品の保存処理装置の第２実施例を示すフロー図である。
【図４】本発明に係る生鮮食品の保存処理装置の第３実施例を示すフロー図である。
【図５】本発明に係る生鮮食品の保存処理装置の第４実施例を示すフロー図である。
【図６】本発明で使用する電解式オゾン水生成装置の要部構造を示す断面図である。
【図７】オゾン氷の残留オゾン濃度の経時変化を示すグラフである。
【符号の説明】
１ 生鮮食品
１ａ 冷凍生鮮食品
２ａ 水洗工程
２ｂ アルカリ水洗浄工程
２ｃ オゾン水洗浄工程
３ 生鮮食品冷凍工程
４ オゾン氷被覆層形成工程
５ 冷凍保存工程
１０ 冷却器
１１ 軟水器
１２ 電解式オゾン水製造装置
１２ａ 陰極側流路
１２ｂ 陽極側流路
１３ オゾン水槽
１４ オゾン水
１５ オゾン水排水
１７ オゾン氷被覆層
２０ オゾン水洗浄装置
２１ 生鮮食品冷凍装置
２４ アルカリ水洗浄装置[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for freezing and storing fresh foods such as seafood, animal meat, vegetables and fruits, and more particularly to a pretreatment method and apparatus for preserving fresh foods in a frozen state.
[0002]
[Prior art]
In fresh foods, maintaining freshness from harvest to consumption and preventing bacterial contamination are extremely important issues, and cold chains are typically stored and transported under specified low-temperature conditions. In reality, however, in reality, sufficient facilities are not always widespread from the viewpoints of distribution costs and facility costs of the low-temperature holding apparatus.
[0003]
On the other hand, recently, the use of ozone is spreading as a sterilizing means with a small environmental load. Ozone has a strong oxidizing power and can be widely used for cleaning, sterilization, deodorization, decolorization, freshness maintenance, and the like. Since ozone does not remain, the safety is high, but there is a drawback that it cannot be stored. Several technologies have been developed and proposed to ensure a certain degree of ozone preservation by making ozone into ice, that is, ozone ice.
[0004]
For example, Japanese Patent Laid-Open No. 6-165637 proposes a method in which cold water in which ozone gas is dissolved is frozen to produce ozone ice, and this is stored in fruit and vegetables containers together with fruits and vegetables and distributed.
[0005]
[Problems to be solved by the invention]
First, in the conventional general freezing method, fresh food such as seafood is pre-frozen in a freezer, so that "slime" and bacteria attached to the surface of seafood and the like are also frozen as they are. As a result, even if the activity by the bacteria could be stopped or suppressed, it was activated with thawing, and in particular, drip discoloration and odor generation that occurred during the thawing process were unavoidable, and at the same time, a decrease in freshness was unavoidable. In addition, due to the release of moisture from fresh food during frozen storage, a certain degree of alteration due to a decrease in water content in the fresh food was inevitable.
[0006]
On the other hand, in the method of transporting perishable food by storing ozone ice in containers such as seafood and fruits and vegetables, sterilization, deodorization and decolorization are performed by ozone water generated by melting ozone ice, so the freshness is maintained. Is relatively good, but its period is very short, and at least it cannot be stored weekly or monthly.
[0007]
Especially for fish and shellfish that have a strong “slim” on the surface of the body, and fish that have many bacteria in the area of the gill and are easily spoiled, it can maintain freshness and quality over a long period of time. It is no exaggeration to say that there is no effective means of preservation.
[0008]
In view of the present situation, the present invention is a perishable food that can prevent long-term preservation while maintaining moisture in fresh food while effectively preventing alteration using ozone even for fish and shellfish that are easily altered. It is an object of the present invention to provide a pretreatment method and apparatus for cryopreservation, and a cryopreservation method.
[0009]
[Means for Solving the Problems]
The present invention has been made from such a viewpoint, and a feature thereof is a processing method for freezing and storing fresh food, and the fresh food is frozen at a freezing temperature of ozone water or lower. It has a freezing step and an ozone ice coating layer forming step of immersing the obtained frozen fresh food in ozone water to form an ozone ice coating layer on the surface thereof. Maintaining the freshness of fresh food and preventing bacterial contamination by forming a coating layer of ozone ice instantaneously while making it easy to come into contact with ozone.
[0010]
As the ozone water to be used, ozone water produced by an electrolytic ozone water production apparatus that produces ozone water on the anode side by water electrolysis is preferable. As a result, the ozone water concentration is kept at a high concentration and the control of the concentration and flow rate becomes extremely easy, so that the industrial use of ozone water is facilitated.
[0011]
In addition, before the said fresh food freezing process, the ozone water washing process which wash | cleans this fresh food with ozone water, or the alkaline water washing | cleaning process wash | cleaned with the alkaline water produced | generated on the cathode side of the said electrolytic ozone water manufacturing apparatus In the case of sterilization and fish and shellfish, the surface of the fresh food is removed, and in the case of seafood, the solid surface of the surface is removed, thereby removing the alteration factor of the fresh food in advance, and then the fresh food. The preferred strategy is to move to the freezing process. In addition, when using both an ozone water washing | cleaning process and an alkaline water washing | cleaning process, it is a preferable method to precede an alkaline water washing | cleaning process.
[0012]
The freezing temperature of the fresh food in the fresh food freezing step is preferably selected to be a temperature sufficiently low from 0 ° C., which is the freezing point of ozone water, that is, −10 ° C. or lower. Preferably it is −20 ° C. or lower, more preferably −40 ° C. or lower. On the other hand, the temperature of the ozone water forming the ozone ice coating layer is preferably cooled to near the freezing point, but it needs to be kept in an unfrozen state. The concentration of ozone water is preferably 5 ppm or more in order to exert a stable ozone effect even after the formation of the ozone ice coating layer.
[0013]
Furthermore, the frozen storage method of the fresh food which preserve | saves the said pre-processed fresh food with a freezer is also this invention, and it becomes possible to maintain freshness over a long term by this.
[0014]
Next, the pretreatment device for freezing and preserving fresh food according to the present invention is produced by an electrolytic ozone water production device that produces ozone water on the anode side by electrolysis of water, and the electrolytic ozone water production device. An ozone water tank for storing the ozone water, an ozone water cooler that maintains the ozone water in the ozone water tank in the vicinity of the freezing point of the ozone water and in an unfrozen state, and the fresh food below the freezing point of the ozone water. A frozen fresh food freezing apparatus for freezing, and a frozen fresh food immersion apparatus for forming an ozone ice coating layer on the surface of the frozen fresh food by immersing the frozen fresh food frozen in the fresh food freezing apparatus in the ozone water tank. It is characterized by being prepared.
[0015]
As an application example of this apparatus, the fresh food is provided with an alkaline water washing device for washing with alkaline water generated on the cathode side of the electrolytic ozone water production device before freezing with the fresh food freezing device, Alternatively, there are a device provided with an ozone water cleaning device for cleaning with ozone water and a device provided with an alkaline water cleaning device and an ozone water cleaning device in series in this order. Thereby, before forming the ozone ice coating layer on the fresh food, the fresh food is washed and sterilized to remove the alteration factor during storage.
[0016]
Further, the ozone water cleaning device has a pipe that is supplied with a part of the ozone water sent from the electrolytic ozone water production device, or a part of the ozone water in the ozone water tank. Some are piped as supplied.
[0017]
Furthermore, a part of the ozone water in the ozone water tank is recirculated to the raw water inlet side of the electrolytic ozone water production device and reused to reduce the amount of water used and improve the concentration of ozone water. There is also.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings. First, the ozone water itself used in the present invention is basically a gas dissolution method in which ozone gas is dissolved in water to generate ozone water, and electrolytic ozone in which ozone water is generated on the anode side by electrolysis of water. In the method for preserving fresh food according to the present invention, which is roughly classified into water production methods, basically, ozone water generated by any method may be used, but high-concentration ozone water can be obtained instantaneously and its concentration An electrolytic ozone water production apparatus that is easy to control and additionally produces alkaline water having a bactericidal action is optimal, so this electrolytic ozone water production apparatus will be described below.
[0019]
FIG. 6 is a cross-sectional view showing the main part of the electrolytic ozone water generator, in which a solid polymer electrolyte membrane 30 (hereinafter simply referred to as “electrolyte membrane”) such as an ozone-resistant fluorine ion exchange membrane. ”Is disposed on one surface of the metal film so that the anode electrode 31 made of a noble metal wire mesh having an ozone generation catalytic function is superimposed on the electrolyte membrane 30, and The cathode electrode 32 is arranged so as to overlap the electrolyte membrane 30. On both outer surfaces of the electrodes 31 and 32, metal lath nets 33 and 34 having corrosion resistance such as stainless steel are disposed over the entire length so that a DC voltage can be applied between the electrodes 31 and 32. Each electrode is connected to the DC power source (not shown). Further, an anode side jacket 35 and a cathode side jacket 36 are respectively arranged on the outside so as to enclose the electrodes 31 and 32 and the lath nets 33 and 34. Each jacket includes an anode-side soft water supply port 37 connected to the anode-side water supply pipe L3b branched from the pipe L3, a cathode-side soft water supply port 38 connected to the cathode-side water supply pipe L3a branched from the pipe L3, and ozone water. An ozone water outlet 39 connected to the pipe L5 and an alkaline water outlet 40 connected to the alkaline water pipe L4 are formed.
[0020]
In such an apparatus, when a direct current voltage is applied between the electrodes 31 and 32 and electrolysis is performed while supplying soft water from the anode-side soft water supply port 37 and the cathode-side soft water supply port 38, water is supplied to the anode 31 side. OH ions (OH −) generated by electrolysis gather, and these OH ions are converted into ozone by the action of the ozone generating catalyst of the anode 31 and immediately dissolved in water to generate ozone water. This ozone water is sent from the ozone water outlet 39 to the ozone water pipe L5. Here, in the vicinity of the outer surface of the anode electrode 31, a complicated intricate flow path is formed by a lath net 33 in which wire meshes are joined together in a staggered manner, so that a large number of small vortex flows are generated on the outer surface of the anode electrode. As a result, the ozone generated on the electrode surface is engulfed in the vortex and quickly dissolved in the water, so that the amount of ozone flowing out with the water flow as ozone gas decreases, that is, the amount of dissolved ozone increases and a high concentration of about 20-30 ppm. It has been confirmed that ozone water is generated.
[0021]
Similarly, hydrogen ions (H +) generated by electrolysis of water collect on the electrode surface on the cathode electrode 32 side and become hydrogen gas, and are released from water. On the cathode surface, the water softener 1 performs ion exchange. Sodium ions (Na +) contained in trace amounts in water are collected and concentrated, and water on the cathode side is made into alkaline water, which is sent together with the hydrogen gas from the alkaline water discharge port 40 to the alkaline water pipe L4. Become. In this way, it is confirmed that alkaline water ions contained in trace amounts in the water together with hydrogen gas are concentrated on the cathode side, and as a result, alkaline water having a pH of 9 to 11 or more is generated as water on the cathode side. Has been.
[0022]
When producing ozone water using the electrolytic ozone water generator 2, the generated ozone water concentration is constantly measured with an ozone water concentration meter (not shown) installed in the ozone water pipe L5. Based on the concentration signal, the supply DC value from the DC power source to the electrolytic ozone water generator is changed to control the ozone water concentration to be kept constant. As a result, ozone water having an arbitrary concentration from several ppm to 30 ppm can be stably generated.
[0023]
Next, the method for preserving fresh food of the present invention using the electrolytic ozone water production apparatus will be described. FIG. 1 is a process chart for storing fresh food according to the present invention. The harvested fresh food 1 is first sent to a washing process. This washing process includes a washing process 2a that is simply washed with water, an alkaline water washing process 2b that is washed with alkaline water generated on the anode side of the electrolytic ozone water production apparatus, and an anode of the electrolytic ozone water production apparatus. There are three types of processes including an ozone water cleaning process 2c for cleaning with ozone water generated on the side. In the case where the target fresh food 1 is vegetables, fruits, etc., it may be sufficient to wash away the dust adhering to the water washing step 2a, but by washing with alkaline water in the alkaline water washing step 2b, It is also possible to perform sterilization washing with alkaline water together with the removal. Incidentally, the alkaline water produced by the electrolytic ozone water production device is equivalent to so-called alkaline water ionized by electrolysis, and it is well known that this alkaline water has a bactericidal action. It is an effective measure to use alkaline water produced as a by-product in the ozone water production device for pre-cleaning of fresh food. Furthermore, it is possible to perform sterilization cleaning more strongly by the ozone water cleaning step 2c. Each of these washing steps 2a to 2c can select only one of these steps, but can also be washed in combination. However, ozone water cleaning has an extremely strong sterilization function, and therefore, when a plurality of cleaning steps are employed, it is preferably employed in the final cleaning step.
[0024]
Needless to say, when the fresh food 1 is a marine product such as fish and shellfish, the water washing step 2a is not performed with fresh water but with seawater. In addition, in the case of fish, there is a strong slime on the surface, and it is difficult to remove completely with some water washing. In this case, washing with the alkaline water washing, ozone water washing or both It is preferable to completely remove the slime in advance, and ozone water cleaning is effective for the complete removal of the slime. In addition, various bacteria are likely to accumulate in the portion of the fish, and the deterioration proceeds from this portion. Therefore, it is preferable to clean the portion of the shell by alkaline water cleaning or ozone water cleaning.
[0025]
The fresh food cleaned in the above-described manner is sent to the next fresh food freezing step 3 where it is frozen to a temperature lower than the freezing temperature of ozone water (approximately 0 ° C.). The purpose of this freezing step is to provide ozone water freezing ability for instantly freezing ozone water adhering to fresh food in the ozone water soaking step 4 of the next step, so it is more than the ozone water freezing temperature. It is necessary to cool it down to a sufficiently low temperature to be frozen. The freezing temperature is preferably −10 ° C. or lower, and in particular, −20 ° C. or lower is preferable, and −40 ° C. or lower is preferable in order to keep the ozone concentration in the ozone ice coating layer described later high over a long period of time. It is preferable if it can be cooled and frozen.
[0026]
Next, the obtained frozen fresh food is sent to the ozone ice coating layer forming step 4 in the next step. Here, the frozen fresh food in a frozen state that is cooled to a low temperature below the freezing point of ozone water is immersed in ozone water to instantly freeze the ozone water around the frozen fresh food, An ozone ice coating layer is formed on the outer peripheral surface of the food. Accordingly, it is essential that the ozone water is kept in a liquid state at a temperature above the freezing point, but it is kept at a temperature as close to the freezing point as possible, that is, at a temperature above 0 ° C and near 0 ° C. Is preferred. When the frozen fresh food is immersed in ozone water maintained at a temperature close to 0 ° C. in this way, an ozone ice coating layer is instantaneously formed on the surface of the frozen fresh food while the frozen state is maintained. It will be. In the case of fish, miscellaneous bacteria are likely to accumulate in the area of the gills, and the quality changes from this area. However, by immersing fresh food in ozone water, Since ozone water enters and freezes, ozone ice becomes ozone water even at this point when thawing, and alteration can be reliably prevented.
[0027]
Next, the frozen fresh food whose outer surface is coated with ozone ice as described above moves to the frozen storage step 5. The frozen storage step 5 referred to in the present invention means that it is stored in a frozen warehouse and kept in a frozen state, or placed in a frozen container for transport or a cold storage container and kept in a frozen state in a consumption area. It means the process of transferring. In this way, the fresh food is frozen and held with its surface covered with ozone ice, so the freshness maintenance effect by freezing, the moisture retention effect in fresh food by the ozone ice coating layer, and the sterilization by ozone Combined with the effect, the fresh food is stably maintained in freshness and quality over a long period of time.
[0028]
Next, the structure of the apparatus which implements the pre-processing method for the freezing preservation | save of the fresh food which concerns on the said invention is demonstrated. FIG. 2 is a flowchart showing a first embodiment of a fresh food pretreatment apparatus according to the present invention. In the figure, clean water such as room temperature tap water used as raw water for ozone water production is supplied from a pipe L1. It is supplied to the cooler 10, cooled to 10 ° C. or less, preferably about 3 to 6 ° C. by an attached cooling device (not shown), and supplied to the water softener 11 through the pipe L 2. In the water softener 11, hard water components such as calcium ions and magnesium ions contained in the clean water are replaced with sodium ions to be softened and divided into two through a pipe L3, one of which is electrolytic ozone water from the pipe L3a. The other side is supplied to the cathode side flow path 12a of the manufacturing apparatus 12, and the other is supplied from the pipe L3b to the anode side flow path 12b of the electrolytic ozone water manufacturing apparatus 12. In the anode side flow path 12b in the electrolytic ozone water generator 12, ozone water having a high concentration of about 10 to 30 ppm is generated as described above, and is sent out as ozone water from the pipe L5. The part is supplied to the ozone water tank 13 via the pipe L6, and the remaining part is supplied to the ozone water cleaning apparatus 20 for the fresh food 1 via the pipe L7. In the cathode side flow path 12a, alkaline water is generated as described above, and is sent out from the pipe L4 as alkaline water.
[0029]
On the other hand, the fresh food 1 is washed with ozone water sent to the ozone water cleaning device 20 and sprayed from the pipe L7. When the fresh food 1 is fish, the slime present on the surface is also decomposed by the ozone water. Removed. In addition, it is also possible to make this ozone water washing | cleaning apparatus 20 into a immersion type instead of a spraying type, In this case, this ozone water washing | cleaning apparatus 20 becomes a washing tank, and the fresh food 1 is immersed in this washing tank. It will be sterilized and washed. Therefore, when the fresh food is a fish, the ozone water comes into contact with the inside of the cavity and the cavity where the penetration of the ozone water cannot be sufficiently achieved by the spraying method, and the external sterilization washing can be sufficiently performed. In addition, the ozone water after washing | cleaning is discharged | emitted out of the system from the piping L8.
[0030]
The fresh food 1 that has been washed and sterilized with ozone water is then sent to a fresh food freezing device 21 where it is frozen at a temperature lower than the freezing point of ozone water (about 0 ° C.) by the attached freezer 22 and frozen fresh food. 1a. The freezing temperature at this time is required to be sufficiently cooled so that the ozone ice coating layer is instantaneously formed at the time of forming the ozone ice coating layer in the subsequent step. It is preferably frozen at a low temperature of -20 ° C or lower, more preferably -40 ° C or lower.
[0031]
This frozen fresh food 1a is supplied to the ozone water tank 13 and immersed therein. The ozone water 14 in the ozone water tank 13 is preferably cooled to a temperature near the freezing point (about 0 ° C.) of the ozone water 14 and freezing by an attached cooler 18. When the frozen fresh food 1a is immersed in the ozone water 14, the ozone water 14 in contact with the frozen fresh food 1a is immediately frozen to form a coating layer 17 of ozone ice on the surface of the frozen fresh food 1a. . The thickness of the coating layer 17 varies depending on the immersion time of the frozen fresh food 1a in ozone water, but is immersed so that the ozone ice coating layer 17 of at least about 0.5 mm, preferably about 1 to 3 mm is formed. It is desirable to adjust the time. The frozen fresh food 1a on which the ozone ice coating layer 17 is formed is held in an environment where the state is maintained, that is, in a freezing room adjusted to a temperature equal to or lower than the freezing temperature of the frozen fresh food 1a. Become.
[0032]
The ozone water tank 13 is continuously supplied with fresh high-concentration ozone water from the pipe L5 and is carried out as ozone ice on the surface of the frozen fresh food 1a. Since the amount is larger, excess ozone water is discharged from the discharge unit 15 to the outside of the tank.
[0033]
Next, FIG. 3 is a flowchart showing a second embodiment of the fresh food pretreatment apparatus according to the present invention. The difference from the first embodiment is that the fresh food 1 is a fresh food in the first embodiment. Although it was washed with ozone water before being fed to the food freezer 21, it is washed with alkaline water in this example. That is, in this example, the alkaline water sent from the cathode side flow path 12a of the electrolytic ozone water production apparatus 12 through the pipe L4 is supplied to the alkaline water washing apparatus 24, and the fresh food 1 is washed with the alkaline water here. It is configured like this. The alkaline water used for cleaning is appropriately discharged from the pipe L15. Since the other configuration is the same as that of the first embodiment of FIG. 2, the same configuration is denoted by the same reference numeral, and redundant description is omitted.
[0034]
Alkaline water generated by the electrolytic ozone water production apparatus 12 corresponds to so-called electrolytic alkaline water ionized water, and has a sterilizing function and a function of decomposing oily components. In such a case, it is sufficient to remove dust, dirt and oils and fats adhering to the surface, so that alkaline water washing is sufficient.
[0035]
Next, FIG. 4 is a flowchart showing a third embodiment of the fresh food pretreatment apparatus according to the present invention, which differs from the first embodiment in the following two points. The first difference is that, in the first embodiment, a part of the ozone water sent from the electrolytic ozone water production device 12 is supplied to the ozone water tank 13, and the rest is supplied to the ozone water cleaning device 20 for the fresh food 1. In this example, the entire amount of ozone water sent from the electrolytic ozone water production apparatus 12 is supplied to the ozone water tank 13, and the ozone water is extracted from the ozone water tank 13 through the pipe L9. This is divided into two through the pipe L10 and a part is supplied to the ozone water cleaning apparatus 20 through the pipe L12, and the remaining part is the anode side that is the ozone water generation flow path of the electrolytic ozone water production apparatus 12 through the pipe L11. This is the point that the flow path 12b is refluxed through the pipe L3b. The second difference is that in the first embodiment, the water is cooled in advance by the cooler 10 and supplied to the electrolytic ozone water production apparatus 12. The cooler 10 is omitted. Since the other configurations are the same, the same reference numerals are given and the duplicate description is omitted.
[0036]
First, the first difference will be described. The ozone water in the ozone water tank 13 immerses the washed frozen fresh food 1a and generates ozone ice on the surface thereof, so there is almost no component eluted from the fresh food, and the ozone in a fresh state It is low-temperature ozone water that is kept in a water state and is cooled to a temperature near the freezing point. Therefore, if this fresh low-temperature ozone water is supplied to the anode-side flow path 12b which is the ozone water generation flow path of the electrolytic ozone water production apparatus 12, the water temperature in the flow path becomes low and the water is generated in the flow path. The solubility of ozone is also increased, and high-concentration ozone water is easily obtained. In addition, since the raw water itself supplied to the anode-side flow path 12b is also ozone water, higher-concentration ozone water is generated, leading to a reduction in the supply amount of the raw water supplied from the pipe L1, thereby saving There is also an effect of recycling.
[0037]
Further, the second difference will be described. By using ozone water supplied to the ozone water cleaning device 20 as cooling ozone water in the ozone water tank 13, the fresh food 1 that comes into contact with the cooling ozone water is also cleaned. Cooling is performed simultaneously with the sterilization, and as a result, there is an effect that the freezing time in the fresh food freezing device 21 in the next process is shortened.
[0038]
Next, FIG. 5 is a flowchart showing a fourth embodiment of the fresh food pretreatment apparatus according to the present invention, which differs from the first embodiment in the following two points. The first point is that the use of alkaline water is not considered in the first embodiment, but in this example, the alkaline water from the pipe L4 is temporarily stored in the alkaline water tank 23, and the inside of the alkaline water tank 23 is used. The alkaline water is supplied to the alkaline water cleaning device 24 through the pipe L13, the pump P2, and the pipe L14. Further, the second difference is that in the first embodiment, the fresh food 1 is cleaned only by the ozone water cleaning device 20 before being supplied to the fresh food freezing device 21. In this example, the alkaline water cleaning device 24 first performs the alkaline water cleaning, and the ozone water cleaning device 20 then performs the ozone water cleaning.
[0039]
First, the first difference will be described. Alkaline water delivered from the cathode side of the electrolytic ozone water production apparatus 12 has little change over time and can be stored for a long time, but ozone water is difficult to store. Therefore, it is necessary to produce ozone water with low storage stability in an amount corresponding to the amount used, but alkaline water with high storage stability can be stored when not in use. It is intended to be used in the device 24. In addition, by using both alkaline water cleaning and ozone water cleaning, which are the second difference, if the amount of ozone water used for cleaning is reduced and the reduced amount is supplemented with alkaline water, electrolytic ozone water The ozone water generation load in the manufacturing apparatus 12 can be reduced, and the operating cost can be reduced. Furthermore, while keeping the production amount of ozone water constant, the alkaline water washing device 24 normally stops or operates at a low load so that the alkaline water is stored in the alkaline water tank 23 and the frozen fresh food in the ozone water tank 13 is stored. As the amount of ozone 1a increases and the amount of ozone water taken out from the ozone water layer 13 as the ozone ice coating layer 17 increases, the amount of ozone water supplied from the pipe L6 to the ozone water tank 13 increases. The amount of ozone water supplied to the cleaning device 20 will decrease. At this point, the alkaline water cleaning device 24 is operated or operated at a high load with the alkaline water stored in the alkaline water tank 23 to perform alkaline water cleaning. Operation that reduces the load of ozone water cleaning is also possible.
[0040]
Although the configuration of the apparatus of the present invention has been described above, the apparatus of the present invention is not limited to the above embodiment, and there are various modifications. For example, in the apparatus shown in FIG. 2, FIG. 3 or FIG. 5, the ozone water in the ozone water tank 13 is returned to the anode-side flow path 12b of the electrolytic ozone water production apparatus 12 as shown in FIG. It is possible to further increase the ozone water concentration and reduce the amount of water used. In addition, if the fresh food 1 is sufficiently cooled by the fresh food freezing device 21, the ozone water is also cooled by the frozen fresh food 1 a immersed in the ozone water tank 13. It is possible to reduce the number of devices and facilitate maintenance by omitting 18. Similarly, the cooler 10 for clean water shown in FIGS. 2, 3 and 5 can be omitted. The alkaline water tank 23 shown in FIG. 5 can also be installed in the apparatus shown in FIGS. 2 to 4, and the alkaline water can be used for other purposes. In addition, it goes without saying that various modifications can be made without departing from the inventive concept described in the claims.
[0041]
Next, the verification test of the method of the present invention will be described. First, in order to confirm how long ozone is stored in ozone ice, an ozone retention confirmation test was performed in the following manner.
[0042]
[Manufacture of ozone ice]
Three types of ozone water with ozone concentrations of 10 ppm, 15 ppm, and 20 ppm are produced by the electrolytic ozone water production apparatus shown in FIG. 6, and each of these ozone waters is sealed in a 75 μm thick nylon / polyethylene bag. A sealed bag containing ozone water with different ozone concentrations was formed. Next, these ozone water sealed bags were immersed in 59% ethanol water cooled to −40 ° C. and frozen to produce ozone ice having different ozone concentrations.
[0043]
[Ozone retention test]
The sealed bags enclosing these ozone ices were broken, and only the ozone ice was taken out from them. Each ozone ice was stored at −20 ° C. and −40 ° C., and periodically sampled to measure the residual ozone amount.
[0044]
〔Test results〕
FIG. 7 shows the change over time in the residual ozone concentration. As is clear from the figure, the residual ozone concentration after 180 days (about half a year) when stored at −20 ° C. is about 0.8 ppm for ozone ice with an initial concentration of 10 ppm, ozone with an initial concentration of 15 ppm and 20 ppm. It was about 1.2-1.4 ppm with ice, and the value of 0.3 ppm or more at which the necessary bactericidal effect by ozone can be expected. From this fact, it can be seen that the initial ozone water is required to be about 5 ppm in order to maintain the ozone concentration of about 0.3 ppm at which a normal bactericidal effect can be expected for at least about half a year. On the other hand, the residual ozone concentration after 180 days when stored at −40 ° C. is about 5.8 ppm for ozone ice with an initial concentration of 10 ppm, about 6.8 ppm for ozone ice with an initial concentration of 15 ppm, and ozone ice with an initial concentration of 20 ppm. The residual ozone value is about 7.7 ppm, which is much higher than that stored at −20 ° C. From this fact, it can be seen that if the fresh food is stored in a state covered with ozone ice, it can be stored while maintaining the bactericidal effect by ozone for at least half a year. It can also be seen that the lower storage temperature is suitable for further long-term storage because the ozone concentration is maintained at a higher value.
[0045]
Next, as an actual fresh food, a comparative test between a frozen storage method according to the method of the present invention using commercially available headless shrimp and a conventional frozen storage method was performed, and the contents thereof will be described below.
[0046]
[Example 1]
(1) Ozone water cleaning process
5 liters of 10 ppm ozone water produced by the electrolytic ozone water production device and 1 kg of ozone ice produced by freezing the ozone water are put in a bucket to adjust the cooling ozone water containing ozone ice, and this cooling ozone water The raw shrimp was prepared by adding 15 raw shrimps to the mixture and stirring for 1 minute, pre-cleaning the raw shrimp with ozone water. In addition, the number of viable bacteria of each raw shrimp (blank) before washing with ozone water and fresh shrimp after washing with ozone water was measured.
(2) Freezing process
Ten ozone-washed shrimps were placed in a basket and placed in a −40 ° C. freezer. After 3 hours, it was confirmed that the shrimps were completely frozen and frozen.
(3) Ozone ice coating layer formation process
The 10 ppm ozone water (room temperature) was stored in a tray, and the frozen shrimp taken out from the freezer was immersed in this ozone water for 5 seconds to form an ozone ice coating layer on the surface of the frozen shrimp.
(4) frozen storage process
The frozen shrimp on which the ozone ice coating layer was formed was placed in a freezer at −40 ° C. and stored frozen.
(5) Defrosting process
When 3 hours had passed after charging in the freezer, the frozen shrimp with the ozone ice coating layer formed was taken out of the freezer and thawed in a 35 ° C. water bath. The viable cell count on the surface of the raw shrimp after thawing and the viable cell count in the drip were measured.
[0047]
[Comparative Example 1]
(1) Fresh water cleaning process
5 liters of tap water and 1 kg of fresh water ice produced by freezing the tap water are put in a bucket to adjust the cooling water, and 15 fresh shrimps are put into this cooling water and stirred for 1 minute. Shrimp preliminary washing was performed to prepare fresh water washing shrimp. The viable cell count of one live shrimp after washing with fresh water was measured.
(2) Freezing process
Ten fresh water-washed shrimps were placed in a basket and placed in a freezer at −40 ° C. After 3 hours, it was confirmed that they were completely frozen and frozen.
(3) Fresh water coating layer forming step
Tap water (room temperature) was stored in a tray, and the frozen shrimp taken out from the freezer was immersed in the tap water for 5 seconds to form a fresh water ice coating layer on the surface of the frozen shrimp.
(4) frozen storage process
The frozen shrimp on which the fresh water ice coating layer was formed was placed in a freezer at −40 ° C. and stored frozen.
(5) Defrosting process
When 3 hours had passed after charging in the freezer, the frozen shrimp with the fresh water ice coating layer was taken out of the freezer and thawed in a 35 ° C. water bath. The viable cell count on the surface of the raw shrimp after thawing and the viable cell count in the drip were measured.
[0048]
[Contrast]
Measurement of the number of viable bacteria in the raw shrimp (sample A1) after cleaning with ozone water in the present invention, raw shrimp after cleaning with fresh water (sample B1) in comparative example 1, and unwashed blank material (sample C0) The result of the value is as shown in Table-1. The number of viable bacteria was measured by measuring the number of bacteria after each sample was crushed with a stomacher, applied to a standard agar medium (3% salinity), and cultured in a 37.5 ° C. incubator for 48 hours. . The relative ratio is a value when the viable count of sample A1 is 100.
[0049]
[Table 1]

[0050]
In addition, the raw shrimp (sample A5) and its drip (sample A5D) after thawing by the method of the present invention, and the number of viable bacteria of the raw shrimp (sample B5) and its drip (sample B5D) after thawing in the comparative example The results of the measurement values are as shown in Table-2 and Table-3. In addition, the measurement of viable count is as above-mentioned.
[0051]
[Table 2]

[0052]
[Table 3]

[0053]
As is clear from Table 1 above, the viable count of the ozone water cleaning sample (sample A) in the present invention is reduced to about 1/6 compared to the uncleaned blank material (sample C). Moreover, it is reduced to about 1/3 compared with the fresh water (tap water) cleaning sample (sample B) raised as a comparative example. From this, it is understood that the ozone water cleaning treatment is effective for the subsequent storage process. In particular, this test was also stored in the comparative example in which the propagation of bacteria was suppressed, and it can be seen that the growth of bacteria was remarkably suppressed as compared with the conventional frozen storage.
[0054]
Further, as apparent from Table 2 above, the viable count after thawing of the sample (sample A5) treated by the method of the present invention is the comparison sample (sample B5) in which a coating layer of fresh water washed and fresh water ice is formed. ) And the number of viable cells after thawing is reduced to about ¼. Similarly, the number of viable bacteria of the drip produced by the method of the present invention (sample A5D) is reduced to about ½ compared to that of the comparative example (sample B5D). In addition, although the said test is a test in the freezing preservation | save in which reproduction of bacteria is suppressed for a short period (3 hours), in the case of long-term preservation | save and refrigeration preservation | save, the difference will become more remarkable. Presumed.
[0055]
【The invention's effect】
As described above, according to the present invention, by immersing frozen fresh food frozen at a low temperature below the freezing point of ozone water in ozone water, ozone ice is generated on the surface of the frozen fresh food to cover the ozone ice. In addition, this ozone ice can maintain an effective ozone concentration for at least a few months or more than a year under freezing, depending on the storage temperature and initial concentration. Therefore, long-term storage is possible while maintaining the quality of fresh food.
[0056]
In addition, by preliminarily sterilizing by washing with ozone water having a sterilizing action before freezing the fresh food, a further effect can be expected for preventing the quality of the fresh food from being altered. In particular, when an electrolytic ozone water production device is used as the ozone water production device, alkaline water is generated on the cathode side, and the alkaline water itself has a bactericidal action. In this case, it is possible to reduce the generation amount of ozone water and reduce the equipment cost and the operating cost. In addition, by making it possible to use ozone water and alkaline water in advance, when a large amount of ozone water is consumed to form the ozone ice coating layer, the pre-cleaning with alkaline water is strengthened and cleaning with ozone water is performed. It is also possible to give a degree of freedom to the operation load of the equipment such as reducing the load.
[0057]
Furthermore, the ozone water concentration in the ozone water tank for forming the ozone ice coating can be recirculated to the anode-side flow path of the electrolytic ozone water production device, so that the concentration of ozone water can be further increased and water resources can be used effectively. Will also contribute.
[0058]
In addition, since the equipment of the present invention has an extremely simple structure, if it is mounted on a fishing boat of a pelagic fishery, an ozone ice coating layer can be formed on the spot and stored frozen. Therefore, even if the fishing period is long, it can be taken home without losing the freshness of the fish, so it has the effect on the fishery itself, such as enabling long-term ocean fishing with a large fishing boat. Expect something great.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a process chart for preservation processing of fresh food according to the present invention.
FIG. 2 is a flowchart showing a first embodiment of the apparatus for preserving fresh food according to the present invention.
FIG. 3 is a flowchart showing a second embodiment of the apparatus for processing and storing fresh food according to the present invention.
FIG. 4 is a flowchart showing a third embodiment of the apparatus for processing and storing fresh food according to the present invention.
FIG. 5 is a flowchart showing a fourth embodiment of the apparatus for processing and storing fresh food according to the present invention.
FIG. 6 is a cross-sectional view showing the main structure of an electrolytic ozone water generator used in the present invention.
FIG. 7 is a graph showing temporal changes in residual ozone concentration of ozone ice.
[Explanation of symbols]
1 Fresh food
1a Frozen fresh food
2a Water washing process
2b Alkaline water washing process
2c Ozone water cleaning process
3 Fresh food freezing process
4 Ozone ice coating layer formation process
5 frozen storage process
10 Cooler
11 Water softener
12 Electrolytic ozone water production equipment
12a Cathode side flow path
12b Anode-side flow path
13 Ozone water tank
14 Ozone water
15 Ozone water drainage
17 Ozone ice coating layer
20 Ozone water cleaning device
21 Fresh food freezer
24 Alkaline water cleaning device

Claims (23)

A pretreatment method for freezing fresh food,
Fresh food freezing step (3) for freezing fresh food (1) below the freezing temperature of ozone water;
It is characterized by having an ozone ice coating layer forming step (4) in which the obtained frozen fresh food (1a) is immersed in ozone water to form an ozone ice coating layer (17) on the surface of the frozen fresh food. A pretreatment method for freezing fresh food. The pretreatment method for fresh preservation of fresh food according to claim 1, wherein the ozone water is ozone water produced by an electrolytic ozone water production device that generates ozone water on the anode side by electrolysis of water. . The fresh food frozen storage according to claim 1 or 2, wherein an ozone water washing step (2c) for washing the fresh food (1) with ozone water is provided before the fresh food freezing step (3). Pre-processing method for. Before the fresh food freezing step (3), an alkaline water washing step (2b) for washing the fresh food (1) with alkaline water generated on the cathode side of the electrolytic ozone water production apparatus is provided. The pre-processing method for the freezing preservation | save of the fresh food of Claim 2. Before the fresh food freezing step (3), an alkaline water washing step (2b) for washing the fresh food (1) with alkaline water generated on the cathode side of the electrolytic ozone water production apparatus, and the alkaline water The pretreatment method for the freezing preservation | save of the fresh food of Claim 2 provided with the ozone water washing | cleaning process (2c) wash | cleaned with ozone water following the washing | cleaning process (2b). The frozen fresh food (1a) is frozen at −10 ° C. or lower in the fresh food freezing step (3), and the ozone water in the ozone ice coating layer forming step (4) is not near the freezing point. The pre-processing method for the freezing preservation | save of the fresh food in any one of Claims 1 thru | or 5 currently maintained at freezing temperature. The said frozen fresh food (1a) is a pre-processing method for the freezing preservation | save of the fresh food of Claim 6 which is frozen to -20 degrees C or less in the said fresh food freezing process (3). The said frozen fresh food (1a) is a pre-processing method for the freezing preservation | save of the fresh food of Claim 6 which is frozen to -40 degrees C or less in the said fresh food freezing process (3). The pretreatment method for frozen storage of fresh food according to any one of claims 1 to 8, wherein the ozone water concentration in the ozone water coating layer forming step (4) is 5 ppm or more. A method for freezing fresh food,
The fresh food (1) is frozen below the freezing temperature of ozone water to form frozen fresh food (1a), which is immersed in ozone water, and the surface of the frozen fresh food (1a) is coated with an ozone ice coating layer (17 ) And the frozen fresh food (1a) having this ozone ice coating layer is stored frozen. The method for freezing and storing fresh food according to claim 10, wherein the ozone water is ozone water produced by an electrolytic ozone water production apparatus that produces ozone water on the anode side by electrolysis of water. The fresh food (1) according to claim 10, wherein the fresh food (1) is preliminarily washed with ozone water and then frozen, and then immersed in the ozone water to form an ozone ice coating layer (17) on the surface thereof. Frozen storage method. The fresh food (1) is washed with alkaline water generated on the cathode side of the electrolytic ozone water production apparatus (12), and then immersed in the ozone water to form an ozone ice coating layer (17 The frozen storage method of the fresh food of Claim 11 which forms). The fresh food (1) is washed with alkaline water generated on the cathode side of the electrolytic ozone water production device (12), then washed with ozone water, and then immersed in the ozone water to The method for freezing and storing fresh food according to claim 11, wherein an ozone ice coating layer (17) is formed on the surface. The method for freezing and storing fresh food according to any one of claims 10 to 14, wherein the fresh food (1) is frozen at -20 ° C or lower and immersed in the ozone water. The method for freezing and preserving fresh food according to any one of claims 10 to 15, wherein the ozone concentration of ozone water in which the frozen fresh food (1a) is immersed is adjusted to 5 ppm or more. A pretreatment device for freezing and storing fresh food,
An electrolytic ozone water producing device (12) for generating ozone water on the anode side by electrolysis of water;
An ozone water tank (13) for storing ozone water generated by the electrolytic ozone water production apparatus (12);
An ozone water cooler (18) that maintains the ozone water in the ozone water tank (13) in the vicinity of the freezing point of the ozone water and in an unfrozen state;
A fresh food freezing device (21) for freezing the fresh food (1) below the freezing point of the ozone water;
The frozen fresh food (1a) frozen in the fresh food freezing device (21) is immersed in the ozone water tank (13), and an ozone ice coating layer (17) is formed on the surface of the frozen fresh food (1a). A pretreatment apparatus for frozen storage of fresh food, characterized by comprising a frozen fresh food immersion apparatus to be formed. An alkaline water cleaning device (24) for cleaning the fresh food (1) with alkaline water generated on the cathode side of the electrolytic ozone water production device (12) before freezing in the fresh food freezing device (21). The pre-processing apparatus for the freezing preservation | save of the fresh food of Claim 17 provided. 18. Fresh food frozen storage according to claim 17, further comprising an ozone water cleaning device (20) for cleaning the fresh food (1) with ozone water before freezing the fresh food freezing device (21). Pre-treatment device for. An alkaline water cleaning device (24) for cleaning the fresh food (1) with alkaline water generated on the cathode side of the electrolytic ozone water production device (12) before freezing in the fresh food freezing device (21). The pretreatment apparatus for the freezing preservation | save of the fresh food of Claim 17 with which the ozone water washing | cleaning apparatus (20) wash | cleaned by ozone water is provided following this. The fresh food according to claim 19 or 20, wherein the ozone water cleaning device (20) is piped so as to be supplied with a part of ozone water sent from the electrolytic ozone water production device (12). Pretreatment equipment for cryopreservation. The ozone water cleaning device (20) is piped so as to be supplied with a part of the ozone water in the ozone water tank (13). Processing equipment. A part of the ozone water in the ozone water tank (13) is refluxed to the raw water inlet side of the electrolytic ozone water production device (12), and the fresh food is stored frozen. Pre-treatment device for.

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