JP2010246413A - Method for washing vegetable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for washing vegetables, which does not reduce a commercial value even with passage of several days after washing and reduces the number of bacteria in high efficiency. <P>SOLUTION: The method for washing vegetables includes a step for washing raw materials, a cutting step, a step for washing after cutting and a rinsing step. The step for washing raw materials washes harvested leaf vegetables without cutting them. The step for washing raw material washes leaf vegetables for a washing time of ≥2 minutes and ≤7 minutes in an aqueous solution of sodium hypochlorite at ≥40°C and <46°C. The cutting step cuts the leaf vegetables washed by the step for washing raw materials. The step for washing after cutting washes the leaf vegetables cut by the cutting step in an aqueous solution of sodium hypochlorite. The rinsing step rinses the leaf vegetables, washed by the step for washing after cutting, with water. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vegetable cleaning method for cleaning leafy vegetables.

  In retail stores such as supermarkets and convenience stores, raw vegetables are sold as products in the form of salads. For such raw vegetables, taking into account the time required for distribution and display and the time from purchase to consumption, at convenience stores, etc., a standard is set for the number of bacteria when 72 hours have passed after washing. Has been.

  In the vegetable washing method according to the prior art, raw vegetables with a controlled low-temperature hot water stream in which the treated hot water is set to 47.5 ° C. and a stirring flow is added to treat the raw vegetables for at least 10 minutes to further remove internal oxygen. A low-temperature treatment method for washing and sterilization of browning and preventing browning is disclosed (for example, see Patent Document 1).

Japanese Patent No. 3680111

  When leafy vegetables are washed with the vegetable washing method according to the prior art, the number of bacteria immediately after washing can be suppressed, but after several days, partial wilting, browning, etc. occur, and the commercial value is lost There is a problem. Moreover, if the temperature is set to a temperature lower than 47.5 ° C., and the vegetables are washed with conditions other than the temperature set in the same manner as in the prior art, there is a problem that a sufficient sterilizing effect cannot be obtained.

  The objective of this invention is providing the washing | cleaning method of the vegetable which can reduce the number of microbes with high efficiency, without reducing commercial value, even if several days pass after washing | cleaning.

  According to the present invention, the vegetable washing method includes an active ingredient washing process, a cutting process, a washing process after cutting, and a rinsing process. In the active ingredient washing process, the harvested leafy vegetables are washed without being cut. In the active ingredient washing step, the leafy vegetables are washed in a sodium hypochlorite aqueous solution having a temperature of 40 degrees Celsius or more and less than 46 degrees Celsius for a washing time of 2 minutes or more and 7 minutes or less. In the cutting step, the leafy vegetables washed in the active ingredient washing step are cut. In the washing process after cutting, the leafy vegetables cut in the cutting process are washed in an aqueous sodium hypochlorite solution. In the rinsing process, the leafy vegetables washed in the washing process after cutting are rinsed with water.

  Further, according to the present invention, when the leafy vegetable is mizuna, in the active ingredient washing step, the mizuna is added for 4 minutes to 7 minutes in a sodium hypochlorite aqueous solution having a temperature of 43 degrees Celsius or more and less than 46 degrees Celsius. Wash at the washing time.

  According to the present invention, when the leafy vegetable is lettuce, the lettuce is 2 minutes or more and 6 minutes or less in the sodium hypochlorite aqueous solution at a temperature of 40 degrees Celsius or more and less than 44 degrees Celsius in the bulk washing process. Wash at the washing time.

  According to the invention, in the post-cutting washing step, the leafy vegetables are washed in a sodium hypochlorite aqueous solution having a temperature of 42 degrees Celsius or more and 44 degrees Celsius or less.

  In addition, according to the present invention, the body cleaning process includes a reciprocating swinging stage. In the reciprocating rocking stage, the leafy vegetables are reciprocally displaced in the sodium hypochlorite aqueous solution.

  According to the present invention, in the bulk washing process, the harvested leafy vegetables are washed without cutting. In the active ingredient washing step, the leafy vegetables are washed in a sodium hypochlorite aqueous solution having a temperature of 40 degrees Celsius or more and less than 46 degrees Celsius for a washing time of 2 minutes or more and 7 minutes or less. In the washing process after cutting, the leafy vegetables cut in the cutting process are washed in an aqueous sodium hypochlorite solution. This makes it possible to efficiently reduce the number of bacteria attached to leafy vegetables that are objects to be cleaned. By performing the active ingredient washing process before the cutting process, the bacteria attached to the surface of the leafy vegetables are washed away, the bacteria are damaged, and the number of bacteria is reduced. It is possible to reduce the number of bacteria that invade inside or between cells of leafy vegetables from the cut surface.

  By controlling the temperature condition to be 40 degrees Celsius or more and less than 46 degrees Celsius, it is possible to prevent the commercial value of leafy vegetables from being lowered even after several days have passed since washing compared to the case of washing in other temperature ranges. Can do. Moreover, compared with the case where it wash | cleans in normal temperature sodium hypochlorite aqueous solution, the food texture of leafy vegetables can be improved. By setting the washing time to 2 minutes or more and 7 minutes or less, it is possible to prevent the leafy vegetables from being damaged as compared with the case where the washing time is set to another time. Also by this, it can suppress that the commercial value of the leafy vegetable several days after washing | cleaning falls.

  According to the present invention, leafy vegetables are defined as mizuna. In the active ingredient washing process, the mizuna is washed for 4 minutes to 7 minutes in a sodium hypochlorite aqueous solution having a temperature of 43 degrees Celsius or more and less than 46 degrees Celsius. Thereby, the temperature and washing time of the sodium hypochlorite aqueous solution in the raw material washing step can be made particularly suitable for mizuna. Therefore, compared with the case where the conditions regarding temperature and time are set to other conditions, the commercial value of mizuna after several days have passed since washing can be improved.

  According to the present invention, leafy vegetables are defined as lettuce. In the raw material washing step, lettuce is washed in a sodium hypochlorite aqueous solution having a temperature of 40 degrees Celsius or more and less than 44 degrees Celsius for a washing time of 2 minutes or more and 6 minutes or less. As a result, the temperature and the washing time of the sodium hypochlorite aqueous solution in the raw material washing step can be made particularly suitable for lettuce washing. Therefore, the commercial value of lettuce after several days after washing can be improved as compared with the case where conditions relating to temperature and time are set to other conditions.

  Moreover, according to this invention, a leaf vegetable is wash | cleaned in the sodium hypochlorite aqueous solution whose temperature is 42 degreeC or more and 44 degrees C or less in the washing | cleaning process after cutting | disconnection. Thereby, the food texture of leafy vegetables can be improved. Moreover, the cut surface of the leafy vegetable formed by the cutting process can be efficiently washed. Therefore, the number of bacteria attached to the leafy vegetables after several days after the completion of washing can be reduced as compared with the case where a washing step at room temperature is performed after cutting.

  Further, according to the present invention, the body cleaning process includes a reciprocating swinging stage. In the reciprocating rocking stage, the leafy vegetables are reciprocally displaced in the sodium hypochlorite aqueous solution. By this, compared with the case where it wash | cleans in the state which does not move by being immersed, sodium hypochlorite can be made to approach between the leaf of leafy vegetables, and it can wash | clean efficiently. Therefore, the reduction of bacteria by washing can be ensured, the quality after washing can be made constant, and the commercial value of leafy vegetables can be prevented from decreasing even after several days have passed since washing. can do.

It is a flowchart showing each process of the washing | cleaning method of the vegetable which concerns on 1st Embodiment of this invention. It is a flowchart showing each step | level of the raw material washing | cleaning process which concerns on 1st Embodiment of this invention. It is a figure showing the number of bacteria immediately after washing | cleaning in 1st Embodiment of this invention and a comparative example. It is a figure showing the number of bacteria after 72 hours in 1st Embodiment of this invention and a comparative example. It is a figure showing the judgment result of the merchandise value after 72 hours in 1st Embodiment and a comparative example of this invention. It is a figure showing the typical mizuna with commercial value and the typical mizuna without commercial value. It is a flowchart showing each process of the washing | cleaning method of the vegetable which concerns on 2nd Embodiment of this invention. It is a figure showing the number of bacteria immediately after washing | cleaning in 2nd Embodiment and a comparative example of this invention. It is a figure showing the number of bacteria after 72 hours in 2nd Embodiment of this invention and a comparative example. It is a figure showing the judgment result of the merchandise value after 72 hours in 2nd Embodiment and a comparative example of this invention. It is a figure showing the typical lettuce leaf which has commercial value, and the typical lettuce leaf which lowers commercial value.

  Hereinafter, a plurality of embodiments for carrying out the present invention will be described with reference to the drawings. In the description of the second and subsequent embodiments, overlapping descriptions may be omitted for portions corresponding to matters already described in the preceding embodiment. When only a part of the configuration is described, the other parts of the configuration are the same as those described in the preceding section. In addition to the combination of parts specifically described in each embodiment, the embodiments may be partially combined as long as the combination does not hinder. Moreover, each embodiment is illustrated in order to embody the technique which concerns on this invention, and does not limit the technical scope of this invention. The technical contents according to the present invention can be variously modified within the technical scope described in the claims.

(First embodiment)
FIG. 1 is a flowchart showing each step of the vegetable cleaning method according to the first embodiment of the present invention. The vegetable washing method according to the first embodiment is a method for washing leafy vegetables in particular. When a leafy vegetable in a cut state is shipped as a raw material such as a salad to a retail store such as a supermarket or a convenience store, the vegetable needs to be washed. In convenience stores and the like, a standard is set for the number of bacteria when 72 hours have passed after washing in consideration of the time taken for distribution and display and the time from purchase to consumption.

  As for the sanitary norms of bento boxes and prawns, it is recommended to store sozai under temperature conditions of less than 10 degrees Celsius or greater than 65 degrees Celsius as a notice of the Director of Food Sanitation of the Ministry of Health and Welfare. It is recommended that the number of living bacteria per gram of specimen (grams, abbreviation “g”) be 1 million or less for unheated vegetables such as vegetables. The standards adopted by convenience stores are also set accordingly. For fresh vegetables, the number of bacteria after washing for 72 hours under conditions of 10 degrees Celsius or less after washing is 1 million or less. It is demanded. Furthermore, those having a bacterial count of 100,000 or less under the same conditions are often placed in a high rank as the level of commercial value. Hereinafter, “° C.” is used as a unit of temperature in Celsius.

  The vegetable washing method includes an active ingredient washing process, a cutting process, a washing process after cutting, and a rinsing process. In the active ingredient washing process, the harvested leafy vegetables are washed without being cut. In the active ingredient washing step, the leafy vegetables are washed in a sodium hypochlorite aqueous solution having a temperature of 40 ° C. or higher and lower than 46 ° C. for a washing time of 2 minutes or more and 7 minutes or less. In the cutting step, the leafy vegetables washed in the active ingredient washing step are cut. In the washing process after cutting, the leafy vegetables cut in the cutting process are washed in an aqueous sodium hypochlorite solution. In the rinsing process, the leafy vegetables washed in the washing process after cutting are rinsed with water.

  In the first embodiment, leafy vegetables are defined as mizuna 10. In the raw material washing step, the mizuna 10 is washed in a sodium hypochlorite aqueous solution having a temperature of 43 ° C. or higher and lower than 46 ° C. for a washing time of 4 minutes or more and 7 minutes or less. The body cleaning process includes a reciprocating rocking stage and a rocking stop stage. In the reciprocating rocking stage, the leafy vegetables are reciprocally displaced in the sodium hypochlorite aqueous solution. In the rocking stop stage, the leafy vegetables are put into a rocking stop state in the sodium hypochlorite aqueous solution. The swing stop state is a state where the swing is stopped.

  In the first embodiment, harvested leafy vegetables that are not cut with a blade or fingers on the leaves, stems, and flower parts are referred to as “original”. The root may be cut with a blade or fingers. In the vegetable cleaning method according to the first embodiment, leafy vegetables purchased at a supermarket are targeted for cleaning. In the supermarket, the original leafy vegetables are arranged within 2 days after harvest. Also in the present embodiment, leafy vegetables purchased at a supermarket and within 2 days from harvest were targeted for washing.

  As shown in FIG. 1, after the start of this process, the process proceeds to the water washing step of step a <b> 1, and the mizuna 10 is washed with water. In the water washing step, in this embodiment, 150 g of mizuna 10 is performed using a trough having a diameter of 30 centimeters (abbreviated as “cm”). Swing Mizuna 10 up and down in the water in the tub. The temperature of water was about 12 ° C to 15 ° C. Although browning does not occur in the washing process, if a browned part is already found, it is removed in the washing process. In the comparative example, in the measurement of the number of bacteria, the number of bacteria when the washing time is zero minutes is measured for leafy vegetables after washing with water.

  Next, the process proceeds to the original cleaning process of step a2, and the original washed by the washing and washing process is washed. The solution used for washing is a sodium hypochlorite aqueous solution, and the concentration of sodium hypochlorite is 200 mg / liter (mg / L). Hereinafter, the unit of liter (liters) of the physical quantity is represented by the abbreviation “L”. In the raw material washing process in the first embodiment, 150 g of mizuna 10 is washed in a 12 L sodium hypochlorite aqueous solution. Hereinafter, the sodium hypochlorite aqueous solution may be simply referred to as “aqueous solution”.

  FIG. 2 is a flowchart showing each stage of the drug substance cleaning process according to the first embodiment of the present invention. The body cleaning process is performed in a constant temperature bath with a gentle flow for temperature adjustment. In the raw material cleaning process, first, the process proceeds to the reciprocating swinging step of step b1, and the mizuna 10 is swung up and down in the aqueous solution for 30 seconds. The swing is one reciprocation every 2 seconds. The flow of the aqueous solution is not so fast as to damage the vegetable raw material, but is a gentle flow for temperature adjustment. By swinging, a relative displacement between the aqueous solution and the active ingredient occurs, and the aqueous solution enters between the leaves of the active ingredient. This allows sodium hypochlorite to come into contact with bacteria adhering to the drug substance and reduce the number of bacteria.

  Next, the process proceeds to the swing stop stage of step b2, and the base body is stopped swinging for 30 seconds. In the oscillation stop stage, there is no relative displacement between the solution and the original material, and the original material is in an oscillation stop state in which the oscillation is stopped. Even in the rocking stop state, as in the reciprocating rocking stage, the bacteria attached to the drug substance are in contact with the sodium hypochlorite aqueous solution and are sterilized by sodium hypochlorite. Next, the process proceeds to the repetition stage of step b3, and the reciprocating rocking stage of step b1 and the rocking stop stage of step b2 are repeated. Then, according to the washing | cleaning time in an original substance washing | cleaning process, an original substance washing | cleaning process is complete | finished by complete | finishing the repetition step of step b3.

  Next, the process proceeds to the cutting process of step a3 shown in FIG. The original material is cut using a blade, and the original material is cut into a size of about 5 cm. Next, it transfers to the washing process after cutting | disconnection of step a4, and the cut leafy vegetables, ie, the mizuna 10, are washed. In the washing process after cutting, the leafy vegetables are washed in an aqueous sodium hypochlorite solution having a temperature of 42 ° C. or higher and 44 ° C. or lower. Specifically, the set temperature is set to 43 ° C., and washing is performed while stirring with a stirring rod for 2 minutes. The post-cutting cleaning step is performed in a 3 L thermostat.

  Next, the process proceeds to the rinsing process of step a5, and rinsing with water is performed. The water used in the rinsing step has a temperature of 10 ° C. or more and 15 ° C. or less, and is performed with 5 L of water. In the rinsing step, stirring is performed with a stirring rod. The water temperature in the washing step and the rinsing step may vary depending on the season. The water temperature in the washing step and the rinsing step is preferably 10 ° C. or lower, but the temperature may not be adjusted and may be carried out in a bucket.

  Next, it transfers to the dehydration process of step a6, and spin-drying | dehydration of the leafy vegetable which was processed by the rinse process is performed for 30 seconds. This is done by putting it in a rotating cake with a diameter of 25 cm and rotating the rotating cake. The power is manual and the maximum rotation speed is 600 rpm. Thereafter, the processing related to the vegetable cleaning method is completed.

  FIG. 3 is a diagram showing the number of bacteria immediately after washing in the first embodiment and the comparative example of the present invention. In FIG. 3, the horizontal axis represents the cleaning time in the active ingredient cleaning step, and the vertical axis represents the number of bacteria in logarithm. Of the polygonal lines shown in FIG. 3, the result of performing the body cleaning process at 40 ° C. is represented as a first polygonal line 11. Similarly, the result at 42 ° C. is represented as the second broken line 12, the result at 43 ° C. is represented as the third broken line 13, the result at 45 ° C. is represented as the fourth broken line 14, and the result at 47 ° C. is represented as the fifth broken line 15. . Regarding the washing of mizuna 10, the number of bacteria immediately after washing was the largest, and the result was the largest in the range from 42 ° C. to 47 ° C.

  FIG. 4A is a diagram showing the number of bacteria after 72 hours in the first embodiment and the comparative example of the present invention. FIG. 4B is a diagram illustrating a determination result of a commercial value after 72 hours in the first embodiment and the comparative example of the present invention. The washed vegetables are stored under a temperature condition of 10 ° C. In FIG. 4A, the polygonal line represents the bacterial count and corresponds to the left logarithmic scale. The bar graph shown as FIG. 4B represents the determination result of the merchandise value and corresponds to the right scale. In FIG. 4A and FIG. 4B, the horizontal axis represents the cleaning time in the drug substance cleaning step. The storage for 72 hours was performed under a temperature condition of 10 ° C. Of the polygonal lines shown in FIG. 4A, the result of performing the body cleaning process at 40 ° C. is represented as a sixth polygonal line 16. Similarly, the result at 42 ° C. is represented as the seventh broken line 17, the result at 43 ° C. is represented as the eighth broken line 18, the result at 45 ° C. is represented as the ninth broken line 19, and the result at 47 ° C. is represented as the tenth broken line 20. .

  Regarding the washing of mizuna 10, the results at 43 ° C and the results at 45 ° C are the best when comparing the number of bacteria after 72 hours. The results when the washing time is 4 minutes or more and the results when the washing time is 7 minutes or less It became the result showing that it was the number of bacteria less than 1 million. The results of washing the base material at 47 ° C. for 10 minutes also showed that the number of bacteria was small. Next, regarding the determination of the commercial value, conditions excluding the conditions regarding the number of bacteria will be described.

  FIG. 5 is a diagram illustrating a typical mizuna 10 having a commercial value and a typical mizuna 10 that lowers the commercial value. FIG. 5 shows the mizuna 10 after being cut in the cutting step. FIG. 5A shows a green mizuna 10 in which the leaves are not rounded and browning and blackening are not observed. This is a typical mizuna 10 with commercial value. Originally green leafy vegetables that are damaged by washing and turn brown are called “browning”, and those that turn black are called “blackening”. FIG.5 (b) represents the mizuna 10 in which the blackened part is seen centering on a leaf vein, although a leaf does not become round. FIG.5 (c) represents the mizuna 10 in which the black turn was not seen but the leaf was rounded. FIG.5 (d) represents the mizuna 10 in which a leaf becomes round and blackening is seen as a whole. In the case of blackening, there may be a case where the whole is not completely black but changes to gray. The mizuna 10 represented by FIG.5 (b)-(d) is the typical mizuna 10 which reduces a commercial value.

  The judgment result of the merchandise value shown in FIG. 4B is a result of judgment based on how many times the leafy vegetables in the experiment had the merchandise value after performing the experiment related to the vegetable washing method ten times. After washing in each experiment, in the obtained mizuna 10, as shown in FIGS. 5B and 5D, if there is at least one mizuna 10 in which blackening is observed, the mizuna obtained in that experiment 10 determines that “there is no merchandise value” as the merchandise value judgment result. Furthermore, if even a single leaf in which the blackened portion is seen in an area exceeding 5% of the area of one leaf is judged as “no commercial value”, it is determined.

  When the mizuna 10 shown in either of FIGS. 5 (b) and 5 (d) is not seen and the round mizuna 10 as shown in FIG. If it is within 30%, it is determined that “there is commercial value”, and if it exceeds 30%, it is determined that “there is no commercial value”. The experimental result when it is not determined that there is no “commercial value” based on such a determination criterion is determined as “commercial value is present”. In FIG. 4B, among the mizuna 10 obtained in 10 experiments, the number of times judged as “commercial value” is shown above the horizontal axis, and the number of times judged as “no commercial value” is , Shown below the horizontal axis.

  FIG. 4B shows a result when the cleaning time is 3 minutes, a result when the cleaning time is 5 minutes, and a result when the cleaning time is 10 minutes. The results when the cleaning times are the respective times are shown side by side in FIG. 4B for convenience. The results arranged side by side for each cleaning time show the difference in temperature of the aqueous solution in the raw material cleaning step, and do not show the difference in time. In the bar graph shown in each cleaning time of FIG. 4B, the leftmost first region 21 represents the result when the temperature of the aqueous solution in the raw material cleaning step is 40 ° C., and is the second second region from the left. 22 shows the result when 42 ° C., the third region 23 in the center is 43 ° C., the fourth region 24 second from the right is 45 ° C., and the fifth region 25 on the right is 47 ° C.

  As shown in FIG. 4B, if the temperature of the aqueous solution in the bulk cleaning process is set to less than 46 ° C., cleaning can be performed with almost no loss of commercial value. More specifically, it was clearly shown that commercial value was maintained below 45 ° C. On the other hand, if the temperature is set to 47 ° C., the commercial value after 72 hours after the cleaning is often lost. The commercial value after 72 hours when the temperature is set to 47 ° C. varies depending on the cleaning time in the active ingredient cleaning process. However, in the experiment of about 20% when the cleaning time is 3 to 5 minutes, The mizuna 10 that lost its value was observed, and when the washing time was 10 minutes, the mizuna 10 that lost its commercial value was observed in all experiments.

  Judging from the results relating to the temperature when washing the mizuna 10 from FIG. 4A, the temperature of the aqueous solution in the bulk cleaning process is preferably 43 ° C. or higher. Moreover, when the result regarding the temperature at the time of washing | cleaning is judged from FIG. 4B, it is preferable that it is less than 46 degreeC. That is, by setting the temperature setting in the washing process of mizuna 10 to 43 ° C. or higher, the increase in the number of bacteria in 72 hours after washing is efficiently suppressed, and by setting it below 46 ° C., 72 hours after washing. It is possible to prevent the commercial value from being lost by the appearance.

  3 and 4A, the number of bacteria represents an average of a plurality of experimental results when a plurality of experiments are performed under the same conditions. In all vegetables including mizuna 10, there are individual differences in the number of bacteria, and it cannot always be said that it is within a certain range. In the experiment, the mizuna 10 purchased at the supermarket is used to perform a water washing process, and further, the water rinsing 10 that is judged to lower the commercial value according to the same standard as described above in the water washing process is removed, thereby reducing individual differences. ing.

  About the washing | cleaning time in an active ingredient washing | cleaning process, the lower limit of the range defined as suitable was judged from the experimental result which performed washing | cleaning time for 3 minutes, and the experimental result which carried out washing | cleaning time for 5 minutes. Moreover, the upper limit of the range determined to be suitable for the cleaning time was judged from the experimental results of the cleaning time of 5 minutes and the experimental results of 10 minutes. By setting the washing time to be 4 minutes or more and 7 minutes or less in a temperature range of 43 ° C. or more and less than 46 ° C., the number of bacteria after 72 hours after washing satisfies the standard of 1 million or less per 1 g of vegetables. it can.

  The number of bacteria was measured by a medium method for counting the number of bacteria generated by culturing. It measured using the material for bacteria count measurement called "BACcT (bakkut)". Specifically, a medium called Petrifilm (trade name of 3M) was used. As a procedure, 45 ml (milliliters, abbreviation “mL”) of sterilized water is added to 5 g of randomly picked vegetables and ground for 1 minute. This can be interpreted as a 10-fold dilution. This is used as it is, or diluted with sterilized water 10 times, 100 times or 1000 times. 1 mL of the liquid diluted 10 times or more is collected and cultured in a medium.

  About general viable bacteria, the produced fungal group (colony) is counted after storage at 35 ° C. for 48 hours. The coliform group was measured by culturing at 35 ° C. for 24 hours using a medium for coliform group, but the coliform group was not detected in all experiments. The bacterial group after culturing is visible, and if the dilution factor is selected, each bacterial group is dispersed on the medium independently, and can be counted. The number of bacterial groups after culture can be interpreted as the same as the number of bacteria before culture.

  When the general viable bacteria are stored under conditions of 5 ° C. or lower, the rate of increase is much slower than when stored under temperature conditions of 5 ° C. or higher. However, in the distribution of products including vegetables from the production area to the consumption area, if the temperature condition is adjusted to 5 ° C or lower and transported, it is difficult to reliably control the temperature condition in units of 1 ° C. It may be below ℃ and may freeze. Therefore, it is often conveyed at a temperature setting of 10 ° C. during distribution. Also in the experiment for confirming the effect by this embodiment, the preservation | save of the vegetable after washing | cleaning was performed on 10 degreeC temperature conditions.

  If the vegetables are simply washed with water in the range of 10 ° C. to 30 ° C., the number of bacteria increases at 10 ° C., and the number of bacteria after 72 hours achieves the standard of 1 million or less per 1 g of vegetables. It is not possible. Also, this standard cannot be achieved by using an aqueous sodium hypochlorite solution. On the other hand, in the vegetable cleaning method according to the present embodiment, a sodium hypochlorite aqueous solution is used, the temperature and time in the cleaning are controlled, and both the raw material cleaning and the cleaning after cutting are performed. Even when stored under the temperature condition of ° C., the above criteria can be satisfied for the number of bacteria after 72 hours.

  In the cleaning of the active ingredient, the vegetable is reciprocally swung in the aqueous solution. As a result, compared to water flow stirring and stirring by bubbling, the vegetables are less damaged, and the reciprocating rocking motion allows the aqueous solution to contact the vegetables efficiently, washing away live bacteria adhering to the surface, or sterilizing. In addition, the number of bacteria can be reduced. For example, if the water body stirring or stirring with a stirring rod is performed in the raw material washing process, leafy vegetables having a long shape like the mizuna 10 are tangled with each other and damaged. On the other hand, since the contact between the vegetable surface and the aqueous solution is achieved by reciprocating rocking motion for cleaning the active ingredient, it is possible to achieve both effective suppression of damage and efficient sterilization.

  According to the first embodiment, the harvested leafy vegetables are washed without cutting in the active ingredient washing process. In the active ingredient washing step, the leafy vegetables are washed in a sodium hypochlorite aqueous solution having a temperature of 40 ° C. or higher and lower than 46 ° C. for a washing time of 2 minutes or more and 7 minutes or less. In the washing process after cutting, the leafy vegetables cut in the cutting process are washed in an aqueous sodium hypochlorite solution. This makes it possible to efficiently reduce the number of bacteria attached to leafy vegetables that are objects to be cleaned. By performing the active ingredient washing process before the cutting process, the bacteria attached to the surface of the leafy vegetables are washed away, the bacteria are damaged, and the number of bacteria is reduced. It is possible to reduce the number of bacteria that invade inside or between cells of leafy vegetables from the cut surface.

  By setting the temperature condition to 40 ° C. or more and less than 46 ° C., it is possible to suppress the reduction in the commercial value of leafy vegetables even after several days have passed since washing, compared to the case where washing is performed in other temperature ranges. it can. Moreover, compared with the case where it wash | cleans in normal temperature sodium hypochlorite aqueous solution, the food texture of leafy vegetables can be improved. By setting the washing time to 2 minutes or more and 7 minutes or less, it is possible to prevent the leafy vegetables from being damaged as compared with the case where the washing time is set to another time. Also by this, it can suppress that the commercial value of the leafy vegetable several days after washing | cleaning falls.

  Moreover, according to 1st Embodiment, leafy vegetables are defined as the mizuna 10. In the raw material washing step, the mizuna 10 is washed in a sodium hypochlorite aqueous solution having a temperature of 43 ° C. or higher and lower than 46 ° C. for a washing time of 4 minutes or more and 7 minutes or less. Thereby, the temperature and washing time of the sodium hypochlorite aqueous solution in the raw material washing process can be made particularly suitable for the mizuna 10. Specifically, according to the above-described configuration, the number of bacteria when stored for 72 hours under a temperature condition of 10 ° C. can be 1 million or less per 1 g, and the commercial value can be maintained. Therefore, the commercial value of the mizuna 10 after several days after washing | cleaning can be improved compared with the case where the conditions regarding temperature and time are set to other condition content.

  According to the first embodiment, the body cleaning process includes a reciprocating swinging stage. In the reciprocating rocking stage, the leafy vegetables are reciprocally displaced in the sodium hypochlorite aqueous solution. By this, compared with the case where it wash | cleans in the state which does not move by being immersed, sodium hypochlorite can be made to approach between the leaf of leafy vegetables, and it can wash | clean efficiently. Therefore, the reduction of bacteria by washing can be ensured, the quality after washing can be made constant, and the commercial value of leafy vegetables can be prevented from decreasing even after several days have passed since washing. can do.

  In particular, when the target of washing is mizuna 10, even if washing is performed in the range of 12 ° C to 15 ° C, or more widely in the range of 10 ° C to 30 ° C, the number of bacteria after 72 hours after washing is efficiently reduced. It was difficult to do, and the mizuna 10 was a washing target in which it was difficult to reduce the number of bacteria compared to other vegetables. On the other hand, in this embodiment, it is set as the structure containing the stepwise washing | cleaning of washing twice as it wash | cleans with an original substance, cut | disconnects, and wash | cleans again, and also by setting temperature and time conditions, In contrast, the number of bacteria can be efficiently reduced.

  Moreover, by setting the temperature condition to 43 ° C. or higher, the number of bacteria can be reduced as compared with the case where washing is performed at a temperature lower than 43 ° C., and the texture after washing can be increased. The texture means, for example, a salad or the like and a crispy texture, and in this sense, the commercial value can be improved.

  For example, in the conventional technique, vegetables may be washed using a detergent in a liquid at 47 ° C. However, with such conventional techniques, it is impossible to control the number of bacteria for a long time and maintain the commercial value in washing mizuna. In particular, mizuna is a vegetable that is difficult to reduce the number of bacteria among other common leafy vegetables. On the other hand, in this invention, by using the sodium hypochlorite aqueous solution of 43 degreeC or more and less than 46 degreeC, it wash | cleans by the washing | cleaning method of the vegetable including an active ingredient washing | cleaning process and the washing | cleaning process after a cutting | disconnection efficiently, The number can be reduced and the commercial value can be maintained for a long time.

(Second Embodiment)
FIG. 6 is a flowchart showing each step of the vegetable cleaning method according to the second embodiment of the present invention. The vegetable cleaning method according to the second embodiment is similar to the vegetable cleaning method according to the first embodiment. Hereinafter, the difference between the second embodiment and the first embodiment will be mainly described. In 2nd Embodiment, leafy vegetables are defined as lettuce. In the drug substance washing step, lettuce is washed in a sodium hypochlorite aqueous solution having a temperature of 40 ° C. or higher and lower than 44 ° C. for a washing time of 2 minutes or more and 6 minutes or less.

  In the present embodiment, lettuce includes a plurality of types classified and distinguished. In the second embodiment, the lettuce includes at least a head lettuce and a non-head lettuce. The heading lettuce is spherically shaped, and the non-heading lettuce has a broader leaf shape than the heading lettuce. Non-headed lettuce is sometimes called leaf lettuce.

  As shown in FIG. 6, in the vegetable washing method for lettuce, the water washing step as in step a1 in FIG. 1 can be omitted. The process proceeds to the original material washing step of step c1, and the original substance is washed. At this time, lettuce is washed in units of one ball. The concentration of the sodium hypochlorite aqueous solution is 200 mg / L as in the first embodiment, and a 12 L thermostatic bath is used. In the reciprocating rocking stage, the base material is rocked at a reciprocating speed of 1 every 2 seconds, and then the rocking stopping stage for 30 seconds is performed after the reciprocating rocking stage for 30 seconds. In the reciprocating swinging stage, the direction in which the base body is swung is the vertical direction. In the bulk cleaning process including the reciprocating swinging stage, it is preferable to clean under the liquid level without exposing the lettuce above the liquid level.

  Next, it moves to the cutting process of step c2, and cut | disconnects to a magnitude | size about 5 cm. This means that lettuce in a spherical shape is cut with a blade without peeling off the leaves one by one, and the size is about 5 cm. Next, the process proceeds to a cleaning process after cutting in step c3, and the cut lettuce is cleaned. In this step, lettuce is washed in a sodium hypochlorite aqueous solution having a temperature of 42 ° C. or higher and 44 ° C. or lower. Specifically, the target temperature is set to 43 ° C., and washing is performed while stirring with a stirring rod for 2 minutes. The post-cutting cleaning step is performed in a 3 L thermostat.

  Next, the process proceeds to a rinsing process in step c4, and rinsing with water is performed. The temperature of water used in the rinsing step is set to 10 ° C. or more and 15 ° C. or less, and 5 L of water is used. In the rinsing step, stirring is performed with a stirring rod. In this step, the water temperature may vary depending on the season. The water temperature in the rinsing step is preferably 10 ° C. or lower, but it can also be carried out in a bucket without adjusting the temperature. Next, the process proceeds to the dehydration process of step c5, and the leafy vegetables that have been rinsed in the rinse process are dehydrated for 30 seconds. This is the same as in the first embodiment, and the maximum rotation speed is set to 600 rotations per minute using a rotation pin. Then, the process which concerns on the washing | cleaning method of the vegetable of this embodiment is complete | finished.

  FIG. 7 is a diagram showing the number of bacteria immediately after washing in the second embodiment and the comparative example of the present invention. In FIG. 7, the horizontal axis represents the cleaning time in the active ingredient cleaning step, and the vertical axis represents the number of bacteria in logarithm. Of the polygonal lines shown in FIG. 7, the result of performing the drug substance cleaning step at 36 ° C. is represented as an eleventh polygonal line 31. Similarly, the result at 38 ° C. is represented as the 12th broken line 32, the result at 40 ° C. is represented as the 13th broken line 33, the result at 42 ° C. is represented as the 14th broken line 34, and the result at 43 ° C. is represented as the 15th broken line 35. The results at 45 ° C. are represented as the 16th broken line 36, and the results at 47 ° C. are represented as the 17th broken line 37. When the number of bacteria immediately after washing was compared with respect to washing of lettuce, good results were obtained in the range of 40 ° C. or higher, and the results at 36 ° C. and 38 ° C. were results of many bacteria.

  FIG. 8A is a diagram showing the number of bacteria after 72 hours in the second embodiment of the present invention and the comparative example. FIG. 8B is a diagram illustrating a determination result of merchandise value after 72 hours in the second embodiment and the comparative example of the present invention. The results shown in FIG. 7, FIG. 8A, and FIG. 8B are the results of experiments that were conducted using a head lettuce as the lettuce. The washed vegetables are stored under a temperature condition of 10 ° C. In FIG. 8A, the polygonal line 38 represents the number of bacteria and corresponds to the logarithmic scale on the left. The bar graph shown as FIG. 8B represents the determination result of the merchandise value and corresponds to the right scale. 8A and 8B, the horizontal axis represents the cleaning time in the active ingredient cleaning process. The storage for 72 hours was performed under a temperature condition of 10 ° C. Of the polygonal lines shown in FIG. 8B, the result of performing the body cleaning process at 36 ° C. is represented as the eighteenth polygonal line 38. Similarly, the result at 38 ° C. is represented as the 19th broken line 39, the result at 40 ° C. is represented as the 20th broken line 40, the result at 42 ° C. is represented as the 21st broken line 41, and the result at 43 ° C. is represented as the 22nd broken line 42. The result at 45 ° C. is represented as a twenty-third line 43, and the result at 46 ° C. is represented as a twenty-fourth line 44.

  Comparing the number of bacteria after 72 hours for washing lettuce, the result at 42 ° C and the result at 43 ° C are the best, and the result when the washing time is 2 minutes or more and the result when the washing time is 6 minutes or less The result showed that the number of bacteria was less than 1 million. The results of washing the base material at 47 ° C. for 10 minutes also showed that the number of bacteria was small. Next, regarding the determination of the commercial value, conditions excluding the conditions regarding the number of bacteria will be described.

  FIG. 9 is a diagram illustrating a typical lettuce leaf having a commercial value and a typical lettuce leaf reducing the commercial value. FIG. 9 shows the leaves of lettuce after being cut in the cutting step. FIG. 9A shows a healthy leaf in which no browned portion is seen. This is a typical lettuce leaf with commercial value. FIG.9 (b) shows the lettuce leaf in which the part browned about 1-2% is seen. FIG.9 (c) shows the lettuce leaf in which the part browned about 5% is seen. FIG. 9 (d) represents a lettuce leaf in which browning is observed at an area ratio of about 50% of the leaf. The lettuce leaves shown in FIGS. 9C and 9D are lettuce that lowers the commercial value.

  The judgment result of the commercial value shown in FIG. 8B is a result of judgment based on how many times the leafy vegetables in the experiment had the commercial value after performing the experiment related to the vegetable washing method ten times. After washing in each experiment, if at least one portion of the obtained lettuce leaves browned by 5% or more in area ratio, the lettuce used in that experiment is judged to have no commercial value. The experimental result when it is not determined that there is no “commercial value” based on such a determination criterion is determined as “commercial value is present”. In FIG. 8B, among the lettuce obtained in 10 experiments, the number of times judged as “commercial value” is shown above the horizontal axis, and the number of times judged as “no commercial value” is Shown below the horizontal axis.

  FIG. 8B shows a result when the cleaning time is 1 minute, a result when the cleaning time is 3 minutes, a result when the cleaning time is 5 minutes, and a result when the cleaning time is 10 minutes. The results when the cleaning times are the respective times are shown side by side in FIG. 8B for convenience. The results arranged side by side for each cleaning time show the difference in temperature of the aqueous solution in the raw material cleaning step, and do not show the difference in time. Of the bar graph shown in each cleaning time of FIG. 8B, the leftmost sixth region 46 represents the result when the temperature of the aqueous solution in the bulk cleaning process is 36 ° C. Similarly, the seventh region 47 second from the left is 38 ° C., the eighth region 48 third from the left is 40 ° C., the ninth region 49 in the center is 42 ° C., and the tenth region 50 third from the right is The results show that when 43 ° C., the second eleventh region 51 from the right is 45 ° C., and the rightmost twelfth region 52 is 47 ° C.

  As shown in FIG. 8B, if the temperature of the aqueous solution in the bulk cleaning process is set to less than 44 ° C., cleaning can be performed with almost no loss of commercial value. More specifically, it was clearly shown that the commercial value was maintained below 43 ° C. On the other hand, the commercial value after 72 hours when the temperature is set to 45 ° C. varies depending on the cleaning time in the raw material cleaning process, but in the experiment of about 20% when the cleaning time is 5 minutes, Lettuce that drops in value is observed. When the temperature of the aqueous solution in the bulk cleaning process is set to 47 ° C., lettuce that loses commercial value is observed in about half of the experiments when the cleaning time is 5 minutes, and when the cleaning time is 10 minutes, In all experiments, lettuce had no commercial value.

  Judging from the results relating to the temperature at which the lettuce is washed from FIG. 8A, the temperature of the aqueous solution in the bulk washing process is preferably 40 ° C. or higher. Moreover, when the result regarding the temperature at the time of washing | cleaning is judged from FIG. 8B, it is preferable that it is less than 44 degreeC. That is, by setting the temperature setting in the lettuce washing step to 40 ° C. or higher, the increase in the number of bacteria in 72 hours after washing is efficiently suppressed, and by setting it to less than 44 ° C., the appearance is 72 hours after washing. Therefore, loss of commercial value can be prevented.

  About the washing | cleaning time in an active ingredient washing | cleaning process, the lower limit of the range set as suitable was judged from the experimental result which performed washing | cleaning time as 1 minute, and the experimental result which carried out washing | cleaning time for 3 minutes. Moreover, the upper limit of the range determined to be suitable for the cleaning time was judged from the experimental results of the cleaning time of 5 minutes and the experimental results of 10 minutes. By setting the washing time to be 2 minutes or more and 6 minutes or less in a temperature range of 40 ° C. or more and less than 44 ° C., the number of bacteria after 72 hours after washing satisfies the standard of 1 million or less per 1 g of vegetables. it can.

  About the number of bacteria, it measured by the same experiment as 1st Embodiment. In addition, in lettuce, the number of bacteria was measured using a medium and culture conditions suitable for each of general viable bacteria and coliforms. The coliform group was negative in all experiments, and the coliform group was not detected.

  According to the second embodiment, leafy vegetables are defined as lettuce. In the raw material washing step, lettuce is washed in a sodium hypochlorite aqueous solution having a temperature of 40 ° C. or more and less than 44 ° C. for a washing time of 2 minutes or more and 6 minutes or less. As a result, the temperature and the washing time of the sodium hypochlorite aqueous solution in the raw material washing step can be made particularly suitable for lettuce washing. Specifically, according to the above-described configuration, the number of bacteria when stored for 72 hours under a temperature condition of 10 ° C. can be 1 million or less per 1 g, and the commercial value can be maintained. Therefore, the commercial value of lettuce after several days after washing can be improved as compared with the case where conditions relating to temperature and time are set to other conditions.

  Moreover, also in the lettuce which was made into the washing | cleaning object in 2nd Embodiment, a food texture can be improved similarly to the mizuna 10 by applying the vegetable washing | cleaning method in this embodiment.

  As shown in FIG. 4A and FIG. 8A, in the experimental results including the first and second embodiments, when the washing time is 5 minutes and 10 minutes, the number of bacteria after 72 hours is Even when the washing time was increased to 10 minutes, it was observed depending on the temperature conditions. About this reason, the chemical change by the cell wall and cell membrane of leafy vegetables being broken may be contributing as one of the factors. However, since the results as described above and the average results shown in FIGS. 4A and 8A are obtained as a whole, the difference in the number of bacteria due to the difference in temperature conditions and the difference in washing time can be said to be an error. It is not a thing.

  The amount of the aqueous solution used in each step of the vegetable cleaning method according to the first and second embodiments, the apparatus, the concentration of sodium hypochlorite in the aqueous solution, and the like are not limited to the above-described configuration. For example, the present invention can be implemented on a larger or smaller scale than the above-described configuration, and an apparatus different from the apparatuses described in the first and second embodiments can be used.

  In the raw material washing process in the first and second embodiments, the leafy vegetable raw material is reciprocally swung in the reciprocating rocking stage, but the aqueous solution in which the leafy vegetable is immersed in the raw material washing process is stirred. This means is not limited to the reciprocating rocking motion. If the aqueous solution can be stirred without damaging the leafy vegetables, in other embodiments, for example, stirring may be performed by gentle water flow, stirring by bubbling, or reciprocating rocking motion, water flow May be agitation by means of a combination of any two or more of agitation and bubbling.

  The vegetable washing method according to the first and second embodiments is intended for washing mizuna and lettuce. However, in the vegetable washing method according to other embodiments, spinach and green onions should be washed. Can do. Even in these leafy vegetables, the number of bacteria and the maintenance of commercial value are maintained by using a sodium hypochlorite aqueous solution in the temperature range of 40 ° C. or higher and lower than 46 ° C. and by setting the washing time to 2 minutes or more and 7 minutes or less. Can be made compatible. This has been confirmed by experiments similar to those in the first and second embodiments.

10 Mizuna 30 Lettuce

Claims (5)

It is an active ingredient cleaning process for cleaning the active ingredients of leaf vegetables that have not been cut,
Ingredient washing process of washing the leafy vegetables in a sodium hypochlorite aqueous solution having a temperature of 40 degrees Celsius or more and less than 46 degrees Celsius for a washing time of 2 minutes or more and 7 minutes or less,
A cutting process for cutting the leafy vegetables washed in the active ingredient washing process;
A post-cutting washing step of washing the leafy vegetables cut in the cutting step in an aqueous sodium hypochlorite solution;
A method for washing vegetables, comprising: rinsing the leafy vegetables washed in the washing process after cutting with water. When the leafy vegetables are mizuna,
The said active ingredient washing | cleaning process WHEREIN: In the sodium hypochlorite aqueous solution whose temperature is 43 degreeC or more and less than 46 degreeC, the said mizuna is wash | cleaned for the washing | cleaning time of 4 minutes or more and 7 minutes or less. The cleaning method of the vegetables as described. When the leafy vegetable is lettuce,
The said active ingredient washing | cleaning process wash | cleans the said lettuce in 2 to 6 minutes washing time in the sodium hypochlorite aqueous solution whose temperature is 40 degreeC or more and less than 44 degree | times. The cleaning method of the vegetables as described.   The vegetable according to any one of claims 1 to 3, wherein the leafy vegetable is washed in a sodium hypochlorite aqueous solution having a temperature of 42 degrees Celsius or more and 44 degrees Celsius or less in the washing step after cutting. Cleaning method. The drug substance cleaning step includes
The vegetable washing method according to any one of claims 1 to 4, further comprising a reciprocating rocking step of reciprocally displacing the leafy vegetable in the aqueous sodium hypochlorite solution.