JP3660571B2 - Lettuce processing method and lettuce pickles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for treating lettuce and pickles of lettuce treated by this method.
[0002]
[Prior art]
In general, vegetables, or are used to eating raw as ingredients for the salad, have been or are used as processed foods as ingredients for pickles. Raw vegetables have many microorganisms attached and cause spoilage by microorganisms, so they cannot be stored for a long period of time, and if they are raw, a large amount of vegetables cannot be ingested at once.
[0003]
In order to prevent the decay of vegetables, add flavor, and make it easy to eat, vegetables are subjected to various treatments such as pickling. For example, microorganisms were killed by adding high-concentration salt to vegetables, or low-temperature treatment was performed, but it was technically difficult to make a low-salt pickle that could prevent spoilage.
[0004]
On the other hand, in order to prevent the decay of vegetables, attempts have been made to suppress the growth of microorganisms by high-temperature treatment. For example, the vegetables are heat-treated with steam at a temperature of 50 ° C. to 85 ° C. for 5 to 30 minutes to kill the microorganisms (see JP-A-6-169690), or the vegetables are placed in 10% to saturated saline at 45 ° C. From 10 to 50 minutes at a moderate temperature to reduce the number of microorganisms (see JP-A-8-289722) or boil vegetables at a temperature of 80 to 100 ° C. depending on the type Thus, it is in a semi-life state (see Japanese Patent Laid-Open No. 10-4872).
[0005]
However, these treatments can be suitably performed on leafy vegetables such as cabbage, Chinese cabbage, and Nozawana, but lettuce is a delicate vegetable that is significantly different from these leafy vegetables and changes color when salted. When the lettuce is heated, discoloration of the core becomes severe. Moreover, even if pickled by any method, a unique odor was generated, and therefore lettuce could not be used as a pickled.
[0006]
[Problems to be solved by the invention]
One problem to be solved by the present invention is to provide a method for treating lettuce that can be processed as a crunchy pickle without generating a unique smell of lettuce.
[0007]
Another problem to be solved by the present invention is to provide a crunchy lettuce pickle without generating a unique odor.
[0008]
[Means for Solving the Problems]
The first problem-solving means of the present invention is to heat the whole with the outer leaves and roots attached without cutting the lettuce, and the temperature of the outer periphery of the lettuce is 55 ° C to 60 ° C. Is maintained, and the temperature of the core is maintained for 3 to 10 minutes so that the temperature does not exceed 45 ° C., and then the heat-treated lettuce is cooled. There is.
[0009]
In the present invention, the lettuce processed by the first means for solving problems, after the outer leaves, remove roots, can be pickled in whole or cut was immersed in a predetermined liquid seasoning.
[0010]
In the first problem-solving means of the present invention, the heat treatment of lettuce can be performed by contacting hot salt water or a temperature seasoning liquid with the lettuce, and the subsequent lettuce cooling process is performed by using cold salt water or the cold seasoning liquid. It can be carried out in contact with heat-treated lettuce.
[0011]
The second problem solving means of the present invention is to provide a pickled lettuce processed by the first problem solving means. In this case, the thing processed by the 1st problem-solving means can be made into the pickle without seasoning (shallow pickle), and can be made into a seasoning pickle by being immersed in a seasoning liquid.
[0012]
In this way, the entire outer leaf and root portion is heated without cutting the lettuce to maintain the temperature of the outer periphery of the lettuce at 55 ° C. to 60 ° C., and the temperature of the core does not exceed 45 ° C. If the heat treatment is continued for 3-10 minutes in the range, and then this lettuce is cooled, a lettuce pickle with a chewy texture can be obtained without causing the distinctive smell of lettuce, discoloration and softening. it can.
[0013]
What should be noted is that the whole leaves and roots are heat-treated without cutting the lettuce, and if the lettuce is cut or the outer leaves or roots are removed, there is no odor. Can't get a crunchy pickle. This seems to be because the root part and the core part help to promote the treatment of the whole lettuce including the outer peripheral part of the lettuce during the heating and cooling treatment.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described in detail with reference to the drawings. An internal structure (cross-sectional structure) of a lettuce 10 is shown in FIG. It consists of an intermediate part 16 surrounding the core part and an outer peripheral part 18 around the intermediate part 16. Although the outer peripheral part 18 has touched soil and air directly and many microorganisms have adhered, since it is directly exposed to sunlight and air, it has the property to have high intensity | strength and heat resistance. On the other hand, since the core part 14 does not touch soil or air, the adhesion of microorganisms is relatively small, but since the growth points of lettuce are concentrated, the core part 14 is vulnerable to heat.
[0015]
In consideration of the characteristics of lettuce, the present invention kills microorganisms in the outer periphery of the lettuce and causes cell death by heat-treating the whole with the outer leaf and root attached without cutting the lettuce. It is to give lettuce a flavor without letting it go crunchy. In order to cause microbial death and cell death, the temperature of the outer periphery of the lettuce is maintained at a temperature of 55 ° C. to 60 ° C., and the heat treatment is continued in a range where the temperature of the core does not exceed 45 ° C. It is necessary to cool the lettuce, and details thereof will be described in detail with reference to FIG.
[0016]
A schematic method of the present invention is shown in FIG. 2, in which first lettuce is prepared (step 1), and this is washed to remove mud and soil (step 2). Thereafter, the lettuce is heated (step 3) and cooled (step 4) as described in detail below.
[0017]
The heat treatment is continued for a predetermined time in a range where the temperature of the outer peripheral portion of the lettuce is maintained at 55 ° C to 60 ° C and the temperature of the core portion does not exceed 45 ° C. The temperature of the outer peripheral portion of the lettuce, 55 ° C. to 60 ° C., is a temperature necessary for causing the death and cell death of microorganisms in the outer peripheral portion. Moreover, the temperature which does not exceed 45 degreeC which is the temperature of a core part is a temperature which a core part does not cause discoloration.
[0018]
The heating means includes (1) low-pressure steam generating means, (2) heated air generating means for heating air with appropriate means such as infrared rays and burners, (3) hot water generating means such as a boiler, and other appropriate means. be able to. In order to heat the lettuce by these heating means, it is preferable to let lettuce pass through the heating means by the conveyor conveying means. However, several lettuce may be brought into and out of the heating area.
[0019]
The low-pressure steam generating means and the heated air generating means can heat the lettuce by blowing steam or heated air into a heating region (for example, a heating tank) through which a conveyor on which lettuce is mounted can pass.
[0020]
Further, the warm water generating means may be one obtained by heating salt water or seasoning liquid in addition to pure water. Therefore, the warm water is not only pure warm water but also warm liquid such as warm salt water and temperature seasoning liquid. Including. This heat treatment with warm water can be performed by sprinkling water in the heating region or by bringing lettuce into the hot water tank supplied to the heating region and immersing it. Most preferred is a method of spraying warm water using a shower nozzle. Hot salt water containing about 5 to 10% by weight of salt is the optimum hot salt water in consideration of the heat transfer rate, controllability of humidity, and subsequent seasoning.
[0021]
When the above-mentioned warm salt water is used as the hot water, the time required for maintaining the temperature of the outer periphery of the lettuce at 55 ° C. to 60 ° C. and continuing the heat treatment in a range where the temperature of the core does not exceed 45 ° C. is 3 to 10 minutes.
[0022]
The heat-treated lettuce is then cooled as shown in step 4 to prevent the lettuce core temperature from rising too high. This cooling treatment can be performed with cooling air, cold water at 5 to 15 ° C. (including cold salt water containing about 1 to 5% by weight of salt, and cold liquid such as cold seasoning liquid). In the case of cold water, the cooling treatment time is 3 to 10 minutes.
[0023]
As shown in Step 5 of FIG. 2, the lettuce that has been heated and cooled using warm and cold salt water can be eaten as a shallow portion of low salt by removing the outer leaves and roots, but preferably As shown in Step 6 of FIG. 2, it can be dipped in a predetermined seasoning liquid and then packaged (see Step 7) for commercialization.
[0024]
As shown in Step 9 of FIG. 2, the heated and cooled lettuce, not the whole, can be cut and then immersed in the seasoning liquid (Step 6) and packaged (Step 7). The commodity is shipped to a predetermined demand place by chilled transportation (step 9).
[0025]
In the heat treatment process and the cooling process in steps 3 and 4, the seasoning liquid can be used by heating or cooling instead of the salt water. In this case, the seasoning liquid immersion process in step 6 can be omitted.
[0026]
Thus, when lettuce is heat-treated for a predetermined time so that the temperature of the outer peripheral part 18 of the lettuce 10 is maintained at a temperature of 55 ° C. to 60 ° C., the outer peripheral part of the lettuce is subjected to sterilization and cell death by this heat treatment. Happens at the same time. When cell death occurs, macromolecules such as intracellular starch, polyphenol, cellulose, and peptin are decomposed by the enzyme to give the lettuce a favorable flavor.
[0027]
Also, when cell death occurs, the microorganism usually starts to act immediately, but since there is no microorganism already, lettuce does not rot even at low salinity and can be kept for long-term storage.
[0028]
On the other hand, since the core part 14 of the lettuce 10 is maintained in a range not exceeding 45 ° C., since the heat treatment is hardly performed, it is in a raw state. Subsequent infiltration of the seasoning liquid gradually causes cell death, causing enzymatic degradation and changing to pickles.
[0029]
Since the intermediate portion 16 of the lettuce 10 has a temperature of 45 to 55 ° C., it becomes pickled while taking an intermediate behavior between the outer peripheral portion 18 and the core portion 14.
[0030]
In this way, lettuce pickles are produced, which does not produce the unique odor that occurs when produced in the same way as normal vegetable pickles, and gives a delicious flavor. Can maintain crunchiness.
[0031]
The work process from step 2 to step 4 in FIG. 2 can be sequentially performed along a series of flows of the conveyor conveying means for conveying lettuce. For example, a washing machine for washing lettuce can be arranged on the uppermost stream side of the conveyor conveying means, and a heat treatment machine and a cooling treatment machine can be arranged sequentially on the downstream side. In this case, the washing machine, the heat treatment machine, and the cooling treatment machine can all be a shower ring (spray) system.
[0032]
【Example】
Preferred embodiments of the invention are described below. In this example, lettuce pickles were produced based on the work process of FIG. 2, but the heat treatment and the cooling treatment were carried out using salt water, not pure water or seasoning liquid.
[0033]
For example, lettuce carried into the belt conveyor is first sent to a cleaning process, where mud and other impurities are removed in this cleaning process, and then sent to a heat treatment process. In this heat treatment step, lettuce passes while sprayed with 7 wt% saline heated to 55 ° C. to 60 ° C., and this transit time was about 5 minutes.
[0034]
After the heat treatment is performed, the lettuce is sent to a cooling step, in which 2% by weight saline solution cooled from 5 ° C. to 15 ° C. is sprayed. The passing time of this cooling step was about 5 minutes.
[0035]
After the heating and cooling processes are thus performed, the lettuce is shaped by cutting off its outer leaves and roots. Then, lettuce is sent to a seasoning liquid immersion process, and it is immersed in a seasoning liquid in this process. The seasoning liquid can be obtained, for example, in a weight ratio of “concentrated soaked seasoning liquid” 1 manufactured by Kawakami Co., Ltd., sodium glutamate 0.2, salt 0.9, and water 9.6. This seasoning liquid is used in a weight ratio of about 0.3 to 3, preferably about 0.5 to 2, with respect to lettuce. Finally, the seasoning liquid is packaged and shipped in chilled form. The ratio of lettuce and seasoning liquid during packaging is 1 / 0.5 to 1/1 in volume ratio.
[0036]
It replaces with said Example, After removing an outer leaf and a root part and shaping, lettuce can be immersed in the same conditions after cutting a lettuce into half cut or 1/4 cut. Thereafter, the cut lettuce can be packaged together with the seasoning liquid and shipped chilled.
[0037]
【The invention's effect】
According to the present invention, as described above, the entire outer leaf and root portion are heat-treated without cutting the lettuce to maintain the temperature of the outer periphery of the lettuce at 55 ° C to 60 ° C, and the core Heat treatment is continued for 3-10 minutes in a range where the temperature of the part does not exceed 45 ° C., and then this lettuce is cooled, so that it does not cause a unique odor of lettuce, nor causes discoloration and softening. You can get crunchy lettuce pickles.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of lettuce used in the production method of the present invention.
FIG. 2 is a block diagram showing work steps of the manufacturing method of the present invention in the order of steps.
[Explanation of symbols]
10 lettuce 12 root 14 core 16 intermediate 18 outer periphery

Claims (3)

The whole heat treatment with the outer leaves and roots attached without cutting the lettuce, the temperature of the outer periphery of the lettuce is maintained at a temperature of 55 ° C. to 60 ° C., and the temperature of the core is A method for treating lettuce, comprising performing 3 to 10 minutes so as to continue within a range not exceeding 45 ° C., and then cooling the lettuce. A lettuce obtained by the method for treating lettuce according to claim 1, wherein after removing the outer leaves and roots, the whole lettuce or cut and immersed in a predetermined seasoning liquid. A lettuce pickle produced by the method for treating lettuce according to claim 1 or 2 .

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