JP6905563B2 - How to manufacture washed baby leaf and how to reduce the number of washed baby leaf - Google Patents

Description

The present invention relates to a method for producing washed baby leaf and a method for reducing the number of bacteria in the washed baby leaf.

In recent years, ready-to-eat vegetables have become more popular, for example, leafy vegetables packed in bags or cups, cut vegetables, salads, and the like. This is because these products have already been washed and sterilized, which saves the trouble of washing.

However, ready-to-eat vegetables have various problems, such as disposal of unsold products and difficulty in controlling orders. The cause of these problems is that the ready-to-eat vegetables are fresh foods, so their consumption period is short.

Therefore, a technique for improving the expiration date of instant vegetables has been developed, and an example is as follows. Patent Document 1 discloses a method for preserving cut vegetables. Specifically, when storing cut vegetables, a bactericidal solution is attached and then washed with water.

Patent Document 2 discloses a method for producing leafy vegetables. Specifically, when the leaves are stored, a bactericidal solution is attached, the bactericidal solution is applied, and then the leaves are washed with water.

Japanese Unexamined Patent Publication No. 2004-655149 Japanese Unexamined Patent Publication No. 2008-237208

An object to be solved by the present invention is to reduce the number of bacteria in washed baby leaf.

The number of fungi in baby leaf is generally high after harvesting and after storage. Therefore, when producing washed baby leaf, it is important how to reduce the number of bacteria. Since it is a fresh food, it is not preferable to perform heat sterilization, and washing is an important step for reducing the number of bacteria.

In order to solve this problem, the present inventors diligently studied and discovered the relationship between the water adhesion rate of baby leaf and the effect of reducing the number of bacteria after washing. The present invention is defined from such a viewpoint as follows.

It is at least washing that constitutes the method for producing washed baby leaf according to the present invention. What is washed here is baby leaf, and the moisture adhesion rate of the baby leaf is 1.0% or less.

The method for producing washed baby leaf according to the present invention comprises at least water removal and washing. What is removed here is the water adhering to the baby leaf, and what is washed is the removed baby leaf.

In addition, the moisture adhesion rate of baby leaf obtained by water removal is preferably 1.0% or less, and water removal is carried out by drying after harvesting or by using a packaging material for transporting baby leaf after harvesting. It is preferably carried out by using a moisture absorbing material.

Then, the cleaning liquid used for washing, at least, preferably those containing hypochlorite or hypochlorite, water removal, and the number of bacteria mesclun obtained by washing, 1.0 × 10 ⁵ It is preferably CFU / g or less.

Furthermore, flow temperature zone washed mesclun produced by the present production method is a chilled zones, total viable count of 24 hours after the production of the washed mesclun produced is, 1.0 × 10 ⁶ It is preferably less than CFU / g.

It is at least washing that constitutes the method for reducing the number of bacteria in the washed baby leaf according to the present invention. What is washed here is baby leaf, and the moisture adhesion rate of the baby leaf is 1.0% or less. It is at least water removal and washing that constitute the method for reducing the number of bacteria in the washed baby leaf according to the present invention. What is removed here is the water adhering to the baby leaf, and what is washed is the removed baby leaf.

In addition, the moisture adhesion rate of baby leaf obtained by water removal is preferably 1.0% or less, and water removal is carried out by drying after harvesting or by using a packaging material for transporting baby leaf after harvesting. It is preferably carried out by using a moisture absorbing material.

Then, the cleaning liquid used for washing, at least, preferably those containing hypochlorite or hypochlorite, water removal, and the number of bacteria mesclun obtained by washing, 1.0 × 10 ⁵ It is preferably CFU / g or less.

Furthermore, flow temperature zone washed mesclun obtained by the present method is a chilled zones, total viable count of 24 hours after the production of the washed mesclun obtainable by this method, 1.0 × 10 ⁶ It is preferably less than CFU / g.

The mechanism by which the effects of the present invention are obtained is presumed to be as follows. By reducing the water adhering to the surface of baby leaf before cleaning the baby leaf, the cleaning solution having a bactericidal effect easily permeates the leaves, thereby enhancing the bactericidal effect.

What the present invention makes possible is to enhance the effect of reducing the number of bacteria during cleaning of baby leaf. By reducing the number of bacteria in baby leaf, the storage stability of washed baby leaf can be improved. Such washed baby leaf can be eaten without subsequent washing.

Flow chart of manufacturing method of washed baby leaf according to this embodiment Difference in the number of bacteria after washing depending on the presence or absence of water removal

<Baby leaf>
Baby leaf means leafy vegetables about 10 to 90 days after sowing. When the term "baby leaf" is used in the present application, the type of baby leaf does not matter, and specifically, one type of baby leaf or a mixture of several types of baby leaf may be used. The size of baby leaf varies depending on the type of plant and is not limited, but is 4 cm or more and 15 cm or less, preferably 12 cm or less, more preferably 10 cm or less from the viewpoint of ease of eating.

The plant used for baby leaf is not particularly limited as long as it is edible, and examples thereof include cruciferous, amaranthaceae, asteraceae, umbelliferae, liliaceae, and chenopodiaceae. Specific examples include sunny lettuce, green curl, salad na, mizuna, beet, mustard greens, green mustard, arugula, spinach, red mustard, romaine, red oak, tasoi, small red mustard, loro rossa, red Asian mustard, pino green, and white kale. , Red mustard, Detroit, Pakchoi, etc.

<Containered salad>
The packaged salad according to the present invention (hereinafter, referred to as “containered salad”) refers to a salad that is packaged and contains at least washed baby leaf. The temperature zone in which the packaged salad is distributed is preferably the so-called chilled (refrigerated) zone. The chilled zone is a distribution temperature zone, which is a temperature zone of 10 ° C. or lower that does not freeze. It is preferably 0 ° C to 10 ° C, more preferably 0 ° C to 5 ° C.

<Manufacturing method of washed baby leaf>
FIG. 1 shows the flow of a method for producing washed baby leaf. The manufacturing method of this baby leaf mainly consists of cultivation, harvesting (S10,) transportation (S20), sorting (S30), water removal (S40), washing (S50), water exposure (S60), and dehydration. Alternatively, it is dried (S70) and packed in a container (S80).

<Cultivation and harvesting (S10)>
The method of cultivating baby leaf is not particularly limited, and examples thereof include hydroponics, soil cultivation, open field cultivation, and cultivation in a closed plant factory. Hydroponics has the advantages of being less affected by the weather and having less bacterial adhesion. Cultivation in a closed plant factory is also preferable from the viewpoint of hygiene and stable production. Here, what is incorporated as a method for cultivating baby leaf and a method for producing baby leaf is the content described in JP-A-2017-060441.

Baby leaf cultivated in this way is harvested. The harvesting method is not particularly limited, and is, for example, a person, a machine, a combination thereof, or the like.

<Transportation (S20)>
One of the purposes of transporting harvested baby leaf is cleaning. The transportation method is not particularly limited, and is, for example, container packing, bag packing, cardboard packing, and the like. However, from the viewpoint of reducing the moisture adhesion rate of baby leaf, it is preferable to pack it in a packaging material having a dehumidifying effect during transportation. This can be substituted for the water removal step described later. In addition, the effect of reducing the number of bacteria during washing, which will be described later, is enhanced.

<Selection (S30)>
The criterion for selecting baby leaf is whether or not the baby leaf is damaged. Damaged means that the baby leaf (leaves and petioles) is broken, chipped, or cut, and the tissue structure inside the leaf is damaged. Some may not look good. Removing the baby leaf that is damaged by these will improve the appearance of the final product.

<Water removal (S40)>
The purpose of removing water from baby leaf is to enhance the effect of reducing the number of bacteria in the washing described later. For this purpose, the time to remove water is before cleaning. The method of removing water is not particularly limited, and is static, air blowing, cold air, hot air, centrifugation, suction by vacuum, use of a hygroscopic material, or a combination thereof. The water removal can be replaced by using a packaging material having a dehumidifying effect during transportation in the transportation. The target of water removal is not particularly limited, but preferably the water adhesion rate is 1.0% or less. As a result, the effect of reducing the number of bacteria by washing is enhanced.

<Washing (S50)>
The purpose of cleaning baby leaf is to remove foreign substances and reduce the number of bacteria. Examples of foreign substances are mud, soil, sand, etc. that adhere to baby leaf. The means for cleaning baby leaf is not particularly limited, but is preferably contact with sterilizing water. The method of contacting the liquid is not particularly limited, but examples thereof include immersion and spraying. The baby leaf is washed once or twice or more. The effect of the solution used for cleaning is to reduce the general viable cell count. Such a cleaning solution is not particularly limited, but for example, hypochlorous acid, hypochlorite, chlorite, sodium hydroxide, potassium hydroxide, calcined calcium, hydrochloric acid, acetic acid, peracetic acid, citric acid. , Fumaric acid, ozone and the like, preferably hypochlorous acid, hypochlorite, and chlorite. Preferred conditions for hypochlorous acid, hypochlorite, and chlorite are a concentration of 10 to 200 ppm and a pH of 4.8 to 8.0. The pH is more preferably 5.0 to 7.0. As a result, the effect of reducing the number of bacteria is enhanced.

<Liquid contact temperature>
When contacting the sterilizing water, the temperature of the sterilizing water is 0 ° C. to 30 ° C., preferably 0 ° C. to 20 ° C., more preferably 0 ° C. to 15 ° C., and most preferably. Is 0 to 10 ° C. If the temperature of the sterilized water is too high or too low, the damage to the baby leaf will be great. For example, the odor of sterilized water is likely to be attached, it is easy to wilt, and it is difficult to keep it for a long time.

<Liquid contact time>
The contact time is not particularly limited, but is 10 seconds to 60 minutes, preferably 10 seconds to 15 minutes, and most preferably 10 seconds to 10 minutes. If the contact time with sterilized water is too short, it is difficult to reduce the number of general viable bacteria. On the other hand, if the contact time is too long, the damage to baby leaf will increase.

<Water bleaching (S60)>
The purpose of exposing baby leaf to water is to remove the fungicide. That is, water exposure is required when the liquid is contacted with sterilized water. In other words, this step is appropriately omitted. The means of water exposure is not particularly limited, but is preferably immersion in water, spraying of water, or the like.

<Bleached water>
The bleached water is not particularly limited, but is, for example, tap water, well water, purified water, or the like. In addition, chlorine contained in water for which necessary sanitary measures have been taken (see Water Supply Law Enforcement Regulations (December 14, 1957, Ministry of Health and Welfare Ordinance No. 45)) is not subject to removal during water exposure. ..

<Water exposure temperature>
The temperature of water exposure is 0 ° C. to 30 ° C., preferably 0 ° C. to 20 ° C., and most preferably 0 ° C. to 10 ° C. If the treatment temperature of water exposure is too high or too low, the damage to baby leaf will increase.

<Water exposure time>
The water exposure time is not particularly limited, but is preferably 1 second to 60 minutes, more preferably 5 seconds to 30 minutes, and most preferably 10 seconds to 10 minutes. If the water exposure time is too short, the effect of removing the fungicide will be low. On the other hand, if the water exposure time is too long, the damage to baby leaf will increase.

<Dehydration or drying (S70)>
The purpose of dehydrating or drying the washed baby leaf is to improve the appearance of the washed baby leaf. The method of dehydration or drying is not particularly limited, and includes standing, blowing, cold air, hot air, centrifugation, suction by vacuum, use of a hygroscopic material, and a combination thereof. Considering the damage caused by the contact between baby leaves and the damage caused by the pressure caused by centrifugation, it is preferable to avoid centrifugation and dry by blowing air. The target of water removal is not particularly limited, but preferably the water adhesion rate is 3.0% or less. The details of the moisture adhesion rate will be described later.

<Packing (S80)>
Baby leaf is packed in a container. The packaging material used for packing the container is not particularly limited, but is a polyethylene bag, cup, or the like.

<Moisture adhesion rate>
The water adhesion rate of baby leaf is a value obtained by multiplying the amount of water attached to the leaves by the weight of the leaves after removing the water by 100. The specific method for measuring the moisture adhesion rate is as follows. The weight (A) of the leaf with water attached is measured. Then, the water adhering to the leaves is wiped off with a paper or the like that adsorbs the water, and the weight (B) of the leaves after removing the adhering water is measured. The moisture adhesion rate can be calculated by applying the following formula.
Moisture adhesion rate (%) = 100 x (AB) / B
<Number of bacteria>
The number of baby leaf bacteria measured is the general viable cell count. The method for measuring the general viable cell count may be any known method, specifically, a pour method using a standard agar medium in accordance with the Food Sanitation Inspection Guidelines (Japan Food Sanitation Association, 2004). be. By washing (S50), the general viable cell count can be reduced by 1.0 to 3.0 orders. The general viable cell count after washing by the main washing (S50) is 1.0 × 10 ^{4 to} 1.0 × 10 ⁵ CFU / g. The general viable cell count 24 hours after the production of washed baby leaf is preferably 1.0 × 10 ⁶ CFU / g or less, and more preferably 1.0 × 10 ⁵ CFU / g or less. Further, it preferred total viable count in the washed mesclun 72 hours after after production is less 1.0 × ¹⁰ 6 CFU / g. This makes it possible to eat without subsequent washing. In addition, according to the hygiene standards for bento boxes and sozai (revised 161 eclipse on June 29, 1979, 188 eclipse, 211 eclipse, 119 eclipse) on October 12, 1995. , total viable count is less 1.0 × ¹⁰ 6 CFU / g.

It is Example 1 that embodies the baby leaf according to the present invention. These examples do not limit the scope of claims according to the present invention.

<Baby leaf>
The baby leaf used in this example is a mixture of pinogreen, spinach, beet and arugula.

<Measurement of bacterial count>
The number of bacteria in this measurement was measured by a method in accordance with the Food Sanitation Inspection Guidelines (Japan Food Sanitation Association, 2004).

<Comparative example 1>
In Comparative Example 1, the harvested baby leaf is packed in a bag, placed in a plastic container, transported to a factory, sorted, washed with washing water containing hypochlorous acid, exposed to water, and then exposed to water. It was dried by blowing the wind. The moisture adhesion rate was measured before washing, and the number of bacteria was measured before washing, after drying, and 72 hours after drying.

<Example 1>
In Example 1, the baby leaf after harvesting was packed in a bag, put in a cardboard box with the mouth of the bag open, and transported to a factory. It was applied and dried. The moisture adhesion rate was measured before washing, and the number of bacteria was measured before washing, after drying, and 72 hours after drying. The test was conducted under the same conditions as in Comparative Example 1 except that corrugated cardboard was used for transportation.

<Evaluation results, summary>
As a result of considering the above test results, the moisture adhesion rate to the surface of baby leaf was reduced by using corrugated cardboard, which is a hygroscopic packaging material, instead of a container during transportation after harvesting. By sterilizing this with washing water that has a bactericidal effect, the effect of reducing the number of bacteria is enhanced, and even 72 hours after the production of washed baby leaf, the number of bacteria remains low compared to the category transported in the container. there were.

As a result, it was found that by reducing the water adhesion rate on the surface of the leaves of baby leaf, in particular, by reducing the water adhesion rate to 1.0 or less, the effect of reducing the number of bacteria during washing is enhanced. It was found that the consumption period can be extended by using the method of the present invention.

The fields in which the present invention is useful are a method for producing washed baby leaf and a method for reducing the number of bacteria in the washed baby leaf.

Claims (9)

A method for producing washed baby leaf, which is composed of at least the following steps:
Washing: It is baby leaf that is washed here, and the moisture adhesion rate of the baby leaf is 1.0% or less. A method for producing washed baby leaf, which is composed of at least the following steps:
Water removal: The water that is removed here is the water that adheres to the baby leaf, and the water adhesion rate of the baby leaf obtained by the water removal is 1.0% or less, and
Washing: What is washed here is the water-removed baby leaf. The manufacturing method according to claim 1 or 2.
The cleaning liquid used for the cleaning contains at least hypochlorous acid or hypochlorite. The production method according to any one of claims 1 to 3.
The number of bacteria mesclun obtained by washing is less 1.0 × ¹⁰ 5 CFU / g. The production method according to any one of claims 1 to 4.
The distribution temperature zone of washed baby leaf produced by the manufacturing method is the chilled zone.
Viable count of 24 hours after the production of the washed mesclun manufactured by this manufacturing method is less than 1.0 × 10 6 ^CFU / g. A method of reducing the bacterial count of washed baby leaf, which is composed of at least the following steps:
Washing: It is baby leaf that is washed here, and the moisture adhesion rate of the baby leaf is 1.0% or less. A method of reducing the bacterial count of washed baby leaf, which is composed of at least the following steps:
Water removal: The water that is removed here is the water that adheres to the baby leaf, and the water adhesion rate of the baby leaf obtained by the water removal is 1.0% or less, and
Washing: What is washed here is the water-removed baby leaf. The method of claim 6 or 7.
The cleaning liquid used for the cleaning contains at least hypochlorous acid. The method according to any one of claims 6 to 8.
The number of bacteria mesclun obtained by washing is less 1.0 × ¹⁰ 5 CFU / g.

Images