JPS6324649B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for making packaged vegetable salads. More specifically, the present invention relates to a method for producing a packaged vegetable salad that can maintain freshness for a long period of time by filling chopped vegetables into a vinyl chloride bag, dehydrating the same under vacuum, cooling it, and vacuum packaging it. One of the present inventors has invented a method for producing a vegetable salad in which pre-cooled vegetables are divided into portions, stirred and mixed in cooling water, and then drained. This invention was published as a patent application as Japanese Patent Publication No. 57-55386. The vegetables produced by this invention can be kept fresh for about one week by filling them into plastic bags, refrigerating them, and shipping them. However, those skilled in the art desire something that can maintain freshness for even longer. In order to solve this problem, the present inventors conducted further research on the production method of vegetable salad, and found that the chopped vegetables were washed with water, drained and dehydrated, and then filled into vinyl chloride film bags. We have discovered that the freshness of vegetable salad can be maintained for more than two weeks under refrigeration by further dehydrating and cooling it under vacuum without sealing it and then vacuum packaging it in the above-mentioned vinyl chloride film bag, resulting in the present invention. did. That is, the present invention provides ``washing chopped vegetables with water, draining them, filling them in a vinyl chloride film bag, dehydrating and cooling them under vacuum without sealing the bag, and then placing the chopped vegetables in the vinyl chloride film bag described above. exhaust,
A method for producing a packaged vegetable salad characterized by vacuum packaging. The term vinyl chloride film above is used to refer to vinyl chloride sheets and films. In addition,
As the vinyl chloride, soft vinyl chloride is advantageous because it is flexible. Vegetables continue to respire even after they are harvested, inhaling oxygen and expelling carbon dioxide and water. After harvest, the respiration rate of vegetables, especially those that have been scarred, increases rapidly, and then gradually decreases. Harvested vegetables, especially vegetable salads made by chopping raw vegetables, are susceptible to damage, so in order to maintain their freshness, cooling methods have traditionally been used to suppress breathing. The method disclosed in the above-mentioned Japanese Patent Publication No. 57-55386 also fully incorporates this cooling means. However, even if shredded vegetables are cooled, salads generally have many scars, so cell fluid flows out, and the enzymes contained therein cause browning, making it impossible to maintain freshness for too long. However, if the cells are washed with water after chopping and then drained, most of the leaked cell fluid will be removed and browning can be prevented. When the shredded vegetables are then exposed to a vacuum, the water content in the vegetables evaporates, and the vegetable salad is cooled and the damaged parts become cork due to the evaporation of water, so it takes much longer than if it were simply refrigerated. Freshness is maintained. Also, placing shredded vegetables under vacuum removes ethylene gas, which is a component that promotes deterioration of freshness, which is advantageous for maintaining freshness. Furthermore, if a vegetable salad is cooled in a refrigerator in a bag made of vinyl chloride film, moisture in the vegetable salad may condense on the inner surface of the cooled bag, and this moisture may promote the growth of bacteria. However, when shredded vegetable salad is placed in a plastic chloride bag and cooled under vacuum, the moisture in the vegetables does not condense on the surface of the bag and is cooled in a dry state, which prevents bacterial growth and is hygienic. The method of the present invention is also superior in this respect. In addition, in the present invention, the vegetable salad in the bag is cooled under vacuum, and then the opening is sealed under vacuum and packaged, so the packaged vegetable salad comes into contact with extremely dilute oxygen, if any at all. Moreover, the carbon dioxide concentration in the packaging bag gradually increases slightly as the vegetable salad breathes, which is very advantageous for maintaining freshness. Due to the comprehensive action of the many factors detailed above, the packaged vegetable salad produced by the method of the present invention maintains its freshness for more than two weeks when refrigerated, and its effect is revolutionary. Currently, vegetable salads are produced in food factories in large consumption areas, hotels, food stores, etc., but in order to maintain the freshness of vegetable salads, it is desirable to produce them in vegetable production areas. The reason for this is that in general, when vegetables are sold as a product, only those that pass the standards to be sold as a product are harvested, and those that fail are discarded. This is because vegetables that would otherwise be discarded due to substandard quality can be used to sell vegetables as they are. Furthermore, waste and unnecessary parts are easily disposed of at the production site without being sent to the consumption site. The degree of vacuum for implementing the method of the present invention is not particularly limited, but the conditions for implementation are preferably 50 to 4.5 mmHg using a vacuum pump, and particularly 10 to 4.5 mmHg.
5 mmHg is preferred. In addition, the temperature of vegetables cooled under vacuum is preferably a temperature of 2 to 5 at which freezing does not occur.
°C is advantageous. When a vegetable salad is cooled under vacuum using the method of the present invention, the moisture in the cut portion of the vegetable evaporates as described above, so a cork layer is formed on the cell wall of the cut portion, scars are removed, and browning of the cut portion is prevented and freshness is maintained. I can do it. Next, the present invention and its effects will be specifically explained with reference to Examples. Example 1 Lettuce is harvested in a field and transported to a work site in a shipping box. Remove unnecessary outer leaves and core. The mud, dust, etc. from these lettuces are washed with clean water in a primary washing machine, and then these lettuces are cut into two pieces. Using a slicer, cut the lettuce into 2 pieces and then cut into cubes.
If dust or insects are found, these foreign substances are carefully removed and the front and back surfaces are washed with high-pressure water using a multilevel washer. Next, the final product is washed under running water to remove impurities, collected in a product hopper, packed in a mesh basket, centrifuged, drained, weighed to 0.5 to 10 kg, and packed in a plastic bag. However, leave the entrance of the bag unsealed. Next, it is put into a box and transported to a vacuum chamber. Operate the vacuum cooling device to reduce the vacuum level of the tank to 5mmHg.
Cooling, exhaust gas, and dehydration are performed. Next, the cooled vegetable salad in a vinyl chloride bag is placed in a vacuum packaging machine, the inside of the plastic bag is evacuated, the entrance of the bag is sealed by welding, the bag is packed in a carton, and the bag is stored in a refrigerator or sent to a consumption site in a refrigerated car. transport. In this case, the lettuce salad was able to maintain its freshness and product value even after two weeks or more had passed since shipment. Examples 2 to 4 “Final washing under running water” of lettuce harvested in the field
The product was treated in the same manner as described in "Example 1" up to the step of step 2, and after removing impurities, it was collected in a product hopper, packed in a mesh basket, centrifuged, and then centrifuged for 5 minutes and 15 minutes.
1kg each after draining for 60 minutes and 60 minutes
Addressed to: Packed in a vinyl chloride film bag. However, do not close the opening of the bag. Next, the vacuum level of the tank was reached to approximately 5 mmHg using a vacuum cooling device, and each
After cooling to ℃, the bag was placed in a vacuum packaging machine and the opening of each bag was sealed by welding. Among these examples, the one with a draining time of 5 minutes is called Example 2, and the one with a draining time of 15 minutes is called Example 3 or the same.
Example 4 is one for 60 minutes. Comparative Example 1 Lettuce was processed in the same manner as in Example 2 up to the final washing step, impurities were removed, collected in a product hopper, packed in a mesh basket, and not centrifuged.
Pack it into a 1kg vinyl chloride film bag. The remaining steps were carried out in the same manner as in Example 2 to obtain a sample lettuce vacuum-packed in a vinyl chloride film. Comparative Example 2 The dirty outer leaves, insects, etc., and core of lettuce harvested in the field were removed in the same manner as in Example 2, and then the lettuce was cut into two pieces. Then, cut the pieces into two pieces, cut into cubes, and pack them into 1kg polyvinyl chloride film bags. The remaining steps were carried out in the same manner as in Example 2 to obtain vacuum-packed sample lettuce. Effect test of washing and dehydration (draining water) The vegetable salads (vinyl chloride film vacuum packaged products) of Examples 2 to 4 and Comparative Examples 1 to 2 were heated at about 5°C.
It was stored in the refrigerator for a specified number of days. Each bag of 10 was opened according to the storage period and inspected by five inspectors (all of whom have specialized knowledge in the production and quality of vegetable salads) according to the following criteria. evaluated. The results are shown in Table 1. From this table, it can be clearly seen that the effect of washing and dehydration, which is an important requirement of the present invention, is "washing with water and draining." Note that if you are not dehydrating, it is better not to wash. Freshness at time of harvest: 9 points Juicy freshness: 7 points Minimum marketable freshness: 5 points Partially marketable freshness: 4 points Not marketable: 3 points Note: In Table 1, 5 people inspected the product. Indicates the average value of the members. 【table】

Claims (1)

[Claims] 1 Wash the shredded vegetables with water, drain them, fill them in a vinyl chloride film bag, dehydrate and cool the bag under vacuum without sealing it, and then vacuum pack it in the vinyl chloride film bag mentioned above. A method for producing a packaged vegetable salad characterized by: