JPH0320220B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing freeze-dried lemons that retain their beautiful shape when sliced, have a good aroma and taste, are not bitter, and have a high shelf life. Sliced lemons are usually 24 pieces from one fresh lemon.
~26 sheets are cut and formed into pieces with a thickness of about 2 mm each, but if they are freeze-dried for storage, etc., the sandbags tend to fall off due to the loss of moisture, making it difficult to use fresh lemons. Difficult to maintain beautiful shape when sliced. Furthermore, when freeze-dried lemon slices are used, the bitter component turpentine contained in the epidermis leaches into black tea, etc., giving it an abnormally bitter taste.
Furthermore, there is a risk that the vitamin C in sliced lemons will be destroyed due to freeze-drying.
There is also a risk that fragrance etc. will be lost. The inventors of the present invention have conducted intensive studies to resolve the above-mentioned disadvantages of freeze-dried sliced lemons, and found that by applying a specific treatment before freeze-drying, the beautiful shape of sliced lemons can be maintained, and the aroma and flavor can be improved. well,
It has been found that freeze-dried lemons with no bitter taste and a long shelf life can be obtained. The present invention was made based on the above findings, and
To provide a method for producing a freeze-dried lemon, which comprises immersing sliced lemons from which turpentine has been removed in an aqueous solution of saccharides and then freeze-drying them. The method for producing freeze-dried lemon of the present invention will be described below.
It will be explained in detail based on its preferred embodiment. In carrying out the present invention, first, sliced lemons are prepared from which turpentine has been removed from the epidermis. In this preparation, fresh lemons are usually first treated with boiling water, preferably immersed in boiling water, to remove turpentine oil in their epidermis. Turpentine oil, which is a bitter component, is not a major concern in the case of fresh lemons, but it has a very strong bitter taste after freeze-drying. The turpentine is eluted and removed. The soaking time for removing turpentine by soaking fresh lemons in boiling water is 30 minutes.
seconds to 4 minutes, preferably 1 to 2 minutes. Next, the fresh lemon that has been treated to remove turpentine as described above is sliced into rounds to form lemon slices. Preferred lemon slices are about 2 mm thick. Next, the sugars of the lemon slices are soaked in an aqueous solution. Examples of the saccharide in this case include sorbitol, glucose, manon sauce, fructose, sucrose, etc., and sorbitol and sucrose are preferably used. The sugar concentration in the aqueous solution is preferably 1 to 10%, more preferably around 5%.
Also, soak the lemon slices for at least 10 minutes, about 30 minutes.
Minutes are preferred. By immersing the lemon slices in an aqueous solution of sugars in this way, it is possible to prevent the sandbags from falling off after freeze-drying, and to allow the lemon slices to maintain their beautiful shape when sliced into slices. That is,
As mentioned above, even if the lemon slices are thinly sliced, the sandbags tend to fall off easily, and sometimes when the lemon is freeze-dried, the moisture evaporates, making the sandbags even more likely to fall off. When immersed in an aqueous solution of sugars, the sugars can fill the gaps between the sandbags and strengthen the bond between the sandbags, thereby preventing the sandbags from falling off after freeze-drying. Can be done. In addition, sugars are added to the lemon slices by soaking them in an aqueous solution of sugars, so if you use the lemon slices directly for tea after freeze-drying, the taste will be mellower and more flavorful. is twitching. In addition, it is preferable that sodium ascorbic acid (vitamin C) is dissolved in the aqueous solution of sugars in a concentration of 0.1 to 0.3%. This makes it possible to reinforce and strengthen the vitamin C that is lost from the lemon slices during freeze-drying. Furthermore, since vitamin C has an antioxidant effect, it is possible to prevent the product from oxidizing. Thereafter, the lemon slices immersed in sugar are drained, frozen, and further freeze-dried to obtain freeze-dried lemons according to the present invention (the present invention). Preferred freeze-drying conditions are under a vacuum of 0.1-0.5 Torr and a shelf temperature of 20-40°C. When the present invention thus obtained is made into a product,
Usually, the product is vacuum packed by vacuum packaging, dehumidified by drying, or a combination of these is used to create a long-term storage product that can be easily used. Incidentally, the treatment for removing turpentine from the epidermis is preferably carried out before slicing as described above, but it may also be carried out after slicing. In addition, the removal treatment of turpentine oil is
The method is not limited to the hot water treatment as in the embodiments, but is not limited to any means that can remove turpentine. As described above, according to the method for producing freeze-dried lemon of the present invention, prior to freeze-drying the lemon slices, the lemon slices that have been treated to remove turpentine are prepared, and the prepared lemon slices are placed in an aqueous solution of sugars. Because it is soaked, it is possible to obtain freeze-dried lemons that retain their beautiful shape when sliced, have a good aroma and taste, are not bitter, and have a long shelf life. By dissolving soda and adding sodium ascorbic acid to lemon slices, effects such as strengthening the vitamin C in the lemon slices that are destroyed during freeze-drying and preventing oxidation of the product can be achieved. Examples of the present invention are shown below. Example M class fresh lemons were heated by immersing them in boiling water for 1 minute and 30 seconds, and then immediately cooled in running water to remove water droplets on the surface. Next, the fresh lemon treated as described above was sliced into rounds with a thickness of approximately 2 mm using a knife (or a slicer may be used). Slice the lemon into 5% aqueous sorbitol solution containing 0.15% sodium ascorbic acid for 30 minutes.
After soaking for a few minutes, water was lightly drained and freeze-dried to obtain a product of the present invention. On the other hand, in parallel with the above-mentioned operation, a control product was obtained by immediately freeze-drying sliced lemons, which were sliced into slices approximately 2 mm thick without being treated with boiling water. Note that the shelf temperature during freeze-drying of the products of the present invention and the control product was 30°C. The comparison results between the product of the present invention and the control product are as shown in the table below. 【table】

Claims (1)

[Claims] 1. Sliced lemons treated to remove turpentine,
A method for producing freeze-dried lemons, which comprises immersing them in an aqueous solution of sugars and then freeze-drying them. 2. The method for producing freeze-dried lemon according to claim 1, wherein the aqueous solution has a saccharide concentration of 1 to 10%. 3. The method for producing freeze-dried lemon according to claim 2, wherein sodium ascorbic acid is contained in the aqueous solution of saccharides. 4. The turpentine oil removal process is performed by immersing the fresh lemon in boiling water before slicing the fresh lemon into rounds.
A method for producing freeze-dried lemon according to claim 1. 5. Soak fresh lemons in boiling water for 30 seconds to 4 minutes.
A method for producing freeze-dried lemon according to claim 4.