JP2013158296A - Frozen dried tomato and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a freeze-dried tomato easy to reconstitute in hot water, and capable of retaining original palate feeling of tomato, and to provide a method for producing the tomato.SOLUTION: A freeze-dried tomato with a bulk specific gravity of 100-200 mg/mL and a strength measured by a destruction test with a texturometer of ≥2 kg/mL is produced through a process of removing a jelly part from tomato, a process of infiltrating and dehydrating by soaking the tomato from which the jelly part is removed in an aqueous solution containing saccharide and common salt, a process of hot-air drying the tomato after infiltration and dehydration, and a process of freeze-drying the tomato after hot-air drying.

Description

  The present invention relates to a freeze-dried tomato and a method for producing the same, and particularly relates to a freeze-dried tomato that can be easily reconstituted with hot water and has an original texture of tomato and a method for producing the same.

  Freeze-dried tomatoes are widely used as ingredients for instant foods such as instant noodles and instant soups. With regard to dried vegetables such as freeze-dried tomatoes, the recent trend has come to require properties such as the original flavor, color tone, texture, etc. as well as the real intention and size.

  Patent Document 1 proposes that dried vegetables having excellent texture and original color of vegetables are produced by hot-air drying vegetables such as tomatoes and then freeze-drying. Patent Document 2 proposes producing a freeze-dried tomato with improved texture by cutting a tomato vertically, immersing it in a sugar solution, and then freeze-drying it.

  However, when dried tomatoes were produced by the method of Patent Document 1, there was a problem that the original texture of tomatoes was not obtained and the hot water reversion was poor. In the case of the method of Patent Document 2, there is a problem that it is difficult to maintain the original texture of tomato.

Japanese Patent No. 2902231 JP 2008-99572 A

  In order to solve the above conventional problems, the present invention provides a freeze-dried tomato that can be easily reconstituted with hot water and can retain the original texture of the tomato, and a method for producing the same.

  The freeze-dried tomato according to the present invention has a bulk specific gravity of 100 to 200 mg / mL.

  The method for producing a freeze-dried tomato according to the present invention includes a step of removing the jelly portion from the tomato, a step of osmotic dehydrating the tomato from which the jelly portion has been removed, a step of drying the tomato after osmotic dehydration, and hot air drying. The method includes a step of freeze-drying tomatoes.

  The present invention can provide a freeze-dried tomato that is easy to reconstitute with hot water and has the original texture of tomato by making the bulk specific gravity of the freeze-dried tomato 100 to 200 mg / mL. Further, the production method of the present invention, after osmotic dehydration of the tomato from which the jelly portion has been removed, is performed in this order by hot air drying and freeze-drying, so that hot water reconstitution is easy and the tomato has an original texture. Freeze-dried tomatoes can be provided.

FIG. 1 is a schematic diagram of a waveform pattern showing a change in the load of a freeze-dried tomato according to an embodiment of the present invention measured by a destructive test using a texturometer. FIG. 2 is a schematic diagram of a waveform pattern showing a change in load of a freeze-dried tomato of one comparative example measured by a destructive test using a texturometer.

  The freeze-dried tomato of the present invention preferably has a bulk specific gravity of 100 to 200 mg / mL, more preferably 120 to 180 mg / mL, and further preferably 120 to 160 mg / mL. When the bulk specific gravity is in the above range, the restoration by hot water reconstitution is easy and the texture such as crunchiness is excellent. In the present invention, the bulk specific gravity can be calculated by putting lyophilized tomatoes in a 200 mL measuring cup to the full extent and weighing the net weight.

  The freeze-dried tomato is preferably 2 kg / mL or more, more preferably 2.5 kg / mL or more, as measured by a texturometer destructive test (hereinafter also simply referred to as strength). More preferably, it is 3.0 kg / mL or more. The upper limit of the strength is not particularly limited, but is preferably 6.0 kg / mL or less. When the strength is in the above range, it has excellent fracture resistance and excellent texture such as crunchiness.

  The lyophilized tomato preferably has a wave number measured by a destructive test with a texturometer of 5 / mL or more, more preferably 6 / mL or more, and even more preferably 7 / mL or more. . The upper limit of the wave number is not particularly limited, but is preferably 15 / mL or less. When the wave number is within the above range, it has excellent elasticity and retains the original texture of tomato.

  In the present invention, a texturometer destructive test is performed using a texturometer GTX-2 (manufactured by Zenken Co., Ltd.), a circular plunger with a diameter of 18 mm, a clearance (raised bottom of the tray) of 3 mm, and a voltage of 1 V. This is done by compressing and crushing. In the waveform pattern showing the load change measured in the destructive test as shown in FIGS. 1 and 2, the maximum value (kg) of the peak height H of the waveform is obtained and divided by the volume (mL) of the sample. Thus, the strength (kg / mL) per unit volume is calculated, and the strength measured by a destructive test with a texturometer is used. Moreover, in the waveform pattern which shows a change of load as shown in FIGS. The wave number measured in the destructive test.

  The freeze-dried tomato of the present invention is preferably produced by osmotic dehydration of the tomato from which the jelly portion has been removed, drying the osmotic dehydrated tomato with hot air, and freeze-drying the hot air-dried tomato.

  In the tomato from which the jelly part (including seeds) has been removed, the pulp part has a high water content and the skin part has a low water content. In the present invention, the tomatoes from which the jelly portion has been removed are subjected to osmotic dehydration, so that the moisture content of the flesh portion is reduced and the skin and the surrounding tissue can be retained as they are. Therefore, even if the tomatoes after osmotic dehydration are dried with hot air, the pulp part is dehydrated rapidly and does not shrink excessively, and the tissue does not become hard. Moreover, it seems that the tissue does not become sponge-like by freeze-drying after hot-air drying, and the original texture and color tone of tomato are maintained.

(Jelly removal process)
The tomato used as a raw material is not particularly limited, and any variety of large tomato, medium tomato (midi tomato), and mini tomato (petit tomato) may be used. For example, large tomatoes such as “Momotaro” (variety name), medium tomatoes such as “Fan Gogh” (variety name), and mini tomatoes such as “Aiko” (variety name) can be used.

  The jelly portion is removed by cutting the tomato into a predetermined size and washing it. Here, the predetermined size is a size suitable for instant food, and is not particularly limited. A preferable size is a die shape having a side of 5 to 25 mm square, and more preferably a die shape having a side of 10 to 20 mm square. In addition, in this invention, before removing a jelly part, a sticker is removed.

(Osmotic dehydration process)
Next, the tomato from which the jelly portion has been removed is permeated and dehydrated. From the viewpoint of reconstitution with hot water, it is preferable to perform osmotic dehydration until the weight of tomato after osmotic dehydration is 60 to 80% of the weight of tomato immediately before osmotic dehydration, and osmotic dehydration until 65 to 75%. Is more preferable.

  From the viewpoint of operability, the osmotic dehydration is preferably performed by immersing the tomato from which the jelly portion has been removed in an osmotic dehydration aqueous solution. As the aqueous solution for osmotic dehydration, an aqueous solution containing a saccharide is preferably used, and an aqueous solution containing a saccharide and sodium chloride is more preferably used from the viewpoint of maintaining the freshness of tomatoes. From the viewpoint of increasing freshness, it is preferably performed by immersing the tomato from which the jelly portion has been removed in an aqueous solution for osmotic dehydration for 2 hours or more under a temperature condition of 2 to 20 ° C. More preferably, it is carried out by immersing in an aqueous solution for osmotic dehydration for 4 to 20 hours under the temperature condition of 12 to 16 hours in an aqueous solution for osmotic dehydration at a temperature of 4 to 6 ° C. More preferably,

  The saccharide is not particularly limited, but a monosaccharide such as glucose (glucose), fructose (fructose), galactose (brain sugar), oligosaccharide (oligosaccharide), such as lactose (lactose), maltose (maltose), And sugar alcohols of these saccharides such as sorbitol (glucitol) can be used alone or in combination of two or more. From the viewpoint of taste and texture, it is preferable to use glucose and lactose as the saccharide.

  The aqueous solution for osmotic dehydration may further contain food additives such as amino acid seasonings, nucleic acid seasonings, pigments, acidulants, yeast extracts, and antioxidants. As the amino acid seasoning, for example, amino acids such as glutamic acid or salts thereof can be used. Moreover, citric acid etc. can be used as said acidulant. As the osmotic dehydrating aqueous solution, it is particularly preferable to use an aqueous solution containing sugar, salt, amino acid seasoning, nucleic acid seasoning, pigment, acidulant, yeast extract, and antioxidant.

  In the osmotic dehydration aqueous solution, the saccharide concentration is preferably 5 to 20% by weight, more preferably 8 to 18% by weight, and even more preferably 12 to 16% by weight. If the saccharide concentration is less than 5% by weight, the osmotic dehydration effect tends to be difficult to obtain, and if it exceeds 20% by weight, excessive shrinkage may occur and hot water restoration may be worsened. In the osmotic dehydration aqueous solution, the concentration of sodium chloride is preferably 0 to 2.0% by weight, more preferably 0.4 to 1.6% by weight, from the viewpoint of taste balance. More preferably, it is 0.8 to 1.2% by weight. In the aqueous solution containing saccharides, the concentration of other additives such as amino acid seasonings other than saccharides and salt is preferably 0 to 5.0% by weight, more preferably 2.5 to 4.%. 0% by weight.

(Hot air drying process)
Next, the tomatoes after osmotic dehydration are dried with hot air. The tomatoes after osmotic dehydration are in a state where additives such as sugars are attached. The hot air drying is preferably performed until the weight of the tomato after hot air drying is 30 to 70% of the weight of the tomato immediately before the hot air drying, and more preferably 35 to 50%. If the weight of the tomato after drying with hot air is less than 30% of the weight of the tomato immediately before drying with hot air, excessive shrinkage tends to occur and the tomato has the original flavor and color. On the other hand, if the weight of the tomato after drying with hot air exceeds 70% of the weight of the tomato immediately before drying with hot air, the texture (texture) resulting from the collapse (sponge formation) of the tomato tissue due to freezing will deteriorate and the resistance to destruction will decrease. There is a risk of inviting.

  In general, in the hot air drying process, the moisture adhering to the surface of the material to be dried is first evaporated, and then the water in the material to be dried is rapidly evaporated and dehydrated. When the material to be dried is tomato, when it is directly dried with hot air, the flesh part with a large amount of water tends to shrink excessively due to the rapid evaporation and dehydration of the water, resulting in a hard tissue. In the present invention, the amount of water in the pulp part is reduced to some extent by osmotic dehydration of tomatoes, and the skin and the surrounding tissue are held as they are. Does not occur and the tissue does not become stiff. Moreover, since the skin and the surrounding tissue are held as they are, the original texture of tomato can be maintained.

  From the viewpoint of preventing discoloration such as scorching due to heat, the hot air drying is preferably performed at a temperature of 40 to 120 ° C, more preferably 60 to 100 ° C, and even more preferably 70 to 90 ° C. What is necessary is just to determine drying time suitably with the kind of tomato after osmosis dehydration to use for hot-air drying, the thickness and loading amount at the time of loading, and a wind speed. For example, the thickness at the time of loading is 30 mm and the wind speed is 1.5 m / sec for 60 to 90 minutes.

(Freeze drying process)
The tomatoes after hot air drying are freeze-dried by a usual method. The degree of vacuum during freeze-drying is preferably 200 Pascals or less, more preferably 133 Pascals or less, and even more preferably 106 Pascals or less. The product temperature during lyophilization is preferably 70 ° C. or lower, more preferably 60 ° C. or lower, and more preferably 50 ° C. or lower. Prior to freeze-drying, so-called preliminary freezing may be performed in which freezing is performed at a temperature of −10 to −45 ° C. for about 10 to 36 hours. The moisture content after lyophilization is preferably 5.0% or less, more preferably 3.0% or less.

Lyophilized tomato invention, L ^*, hue indicated by a ^* and b ^* of the raw tomatoes L ^*, approximates a hue represented by a ^* and b ^*, holds the original color tomatoes.

  The freeze-dried tomato of the present invention can be easily restored and eaten with normal hot water reconstitution. In other words, as used in instant noodles, instant soups, etc., hot water is added and soaked for several minutes to return to an eatable state. Of course, it can be restored even if cooked.

  Hereinafter, the present invention will be described more specifically with reference to examples. The present invention is not limited to the following examples.

Example 1
(1) Jelly part removal process After removing the sticky from the tomato (Hokkaido "Momotaro"), the jelly part was removed by cutting into a 16 mm square die and washing with water.
(2) Osmotic dehydration step After 665 g of tomatoes from which the jelly portion had been removed was immersed in an aqueous solution for osmotic dehydration containing 7.5% by weight of lactose and 7.5% by weight of glucose at 5 ° C. for 12 hours to perform osmotic dehydration. The aqueous solution for osmotic dehydration was removed. The weight of tomato after osmotic dehydration was 510 g.
(3) Hot air drying process The tomatoes after osmotic dehydration were hot air dried at 85 ° C. for 90 minutes. The weight of tomato after drying with hot air was 208 g.
(4) Freeze-drying process The tomatoes after hot-air drying were arranged in a tray and pre-frozen at −30 ° C. for 24 hours. After pre-freezing, vacuum freeze-drying was performed under the conditions that the product temperature was about 50 ° C. and the degree of vacuum was 133 Pascal or less. In addition, before pre-freezing, tomato was sterilized by processing for 10 minutes with 70 degreeC steam. The weight of the tomato after lyophilization was 43 g, and the moisture content was 1.7%.

(Example 2)
In the osmotic dehydration step, 7.5% by weight lactose, 7.5% by weight glucose, 0.5% by weight is replaced with an aqueous solution for osmotic dehydration containing 7.5% by weight lactose and 7.5% by weight glucose. Except for using an aqueous solution for osmotic dehydration containing 0.1% by weight of red potato pigment ("Rike Color R100" manufactured by Riken Vitamin Co., Ltd.) and 0.1% by weight of paprika pigment ("Paprika Base 70R" manufactured by Saneigen FFI Co., Ltd.) Produced freeze-dried tomatoes in the same manner as in Example 1. In Example 2, the weight of the tomato from which the jelly portion was removed was 665 g, the weight of the tomato after osmotic dehydration was 511 g, the weight of the tomato after hot air drying was 203 g, and the weight of the tomato after lyophilization was It was 40 g. Moreover, the moisture content of the tomato after freeze-drying in Example 2 was 1.8%.

(Example 3)
In the osmotic dehydration step, instead of the aqueous solution for osmotic dehydration containing 7.5 wt% lactose and 7.5 wt% glucose, 4.5 wt% lactose, 7.5 wt% glucose, 1 wt% Citric acid, 1% by weight sodium chloride, 1% by weight sodium glutamate, 0.5% by weight yeast extract ("Vertex IG20" manufactured by Fuji Food Industry Co., Ltd.), 1% by weight edible processed oil ("Ematech" manufactured by Riken Vitamin Co., Ltd.) A freeze-dried tomato was produced in the same manner as in Example 1 except that an aqueous solution for osmotic dehydration containing S-500 ") was used. In Example 3, the weight of the tomato from which the jelly portion was removed was 665 g, the weight of the tomato after osmotic dehydration was 432 g, the weight of the tomato after hot air drying was 192 g, and the weight of the tomato after lyophilization was It was 40 g. Moreover, the moisture content of the tomato after freeze-drying in Example 3 was 1.8%.

Example 4
In the osmotic dehydration step, 7.5% by weight of lactose, 7.5% by weight of glucose, 4.5% by weight is replaced with an aqueous solution for osmotic dehydration containing 7.5% by weight of lactose and 7.5% by weight of glucose. % Lactose, 7.5% glucose, 1% citric acid, 1% salt, 1% sodium glutamate, 0.5% yeast extract ("Vertex IG" manufactured by Fuji Food Industry Co., Ltd.) ) 1% by weight of edible processed fats and oils (“Ematech” manufactured by Riken Vitamin Co., Ltd.), 0.5% by weight of red koji pigment (“Rike Color R100” manufactured by Riken Vitamin Co., Ltd.) A freeze-dried tomato was prepared in the same manner as in Example 1 except that an aqueous solution for osmotic dehydration containing “Paprika Base 70R” manufactured by FFI Co., Ltd. was used. In Example 4, the weight of the tomato from which the jelly portion was removed was 665 g, the weight of the tomato after osmotic dehydration was 406 g, the weight of the tomato after drying with hot air was 192 g, and the weight of the tomato after lyophilization was It was 42 g. Moreover, the moisture content of the tomato after freeze-drying in Example 4 was 1.9%.

(Comparative Example 1)
Freeze-dried tomatoes were prepared in the same manner as in Example 1 except that the tomatoes after osmotic dehydration were not dried with hot air but arranged in a tray as they were and subjected to the freeze-drying step. In Comparative Example 1, the weight of the tomato from which the jelly portion was removed was 665 g, the weight of the tomato after osmotic dehydration was 510 g, and the weight of the tomato after lyophilization was 43 g. Moreover, the moisture content of the tomato after the freeze-drying of the comparative example 1 was 1.9%.

(Comparative Example 2)
Lyophilized tomatoes were produced in the same manner as in Example 2 except that the tomatoes after osmotic dehydration were not dried with hot air but arranged in a tray as they were and subjected to the freeze drying step. In Comparative Example 2, the weight of the tomato from which the jelly portion was removed was 665 g, the weight of the tomato after osmotic dehydration was 511 g, and the weight of the tomato after lyophilization was 41 g. Moreover, the moisture content of the tomato after the freeze-drying of the comparative example 2 was 2.0%.

(Comparative Example 3)
Freeze-dried tomatoes were produced in the same manner as in Example 3 except that the tomatoes after osmotic dehydration were not dried with hot air but arranged in a tray as they were and subjected to the freeze-drying step. In Comparative Example 3, the weight of the tomato from which the jelly portion was removed was 665 g, the weight of the tomato after osmotic dehydration was 432 g, and the weight of the tomato after lyophilization was 44 g. Moreover, the moisture content of the tomato after the freeze-drying of the comparative example 3 was 2.1%.

(Comparative Example 4)
Freeze-dried tomatoes were prepared in the same manner as in Example 4 except that the tomatoes after osmotic dehydration were not dried with hot air but arranged in a tray as they were and subjected to the freeze-drying step. In Comparative Example 4, the weight of the tomato from which the jelly portion was removed was 665 g, the weight of the tomato after osmotic dehydration was 406 g, and the weight of the tomato after lyophilization was 39 g. Moreover, the water content of the tomato after freeze-drying in Comparative Example 4 was 2.2%.

(Comparative Example 5)
A freeze-dried tomato was obtained in the same manner as in Example 1 except that the osmotic dehydration step was not performed and 665 g of tomato from which the jelly portion had been removed was dried with hot air at 85 ° C. for 90 minutes until it reached 247 g. The weight of the tomato after lyophilization in Comparative Example 5 was 37 g, and the moisture content was 1.8%.

The bulk specific gravity and hue (L ^* , a ^* and b ^* ) of the freeze-dried tomatoes of Examples and Comparative Examples were measured as follows, and the results are shown in Table 1 below. Further, a destructive test was performed using a texturometer, and the strength (kg / mL) and the wave number (number / mL) in the waveform pattern were measured and calculated. The results are shown in Table 1 below.

(Bulk specific gravity)
The lyophilized tomato was put into a 200 ml measuring cup, and the net weight was weighed to calculate the bulk specific gravity (mg / mL). The measurement was performed for each sample at n = 10, and Table 1 below shows the average value.

(Color difference)
L ^* , a ^* and b ^* were measured using a simultaneous photometric spectroscopic color difference meter (SQ-2000 model, manufactured by Nippon Denshoku Industries Co., Ltd.). Raw tomato skins L ^*, a ^* and b ^*, lyophilized tomato whole L ^* including also internal phase, was measured a ^* and b ^*. The measurement conditions were reflection measurement, no regular reflection, and the measurement site area was 10φ. The measurement was performed for each sample at n = 10, and Table 1 below shows the average value.

(Destructive testing)
A destructive test was performed using Texturometer GTX-2 (manufactured by Zenken Co., Ltd.). Specifically, a 18 mm diameter circular plunger was used, the clearance (bottom raising of the tray) was 3 mm, the sample was compressed and crushed under a voltage of 1 V, and the change in load at that time was measured. In the waveform pattern indicating the change in load, the maximum value (kg) of the peak height of the waveform was obtained, and the strength (kg / mL) per volume (mL) of the sample was calculated. Further, in the waveform pattern indicating the change in load, the wave number (pieces) was obtained, and the wave number (pieces / mL) per volume (mL) of the sample was calculated. The measurement was performed for each sample at n = 10, and Table 1 below shows the average value.

As can be seen from Table 1, the freeze-dried tomatoes of Examples 1 to 4 obtained by performing osmotic dehydration, hot-air drying, and freeze-drying in this order had a bulk specific gravity in the range of 100 to 200 mg / mL. In addition, the freeze-dried tomatoes of Examples 1 to 4 had a strength of 2 kg / mL or more and a wave number of 5 / mL or more in a destructive test with a texturometer. Further, the values of L ^* , a ^* and b ^* of the freeze-dried tomatoes of Examples 1 to 4 are little different from the values of L ^* , a ^* and b ^* of the raw tomatoes, and the freezes of Examples 1 to 4 Dried tomatoes kept their original color.

On the other hand, the freeze-dried tomatoes of Comparative Examples 1 to 4 that have not been hot-air dried and the freeze-dried tomato of Comparative Example 5 that has not been subjected to osmotic dehydration have a bulk specific gravity of 91 mg / mL or less, in a destructive test with a texturometer. The intensity was less than 1.5 kg / mL, and the wave number was less than 5 / mL. Moreover, the values of L ^* , a ^* and b ^* of the freeze-dried tomatoes of Comparative Examples 1 to 5 are largely different from the values of L ^* , a ^* and b ^* of the raw tomatoes, and the freezing of Comparative Examples 1 to 5 Dried tomatoes lost their original color tone.

  Moreover, when it put in the hot water of 90 degreeC, the freeze-dried tomato of Examples 1-4 restored | regenerated within 1 minute, and the tomato original texture, flavor, and color tone were shown. On the other hand, the freeze-dried tomatoes of Comparative Examples 1 to 4 could be restored within 1 minute, but did not show the original texture, flavor and color tone of the tomatoes. Moreover, the freeze-dried tomato of Comparative Example 5 was poor in hot water, and did not show the original texture, flavor and color tone of the tomato.

  The freeze-dried tomato of the present invention can be used as an ingredient for instant foods such as instant noodles and instant soups.

H Waveform peak height W Wavenumber

Claims (5)

  A freeze-dried tomato having a bulk specific gravity of 100 to 200 mg / mL. The freeze-dried tomato according to claim 1, wherein the freeze-dried tomato has a strength measured by a destructive test with a texturometer of 2 kg / mL or more. A method for producing a freeze-dried tomato according to claim 1 or 2, wherein the freeze-dried tomato is produced.
Removing the jelly portion from the tomatoes;
Osmotic dehydration of the tomato from which the jelly portion has been removed;
A process of drying the tomatoes after osmotic dehydration with hot air,
The manufacturing method of the freeze-dried tomato characterized by including the process of freeze-drying the tomato after hot-air drying.   The method for producing a freeze-dried tomato according to claim 3, wherein the osmotic dehydration is performed by immersing the tomato from which the jelly portion has been removed in an aqueous solution containing sugars.   The method for producing a freeze-dried tomato according to claim 3, wherein the osmotic dehydration is performed by immersing the tomato from which the jelly portion has been removed in an aqueous solution containing sugars and salt.

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