JP4131961B2 - Production method of plum extract - Google Patents

Description

  The present invention relates to a method for producing a plum extract with a high content and high quality of umefural.

  As a method for producing a plum extract containing umefural, a method of reducing the moisture content of the plum extract raw material to 10 to 40% by mass in the concentration step, and then maintaining the moisture content in the heating step (see Patent Document 1) has been proposed. ing.

Japanese Patent No. 3452263

  However, in the above method, since a heating step is provided after the concentration, when trying to obtain a plum extract with a high content of umefural, if the concentration is concentrated to 20% by weight or less in the concentration step, the concentrated solution becomes muddy and highly viscous. Then, even if heating is performed while keeping the water content constant, a large amount of umefural is produced, but air is trapped in the plum extract by stirring during heating. Therefore, immediately after kneading the plum extract obtained by the conventional production method, the air bubbles are bitten and the surface is uneven and the appearance is poor and the product value is low. It had to be neglected or forced to deaerate, and it took a lot of time and effort.

  In view of the above circumstances, the present invention aims to provide a method for producing a plum extract that can produce a plum extract containing umefural and excellent in quality without air entrapment with good workability. Yes.

In order to achieve the above object, the method for producing plum extract according to claim 1 of the present invention (hereinafter referred to as “production method according to claim 1”) is a plum extract containing umefural by heating and concentrating plum juice. A raw material plum juice having a water content of 30% by weight or more is heated while maintaining a state where the water does not evaporate to produce 5-hydroxymethyl-2-furfural and umefural. It is characterized by comprising a heating step and a reduced pressure concentration step for concentration under reduced pressure to 20% by weight or less after completion of the heating step.

  The production method of plum extract according to claim 2 of the present invention (hereinafter referred to as “production method of claim 2”) is the production method according to claim 1, wherein the plum juice is a desalination solution of plum vinegar. It is characterized by that.

  The production method of plum extract according to claim 3 of the present invention (hereinafter referred to as “production method of claim 3”) is the production method according to claim 1 or 2, wherein the heating step is performed under pressure. It is characterized by being performed.

In the production method of the present invention, the water content of the raw plum juice in the heating step is not particularly limited as long as it is 30% by weight or more, but preferably 35% by weight or more and 50% by weight or less.
Moreover, as raw material plum fruit juice, although it does not specifically limit, any 1 type chosen from the group which consists of the squeezed juice squeezed from the plum fruit, the desalinization processing liquid of plum vinegar, and plum syrup is used, for example. Juice, ume vinegar desalting solution or ume syrup may be used as they are, but it is preferable to adjust the water content to 35 wt% or more and 50 wt% or less by concentration under reduced pressure.

In the present invention, plum vinegar is a fruit juice component extracted from plum fruit by osmotic pressure when plum fruit is soaked in salt, and contains substantially saturated salt.
The desalting treatment liquid is obtained by removing salt from the ume vinegar by, for example, an electrodialysis method using an ion exchange membrane, a desalting method using a reverse osmosis membrane, or the like.

  Plum syrup is a fruit juice component containing a large amount of sugar extracted from plum fruit by osmotic pressure when the plum fruit is soaked in sugar.

Furthermore, the obtained plum extract may be reheated. That is, the concentration of umefural can be further increased by heating.
Reheating can be performed not only under normal pressure and pressure, but also under reduced pressure or without stirring.

  The quantification of the obtained memefural is not particularly limited, but the concentration is unstable due to the hygroscopicity of the memefural, and therefore the volume of the 50th issue of the Japanese Food Science Association (issued April 15, 2003) It is preferable to use the method for quantitative determination of umefural in plum extract described on pages 188 to 192.

  As described above, the method for producing a plum extract according to the present invention is a method of pressurizing and heating a raw plum juice having a water content of 30% by weight or more and a relatively low viscosity. First, 5-hydroxymethyl- Since 2-furfural and umefural were produced, there was almost no air entrainment in the plum juice in the heating step. Then, after the heating process is completed, the water content is reduced to 20% by weight or less under reduced pressure, so that no air is trapped in the concentration process and a deaeration effect can be obtained. Therefore, it is possible to produce a plum extract containing a large amount of umefural, excellent in quality without air entrapment, and ready for shipment with good workability.

  In addition, if the desalination treatment solution of ume vinegar is used as plum juice as in the production method of claim 2, ume vinegar which has no utility value and has a big problem as industrial waste after umeboshi production is produced. Effective use. In other words, it can greatly contribute to the effective use of resources and environmental protection.

  If the heating step is performed in a pressurized state as in the production method of claim 3, 5-hydroxymethyl-2-furfural and umefural can be generated in a short time, and the working efficiency is dramatically improved. To do.

Hereinafter, embodiments of the present invention will be described in detail.
The method for producing a plum extract of the present invention is, for example, by concentrating a squeezed juice squeezed from plum fruit to a water content of 35 wt% to 50 wt% to obtain a raw plum juice, and then the raw plum The fruit juice is heated at 100 ° C. to 150 ° C. (preferably around 120 ° C.) for 2 hours in a closed container such as a pressure cooker while keeping the water content almost constant, and 5-hydroxymethyl-2-furfural and umefural are added. After carrying out the heating step to be generated, it is concentrated under reduced pressure until the water content becomes 20% by weight or less.

(Example 1)
Plum fruit juice (brix value 62.4) with a moisture content of 37.6% by weight obtained from the juice of plum fruit is placed in a pressure cooker and heated at 120 ° C for 4 hours while maintaining the state where moisture does not evaporate. Content and brix value of 100 g of plum juice of 5-hydroxymethyl-2-furfural (hereinafter referred to as “HMF”) and umefural (hereinafter referred to as “MF”) after 2 hours and 4 hours from the start The results are shown in Table 1 together with the water content calculated from the Brix value.
In addition, content of HMF and MF was measured using HPLC (high performance liquid chromatography) according to the determination method of the memefural in the ume meat extract described in the above-mentioned Journal of Japan Food Science and Technology Association.

It can be seen from Table 1 that HMF and MF are generated by heating, and the amount peaks in 2 hours. When the heating time is longer than 2 hours, HMF and MF decrease.
The increase in the amount of water is thought to be due to water being generated at the same time as HMF and MF are generated by the dehydration reaction involving citric acid and sugar.

(Example 2)
While maintaining the state where the moisture does not evaporate, the plum juice (brix value 62.4) having a water content of 37.6% by weight obtained from the squeezed juice of ume fruit of a lot different from Example 1 was placed in the pressure kettle. The contents and Brix values of HMF and MF in 100 g of plum juice after 1 hour and 2 hours were measured, and the results are shown in Table 2 together with the water content calculated from the Brix values. In addition, after the completion of heating for 2 hours, the plum extract was concentrated under reduced pressure for 1.5 hours in a non-stirred state while maintaining the inside of the pressure kettle at 45 ° C. to 55 ° C. to obtain a plum extract containing a high concentration of MF. The obtained plum extract had no air bite and the surface was smooth and mirror-like. Further, the contents and brix values of HMF and MF in 100 g of plum juice at 1 hour and 1.5 hours after the start of concentration were measured, and the results are shown in Table 3 together with the water content calculated from the brix value. .

  From Table 2 above, it can be seen that the contents of HMF and MF reach a substantially peak in a heating time of 2 hours. Moreover, it can be seen from Table 3 that in the vacuum concentration step, the concentrations of HMF and MF increase in proportion to the concentration.

(Comparative Example 1)
Plum juice (brix value 62.3) with a moisture content of 37.7% by weight obtained from the squeezed plum fruit juice was placed in a pressure cooker, and the moisture content was maintained at 40 ° C while maintaining a moisture content of 17.3% by weight ( After concentration under reduced pressure until the Brix value reaches 83.1), the temperature in the pressure kettle is heated to 100 ° C. with stirring, and the heating is continued at 100 ° C. for 4 hours while keeping the water content almost constant. The heating temperature was raised to 110 ° C. and the mixture was heated for 3 hours to obtain a plum extract containing a high concentration of MF.

The obtained plum extract had a bite of air, the surface was uneven, and the appearance was poor. Moreover, there were many insoluble matters.
Moreover, the content and Brix value in 100 g of plum juice of HMF and MF were measured every hour from the start of heating, and the results are shown in Table 4 together with the water content calculated from the Brix value.

(Comparative Example 2)
Plum fruit juice (brix value 62.3) obtained from the juice of plum fruit was concentrated under reduced pressure at 70 ° C to 75 ° C until the water content reached 19.2% over 3 hours. The plum extract was obtained, and the content and Brix value of HMF and MF in 100 g of plum juice were measured every hour from the start of vacuum concentration, and the results are shown in Table 5 together with the water content calculated from the Brix value. In addition, the obtained plum extract did not bite in air, and the surface was smooth and looked good like a mirror surface.

  From Table 5 above, it can be seen that umefural is not contained at all in the obtained plum extract only by vacuum concentration at a relatively high temperature, although it is 100 ° C. or lower. That is, when the plum extract is produced only by concentration under reduced pressure, air is not trapped and the surface becomes smooth like a mirror surface, but it is well understood that the purpose of containing umefural cannot be achieved.

(Example 3)
The raw material is a desalinized treatment solution of 74.5 wt% plum vinegar (Brix value 25.5) reduced from a salt concentration of 23.2 wt% to 0.1 wt% by electrodialysis using an ion exchange membrane. While obtaining as plum juice, this raw plum juice was concentrated under reduced pressure until the water content became 37.5 wt% (Brix value 62.5) to obtain concentrated plum juice. This concentrated plum juice is put in a pressure kettle and heated at 120 ° C. while keeping the moisture from evaporating, and the contents and brix values of 100 g plum juice of HMF and MF after 1 hour and 2 hours are measured. The results are shown in Table 6 together with the water content calculated from the Brix value.

  Moreover, after completion of heating for 2 hours, the plum extract was concentrated under reduced pressure for 1.5 hours in a non-stirred state while maintaining the inside of the pressure kettle at 45 ° C. to 55 ° C. to obtain a plum extract containing a high concentration of MF. The obtained plum extract had no air bite and the surface was smooth like a mirror surface and had good non-image quality. It was organoleptically good as well as plum extract produced from plum juice. In addition, the contents of HMF and MF in plum juice after 1 hour and 1.5 hours from the start of concentration and the Brix value were measured, and the results are shown in Table 7 together with the water content calculated from the Brix value. .

  From Table 6 above, it can be seen that the content of HMF and MF reaches a substantially peak in 2 hours of heating time. Moreover, it can be seen from Table 7 that the concentration of HMF and MF is higher in the vacuum concentration step than in the concentration step. The reason why the content of umefural is slightly lower than that of the method of Example 2 is considered to be that the fruit juice component is lost simultaneously with the salt during the desalting treatment.

(Example 4)
While maintaining the state where the moisture does not evaporate, the plum juice (brix value 62.3) having a moisture content of 37.7% by weight obtained from the squeezed juice of ume fruit of a lot different from Example 1 is placed in the pressure kettle. For 2 hours, and after heating, while concentrating to 45 ° C to 55 ° C, concentrating to 19.6 wt% moisture (Brix value 80.4), heating the concentrated plum extract to 110 ° C for an additional 3 hours A plum extract containing high concentration of MF was obtained. The obtained plum extract had fewer insolubles than those of Comparative Example 1, and had good quality.

  And the content and brix value in 100 g of plum juice of HMF and MF every hour during primary heating, and the content and brix value of 100 g of plum juice in HMF and MF every hour during reheating after concentration The results are shown in Table 8 together with the water content calculated from the Brix value.

  From Table 8 above, it can be seen that a plum extract containing a high concentration of MF can be obtained in a shorter time than the method of Comparative Example 1. It can also be seen that when the reheating time is longer than 2 hours, the amount of MF produced decreases.

Claims (3)

A method for producing a plum extract, which is a method for producing a plum extract containing umefural by heating and concentrating plum juice, and heating the raw plum juice having a water content of 30% by weight or more while maintaining the state in which moisture does not evaporate. A method for producing a plum extract, comprising: a heating step for producing hydroxymethyl-2-furfural and umefural, and a vacuum concentration step for concentrating the water to 20% by weight or less after completion of the heating step.   The method for producing a plum extract according to claim 1, wherein the plum juice is a desalting solution of plum vinegar.   The manufacturing method of the plum extract of Claim 1 or Claim 2 with which a heating process is performed in a pressurized state.