Method of producing odorless ripe juice of houttuynia cordata

A method of producing an odorless ripe dokudamiso juice comprises the steps of preparing a green juice from fresh dokudamiso, heating the green juice prepared at a temperature of 70.degree. to 80.degree. C. for 10 to 30 minutes or roughly filtering the prepared green juice, and oxidizing it. This method permits the dokudamiso components having medicinal effects to be easily provided at any time in a form which allows internal use.

BACKGROUND OF THE INVENTION 
The present invention relates to a method of producing an odorless ripe 
juice containing the components of Houttuynia cordata (referred to as 
"dokudamiso" hereinafter), which have medicinal effects, from raw 
dokudamiso. 
Dokudamiso contains abundant amounts of quercitrin, which is a flavonol 
glucoside having a cardiotonic function, an intestine regulating function, 
a blood pressure regulating function and a detoxicating function, and 
other components having medicinal effects. Dokudamiso has been therefore 
used as a folk medicine for a long time. As is generally known, however, 
dokudamiso has a strong, unpleasantly peculiar odor. To use it, it is 
therefore necessary to extract the quercitrin from dokudamiso by squeezing 
or leaching and then to decompose or remove the odor components. 
It is known that the odor components of dokudamiso are laurin aldehyde and 
caprin aldehyde, which are irrelevant to the medicinal effects thereof and 
which can be substantially completely removed by drying or steam 
distillation. In most cases, dokudamiso is therefore utilized through the 
internal use of an odorless exudate obtained by a method of decocting dry 
dokudamiso. Although this method has an advantage in that the effective 
components of dokudamiso can be used throughout all seasons if dry 
dokudamiso only is prepared, it is tedious to decoct dry dokudamiso for 
each internal use of the odorless exudate. 
A method of utilizing dokudamiso without drying is proposed in which a 
dokudamiso green juice is deodorized and then internally used (Japanese 
Patent Publication No. 59-7692). In the deodorizing method, a yeast and a 
carbon source therefor are inoculated into the dokudamiso green juice, 
which is then fermented, and the thus-obtained suspension is filtered. In 
this method, however, since the odor components of dokudamiso are 
decomposed or converted into odorless compounds during the process of 
alcoholic fermentation using a yeast, deodorization takes much time, and 
it is necessary to be extremely careful regarding the management of the 
alcoholic fermentation process so as to prevent putrefaction and the 
occurrence of mold. This method also has the problem that, since the 
deodorized dokudamiso juice contains alcohol in a content substantially 
the same as that in alcoholic beverages, the juice becomes hard to drink 
for the aged or infant. 
Accordingly, it is an object of the present invention to provide a method 
of producing a dokudamiso juice by which dokudamiso green juice can be 
deodorized by a deodorizing method without using alcoholic fermentation to 
improve the taste and provide the effective components of dokudamiso in a 
form which allows them to be drunk easily. 
It is another object of the present invention to provide a method of 
effectively producing in a short time a dokudamiso juice which is suitable 
for drinking and which contains the dokudamiso components having medicinal 
effects. 
SUMMARY OF THE INVENTION 
A method of producing a dokudamiso juice in accordance with the present 
invention comprises the steps of preparing a green juice from fresh 
dokudamiso, heating or roughly filtering the juice and then oxidizing it. 
DETAILED DESCRIPTION OF THE INVENTION 
Although any desired method for first preparing dokudamiso green juice can 
be used, the green juice is generally prepared by grinding dokudamiso, 
which should be as fresh as possible, for example, crushing it by a hammer 
crusher, to form a slurry, compressing the slurry formed and then removing 
the lees. When the cell walls are decomposed by an enzyme such as 
pectinase or the like which is added in the process of preparing the green 
juice or to the green juice obtained, the yield of the green juice and the 
efficiency of the subsequent oxidation are effectively increased. 
An appropriate heating apparatus such as a corrugated tube-type heating 
apparatus is used for heating the thus formed green juice. It is 
preferable that the heating temperature be 70 to 80.degree. C., and the 
heating time be about 10 to 30 minutes. A heating temperature of 
80.degree. C. or more is unsuitable because it destroys the components 
having medicinal effects. However, not all the heating process need be 
effected in a heating apparatus, and the green juice may be heated to the 
predetermined temperature in a heating apparatus and then transferred to a 
tank in which the juice is subjected to the above thermal treatment while 
standing at room temperature. 
The heat treatment causes the sterilization of the green juice, and 
oxidation (owing to the dissolved oxygen) and evaporation of most of the 
aldehydes, which are the odor components, to produce a green juice having 
an odor ranging from slightly unpleasant to substantially odorless, in 
correspondence with the treatment conditions used. 
When the green juice obtained is roughly filtered, only solid matter, which 
is rapidly deposited when the juice is allowed to stand, may be separated. 
For example, the rough filtration may be carried out by using an 
appropriate filter, such as a filter press, in which filter cloth is used 
as a filter medium or by centrifugation which exhibits the same separating 
effect as caused by the filtration. 
Since most microorganisms adhering to the raw dokudamiso material adhere to 
the lees (sediment) in the green juice, the microorganisms are removed 
from the green juice by the rough filtration. In addition, since most of 
the aldehydes, which are the odor components, are filtered off, the 
unpleasant odor is significantly reduced. 
The oxidation is carried out by using oxygen gas, an oxidizing agent, or 
combination thereof, after the heat treatment or the rough filtration The 
oxidation by oxygen gas is effected by blowing the oxygen gas into the 
green juice to generate fine bubbles after the heat treatment or the rough 
filtration. The oxygen gas may be generated from an oxygen bomb or an 
oxygen generator, or air from which microorganisms are removed may be 
used. When an oxidizing agent is used, the oxidizing agent is added to the 
green juice and mixed therewith in an appropriate reactor or storage 
vessel, followed by reaction, as occasion demands, under heating. Examples 
of oxidizing agents that may be used include ammonium persulfate, benzoyl 
peroxide and the like, which can oxidize the aldehydes to form the 
corresponding carboxylic acids and which can be used in food. The 
treatment by combination of oxygen gas and an oxidizing agent is 
particularly preferable because the purpose of the treatment can be 
achieved in a very short time. The oxidation treatment causes the complete 
decomposition of the odor components remaining after the heat treatment or 
the rough treatment so as to make the juice odorless. The oxidation causes 
no destruction of the components of dokudamiso having medicinal effects. 
Although a clear explanation has not been made, it is thought that 
complicated chemical reactions simultaneously take place between many 
other components of the green juice to produce a mellow taste in the same 
way as in ripening of a liquor during preservation after the completion of 
fermentation. Namely, the dokudamiso juice of the present invention not 
only has no unpleasant odor but also has pleasant taste and good body. The 
juice is thus made easier to drink without any hesitation (this change 
being termed "ripeness" in this specification). 
In the present invention, the dokudamiso green juice is deodorized and 
ripened by the above-mentioned method so that an odorless juice having a 
good taste and containing the dokudamiso components having medicinal 
effects can be easily produced in a short time. Since the juice itself 
obtained is drinkable without any hesitation and has no peculiarities, if 
flavorings such as sweeteners or souring agents, spices and the like are 
added to the juice, it can be used as a tasty health drink having the 
medicinal effects based on quercitrin. The juice can also be used in the 
production of alcoholic drinks containing components such as quercitrin 
having medicinal effects if it is fermented by using a yeast and a carbon 
source such as sugar, honey or the like. The present invention therefore 
permits the dokudamiso components having medicinal effects to be easily 
provided at any time in a form which allows easy drinking.

EXAMPLE 1 
Fresh dokudamiso was chopped, crushed and squeezed to obtain a green juice 
containing 4.8 mg/100 g of quercitrin. The thus-obtained green juice was 
then introduced into a corrugated tube-type heating apparatus used for 
food in which it was heated at 80.degree. C. for 1 minute. The green juice 
was then introduced into a tank having no cover in which it was allowed to 
cool for 4 days. 
After heat treatment, although the color of the green juice had changed to 
ocher, and the unpleasant odor had mostly disappeared, it could be taken 
only with some reluctance and had a bad taste. 
Benzoyl peroxide serving as an oxidizer was added to the juice in an amount 
of 66 g per kiloliter of the juice, and, at the same time, 15 Kg of oxygen 
gas was blown into the juice over a time of 8 hours. After the treatment, 
the juice was a clear amber liquid which gave none of the unpleasant odor 
peculiar to dokudamiso and was well ripened so as to have a good taste. 
The juice also contained 4.1 mg/100 g of quercitrin, showing substantially 
no loss of quercitrin caused by heat treatment and oxidation of the green 
juice. 
EXAMPLE 2 
Fresh dokudamiso was chopped, crushed and squeezed to obtain a green juice 
containing 4.8 mg/100 g of quercitrin. The thus-obtained green juice was 
roughly filtered by using a filter press. 
After filtration, although the unpleasant odor of the green juice mostly 
disappeared, it could be taken only with some reluctance and had a bad 
taste. 
Benzoyl peroxide serving as an oxidizer was added to the juice in an amount 
of 66 g per kiloliter of the juice, as well as 15 Kg of oxygen gas being 
blown into the juice over a time of 8 hours. After the treatment, the 
juice was a clear amber liquid which gave none of the unpleasant odor 
peculiar to dokudamiso and was well ripened so as to have a good taste. 
The juice also contained 4.1 mg/100 g of quercitrin, showing substantially 
no loss of quercitrin caused by oxidation of the green juice.