Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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73299-13
METHOD OF KEEPING QUALITY OF AGRICULTURAL PRODUCTS AND FOODS
BACKGROUND OF THE INVENTION
The present invention relates to a method of keeping quality of
agricultural produc~s and foo,is. In other words, the present invention
relates to a method of protecting the quality of agricultural products
and foods from dama~es caused by various kinds of reasons during the post
harvest dis~ributions.
There are many reasons why agricultural products and foods are
deteriorated during the post harvest distributions. Some are caused by
insects and mites. In other to solve the problems gas fumi~ation,
sterili~ation (at high or low temperature), elimination, suppression (low
temperature, drying, hi~h conc~J~ration, vacuum, food additives), p~k~ing
material, etc. are usually applied. However, the problem are still unresolved. Peopl~ pay more attentioni to the safety of foods recently. Any
chemical residue should not be left in a~ricultural products and foods
after the treatments to keep good quarities.
SUMMARY OF THE I~NllON
The ~.esel.~ invention relates to a method of keeping quality of
agricultural ~.~du~ts and foods with non-residual or little residual
treatment of ~he agricultur~1 produc~s and foods.
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DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a method o~ protecting agricultural
products and foods from biological damages which comprises treating the
agricultural products and foods with 5 to 60 atmosoheric pressure.
Any agricultural products and foods can be treated by the method of
the present invention. For example, such agricultural products and foods
as cereals, beans, root crops, spices, flowers, vegetables, drug plants,
seeds, woods, paper, fibers, processed products of these materials, rice
powder, wheet flour, cakes, candys, dried foods, books etc. can be treated.
Agricultural products ~md foods are damaged their qualities by various
kinds of living creatures such as insects and mites. In this invention,
these harmful creatures are elinminated by using (1) pressure treatment,
(2) rapid depressure treatment following high pressure teeatment or
(3) pressure treatment with gases thak are composed of single or two or
more kinds of gases.
Agricultural products Imd foods contaminated with insects or mites are
treated wi~h 10-25 atmospheric pressure (preferably 20 atmosphere). In the
cases where eggs are supposed to be laid, 20-40 atmospheric pressure
(preferably 30 atmosphere) hals to be applied. In the most cases 10-20
atmospheric pressure will be applied.
The time needed to reach the final pressure will be 20~60 minutes or
even less than 20 minutes and will be decided depending on the size of
treating containers, on the kinds of agricultural products and foods, on
the varieties o~ insects and mites contaminated.
Once the expected pressure is reached the pressure will be released
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either immediately or after being kept under the presuure for some time
less than 60 minutes (normally one second to 60 minutes, preferably
one minute to 30 minutes). The depressure treatment will be finished rapidly
(normally one second to 10 minutes) or gradually within 20-60 minutes
depending on the size and kind of containers used.
Any tightly sealed container can be used for the method o~ the present
invention. As the ~Les~u~e gas, any gas such as carbon dioxide, air, ozon
and nitrogen etc. are applicable. For the treatment of powdery materials
carbon dioxide and nitrogen ga,ses are favorable to avoid explosinos.
Materials can be treated either by continuously or batchwise.
Any single gas can be applied for this purpose and the gas can be
used together with such a gas that can sterilize microorganisms~or kill
insects. Such gases can be found amomg the known fumi~ation gases.
However, in the present invenl;ion, we have to consider the least chemical
~esidue and the least envirc ~ tal pollution, and so extremely low
concentration of these gases that is not effective enough in the usual
treatment will be used. For Isxample, to eliminate Sitophillus zeamais
pho~sphine (PH3) concentration can be as low as 50-100 ~ g/l and
methyl bromide (BrCH3) concentration can be as low as 250~500 ~g/l.
The gas pressure will be deci~ded depending on the kinds o~ insects
and mites or on the growth st~ees o~ these creatues. To eliminate eggs
20-30 atmospheric pressure wilI be needed, but to eliminate lavae,
pupae and adult 10~20 atmospheric pressure will be usually applied.
According to the present invention, du~ing the pressure treatment
and/or depressure treatment, no toxic chemical is used and so there is
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not any hazardous chemical residue in the treated agricultural products
and foods. By the method of the present invention, insects and mites
will be eliminated effectively without causing environmental pollution
problems. Even in the case ~Ihere toxic chemicals is applied the
chemical concentration is extremely low. The method of the present
invention is perfectly new, effective and safe to eliminate small
living creatures such as insects and mites in agricultural products
and foods. The present invent;ion will contribute to protect foods and
materals sa~ely fro~n post harvest deterious.
The present invention will be explained with re~erence to the
folowing examples. Any conventional modifications in the technlcal
field of the invention are ine~luded within the scope of the present
invention.
Example 1
Beetles tSitophilus zealnais, 50 adults) and rice grain (25g) were
kept in a sealed box under 35 atmospheres for five minutes and the
high pressure was then released to one atmosphere in about ten second.
By this treatment all beetles were killed, but there was no un~avorable
effect to the quality of rice grain.
Example 2
Uites (100 adults of Tyrophagus dimidiatus) and pepper powder (lOg)
were sealed in a container under 20 atmospheres for ten minutes and
the high pressuLe was then released to one atmosphere in about ten second.
By this treatment all beetles were killed, but there was no un~avorable
effect to the quality of pepper powder.
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Example 3
Moth larvae (Plodia interpunctella, 25 larvae) and wheat flour (50g)
were kept in a sealed box unde!r 50 atmosph~res for five minutes and
the high pressure was then released to one atmosphere in about ten second.
By this treatment all beetles were killed, but there was no unfaYorable
effect to the quality of wheat; flour.
Example 4
Moth pupae (Ephestia cautella, 25 pupae) and wheat flour (30e)
were kept in a sealed box under 60 atmospheres for three minutes and
the high pressure was then re].eased to one atmosphere in one minute.
By this treatment all pupae were killed, but there was no unfavorable
effect to the quality of wheal; flour.
Example 5
Insect adults (Thrips, Chaetanaphothrips orchidie, 10 adults)
and a branch of orchid flower was put into a wirecage and the cage
was kept in a sealed box under 15 atmospheres for 12 minutes. The
pressure was then released to one atmosphere in 10 minutes. By this
treatment all adults were killedl but the flower was still in
good condition.
Example 6
Beetle eggs (Tribolium castaneum, 20 eggs) and wheat flour (lOg)
were kept in a sealed box under 60 atmospheres for 35 minutes and
the high pressure was then re!leased to one a~o~ph~re in five minutes.
By this treatment all eggs were killed, but there was no unfavorable
ef~ect to the quality of wheat flour.
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Example 7
Insect (Ctenolepisma villosa, 20 adults) in a paper bag was put
into a wirecage~ The cage was ~ept in a sealed box under 55 atmospheres
for 5 minutes and the high pre!ssure was then released to one atmosphere
in one minute. By this treatment all adults were killed, but there was
no unfavorable effect to the quality of paper bag.
Example 8
Beetle eggs (Cryphalus i~ulvus, eg~) was put into a small hall
prepared in the wood. The wood with egg was kept in a sealed box under
50 atmospheres ~or 20 minutes and the high pressure was then released
to one atmosphere in one minute. By this treatment all eggs were
killed, but there was no un~avorable ef~ect to the quality o~ wood.
Example 9
Beetle pupae (Atta~enus piceus, 10 pupae) were put into a wirecage
together with dried bonito. The cage was kept in a sealed box under
50 atmospheres o~ ni.tro~en ga's ~or 3 minutes and the hi~h pressure was
then released to one atmosphere in 30 seconds. By this treatment all
pupae were killed, but there was no un~avorable e~ect to the quality
o~ the dried bonito.
Example 10
Beetles (Sitophilus 7~m~i~t 20 adults) and rice 6rain (30g) were
kept in a sealed box under 20 atmospheres of C02 gas for ~ive minutes
and the high pressure was the!n released to one atmosphere in one minutes.
By this treatment all beet1es were killed, but there was no un~avorable
effect to the quality of the rice.
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Example 11
Beetles (Sitophilus 7,~r i.~, 20 adults and 20 larvae) and rice
grain (30g) were kept in a sealed box under 20 atmospheres of C02 gas
for five minutes and the high pressure was then released to one
atmosphere spending 3 minutes. By this treatment all adults and larvae
were killed, but there was no unfavorable effect to the quality o~
the rice.
Example 12
Beetle adults (Sitophilus zeamais, 20 adults) and rice grain (30g)
were kept in a sealed box and C02 gas was filled up to 60 atmospheres
and then the gas was released to one atmosphere in about 10 minutes.
By this treatment all adults were killed, but there was no un~avorable
ef~ect to the quality of the rice.
Example 13
Beetle e~g (Sitophilus 7e~ eggs werelaid into 15 g of rice
while 25 adult beetles were kept in the rice for a week) in 15 g o~ rice
were kept in a sealed box under 30 atmospheres o~ C02 gas for five
minutes and the hi8h pressure was then released to one atmosphere in
one minute. By this treatment all eggs were killed, but there was
no un~avorable e~ect to the quality of the rice. From the rice which
was not treated with C02 gas many larvae were born and adult beetles
appeared later.
Example 14
Beetles (Sitophilus 7e~ , 20 adults) and rice grain (30g)
were put into a sealed box and C02 gas was gradually filled in the box.
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Af'ter 15 minutes the pressure reached to 20 atmospheres and then the
high pressure was released to one atmosphere in one minu-te. By this
treatment all beetles were killed, but there was no unfavorable effect
to the quality of the rice.
Comparative Example 1
Beetle eggs(Sitophilus zeamais, 300 eggs) were sealed in a box
under 15 atmospheres of C02 gas for five minutes and the high pressure
was then released to one atmosphere in one minute. By this treatment
larvae appeared from 203 of e~gs, but there were no larvae from 97 of eggs.
Comparative Example 2
Beetles eggs (Sitophilus zeamais, 300 eg~s) were sealed in~a box
with PH3 gas (50~ g/l) for 20 minutes. The box was opened to the air
and all the eggs survived producin~ larvae.
Example 15
Beetle eggs (Sitophilus zeamais, 300 eggs) were sealed in a box
with PH3 gas (50~g/1) and then C02 gas was filled up to 15 atmospheres.
After five minutes the pressure was released to one atmosphere in one
minute. By this treatmenk no larvae appeared at all later and all
eggs were killed.
Comparative Example 3
Beetles larvae (Sitophilus zeamais, 200 lavae) were sealed in a
box with PH3 gas (100 ~ g/l) for 20 minutes. The box was then opened
to the air and within one month all the lavae became to a~ult beetles.
Comparative Example 4
Beetle larvae (Sitophilus 7~ , 200 lavae) were sealed in a box
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with 5 atmospheres of CO2 gas for 5 minutes. The box was then opened
to the air in one minute and 35 larvae were killed, but 165 lavae were
survived.
Example 16
Beetle larvae (Sitophilus zeamais, 200 lavae) were sealed in a box
with PH3 gas (lO0 ~g/l) and then C02 gas was ~illed up to 5 atmospheres.
After 5 minutes the pres~ e was released to one atmosphere in one minute.
By this treatment all larvae were killed.
Comparative Example 5
Beetle eggs (Sitophilus zeamais, 300 eggs) were sealed in a box with
BrCH3 (500~ g/l) for 20 minutes. The box was then opened to the air and
later larvae appeared from all o~ the eggs.
Example 17
Beetle eg~s (Sitophilus 7,e~m~;~, 300 eggs) were sealed in a box
with BrCH3 (500 ~g/l~and then C02 gas was ~illed up to 5 atmospheres.
A~ter five minutes the pressure was released to one atmosphere ln one minute.
The box was then opened to th~ air and later no larvae appeared from
all of the eggs. By this treatment all eggs were killed.
Comparative Example 6
Beetle eggs (Sitophilus 7e~ 200 lavae) were sealed in a box
with BrCH3 (500 ~ g/l) for 20 minutes. The box was ~hen opened to the
air and after within a month all the lavae bacame to adult.
Comparative Example 7
Beetle larvae (Sitophilus 7e~r~i~, 200 lavae) were sealed in a box
with 5 atmospheres o~ C02 gas ~or 5 minutes. The box was then opened
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to the air within a minute. By this treatment 35 larvae were killed,
but 165 larvae were found to became to adult later.
Example 18
Beetle larvae (Sitophilus zeamais, 200 lavae) were sealed in a box
with BrCH3 (500 ~ g/l) and C02 eas was filled up to 5 atmospheres. After
five minutes the ~e~u~e was released to one atmosphere in one minute.
The box was then opened to the air and all of the lavae were found to be killed.Example 19
In the method of Comparative Example 7, the pressure reached to
20 atmospheres and the larvae were hold for five minutes. After this
treatment only 4 larvae were survived, but the rest 196 lavae were
all killed.
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