Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02344598 2001-04-19
S P E C I F I C A T I O N
VACUOUSLY COOKED CORN AND VACUOUS COOKING METHOD
OF CORN
BACKGROUND OF THE INVENTION
This invention relates to vacuously cooked corn and vacuous
cooking method of corn.
Conventionally we have so-called retort-pouched foodstuffs
in the area of vacuously packed foodstuffs. Retort-pouched
foodstuffs are regulated by JAS standard for its application items,
quality standard, designation basis, and method of sterilization by
heat under pressure in airtight packing is indicated.
Cooking and production process of conventional vacuously
packed foodstuffs supplied at normal temperature, such as corn
provided as retort-pouched foodstuffs, comprises processing flows of
boiling, steaming, then being vacuumed in film packing, being
heated at high temperature (usually at more than 120 degree
centigrade) for sterilization.
However, the following defects are observed in corn
provided by above-mentioned processing.
(1) fauality feature
Because of storing and distribution at normal temperature,
starch aging into alpha-decay causes deterioration in quality
feature and taste.(aging is accelerated most under temperature
between 2 and 3 degree centigrade).
(2) Taste and flavor
Because of heat treatment (blunting) on peeled corn
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CA 02344598 2001-04-19
through boiled water or hot steam, good taste and flavor is apt to be
washed into water and to be deteriorated.
(3) Nutrient
Because of heat treatment (blunting) through boiled water
or hot steam, water-soluble nutrient is apt to be wasted. Because of
retort treatment (hot temperature and high pressure), Vitamin B1 is
apt to be destroyed.
It is, therefore, an object of the invention to provide
foodstuffs of processed corn without above-mentioned defects,
especially to provide vacuously cooked corn and vacuous cooking
method of corn without defects.
In order to accomplish the object, the present invention
resides in that the corns are totally adhered with seasoning solution
or water, then sealed vacuously, and processing by heating
afterwards.
Furthermore, in order to accomplish the object, the present
invention resides in that the method of vacuous cooking corn
comprises adhering corn totally with seasoning solution or water,
then sealing vacuously, and processing by heating afterwards.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Then, the invention will be now described with reference to
the preferred embodiments of processing of vacuously cooking corn.
In order to make the description more simplified, the description are
based upon mostly whole corn, while usually it is classified (1)
whole corn, (2) cut corn.
Preparation process of vacuous cooking is now described as
follows.
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(1) Selection of raw materials:
In the case of whole corn, in order to prepare material equal
quality, selection is made from the point of good maturity, freshness,
and deformation, row in line. It is almost similar standard in the
case of cut corn.
(2) Peeling:
(3) Washing:
Downy hair, or other filth is washed away.
(4) Trimming:
Corn remained to the core is less than 1 cm after cutting
work. In the case of cut corn, cut surface is be in fair level, for
example, food cutter shall be used so that edible part makes 4 cm
length equal.
(5) Rough selection:
Ol Remove thoroughly remained rind and downy hair.
2~ Remove those with distortion, bending, uneven grain size,
irregular line up.
3~ Remove those with grain missed, discolored, freak.
~ Cut down at right angle distorted top with length of more
than 2 cm.
~5 Remove those abnormal with less-matured or excessive
matured grain.
~ Remove those with more than 3 percents damaged grain.
In the case of cut corn, disregard above U and ~6~, because
of nothing to do with the cut corn.
After above preparation process, following process is be
carried out.
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(6) Adhering of solution:
After above preparation process, adhering process on corn is
carried out, such as being dipped in solution. The process shall be
necessary for the purpose of seasoning to corn, generally to make
sweetness conspicous, dip in salt solution. When sweetening is not
necessary, solution may be just water. Though range of salt density
and its sweetening effect might be recognized, as general guidance,
dipping in saturated salt water for one or two minutes is considered
practical.
Furthermore, solution adhered to corn in these process
works as heat conductive agent during corn heating process after
vacuous sealing process.
(7) Packing:
Packing material is chosen from viewpoints of its proof
against heating temperature, cooling temperature, air-tightness,
water-tightness, and strength. Namely packing material is enough
proof against heating at 100 degree centigrade for 60 minutes,
cooling at minus 30 degree centigrade, and also enough proof
against vacuous sealing condition for air-tightness through
after-mentioned production process in sealed packing, and also
enough physical strength for handling through delivery and
transportation. One of the raw materials found suitable as packing
material is those with trade name of "Dia-milon M" supplied by
Mitsubishi Resin Company.
The packing material is of the multi-layer film with 80 micro
millimeter thickness made of either nylon, polyester, polyethylene.
In the case of whole corn, packing is made entirely with
stem.
(8) Vacuous sealing:
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Vacuous sealing is carried out by evacuating air in packing
and sealing. This process is substantially important in this
invention, where thorough evacuation of air shall be made for
sufficient heat delivery to corn from outside and then sealing is
made (for example, air evacuation into vacuum condition for more
than 90%, preferably about 97%) and sealing is made in order to
vacuous condition in packing is be duly maintained. Insufficient air
evacuation causes residual air to obstruct heat conductivity and to
prevent heating corn fully in heating process described later.
(9) Heating:
Heating process is carried out for cooking corn by heating
and also in order to penetrate solution with contained seasoning, for
example, salt and water in saltwater solution into cor n grain.
Heating temperature and processing period is very dominant for
finish of product (sweetness, grain hardness, eating touch, color
fading into brown, number of residual bacteria etc.). The invention
recommends temperature of steam or boiling water of between 90
degree and 100 degree centigrade for the heating period between 25
and 40 minutes, preferably about 30 minutes.
Too low heating temperature, or not enough heating period
results in insufficient cooking corn, insufficient heat delivery from
heat source outside (steam or boiled water) to corn, further results
in insufficient penetration of salt solution causing want of
sweetness, too hard grain, inferrior eating touch, increased number
of residual bacteria.
On the other hands, too hot heat temperature, excessive
heating period results in grain too soft, color fading into brown
(temperature higher than 100 degree centigrade changes sugar
ingredient brown), also resulting smelling out from non-edible stem
part).
(10) Rapid cooling
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Rapid cooling is carried out to avoid increasing of number of
bacteria which would occur when slow cooling carried out.
It is recommended that temperature of corn core should be
cooled down into lower than 10 degree centigrade within 90 minutes,
this invention indicates cooling process after heating process by
dipping in cooled water (temperature below than 13 degree
centigrade) so that temperature of corn core is cooled down lower
than 13 degree centigrade.
(11) Rapid refrigerating:
Rapid refrigerating is carried out so that temperature of
corn core is refrigerated to lower than minus 18 degree centigrade.
(12) Storing:
Corn Rapidly cooled and refrigerated through said process is
stored at temperature lower than 18 degree centigrade so that they
can be delivered through transportation condition on necessary
occasion.
(The other preferred embodiment)
The description above referred to the case of solution
adhered to corn is be of salt water or just water, however other
seasoning ingredient can be adopted. For example, solution might be
water containing other kinds of dressing.
In this case, the processing method, in principle, may be of
those similar to the description above.
The invention described here above has an effect
conspicuous compared to the conventional retort pouch foodstuffs,
as described below.
(1) Taste and flavor contained in the corn remain as they are,
because heating and cooking process are carried out in sealed
packing. These effects are more conspicuous for foodstuffs of highly
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freshness.
(2) Soluble ingredients of nutrient contained in foodstuffs are
kept and remained because heating and cooking process is carried
out in vacuously sealed condition.
(3) By means of storing and delivery made at refrigerated
condition, starch aging into alpha-decay can be avoided, and they
can be eaten by re-heating to normal condition just before eating
with good quality sensibility and taste same as those of soon after
heating and cooking process.
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