Note: Descriptions are shown in the official language in which they were submitted.
CA 02478927 2004-09-30
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A Method For Manufacturing Refrigerated Or Frozen Dough
For Chinese Deep Fried Dough Or Bread Stick
Background
This invention relates to a method of manufacturing refrigerated or frozen
dough for Chinese deep
fried dough or bread stick. The deep fried dough or bread stick is a kind of
Chinese traditional snack,
and one of the most popular snacks in China. It is termed "Youtiao" in
Chinese. It is produced by
preparing dough, sheeting and cutting the dough into strips, and then deep-
frying with cooking oil
l0 maintained at a temperature range between 130 and 170 °C.
In general, it is desirable for the stick to have both the crispy mouth feel
touch proper to outside of
the stick, and the soft texture mouth feel touch of its inside. Such combined
mouth feel touch is
present usually in the stick immediately after frying.
In China, the deep-fried dough or bread stick is a popular snack, especially
for breakfast. However,
since it is difficult to prepare the dough, people normally go to a nearby
snack bar or restaurants to
buy it rather than to cook it at home. Even in modern China, where the ready-
made flour for the
deep fried dough or bread stick is available in supermarkets, it is still rare
for people to buy the flour,
and prepare and cook the stick at home, because it will still take several
hours to prepare and
develop the dough with the flour before frying.
Abroad (outside of China in general); the deep fried dough or bread stick is
normally not served at
Chinese restaurants because it is too expensive to have such a kind of snack
at restaurants from the
view of consumers, and the profit margin is too low to sell it at an
acceptable price from the point of
view of restaurant owners. Therefore, the deep fried dough or bread stick is
normally only available
in supermarkets. However, when the stick is sold in a supermarket, it cannot
be offered in the fresh
fried state, because normally at least several hours, even a day, have elapsed
since being fried. As a
result, the crispy mouth feel touch and the taste of the stick is lowered.
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Therefore, it is necessary to provide a method for providing ready-to-cook
dough for the stick so
that the consumer may just open the package and put the dough into cooking
oil, and have the fresh
fried sticks within a few minutes.
Detailed descn~tion of the invention
The invention relates to refrigerated or frozen dough for Chinese deep fried
dough or bread stick, or
Chinese deep-fried wand of dough. In case of confusion with the product name
in English, the term
"Youtiao" in Chinese should be used.
There is no definite formula for the dough, and people usually make the dough
in accordance with
their own experience. By collecting and testing all the formulae found in
literature, the traditional
formula of the dough may be stated as follows.
Ingredients Percent By weight (approx.)
Flour 55-61
Water 33-4a
Sodium Carbonate (NaZC03) 0.6-1.4
Edible Alum (A1K(S04) 2 .12H20) 1.2-2.1
Salt 0.7-2.6
With such a formula, the following chemical reactions are expected during
preparing, developing
and cooking the dough. When mixed with water, flour becomes a cohesive,
resilient body of dough.
Under the reaction of added leavener, the gluten protein from the flour forms
a resilient, extensible
matrix. At the same time, dextrose, alcohol and carbon dioxide, together with
some organic acid and
ester, are produced.
(C6HmOs)" +nHzO lasvner .~nC~H~206
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RCOOH + CZ HSOH H RCOOCZHS + HZO
The COZ forms holes or voids in the dough and, as a result, rises and expands
the dough. More C02
can be produced by adding Na2C03.
2RCOOH + Na2 C03 = 2RCOONa + COZ T +Hz0
Naz C03 + H20 = NaHC03 + NaOH
During flying, NaHC03 may dissolve to form more CO2, and thus create more
expansion.
2NaHC03 Hea~NaZC03+CO, 1'+HZO
The byproduct NaOH may deteriorate the taste of the stick to some extent.
Therefore, alum is added
to neutralize NaOH.
2A1K(S04)2 ~ 12H20 + 6NaOH = 2A1(OH)3 + 3Na2S04 +KZS04 + 24H20
In the traditional formula, the ratio of the added alum to the added sodium
carbonate is a key factor
for the stick. In general, a ratio of 2:1 is preferred.
2~
Although the traditional formula provides the best taste for the stick, it has
been criticized as an
unhealthy formula because the final product contains a high content of
aluminum. Aluminum is
usually considered to be a harmful element in the human body. Effort has been
made to modify the
formula in order to reduce the content of aluminum in the stick. However, no
proper solution has
been found to replace alum in the stick because the taste of the stick is
always lowered to some
extent without the addition of alum. Therefore, a proper balance between the
taste of the stick and
the content of aluminum in the stick has to be achieved. By trial;, therefore,
an alternative formula
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has been tested, and a significant reduction of the content of aluminum in the
stick has been
achieved without lowering the taste of the stick. In the formula, sodium
carbonate is replaced by
baking soda (sodium bicarbonate) and baking powder, and the details of the
formula are as follows.
Ingredients Percent By weight
(approx.)
Flour 55-61
Water 33-43
Sodium Bicarbonate (NaHC03) 0-0.81
Baking Powder 0-0.81
Edible Alum (AlK(S04) 2.12H20) 0.10-0.36
Salt 0.7-2..6
Baking powder is a combination of baking soda plus a few other things, most
importantly a dry acid.
When the baking powder is mixed in dough with water, the dry acid and the
baking soda can react
together and release carbon dioxide. Specifically, the baking powder
containing slower-acting acid
reacts slowly at room temperature, and releases more of the gas when heated.
This is more desirable
for Chinese deep fried dough or stick because it requires release of the gas
only when it is heated up
(during deep fry).
The ingredients shown above are mixed for preparing the dough as shown in
Figure 1. Since alum is
normally supplied in a granular form, it needs to be dissolved before mixing
with flour and other
ingredients. In the method, therefore, first the alum is dissolved into hot
water. Salt may be added
after the water has been cooled down to 30 °C by adding cool water. The
flour, baking soda and
baking powder are all in a powder form, and therefore they may be evenly mixed
together by mixing
and stirring. Then, the prepared water containing alum and salt is added,
mixed, stirred and kneaded
to form the dough. The dough needs to stand for a half of hour to develop the
gluten of the dough.
Two more kneading processes should be applied at intervals of 30 minutes to
make the ingredients
evenly distributed in the dough. Each of the kneading processes may take
approximately 5 to 10
minutes. Then, let the dough stand for two hours to develop. Tests have showed
that the two-hour
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period is the most ideal period for the dough to develop. Too long or too
short a period all resulted in
insufficient expansion of the final dough when it is fried. The reason for
this is presumably that the
dough does not develop sufficiently if the time is too short, and too much gas
might be lost if the
time is too long.
The objective of the present invention is to provide a method fo:r preparing
"ready-to-cook" dough
for the deep fried dough or bread stick, and the dough prepared this way can
be stored for a period
of a month or longer, so that the dough may be sold in supermarkets. For such
a purpose, the dough
may be preserved either in a refrigerator as refrigerated dough, or in a
freezer as frozen dough.
The packaging process includes the sheeting, cutting and packaging of the
dough. Commercially
available dough sheeting equipment may be used to sheet the dough down to a
thickness between 5
and 25 mm, and a width between 50 and 150 mm. Then, the prepared dough sheet
is lightly oiled on
both surfaces, and then the dough sheet is cut into strips, according to the
following size:
Length Width Thickness
50-150 mm 10-40 mm 5-25 mm
The edge of the cutting blade, which is used to cut the dough sheet, is
lightly oiled so that the strips
will not stick together during the packaging process.
The dough sheet and strips may be packaged for storage. For refrigerated
dough, tests showed that a
black substance formed on the surface of the dough in two to three; days if
the dough is not packaged
with a vacuum. The black substance is presumably a product of the reaction of
the baking soda with
water and air. Therefore, the refrigerated dough must be packaged with vacuum
and kept below 5 °C.
Such packed dough may be kept in refrigerators for two weeks, without any
spoilage.
For frozen dough, tests showed that if the package is sealed properly, a
vacuum is not necessary and
the dough may be kept in freezers at a temperature below -10 °C for a
period as long as two months
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without any spoilage.
The packaged dough is ready for sale in supermarkets. When the dough is going
to be deep-fried,
the refrigerated dough may be immediately fried in cooking oil kept at a
temperature between 130 -
170 °C after the package is opened and the dough sheet or strip is
removed. For the frozen dough,
however, a period of four hours or longer is needed for defrosting the frozen
dough at room
temperature ( around 20 °C) before it can be deep-fried. It should be
emphasized that the dough can
only be deep-fried when the dough is completely defrosted, whereas partially
defrosted dough is
inhibited for frying because it might cause an explosion and splashing of the
cooking oil. A better
practice is to remove the frozen dough from the freezer and to place it in the
refrigerator, and where
it can be kept overnight, or for a period of 12 hours or longer, so that it is
completely defrosted
before it is fried.
Description of the drawings
t5 Figure 1 is a flow chart showing the processing procedure of tile
refrigerated or frozen dough for
Chinese deep-fried dough or bread stick ("Youtiao" in Chinese).
Examples of The Invention
The present invention will now be illustrated with examples. It should be
noted that these examples
are not intended for limiting the invention.
In the following, the first group of examples illustrate the trial formulae,
and the second group of
examples demonstrate the packaging tests.
Many formula trials were tested, and some of the tests are shown in Table 1.
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Table 1
N~C03 P a g Alura Comment
No (~'~'t~%)
(wt.%)
Month Feel Taste
(wt.%)
1 0.81 - 0.81 Too hard Good
2 0.81 - 0.46 Soft and Crispy Better
3 0.35 0.46 0.23 Hard and Crispy Good
4 0.4b 0.35 0.23 Soft and Crispy Best
- 0.81 0.81 Soft and Less Crispy Good
It is noted that the most important ingredients in the formulae are baking
soda., baking powder and
alum. It appears that baking soda and baking powder may, to some extent,
replace each other.
5 However, a proper combination of these two may provide the best mouth feel
as well as the best
taste. For example, Test No. 4 in Table 1 appears to give the best result.
Alum appears not only to
affect the mouth feel, but also the taste. Too much addition of alum appears
to make the stick too
hard, but too little addition of alum not only makes the stick less crispy but
also deteriorates the taste
to some extent.
l0
Many packaging tests were conducted, and some of the tests are listed in Table
2.
Table 2
No Dou h Vacuum pDaod Comment
g ( Y)
1 RefrigeratedNo 2 Black substance occurred
2 RefrigeratedYes 14 No spoilage
3 RefrigeratedYes 21 Slight spoilage
4 RefrigeratedYes 28 Obvious spoilage
5 Frozen Yes 90 No spoilage
6 Frozen No 30 No spoilage
7 Frozen No 60 No spoilage
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There seems to be little problem with the dough stored in freezers if the
package is properly sealed,
and vacuum is not required in the package. In contrast, however, for the dough
stored in refrigerators,
vacuum packaging is required to prevent the dough from spoilage during a
reasonably long period,
such as a minimum of two weeks.
Although the invention has been described with some examples, it should be
noted that various
modifications and variations could be easily made by those skilled in the art
without departing from
the spirit of the invention. Accordingly, the foregoing disclosure should be
interpreted as illustrative
only, and is not to be interpreted in any limited sense. The present invention
is limited only by the
scope of the following claims.
