Note: Descriptions are shown in the official language in which they were submitted.
07~39
FR~ZEN sRE~D sul~sLE EoR HE~TING IN A MIcRowAvE OVEN
EACKGROUND OF THE INVENTION
Eield of the Invention
This invention relates to frozen bread suitable for
heatiny in a microwave oven.
Prior Art Stat~ment
~ hen conventional bread is frozen and then heated in
a microwave oven, not only dose it have a strong "pull"
(defined as excessive resistance to a pulling force) and is
not cut cleanly with the teeth when eaten, but the
phenomenon of "shrinkage" is unavoidable. The problem of
"pull" will not occur if frozen bread is allowed to thaw
naturally at room temperature, but in the case of bread in
which food products of high moisture content are baked into
or placed between slices of bread, thawing at room
temperature is time-consuming and unsanitary. To remedy
this situation, it is desirable to create a type of frozen
bread which when thawed by heating in a microwave oven for
a short amount of time (e.g., 30-60 seconds) has none of the
above "pull" or "shrinkage", but rather becomes fluffy,
appetizing bread.
Japanese Patent Application Public Disclosure No.
63-287435 proposes a method of solving the problem of "pull"
by mixing into the bread dough a markedly higher than
normal proportion of fat and oil to flour, namely, 10-30 %
z~o~
by weight. However, when the frozen bread obtained by this
method is heated in a microwave oven, shrin~age occurs, it
becomes too soft, lacks fluffiness and its outside surface
wrinkled.
Therefore, it is an o~jeet of the present invention
to ~rovide frozen bread which when thawd by heating in a
microwave oven will give fluffy ~'just-baked" bread in which
there i5 no "pull" and shrinkage does not occur.
SUMM~RY OF THE INVENTION
The frozen bread of this invention is characterized
by being made by baking bread dough comprising mainly ~leat
flour with an emulsifying agent content of 0.S-6% by weight.
The emulsifying agent content of bread dough
according to this invention is 0.5-6% by weight with
respect to wheat flour, preferably 1-S% by weight. While
emulsifying agent is used in making conventional bread, it
is typically present in quantities of less than 0.5% by
weight. However, the present invention lies in an
emulsifying agent content significantly higher than nonmal,
so that this emulsifying agent content will preven-t
transpiration of moisture when thawed by heating in a
micowave oven, thus preventing the bread from drying out,
controlling aging of the bread and preventing the "pull"
phenomenon. If the emulsifying agent content is less than 0
5% by weight, bread with strong "pull" will result, while
~ 3~C37
if -the content exceeds 6% by weight, the bread will brittle
during freezer storgae and be crumbly even after thawing.
Usable emulsi~ying agents include fatty acid esters
of sucrose, polyglycerol, esters, lecithin or the like,
preferably a palmitic acid ester of sucrose, stearic acid
ester of sucrose or the like.
Note that when bread is made by means of the sponge
dough process, the emulsifying agent may be divided among
-the sponye dough and final kneading ingredients.
Frozen bread to which a fatty acid ester of sucrose
is added as in the above has no 'ipull" and is cut cleanly
with the teeth when eaten, but a certain amount of shrinkage
will occur. In this case, by adding egg white to the bread
dough in such quantity which, if converted to powder, would
be 10-60% by weight of the added fat and oil content, the
spongy tissue of the bread will be suitably formed, giving
fluffy bread with no shrinkage. If the egg white content is
less than 10% by weight of the added fat and oil content,
shrinkage will occur, while a content of greater than 60%
i5 not ~referable since since the dough will become hard.
The fat or oil added to the dough in this invention
need not be any particular type of fat or oil. Specifically,
fats and oils act to improve flavor and prevent drying and
are thus typically added to the bread dough. Thus the fat
and oil content of the dough is used as the basis for the
egg white content in this invention, namely 10-60% if
~ O~ 7 ~
converted to powder. Normally a ratio of fat and oil
content to flour of about 3-9% by weight is sufficient.
Usable fatas include butter, margarine, palm oil, cocoa
butter and other fats which congeal at room temperature, or
alternately linseed oid, soybean oil, sesame oil, peanut
oil or other vegetable oil, any of which may be used
singularly or mixed in various proportions. In addition,
fats and oilsa may be added to the bread dough in the fonm
of vegetable shortening.
Other typical additives may be added to the bread
dough, which is then allowed to rise, divided, molded, etc.
by normal methods to make it into bread which is then frozer~
DESCRIPTION OF THE EXAMPT.F~
The invention will be described below in detail by
means of examples which in no way limit the invention.
X0~L070
ExamEle 1
Sponge douyh was prepared using the following
ingredients.
Sponye dough
Inyredient Quantity
(9) (%)
Bread flour 350 35
All-purpose flour 350 35
Yeast food 1.5 0.15
Yeast 25 2.5
Fatty acid ester of sucrose 14 1.4
Water 400 40
Note that a stearic acid ester of sucrose was used
as the fatty acid ester of sucrose.
The above ingredients were placed in a 2 kg-capacity
vertical mixer (supplied by Aikosha Mfg. Co. Ltd., model
AM~lS) and mixed at low speed (150 rpm) for 3 minutes and at
medium speed (250 rpm) for 2 minutes. The mixture was
kneaded at a te~perature of 26- C and allowed to rise for 4
hours.
Then the final kneading was carried out using the
following inyredients.
20~7al9
F~al kneading dough
Ingredient Quantity
(g) (%)
Sponge dough from above All
Bread flour 150 15
All-purpose flour 150 15
Sugar 100 10
Table salt 20 2
Mbrgarine 50 5
Fatty acid ester of sucrose 6 0.6
Water 200 20
All of the above ingredients other than margarine
were placed in a 2 kg-capacity vertical mixer and mixed at
low speed (150 rpm) for 2 minutes, at medium speed (250
rpm) for 2 minutes after which margarine was added and then
mixed with at high speed ~350 rpm) for one minute. The
dough was allowed to rest for 10 minutes at a temperature
of 280 C. The bread dough thus obtained was divided into
60 9 portions, rounded, allowed to rest for an additional
10 minutes, placed in pans, proofed for 50 minutes at 38 o
C and 75% humidity, and after proofing was baked for 9
minutes in a batch-type oven with an upper temperature of
180 C and lower temperature of 100 C.
2~07(~19
Exa~le 2
Sponge dough and final kneading were prepared as in
EXample 1 using the follwoing ingredients.
Sponge dough
Ingredient Quantity
(g) (%)
Bread flour 350 35
All-purpose flour 350 35
Yeast food l.S 0.15
Yeast 25 2.5
Fatty acid ester of sucrose 14 1.4
Water 400 40
Note that a stearic acid ester of sucrose was used
as the fatty acid ester of sucrose.
2(~0~
Final kneading dough
Ingredient _ Quantity
(9) (%)
Sponge dough from above All
Bread flour 150 15
All-purpose flour 150 15
Sugar 100 10
Table salt 20 2
Fatty acid ester of sucrose 6 0.6
Egg white 2 0.2
Mbrgarine 50 5
Water 200 20
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Z 03L~ 7 ~ 9
Test 1
The bread made in EXamele 1 abo~e was frozen at -20
o C and then thawed by heating in a microwave oven until
warm. The bread was subjected to organoleptic evaluation
by 10 research panelists and the strength of its "eull"
measured. Using a rheameter (made by K.K. E`udo Kogyo), the
strength of the 'Apull" was measured as -the distance in cm
over which bread is pulled from the start of pulling untill
it exhibited maximun stress and parted. This pulling
distance and -the results of the organoleptic evaluation are
compared in Table 1.
The conditions of the measurement were as follows:
Range 2K
Chart speed 12 om/min.
Table speed 6 cm/min.
Adapter no. No. 17
Sample size 1.5 cm x l.S cm x 7 cm, cut
from center of product
Under the above conditions, one centimeter of both
the top and bottom of the sample was clamped in the adapter
and pulled apart at a fixed speed t6 cm~min.) to detenmine
the distance in om until the bread begins to pull apart.
As is apparent from the results in Table lA and
Table lB, '~pull" is considered to be absent if the pulling
length is 1.57 cm or less.
20~0~7(39
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-1 1-
21~3~ 9
Test 2
l'he bread manufactur0d in E~n?le 2 above was frozen
at -20 o C along with co~nercially avialable bread as a
control~ Both types of bread were then heated for 60
seconds in a microwave oven (500 W) until warm, and then
organoleptically evaluated by 10 research panelists. The
results are shown in Table 2.
Table 2
Test item Cbmmercial bread Bread fran EXample 2
_
Appearance Shrinkage evident; No shrinkage evident;
bread appears appearance is the
slightly sunken. same as fresh-baked
bread.
Sensation Texture seems heavy, No pull, texture is
upon lacking softness. fluffy and airy.
eating Pull is strong; has
a gumrlike texture.
_
- 1 2 -
2C~l07~9
EXample 3
Bread was made using the same ingredients as in
Exampel 2, but the egg white content was varied to 10%, 60%
and 80% of the at and oil content, and the effects of
changing the egg white content were examined after bread
was thawed in a similar manner. The results are compiled in
Table 3~
Table 3
Appearance Sensation upon eating
Wrinkles on surface, Lacks airiness, feels
Cbntrol shrinkage evident, sticky inside mouth,
bread appears slightly heavy texture.
sunken.
No wrir~les on Airy and does nat feel
10 % surface~ sticky inside mouth.
no shrir~age.
No wrilikles on Fluffy and does not feel
60 % surface, sticky inside mouth.
no shrinkage.
No wrinkles on Hard texture; tastes
80 % surface, dry.
no shrinkage.
_.
- 1 3 -
2 ~L0
As described above, the frozen bread of this
invention, when thawed by heating in a microwave oven, has
no "pull" and drying out of the surface does not occur. In
particullar, when egg white is addecl, the spongy tissue of
the bread will be well fonmed and shrinkage does not occur,
giving bread with a fluffy, airy texture having the
appearance and sensation upon eating of that of fresh-baked
bread.
- 1 4 --
