Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02249167 1998-09-30
Microwave-Expandable Snack Food Product
Field of the Invention
This invention relates to snack foods and more particularly to a snack food
which is microwave expandable and a process for making such.
Back~round of the Invention
Extrusion cooking is a known process for making a variety of food products
which are preferably expanded. Within the realm of extrusion cooking there are
different methods to produce an expanded, extruded product. In one method, puffed
products are prepared by extruding a cooked dough at high moisture content, hightemperature and high pressure. As the product escapes from the die into atmospheric
pressure, the sudden pressure reduction causes excess moisture to flash off and the
product to puff. The product is then allowed to sufficiently dry. Alternatively, "half
products" are cooked and extruded. Such "half products" require additional cooking
of the extruded product in order to produce a puffed, edible product. Cooking the
dough by rapid heating or depressurizing such as by deep frying or heating in a
convection oven causes such "halfproducts'7 to puffout or expand. ~ltt~ tively, the
dough can be "gun puffed" by rotating precut pieces in a sealed, heated drum under
p1es7~u1~;. Upon a release of the pressure inside the drum, the precut dough pieces
expand or puff up.
Another method by which "half products" can be expanded or puffed is by
microwaving. Microwaving is a highly desirable cooking method because it is veryrapid. U.S. Patent 4,950,492 describes a method for making microwave puffed or
expanded snack product in which no fats or oils are used. A flour-free dough is made,
shaped into desired pieces and then steamed for several hours. Once sufficientlysteamed, the dough is then cooled by refrigeration and finally frozen. The resultant
frozen product is then microwaved to puff the product. While this patent does describe
a method for producing a microwavable snack food, the method requires several steps
and therefore is very time consuming and also very costly from a production stand
CA 02249167 1998-09-30
point. The half-product is not shelf stable at room temperature and requires
refrigeration until microwaving.
U.S. Patent 4,990,348 describes a method for making a microwave-puffable
snack food which is extruded as a hot melt from an extruder die. The hot extrudate
may be then coated with flavorings such as sugar coating compositions before it is
allowed to cool. The cooled product is then microwaved to produce a puffed snackfood product. The method of this patent does not however, produce a product which
adequately and consistently puffs during microwaving and thus is not as highly
desired as an instant type of snack food. Furthermore, flavoring is added to thesurface of the product resulting in a coated puffed snack food which makes handsgreasy, sticky and smelly as the coated flavoring rubs off onto the hands when eating.
There is therefore a need to develop an improved method for the production of
a microwave-expanded snack food product which obviates the problems associated
with the methods of the prior art and which also produces a better product with more
desired characteristics and more consistent puffing qualities than microwave-puffed
snack foods pre$ently known and available.
Summ~rv of the Invention
In accordance with the present invention there is provided a novel method for
the production of a microwave-expanded snack food product that is rapid and
economical and which produces a product that consistently puffs up when
microwaved. Furthermore, the method of the present invention consistently produces
a flavored microwave snack food which after microwaving does not lose its flavor,
nor does the flavoring rub off onto the hands when eaten.
According to an object of the present invention there is provided an improved
method for producing a shelf-stable, flavored extruded product having a moisturecontent of not more than 18% by weight, which half-product upon microwaving can
be expanded into a flavored expanded snack food, the process comprising: --
(a) forming a dough within an extruder by introducing and mixing flour
not having more than 10% by weight total protein content, adding 1 to 7% by weight
flavoring or seasoning, adding 3 to 5% by weight oil, and adding sufficient water to
form a dough having a total moisture content of 20 to 45% by weight;
CA 02249167 1998-09-30
(b) advancing and cooking the dough to gelatinize the starch contained in
the flours, at a temperature between 100~C to 120~C for approximately 30 to 60
seconds;
(c) cooling the cooked dough and extruding it through an ~pl'upliate
shaped extruder die opening of an applo~liate shape and cutting, without c~ ing any
expansion, thereby producing a cold extrudate of flavored cooked dough in an
ap~ iate shape and size; and
(d) drying the extrudate to a moisture content of less than 18% to yield a
shelf-stable flavored, half-product which can be forrned into a puffed flavored snack
product.
According to another object of the present invention is a microwave puffed
flavored snack product which has a flavoring encapsulated within the product.
Detailed Description of the Preferred Embodiments
The present invention relates to snack foods which upon microwaving form a
puffed, crisp, flavored product. The present invention also relates to an improved
process for making such a product.
The flavored snack food is prepared by mixing and forming a dough
comprising flour, edible oil and flavorings. Flour suitable for use in the present
invention can be any variety of flours having a protein content of less than about 10%
by weight. More proteinaceous flours produce a product which does not sufficiently
puffupon microwaving. Flours suitable for use include but are not restricted to
wheat, corn, rice, tapioca, rye, potato, soy and other vegetable flours and Illi~lulc;s
thereof.
Edible oil is added to the flour in an amount of about 3 to 5% by weight. Any
vegetable or animal oil is suitable for use in the present invention. Alternatively,
lecithin can be used as a substitute for the oil, however, in smaller quantities. The
amount of lecithin should not exceed 1% by weight as it may create an off-flavor in
the final microwaved product. Both the oil and the lecithin act as a binder and help
hold the flavoring within the gel~tini7e~1 starch upon extrusion cooking.
Flavorings and other taste-imparting or improving compositions are added to
the extruder in an amount of 1 to 7% by weight and incorporated into the dough and
CA 02249167 1998-09-30
hence do not escape or are volatilized, since they will be "encapsulated" within the
final puffed product. Since the flavors are "encapsulated" within the final unpuffed
product (and not coated like in other processes), several different flavored products
can be added into a final retail pack. On microwaving, the pack will yield different
flavored puffed pieces, without creating any "mixed-up" flavors. Since the flavors are
encapsulated within the product, they will not coat the hands when being eaten.
Flavourings suitable for use in the present invention include, but are not iimited to,
sugar cont~ining compositions, salt, bacon or simulated bacon, sour cream and onion,
barbecue, salt and vinegar, hickory smoked, ranch, jalapeno, dill pickle, ketchup and
cheese. Several flavorings can also be incorporated into the dough at one time.
Other ingredients may also be added to the dough during the short extrusion
cooking process. Such ingredients include, but are not restricted to preservatives
andlor food colourings and leavening agents.
Water is added to the extruder in order to form a dough having a moisture
content of about 20 to 40% by weight. The dough is then heated within the extruder
barrel to a temperature of about 110~C to 120~C while the dough is being massaged in
order to gelatinize the starch within the flours which helps to encapsulate the flavoring
components. This results in the formation of a plastic type of dough. The residence
time inside the extruder is only about 30 to 60 seconds. The cooked dough is
extruded at a pressure of approximately 5 to 15 psi through a cooling end of theextruder into an appropriate shaped die opening, without causing any expansion,
thereby producing a cold extrudate of flavored cooked dough in an ~propl;ate shape
which is cut into a suitable size through the use of a rotary cutting knife attached at the
die opening.
It is to be understood by those skilled in the art that any type of extruder,
including single and double (twin) screw types, can be used in the method of thepresent invention. When using a twin screw extruder, it is not necessary to form a
dough with 30 to 45% moisture. Instead a drier loose, crumbly dough mixture may be
formed with a lower amount of total moisture (20 to 30%).
The drying process for the wet dough takes about 5 to 7 hours under a
controlled temperature and humidity or up to 48 hours under normal room
tempel~u.es and humidities. The extruded product is allowed to dry to a final
CA 02249167 1998-09-30
moisture content of about 12 to 18% and preferably from about 11 to 13%. If the final
moisture content exceeds 13%, antimicrobial agents may be required to be added to
address the potential for microbial spoilage. This final half product with 1 1 to 13% is
shelf stable with no subsequent loss in moisture content upon proper storage.
In order to puff the product, about SO to 1 OOg of the half product is placed,
preferably in a packaging material suitable for microwaving (similar to ones currently
used for Microwave Popcorn), and then microwaved for about 1 to 3 minutes
depending on the type and style of microwave oven used. The time required for
microwaving also depends on the quantity of product being puffed at one time. It is to
be understood that any commercially available microwave is suitable to use to puff the
flavored half product of the present invention. It is also understood by those skilled in
the art that any type of expansion cooking can be used to puff the produce in addition
to microwaving.
The resultant flavored puffed product is light and crispy. In addition, since the
flavor is incorporated and encapsulated within the product, it does not rub offon the
hands when being consumed. As a microwaved snack, the puffed product is suitablefor calorie-sensitive consumers.
The shape of the half product plays an important role in its microwaveability.
The best results were obtained using half products of continuous shape such as round
balls 0.5" (11 mm) diameter sphere, or round wafers 1-1.5" (22-33 mm) diameter and
0.1" (2.2 mm) thick or an "onion ring" shape. Square, rectangular or cube shapedproducts may also be extruded, although the corners generally do not microwave as
well.
The product can also be puffed up (expanded) when subjected to deep fat
frying.
The method of the present invention can be used to produce a packaged line of
microwave snack foods of various flavors in separate individual packages or a
combination of different flavored products within the same package, which can bedistributed to retail stores. The packages can be sold as individual packages or in
multiples suitably packaged as multipacks. Alternatively, the products can be
packaged and sold already expanded.
CA 02249167 1998-09-30
In summary, the present invention provides a method which, is both rapid and
economical and produces a microwavable flavored half product. Once microwaved,
the product puffs to form a crispy snack food that is both, light textured and with an
encapsulated flavor such that the flavoring does not rub off on to the hands when
eaten.
The following examples are provided for a better understanding of the present
invention and are not intended to limit the invention.
Example 1
A 4,000 g dry mix containing the following:
Potato flour 1,520g
Rice flour 1,400g
Wheat flour (all purpose) 960g
*Seasoning mix 120g
was used to prepare a uniform, non-sticky dough, by mixing and adding gradually
2,200g of cold water in a Hobart mixer, at medium speed.
The dough was then processed through a pilot plant, single screw extruder 2"
(44mm) diameter screw equipped with four equal zones each connected to either
steam or cold water. The cooker extruder was operated to mix the material further
under low shear and subject the mix to a higher temperature (110~C) in Zone 1 - the
first zone from the input end of the barrel of the extruder barrel, and cool towards
Zones 3 and 4 - the output end of the barrel. For the best results, the product was
cooked to 110~C (using steam) in Zone 1 and cooled to 60~C or less (using cold
water) in Zone 4; Zones 2 and 3 were neither heated or cooled. The cooked dough
emerging from 0.5" (1 lmm) round die at the output end of the extruder was cut into
0.5" (1 lmm) length (almost round, ball-shaped pieces) by a rotary knife. The half
product extrudate had the appearance of a semi-translucent, dense unexpanded 1/2''
(1 lmm) diameter balls.
After being discharged from the extruder, the formed pieces were slowly dried
at 50 to 55~C (relative humidity 40 to 50%) for about 7 hours or until the moisture
content of 12-13% range was reached.
CA 02249167 1998-09-30
When 50g sample of the dry half product was placed in an empty 'popcorn"
bag and microwaved (770 W, Panasonic Genius Oven) for 2 minute~, the product
puffed up to about 4 times its original volume, with a typical snack-like, puffy light
and yet crispy texture with a pleasant sourcream and onion flavor. The product was
neither sticky or oily to touch and did not leave any residue or flavoring onto the
hands when eaten.
*Sourcream and onion seasoning mix comprising of salt, monosodium glut~m~te,
sugar, salt, citric acid, sourcream powder, black pepper garlic and onion powders.
Example 2
A 4,000 g dry mix cont~ining the following
Potato flour 1,500g
Rice flour 1,300g
Corn starch (redried) 920g
**Seasoning mix 280g
was used to prepare a uniform, non-sticky dough, using 2,400 g of cold water andextruded and further dried as described in Example 1. The normal operating
temperature in Zone 1 was m~int~ined at 100~C (using steam) and Zone 4 was cooled
by cold water; Zones 2 and 3 again, were neither heated or cooled.
**Ranch seasoning mix #NP49440R24 ~ 7% from Flavorite Laboratories Inc.
Example 3
The procedure of Example 1 was repeated by using 4,000 g dry mix con~ining the
following
Rice flour 3,000g
Wheat flour (all purpose) 600g
Soy flour 320g
***Seasoning mix 80g
was used to prepare a uniform, non-sticky dough, using 2,350g of cold water and
extruded and further dried as described in Example 1. The normal operating
temperature in Zone 1 was m:~int:lined at 110~C (using steam) however Zones 2, 3 and
4 were neither heated or cooled.
CA 02249167 1998-09-30
***Hickory barbecue seasoning mix #NP54989Rl (~ 2% from Flavorite Laboratories
Inc.
Example 4
Experimental details are as follows:
6920 - Recipe Reference Number Customer recipe Ref: 4
Dry mix for snack
Kilo~rams Pounds Percent In~redient Supplier FurnishedBy
35.23 77.65 38.70 Potato Starch Avebe W
32.42 71.44 35.69 Rice Flour Rivland W
22.25 40.03 24.49 SoftWheatFlour SoftAs Silk W
0.94 2.06 1.03 Salt
Totals: 90.84 200.18 100.00
6919 - Recipe Reference Number Customer Recipe Ref: 3
SlurrY for Snack
Kilo~rams Pounds Percent In~redient Supplier FurnishedBy
1.14 2.50 25.00 Barbecue Flavour C
3.41 7.50 75.00 Vegetable Oil W
Totals: 4.55 10.00 100.00
Comments:
In the above recipe, the total starch level is m~int~ined above 80% and hence the final
microwaved product gives lighter and softer textures.
Vegetable oil is included in the recipe as a processing aid to reduce stickiness, control
expansion and to impart a more uniform cellular structure in the final product.
Extruder Model:TX57 from Wenger Manufacturing
Run Number 980625.104 980625.105 980625.106
Process details
Dry Recipe Moisture %wb
DryRecipe Density kg/m3 804 604 604
CA 02249167 1998-09-30
Dry Recipe Rate kg/hr 148 158 155
Feed Screw Speed rpm 21 18 21
PRECONDITIONING INFORMATION:
Preconditioner Speed rpm 300 300 300
Steam Flow to Preconditioner kg/hr 17 15 15
Water Flow to Preconditioner kg~r 17 15 15
Preconditioner Discharge Temp. ~ C 81 81 81
Moisture Entering Extruder % wb
E~TRUSION ~FORMATION:
Extruder Shaft Speed rpm 199 199 200
Extruder Motor Load % 67 65 65
Steam Flow to Extruder kg/hr 4 4 5
Water Flow to Extruder kg/hr
ExtruderAdditiveRate kg/hr 6 6 6
Control/Temperature lstHead ~C 60/65 60/65 60/65
Control/Temperature 2nd Head ~ C 100/101 100/100 100/101
Control/Temperature 3rd Head ~ C 100/102 100/103 100/102
ControVTemperature 4th Head ~ C 80/79 80/81 80/81
Control/Temperature 5~ Head ~ C 70/70 70/71 70/71
Control/Temperature 6~ Head ~ C
Control/Temperature 7th Head
Control/Temperature 8th Head
Control/Temperature 9~ Head
HeadlPressure kPa5/62705/5880 5/6050
Knife Drive Speed rpm1128 591 303
FINAL PRODUCT INFORMATION:
Extruder Discharge Moisture % wb
Extruder Discharge Rate kg/hr
Extruder Discharge Density kg/m3
Dryer Discharge Density kg/m3
Extruder Performance Stable Stable Stable
Duration of Run min
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Final Product Description Round
Customer Recipe Number 4 4 4
Run Rating Good Good Good
REFERENCE NI~MBERS: s
Main Recipe 6920 6920 6920
Precond. Additive 1 Recipe
Extruder Additive 1 Recipe 6919 6919 6919
Preconditioner Configuration 109 109 109
Extruder Configuration 818 818 818
Die and Knife Configuration 3862 3862 3862
Product Analysis (shown below)9456 9457 9458
Three samples with different widths were prepared:
980625-104: Thin cut DS/600psi
980625-105: Same product with thicker cut: DS/510 psi
980625-106: Thickerproduct, same conditions: DS/500 psi
CO = Cooling Oil CW = Cooling Water S - Steam N = No Thermal Fluid
HO = Hot Oil HW = Hot WaterPSIG = Pressure
Product Analysis:
Number 9456 9457 9458
PRODUCT MOISTURES
Dryer discharge %wb 12.09 12.61 13.02
Comments:
Properly dried snack pellets expand better following a stabilization period of
approximately one or two days during which time the moisture migrates from the
interior of the product and eventually an equilibrium within the final product.
CA 02249167 1998-09-30
Example 5
Consideration must be given in the selection of cereal grains, starches, proteins and
other minor ingredients when this snack food is designed. For example, a potato
snack will puff at a lower temperature or cook in a shorter time in the microwave oven
than a rice or wheat snack of the same thickness and shape. After puffing, different
ingredients have a different finished color. Rice is whitish, corn-yellow and potato is
golden brown.
In the following example, a higher level of potato flour is used giving a final product
that is softer in texture with a delicate potato flavor.
6955 - Recipe Reference Number Customer Recipe Ref: 2
Drv mix for snack
Kilo~rams Pounds Percent In~redient Supplier FurnishedBY
113.50 250.15 67.08 Potato Granules Idaho Pacific W
52.51 115.07 30.86 Soft Wheat Flour Soft As Silk W
3.50 7.70 2.06 Salt
Totals: 169.21 372.92 100.00
6957 - Recipe Reference Number Customer Recipe Ref: 4
Slurry for snack
Kilo~rams Pounds Percent In~redient Supplier Furnished By
3.63 8.00 40.00 B.B.Q. flavor TFF C
5.45 12.01 60.00 Vegetable Oil W
Totals: 9.08 20.01 100.00
Extruder Model:TX57from Wenger Manufacturing
Rurl Number 980727.104980727.105
DRY RECIPE INFORMATION:
Dry Recipe Moisture %wb 8.81
DryRecipe Density kg/m3 762 762
Dry Recipe Rate kglhr 150 150
Feed Screw Speed rpm 35 36
-
CA 02249167 1998-09-30
PRECONDITIONING INFORMATION:
Preconditioner Speed rpm 300 300
Steam Flow to Preconditioner kg/hr 17 17
Water Flow to Preconditioner kg/hr 17 17
Preconditioner Discharge Temp. ~ C 80 79
Moisture Entering Extruder % wb 24.02 24.71
EXTRUSION INFORMATION:
Extruder Shaft Speed rpm 199 199
Extruder Motor Load % 47 46
Steam Flow to Extruder kglhr
WaterFlowto Extruder kg/hr 5 5
Extruder Additive Rate kg/hr 5.5 5.5
Control/Temperature lstHead ~C 60/65 60/65
Control/Temperature 2nd Head ~ C 100/100 100/100
Control/Temperature 3rd Head ~ C 100/105 100/103
Control/Temperature 4tll Head ~ C 50/57 50/59
Control/Temperature 5th Head ~ C 50/50 50/50
Control/Temperature 6th Head ~ C
Control/Temperature 7th Head
Control/Temperature 8~ Head
Control/Temperature gth Head
Head/Pressure kPa
Knife Drive Speed rpm
FINAL PRODUCT INFORMATION:
Extruder Discharge Moisture % wb 22.98 20.83
Extruder Discharge Rate kglhr
Extruder Discharge Density kg/m3
Dryer Discharge Density kg/m3
Extruder Performance Stable Stable
Duration of Run min 15 15
Final Product Description Round
CustomerRecipe Number 2 3
CA 02249167 1998-09-30
Run Rating Good Good
REFERENCE NUMBERS:
MainRecipe (as shown above) 6955 6956
Precond. Additive 1 Recipe
ExtruderAdditive 1 Recipe (above) 6957 6967
Preconditioner Configuration 108 108
Extruder Configuration 818 818
Die and Knife Configuration 3903 3903
Dryer Formula 9457 9458
Product Analysis 9550 9551
980727-104: Tried to run with the same conditions as previous runs from 980626-104.
Had problems with product being top hot and bubbling off extruder. Lowered head
temps on Zones 4 and 5 and took all steam out of extruder barrel and added 4% water
to barrel. Made good product aQer.
980727-105: Preconditioner water temp ambient > Extruder water temp ambient >
Knife drive speed 676.
CO = Cooling Oil CW = Cooling Water S - Steam N = No Thermal Fluid
HO = Hot Oil HW = Hot Water PSIG = Pressure
Product Analysis:
Number 9550 9551
PRODUCT MOISTURES
Dry recipe %wb 8.61
Preconditioner discharge %wb 24.02 24.71
Extruder Discharge %wb 22.9820.83
Dryer Discharge %wb 12.2011.80
CA 02249167 1998-09-30
In summary, the present invention provides a method which is both rapid and
economical and produces a microwavable flavored half product. Once microwaved,
the product puffs to form a tasty crispy snack food with both a light and flavored
texture.
Although preferred embodiments have been described herein in detail, it is
understood by those skilled in the art that variations may be made thereto without
departing from the scope of the invention.
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