Caballero B. (ed.) Encyclopaedia of Food Science, Food Technology and Nutrition. Ten-Volume Set

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therefore, suitable for ohmic heating. If both the

liquid and solid phases of a product contain sufficient

dissolved ionic salts, heat penetration is more rapid

than with conventional heating. (See Heat Treatment:

Electrical Process Heating.)

Design of Ohmic Heaters

0052 The ohmic heater is based on a well-known principle,

and the apparatus provides an alternative to tubular

or scraped-surface heat exchangers for the processing

of viscous and particulate food materials. The design

of an ohmic heater relies on the principle that an

electrical potential is generated across a moving

column of product. For safety reasons, the heater

column inlet and outlet electrodes are earthed.

0053 Figure 2 illustrates the electrical configuration and

construction of the electrical resistance heater.

0054 The heater column is arranged in such a manner

that an upward flow occurs in the column while the

product is progressively heated to the required tem-

perature. Back pressure is maintained at a constant

1 bar when heating products up to 90



C, but a pres-

sure of 4 bar is required up to the maximum tempera-

ture of 140



C. The back pressure is controlled by

regulation of the pressure on the surface of the prod-

uct in a presterilized tank using sterile compressed air.

Acceptability and Applications

0055The ohmic process offers several advantages over

more conventional particulate processing methods.

These are:

0056the ability to handle food materials containing

particles as large as 25 mm

;

0057the absence of moving parts (feed pump excluded),

which can damage shear-sensitive food products;

0058the ability to heat food products in a continuous

flow without the need for any heat-transfer sur-

faces;

0059a considerably reduced risk of fouling;

0060the generating of heat in the product solids

without reliance on thermal conductivity through

liquids;

0061the absence of noise during the operation;

0062low maintenance costs;

0063the ease of control and instantaneous start up or

shut down;

0064Examples of food products which have been pro-

cessed successfully in this manner with minimal struc-

tural damage include meat chunks, prawns, diced or

sliced carrots, baked beans, and sliced mushrooms.

Fruits, such as diced apple and whole strawberries,

have also been successfully heat-treated using the

ohmic heating principle, and product quality report-

edly varies from good to excellent. Ohmic heating has

been developed by the APV company as a feasible

practical process, and the reader is referred to the

article on ohmic heating for further information.

Other Processes

0065To conclude this article, attention will be given to

less well-known, product-specific processes, namely

cold pasteurization, pasteurization by extrusion,

thermization and chemical preservation by hydrogen

peroxide.

Cold Pasteurization

0066As the name implies, the cold pasteurization tech-

nique does not make use of heat to reduce the micro-

bial load. Instead, microporous membrane filters are

used to retain the majority of bacteria and yeasts. In

this respect, the technique is similar to any other

pasteurization process. This process is mainly used

in the case of heat-sensitive products, such as draught

Product outlet

Plastics electrode

housing

Electrode

Product inlet

Interconnecting

plastic-lined

stainless steel

tube

50 Hz

power supply

fig0002 Figure 2 Electrical configuration and construction of the elec-

trical resistance heater. From Skudder PJ, Biss CH and Coombes

SA (1988) Ohmic heating: a breakthrough in profitable food

manufacture. Food Review 15(5): 24, 27.

PASTEURIZATION/Other Pasteurization Processes 4405

beer, wine with less than 17% alcohol (especially

sparkling wine) and pulp-free fruit juices. (See Filtra-

tion of Liquids.)

Pasteurization by Extrusion

0067 Although extrusion may not, in general, be compar-

able with conventional pasteurization, research has

shown that the microbial load of thermosensitive

food powders, such as egg white powder or whey

powder, could be reduced by an extrusion process

without any loss of functional properties of proteins

and carbohydrates, for example. This advantage,

however, depends on the barrel temperatures and con-

tact times, since high temperatures combined with

longer contact times lead to a loss of functional prop-

erties as a result of mechanisms such as starch gelatin-

ization and protein denaturation. The feasibility of

this process as a form of pasteurization is not very

clear, and therefore requires further investigation.

(See Extrusion Cooking: Principles and Practice.)

Thermization

0068 The thermization process is a subpasteurization heat

treatment of milk at 62–65



C for 10–20 s, followed

by refrigeration. It is used as a prepasteurization

treatment of raw milk to safeguard milk quality

during prolonged storage in insulated silos. The pro-

cess is also used as a postpasteurization treatment of

dairy products. Research has shown that this process

effectively reduces both the total and psychrotrophic

bacterial counts, enabling thermized milk to be stored

for up to 3 days longer at 8



C. In this way, detectable

sensory changes and the concomitant decrease in

shelf-life are limited.

0069 Thermization is only successful if applied to raw

milk and products of good quality.

Chemical Preservation by Hydrogen Peroxide

0070 Hydrogen peroxide is undoubtedly a most effective

germicidal agent. It has been proven as an effective

bacteriostatic and bactericidal agent and has been

used in a treatment (30 min; 49–55



C, 0.08% by

weight) that has been suggested as a substitute for

pasteurization. The peroxide concentration, tempera-

ture used, exposure time, and bacterial species and

number all influence the effectiveness of the process.

(See Preservation of Food.)

0071 Treatment by this method destroys coliforms, an-

aerobic spore-formers and also a number of patho-

gens. The most resistant pathogen has been found to

be Mycobacterium tuberculosis. Treatment at levels

of 0.115% (v/w) hydrogen peroxide, however,

completely inactivates this pathogen. Gram-positive

organisms are not inactivated to the same extent as

Gram-negative organisms.

0072Application of hydrogen peroxide as a milk preser-

vative has been attempted in the dairy industry. Cer-

tain countries with underdeveloped milk collection

industries and high environmental temperatures

have expressed interest in this preservation method.

The addition of catalase after exposure or the catalase

from microorganisms and leucocytes, together with

heat treatment, completely destroys or decomposes

the hydrogen peroxide. The breakdown products

(water and oxygen) are virtually undetectable in milk.

0073Hydrogen peroxide treatment of milk may be ap-

plied to reduce the total bacterial count and to extend

the keeping quality. This treatment should, however,

be supplemented by approved processing methods to

ensure complete destruction of all pathogens. The

question of whether hydrogen peroxide treatment of

milk may be allowed depends on the specific country

and its health regulations.

See also: Campylobacter: Properties and Occurrence;

Canning: Principles; Escherichia coli: Occurrence;

Extrusion Cooking: Principles and Practice; Filtration of

Liquids; Heat Transfer Methods; Heat Treatment:

Electrical Process Heating; Irradiation of Foods: Basic

Principles; Applications; Processing Technology; Legal

and Consumer Aspects; Listeria: Properties and

Occurrence; Mycobacteria; Preservation of Food;

Shigella; Staphylococcus: Properties and Occurrence

Further Reading

Coghill DM, Mutzelburg ID and Birch SJ (1982) Effect of

thermization on the bacteriological and chemical quality

of milk. Australian Journal of Dairy Technology 37(2):

48–50.

Decareau RV (1985) Microwaves in the Food Processing

Industry. London: Academic Press.

Jay JM (1986) Modern Food Microbiology, 3rd edn. New

York: Van Nostrand.

Kang KH, Yoon KB and Pack MY (1983) Microbial con-

tamination of raw milk and prevention with hydrogen

peroxide. Korean Journal of Animal Sciences 25(4):

296–302.

Potter NN (1986) Food Science, 4th edn. Westport, CT:

AVI.

Skudder PJ, Biss CH and Coombes SA (1988) Ohmic

heating: a breakthrough in profitable food manufacture.

Food Review 15(5): 24, 27.

Urbain WM (1986) Food Irradiation. Orlando, FL:

Academic Press.

Young GS and Jolly PG (1990) Review: microwaves: the

potential for use in dairy processing. Australian Journal

of Dairy Technology 45(1): 34–37.

4406 PASTEURIZATION/Other Pasteurization Processes

PASTRY PRODUCTS

Contents

Types and Production

Ingredient Functionality and Dough Characteristics

Types and Production

J B Harte, Michigan State University, East Lansing, MI,

USA

Background

0001 There are many types of pastry dough. Shortcrust or

standard plain pastry contains four ingredients –

flour, fat, water, and salt – that are mixed, rolled,

and cut into shapes. Alterations in the proportions

of these ingredients, the addition of other ingredients,

and the employment of various mixing and manipu-

lation techniques produce popular pastry doughs,

such as puff, choux, and strudel pastries. It is the

purpose of this article to outline popular pastry var-

ieties and present some common small- and large-

scale production methods.

Plain Pastry

Pie Crusts

0002 Shortcrust pastry or piecrusts are prepared by cutting

solid fat into the flour and salt, and gradually adding

water to obtain the consistency for rolling the dough

into the desired shape. A low-protein, pastry flour is

used to prevent the development of gluten in the pie

dough. Limiting the mixing step after the addition of

water and limiting reworking of dough will also help

to prevent gluten development that would result in a

tough crust.

0003 Medium-flaky crust is obtained by cutting the fat

into lumps the size of rice or coarse cracked corn.

Flakier crusts are obtained by chilling the water and

sometimes the flour to 1.7–4.5



C prior to mixing,

cutting fat into larger pieces and/or keeping the

mixing step as short as possible. Chilling the dough

before rolling also helps to keep the fat firmer. A

mealy crust forms when the flour and shortening are

mixed thoroughly. The dough should be at about



C after mixing and may be held there for 3–4h

in order to distribute the moisture more evenly. The

type of fat used also affects the flakiness or mealiness

of the crust. Rolling of the dough should start from

the center and continue in the direction that will

produce the desired shape and thickness.

0004Many varieties of pie crust dough, with fat contents

ranging from less than 50 to 75%, are used. Pie crusts

can also be prepared with a combination of shortcrust

dough and short pastry (pa

te de sucre or flan pastry)

or with short pastry alone. Pie crust dough can be

used for two-crust, fruit-filled pies, single-crust, and

soft-filled pies. The typical one- and two-crust pies

are approximately 23 cm in diameter and serve six to

eight people. Crusts are also used for baked meat or

fish pies, quiches, tarts, and turnovers. Fruit-filled

turnovers can be made from dough scraps.

0005In two-crust fruit pies, the bottom crust should

be slightly thicker than the top in order to support

the fruit filling. Placement of cooled fruit filling in the

prepared pie crust allows it to bake adequately before

the filling begins to boil. Two to four cuts should

be made in the upper crust to vent the steam during

baking. Crusts are baked at 281–232



C, reducing the

moisture content to a low level.

0006Two types of machines are used to form pies. Pie

crusts can be produced commercially on a small-scale

basis using a pie press that shapes dough balls into

pastry sheets. Alternatively, pies can be formed by

automatic sheeting and cutting. The rotary pie ma-

chine mixes the dough, reduces its thickness and cuts

it into 7.5 12.5-cm sections. These pieces are auto-

matically cross-rolled into thin, round pie pastry

sheets that are manually placed into the pie plates.

The top crust is placed on top after the filling is added

to the bottom crust. The rotary pie machine then

finishes the pie by crimping, scaling, and trimming.

0007The straight-lined pie type is another example of a

sheeting and cutting machine that is more completely

automated than the rotary pie machine. Pie dough is

divided in two and separately reduced, cut into

7.5 11.5-cm pieces and cross-rolled into the top and

bottom round pastry sheets. The pastry is automatic-

ally placed into the pie plate, filled, topped with an-

other cut pastry sheet, sealed, crimped, and trimmed.

Short Pastry

0008Short, pa

te de sucre or flan pastry is a rich dough

containing a large amount of fat and, unlike standard

PASTRY PRODUCTS/Types and Production 4407

pastry, eggs and sugar. This pastry is used for biscuits,

tarts, some pies, and the bottom and sides of fruit

flans and cheesecakes. If a nonsweet pastry is desired

for meat, vegetable, or seafood dishes, other ingredi-

ents, such as Parmesan cheese, may be substituted for

the sugar. Smooth blends of shortcrust and pa

te de

sucre doughs are often used for pie shells and cream

rolls. Chocolate or cocoa may also be added to these

blends.

Puff Pastry

0009 Puff pastry is lighter, flakier, and more delicate than

standard shortcrust or flan pastry. It contains a higher

fat level and has a unique preparation method that is

critical for preparation of a successful product. This

pastry can be used for a wide variety of products,

including turnovers, shells filled with whipped

cream, custards or fruit, vol-au-vents, and sausage

rolls, and is considered a staple in commerical

bakeries.

0010 The pastry is prepared with a high-protein flour

(bread), water, salt and shortening. A firm, plastic

shortening, equal to 50% of the dough weight and

containing some moisture, is optimum. Other ingre-

dients, such as eggs and acids (cream of tartar, vin-

egar, or lemon juice) can be used. There are three

commonly used methods for mixing and handling

the puff pastry dough – the French (roll-in), English

(roll-in), and the Scottish (all-in) method.

0011 The French method involves rubbing a portion of

pastry fat into the flour to lubricate the gluten. A

portion of the water, acid, and eggs is placed into

the center of a ring made from the mixed flour and

shortening. The dough is mixed well, and the proced-

ure is repeated until all the ingredients, with the ex-

ception of the remaining fat, have been added. The

dough is rolled into a rectangle, 1.25 cm thick with a

thinner outside border, and the fat is rolled to the size

of the thicker dough. After the fat is placed on

the thicker dough, the thinner dough is folded over

on the thicker dough, and the thinner dough is folded

over, making a type of pocket. The fat and dough is

then rolled into a rectangle. One half-turn of the

dough is formed by folding one end of the dough

two-thirds of the way down the rectangle and folding

the opposite end to cover the first fold (see Figure 1b).

The new rectangle is three layers of pastry fat separ-

ated by dough layers. The dough is relaxed, and the

rolling procedure is repeated after turning the dough

through 90



for a total of six half-turns. The French

method of puff pastry preparation is the most popular

but is not used by some, because it is complicated and

difficult to produce under high-speed commerical

manufacturing processes.

0012The English method is the most popular in the

USA. The dough is sheeted into a rectangular shape,

and the roll-in fat is spread uniformly over two-thirds

of the area. Three-fold pastry preparation (Figure 1)

is used to form three dough layers separated by two

layers of fat.

0013The Scottish method is similar to pie-crust prepar-

ation, simple, and widely used commercially. All the

pastry fat is broken into lumps (5 cm) and mixed

loosely in the flour. The remaining ingredients are

then added to form a lumpy dough. The rolling pro-

cedure is the same as the French method with the

addition of one extra half-turn. After the final rolling,

the dough is shaped and relaxed before baking. For

maximum volume, puffed pastries should be baked at

high temperatures (204–212



C). The Blitz method is

a modification of the Scottish method that partially

develops the gluten prior to adding the firm

shortening.

0014Two mechanical mixers are commonly used in

batch commercial pastry production. The low-speed,

double-arm mixing machine with a large dough bowl

and slow mixing produces a good-quality commerical

puffed pastry. The Scotch pastry method must

be followed when the high-speed mixer is used in

large-scale, high-product-capacity operations. Care-

ful timing is critical with these mixers to prevent

overmixing that results in an intimate mixing of fat

with the dough and formation of a short rather than a

(a) (b) (c)

fig0001 Figure 1 Three-fold pastry preparation: (a) the dough is rolled into a rectangle; (b) one end of the dough is folded two-thirds of the

way down the rectangle: (c) the opposite end is folded to cover the first fold.

4408 PASTRY PRODUCTS/Types and Production

puffed pastry. After mixing the dough, any of the

methods described in the commerical pastry prepar-

ation section can be applied. Continuous puff pastry

dough-production equipment extrudes the dough and

shortening into a double-layer continuous tube with

the shortening in the center layer. This is flattened and

reduced by a dough stretcher. The sheet is folded,

stretched, and thinned. Pieces are cut into their final

shape for pastry shells, cheese or savory sticks, napo-

leons (mile feuilles), turnovers, sugar crisps, etc. Prod-

ucts prepared with this continuous process are usually

intended for wholesale distribution. Thus, their size

and flakiness are limited to prevent breakage during

shipping.

Choux Pastry (pa

te e

chou)

0015 A wide variety of pastry products are made using

choux paste: cream puffs, e

clairs, French crullers,

soup nuts, and decorative shapes used for pastry gar-

nishing. Choux pastry differs from other pastries

in that it is cooked before it is piped or spooned. It

is composed of 150–200 parts eggs, 100 parts flour,

100 parts shortening (butter) and approximately 200

parts water. Flour is quickly stirred into a mixture of

liquid, seasoning and fat, which is heated to boiling.

The fat must be completely dispersed in the hot liquid

to form a proper emulsion. Stirring continues until

the smooth, gelatinized paste no longer sticks to the

pan. The mixture is cooled, and the eggs are beaten

into the choux mix one or two at a time, mixing well

after each addition. Liquid may be gradually added to

make the final paste the desired soft consistency. A

small amount of chemical, fast-acting leavening can

be added to this liquid to obtain the smooth consist-

ency and maximum pastry volume. The paste is

spooned or piped on to parchment-paper-lined pans

and baked at 215–226



C until crisp. (See Leavening

Agents.)

0016 Choux pastry can be prepared using a continuous

extrusion process. The extruder has groups of pro-

cessing zones provided by varying the pitch of the

screw. Throughout these zones, ingredient mixing,

kneading, starch gelatinization, and comminuted/

homogenization are accomplished. The final step in-

volves extrusion of the dough through a die, forming

the desired choux pastry shape. (See Extrusion

Cooking: Principles and Practice.)

Strudel Pastry

0017 The dough used to prepared strudel can be of the puff

pastry type or can be made from water, seasoning,

eggs, shortening or oil, and high-protein flour. Op-

tional ingredients include sugar and lemon juice. The

fat is mixed or cut into the flour mixture, and the

liquid ingredients are added gradually. The dough is

made into a ball, kneaded, and shaped into a rect-

angular form, relaxed, then rolled and gently

stretched to obtain very thin, transparent dough. Oil

is brushed on the thin layers. Home preparation by

hand stretching is difficult. Commercial methods

have been developed to prepare thin sheets. Strudel

pastry and Fillo (phyllo) dough, which is similar to

strudel, are frozen. These are sold in wholesale and

retail markets and have wide applications for the

home baker. Strudel filling is placed at one end of

the pastry, and the dough is rolled over the filling as

in the preparation of a Swiss roll. Relaxed strudel is

baked at 218–233



Yeast-leavened Pastry

Danish Pastry

0018Danish pastry is a rich pastry that combines the prin-

ciples of puff pastry and fermented, sweetened dough.

The dough contains high-protein flour (11.5–12%)

that is often combined with up to 30% pastry flour

for easier handling during lamination. Other ingredi-

ents include butter or margarine, yeast, sugar,

shortening, milk solids, eggs (optional), salt, and

flavoring. Fat containing moisture will help produce

steam for leavening and flakiness. The total amount

of fat can range up to 50% of the pastry dough.

Sheeting and folding fat between layers of dough

forms thick films of fat separating dough layers.

Two types of Danish pastries are made in the USA.

The European style is made from lean sweet dough

that has a short shelf-life. The American style is more

common and is made from a richer dough with a

longer shelf-life.

0019There are two commonly accepted mixing proced-

ures for the preparation of Danish pastry: conven-

tional (three- or four-fold) or the short mixing time

method, and the lamination or the long-mixing-time

method, which is used for automated, high-speed

sheeting systems. In the conventional three-fold

method (Figure 1a–c), all the ingredients are com-

bined with the exception of the rolled-in fat. A rect-

angle is formed by rolling the dough to a thickness of

1.25 cm. A large portion of roll-in pastry fat is evenly

distributed over two-thirds of the dough, and the

rectangle is folded in thirds, starting with the portion

without fat. The dough is then rolled into a rectangle

of 1.25-cm thickness and folded into four equal parts.

After retarding, the dough is rerolled, and the proced-

ure is repeated two more times. The four-fold or

book-fold technique (Figure 2a–c) involves distribut-

ing fat over the center 50% of the dough and folding

PASTRY PRODUCTS/Types and Production 4409

the two ends of the original rectangle to the dough

center. One end is folded over the other fold to line up

with the far edge. The retarding and refolding steps

are then repeated, similar to the procedure described

for the three-fold method.

0020 The gluten structure is developed during the lamin-

ating rather than during mixing. The commercial

lamination method involves layering the shortening

between two pieces of dough. This can be accom-

plished by extruding dough around the shortening,

or high-speed pumping of the shortening between two

continuous dough sheets. Automatic or overlapping

of 45–60-cm dough pieces is followed by sheeting.

This process is repeated two more times before

cutting.

0021 The retarded dough may be shaped into a wide

variety of pastries, including crescents, sticks, rings,

filled pockets, and rolls. Individual pastries are baked

at 193–204



C. Larger Danish products, such as coffee

cakes, are baked at lower temperatures, 176–190



to prevent over-browning before the pastry structure

is set.

Croissants

0022 The croissant is a popular, sweetened, yeast-raised

product that is delicate and flaky. It has a medium-

grain texture and the shape of a crescent. Dough

composition and preparation techniques are similar

to those of Danish pastries, with total fat contents

ranging from 25 to 50%. The rolled in fat is a critical

component for laminated yeast doughs that should

have the same consistency as the dough. It provides

the two-dimensional gluten framework that results

in the characteristically flaky croissant. Additional

ingredients are sugar, salt, whole eggs, yeast, and

water. Dough (19



C) is mixed completely, without

over-developing the gluten, for 1 min in a vertical

high-speed mixer. The dough is extruded, and fat is

extruded on top. It is then flattened, rolled and

rerolled, and laminated for a total of 36 layers.

Most of the gluten development occurs during the

lamination step. Retarded dough is rolled and cut

into triangles with slightly longer sides than the

base. Filling is added, and the dough is rolled with

four rotations, leaving the peak touching the baking

sheet. The ‘rolled’ pastries are proofed and then

baked at 163–204



Toaster Pastry

0023Toaster pastries are convenience pastry products that

are popular in the USA. These breakfast or snack

pastries are made from a filled dough, formed into a

shape and size that can fit into a toaster. The pastry

dough is prepared from soft wheat flour, sugar,

shortening, chemical leavening, salt, flavorings, and

colors. It is baked just enough to set the dough and

reduce the moisture content, thus extending the prod-

uct shelf-life. Although many are shelf-stable, many

new varieties are frozen. Browning is completed in

the toaster.

Commercial Preparation of Pastry

0024Most pastry products evolved after long periods of

small-scale, manual preparation followed by high-

speed, automated production in this century. High-

capacity production of pastry is made possible by

elimination of manual dough manipulation and auto-

mation of the pastry production process. Processing

time is shortened by elimination of roll-in steps, and

reducing resting times between fold-in steps. Vari-

ations exist in the continuous production methods

for the different pastry types such as pie, Danish,

and puff pastries. However, common to all are the

sheeting, depositing, lamination, and cutting steps.

0025An example of an automated pastry production

system is presented in Figure 3. The dough is mixed

and carried to the sheeter head, or three-roll laminat-

ing head, by the dough feeder and conveyer belt. The

sheeter head unit consists of three rollers with adjust-

able speeds for producing perfect sheeted pastry. Two

are feed rollers, one with deep grooves and the other

with fine triangular grooves. The third roller has a

smooth surface and is located underneath the feed

rollers. Fat layers can be added to the first dough to

(a) (c)(b)

fig0002 Figure 2 Four-fold pastry preparation: (a) the dough is rolled into a rectangle: (b) both ends of the dough are folded halfway down the

rectangle; (c) one folded end is turned to cover the opposite fold.

4410 PASTRY PRODUCTS/Types and Production

produce the flaky texture of pastries. A second sheeter

head adds another dough layer over the fat. If the

Scottish system is used, all the fat is incorporated

into the dough, a fat extruder is not needed, and

only one sheeter head unit is required.

0026 Dusting flour boxes distribute small amounts of

flour on the conveyor belt, to prevent sticking, and

to the top of the dough sheets prior to cross-rolling.

Conical cross-rollers travel across the belt width,

thinning and spreading the dough sheet to the desired

thickness. Further sheeting occurs at the two-roll

sheeter, reducing dough thickness. Several systems

can be utilized to obtain the desired flakiness by

controlling the number of times the pastry is folded.

002 7 The book-fold method (Figure 2a–c) involves

folding the dough sheet and then turning it through



C and sheeting the dough, repeating the proced-

ure to obtain the optimal flakiness. Another method

involves continuous folding and sheeting of the

dough. A third method uses a guillotine to cut the

dough sheet into pieces (50 60 cm) and then stacks

then with a retracting conveyor. The dough pieces are

placed on another conveyor belt operating at a 90



angle to the first belt. The pieces are stacked five

layers high by this process, after which the dough

sheets are reduced in thickness. Another method util-

izes a curling arm, or roll winder, which coils the

dough sheet covered with extruded fat into five

layers. A final technique uses a ring extruder that

produces a very uniform, hollow dough cylinder,

lined with fat. This method is particularly suited for

long-shelf-life pastries. For all methods, the dough

sheets can be reduced in size by pressing, cross-

rolling, and running between a multiroller device.

This multiroller allows the dough sheet to be

manipulated when in contact with the small rollers,

which press the dough on to the larger roller. The

small rollers revolve individually as the whole group

of small rollers also rotate together in a loop. The

dough is allowed to relax when it is between the

rollers and is not touching the large roller. A similar

stretcher system with a larger number of small rollers,

but without the bottom roller, has also been used. The

final pastry production steps repeat the sheeting and

reducing steps, depending on the necessary dough

thickness and desired flakiness. Preparation of indi-

vidual pastries of varying sizes and shapes depends

upon the type of cutting, depositing and shaping

equipment utilized.

See also: Extrusion Cooking: Principles and Practice;

Leavening Agents

Further Reading

Doerry W (1998) Formulation and production of puff

pastries. AIB Research Department Technical Bulletin

XX (2): 2–5.

Friberg BO (1990) The Professional Pastry Chef, 2nd edn.

pp. 14–23, 29–34, 94–97. New York: Van Nostrand

Reinhold.

Goodsell GR (1985) Making Danish – basics that determine

quality results. Bakers Digest 59(3): 16–21.

Loving HJ and Brennesis LJ (1981) Soft wheat uses in the

United States. In: Yamazaki WT and Greenwood CT

(eds) Soft Wheat: Production, Breeding, Milling and

Uses, pp. 169–207. St. Paul, MN: American Association

of Cereal Chemists.

Matz SA (1987) Formulas and Processes for Bakers, pp.

1–26, 39–55, 58. McAllen, TX: Pan-Tech Inter-

national.

21 3 4 5 6 7 8 9 11 10

fig0003 Figure 3 Automated pastry production system. (1) Supply table; (2) flour duster; (3) three-roll laminating head; (4) fat pump; (5) three-

roll laminating head; (6) flour duster; (7) cross-roller; (8) guiding rollers; (9) two-roll sheeter; (10) retracting belt; (11) guillotine. From

Rijkaart C (1984) Producing the Perfect Pastry. Food Manufacture 59: 29 with permission.

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Ingredient Functionality and

Dough Characteristics

S L Andrews and J B Harte, Michigan State

University, East Lansing, MI, USA

This article is reproduced from Encyclopaedia of Food Science,

Introduction

0001 Traditional pastry or pie crust is a simple dough

made from four primary ingredients – flour, fat, salt,

and water. Numerous pastry varieties have been

developed by slightly altering ingredients, their

amounts, mixing methods, and shaping. Common

ingredient modifications include the amount or type

of fat, the protein content of flour, the substitution of

milk for water, use of chemical leavening agents and

yeast, and the addition of other ingredients such as

eggs, sugar, acid, and flavorings. It is the purpose of

this article to outline pastry ingredient functionality

and their proportions and desirable pastry character-

istics. US and equivalent UK pastry terms are

presented in Table 1.

Functionality of Ingredients

Flour

0002 Flour is the main ingredient in pastry, and the type of

flour used affects the characteristics of the pastry.

Protein in flour yields gluten wherever the flour

is dampened with water and manipulated. Gluten

development increases as the flour’s protein content

increases and as the amount of added water increases.

Gluten development can be minimized by incorpor-

ating fat and flour before water is added. This method

insulates flour proteins from added water and limits

gluten development. The extent of gluten distribution

throughout pastry and the amount of gluten formed

determine whether pastry is crumbly, with a tendency

to be compact and tough, or tender and flaky. When

dough is rolled and baked, gluten is denatured by

heat, which contributes additional toughness. High-

protein flours yield more gluten, which results in a

more cohesive dough. In contrast, pastry flour and

other low-protein flours do not yield as much gluten

and tend to make a tender pastry which crumbles

and cannot hold its shape. A mixture of high

gluten or plain flour blended with a soft cake or

pastry flour can be used to achieve the desired protein

concentration.

0003In choux pastry a high-protein (12–13%) flour is

used. During baking, egg and flour proteins in choux

pastry coagulate, preventing steam and gas from leav-

ing the pastry, and setting the pastry into the desired

form. High-protein (13%) flour is also used in yeast-

leavened Danish pastries. For croissants, a 12.5%

protein flour is recommended. (See Flour: Analysis

of Wheat Flours.)

Fat

0004Fat contributes tenderness, or shortness, to pastry.

Depending on the type of pastry, the fat content can

range from 25% to almost 75% of the dough. Fat

tenderizes pastry by waterproofing flour particles.

The polar groups in water have an affinity for the

polar groups in both the protein and starch. Polar

carbonyl groups and the double bonds in unsaturated

fatty acid moieties make it possible for fat to unite

with polar groups on the surface flour particles. The

remaining portions of the fat molecule have no affin-

ity for the flour or water and act as a mechanical

barrier, preventing contact of the water and protein

in the flour.

0005A fat’s ability to interfere with gluten formation is

known as its shortening power. Pure fats have more

shortening power than do butter or margarine which

contain 16% water. Even pure fats, such as lard,

hydrogenated shortenings, and oils, exhibit different

characteristics in a pastry product. Oil is more dense

than lard, which is more dense than shortening. In

addition, liquid fats have more spreading power and

are able to coat flour more evenly and completely.

The higher the ratio of liquid to crystals, the greater

the covering power of the fat.

tbl0001 Table 1 US and equivalent UK pastry terms

US UK

Standard plain pastry Shortcrust pastry

Short pastry Pa

te de sucre or flan pastry

Cookies Biscuits

French puff pastry Flaky pastry

Scottish puff pastry Rough puff pastry

4412 PASTRY PRODUCTS/Ingredient Functionality and Dough Characteristics

0006 In addition to making pastry tender, fats also con-

tribute desirable flakiness by separating the dough

into layers or flakes. Oils, on the other hand, tend to

coat each particle of flour. As a result, water contact

with the flour is limited, little gluten is developed, and

a tender but crumbly, or even greasy, pastry results.

A flaky, tender pastry can be made with oil, but,

because oil mixes so easily with flour, the mixing

must be carefully monitored. Oil and flour should

be mixed until the particles are the size of peas. Over-

mixing will cause particle size to decrease, resulting in

a crumbly pastry.

0007 Plastic fats, having the properties of both liquid

and crystalline fats, tend to make a more flaky prod-

uct which is tender. Lard is considered an excellent

pastry fat because of its shortening action, desirable

plasticity, and dispersibility which enhances flakiness.

Selection of fat depends on a number of factors, in-

cluding ambient temperature, method of processing,

and desired crust characteristics (mealy or flaky). (See

Fats: Uses in the Food Industry.)

0008 Puff pastry dough contains up to 100 parts of a

good-quality, high-protein flour, 58 parts of water,

and two parts of salt. A firm, plastic, shortening,

equal to 50% of the dough weight and contain-

ing some moisture, is optimum. Fat containing mois-

ture will help to produce steam for leavening and

flakiness.

Liquid

0009 The liquid most frequently used in pastry is water, but

liquid is often contributed by the addition of milk and

eggs, and even fats such as butter and margarine

which are 16% water. Liquid is needed to hydrate

the flour, develop gluten, and provide cohesion to

the dough. Without liquid, the flour particles would

not adhere to form a dough. With insufficient liquid

the dough crumbles and is difficult to handle. Too

much liquid causes excessive gluten formation, pro-

ducing a tough pastry. While too much liquid is un-

desirable in pastry doughs, liquid is essential in choux

pastry for maintaining the desired soft consistency of

the paste. Liquid in the form of water or milk is

gradually added to produce the final paste consist-

ency. If the paste is too thick, the baked volume will

be low and the shell will be thick.

0010 To promote flakiness, water used in pie dough

mixtures should be chilled. This limits homogeniza-

tion during dough mixing by creating hard fat par-

ticles. Ice water may also be used. Liquid is also

necessary for leavening. When baked, liquid in pastry

dough produces steam, leavening the product and

separating the individual flakes. Fat containing

moisture will also help to produce steam for leavening

and flakiness.

Salt

0011Salt functions as a seasoning and is not required to

produce a successful pastry product. A crust without

salt will produce a flat-tasting crust. However, its

omission does not affect the mechanical aspects of

the pastry.

Other Ingredients

0012Eggs Eggs are incorporated into several pastries,

including choux paste, short (pa

te de sucre, or flan

pastry), and croissant doughs. Eggs are optional

ingredients in yeast-leavened Danish and puff pastry

doughs. Egg yolks can function to lubricate the

gluten, while the whites aid in baked pastry volume.

Eggs contribute richness, structure, and increased

keeping qualities. In choux pastry, for which 90–100

parts whole egg is beaten into a mixture of 60 parts

high-protein flour (12–13%), 100 parts water, 40

parts shortening, and two parts seasonings to form

a very thick paste, the primary functions of eggs

are dough emulsification, leavening, and supplying

moisture.

0013Acids Acids such as cream of tartar, vinegar, or

lemon juice are used in some pastry formulations.

Acids relax the gluten, thus improving the ease of

rolling. If too much acid is added, the dough will be

sticky and difficult to handle and roll. (See Acids:

Natural Acids and Acidulants.)

0014Sugar Sugar helps to tenderize the dough, adds

extra flavor, and promotes crust browning. Lactose,

the simple sugar found in milk, also contributes to

product browning. (See Lactose.)

0015Milk In some pastries, milk replaces water as the

source of liquid. Milk adds crust color by providing

lactose, which promotes Maillard browning during

baking. Milk solids strengthen the interior cell struc-

ture, which helps to maintain pastry flakiness. Milk

can also aid in producing a thin, smooth crust. (See

Browning: Nonenzymatic.)

0016Yeast Yeast is used in croissant and Danish pastry

doughs to provide leavening through the production

of carbon dioxide. Danish pastry doughs may contain

a high concentration of yeast to offset the growth-

inhibiting effects of added sugar.

Proportions of Ingredients (by Weight)

0017For a traditional plain (shortcrust) pastry, 100 parts

flour (average 115 g per cup) are used for each 42–59

parts fat. The optimal amount of plastic fats, such as

lard, is 44 parts to 100 parts of flour. If less than 44

PASTRY PRODUCTS/Ingredient Functionality and Dough Characteristics 4413

parts are used it may become difficult to mix in the

water without overdeveloping the gluten. When

liquid fat such as vegetable oil is used, 42 parts should

be used to each 100 parts of flour. If more than 59

parts of fat are used, the pastry becomes crumbly and

greasy. Within the recommended range, the smaller

the proportion of fat, the greater the likelihood of

developing excessive gluten. For each 100 parts

flour, 2.5 parts salt are used for flavoring.

0018 A minimal amount of water must be added to

develop gluten (flakiness). If too little water is

added, the pastry will be crumbly, but too much

water will cause excessive gluten development and

the pastry will be tough. A mixture of 31 parts

water to 100 parts flour is sufficient to provide flaki-

ness without promoting toughness. When a minimal

amount of fat is used, careful measurement of liquid

becomes even more important. A difference of as little

as 2.5 parts water per 100 parts flour can cause

a discernible difference in the tenderness of the

pastry.

Pastry Characteristics

0019 Tenderness and flakiness are two desirable character-

istics of pastry products which can occur together or

separately. Up to an optimum, tenderness increases as

fat is increased, as a result of the shortening power or

ability of the fat to coat the gluten strands, interfering

with gluten structure. The fat can also function to

coat the flour particles and prevent water from fully

hydrating the flour, thus preventing gluten formation.

Higher temperatures increase the ability of the fat to

spread, coating the gluten and increasing tenderness.

Keeping fat and water cold will serve to promote a

flaky, tender pastry which is not greasy or too tender.

A product which is too tender becomes crumbly and

too hard to handle. Overmanipulation, including

kneading of pastry dough, has the opposite effect.

As the dough is kneaded, rerolled, or mechanically

overmixed, the pastry becomes tough as a result of

excess gluten formation. Toughness can also be

caused by adding too much liquid, or by the presence

of excess flour during rolling.

0020 Flakiness results from partially hydrated flour or

dough being layered between thin sheets of fat. Pastry

layers are separated during baking as steam and, to

some extent, air separates the layers. These fat layers

must coat the flour sufficiently to produce layers, yet

not enough to cause the pastry to crumble. Cutting fat

into the flour in large particles promotes flakiness.

Medium-flaky pastry is made by cutting fat into small

lumps, while a mealy crust will form when the flour

and shortening are mixed thoroughly. Use of cold

water helps to promote flakiness in the final product.

For long flaky pastry the fat is cut into larger lumps

and the lumpy, sticky dough is rolled three times,

turning three times for each roll. The harder fats do

not spread as readily as softer fats and thus are more

likely to have flour particles adhering to the fat.

Optimum mixing time for desirable tenderness is

longer when harder fats are used. Dough rerolling

and folding increase flakiness. Increased gluten devel-

opment can hold steam more efficiently and separate

the dough into layers. The resultant increased tough-

ness may be reduced by rolling small pieces of fat

between the dough layers.

Dough Retardation and Relaxation

0021During dough mixing and handling, fat must remain

cold enough so that it does not soften during prepar-

ation. This is especially true for roll-in fat products,

such as puff and Danish pastries. Additional fat

folded into the dough creates numerous layers of

dough and fat. To prevent changes in fat properties

that occur quickly at elevated temperatures, dough is

retarded or relaxed at refrigerator temperature be-

tween sheetings. To prevent greasiness and decreased

volume during baking, cooled pastry should reach

ambient temperature slowly.

Leavening

0022In pastry, leavening occurs when heated liquid creates

steam, and individual layers (flakes) are separated.

Baking temperature is important to insure sufficient

leavening. Too low a temperature will not allow the

optimum production of steam for aeration, while

an oven temperature that is too high will result in

premature setting of the proteins and low pastry

volume. Leavening also occurs as air expands during

baking.

0023In yeast-leavened Danish pastry and croissant

doughs, yeast is added for additional leavening from

carbon dioxide. In choux paste, a small amount of

chemical, fast-acting leavening – ammonium bicar-

bonate and baking powder (1:1) (14 g per 454 g

extra liquid) – can be added to this liquid to obtain

the smooth consistency and maximum pastry volume.

In choux pastry, if eggs are used to soften the paste,

the liquid and chemical leavening mixture is not

needed. Leavening of the choux paste during baking

occurs by expansion of the eggs; carbon dioxide is

released from the chemical leavening agents, and

steam is formed from heated liquids in the paste.

Flour and egg protein coagulate to set the shape of

the aerated pastries. (See Leavening Agents.)

See also: Acids: Natural Acids and Acidulants; Browning:

Nonenzymatic; Fats: Uses in the Food Industry; Flour:

Analysis of Wheat Flours; Lactose; Leavening Agents

4414 PASTRY PRODUCTS/Ingredient Functionality and Dough Characteristics