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

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processes is extrusion-based, similar to the process for

making pellets. The main difference is that FCP are

not dried to below 12% moisture to be stored or sold.

They are also cooked less during the extrusion step.

After extrusion, they are fried to remove moisture and

complete the cooking process. Fabricated chips are

usually sheeted out of the extruder and cut into a

shape which simulates a potato or a tortilla chip.

Corn Chips and Simulated Potato Chips

0038 Commercial simulated potato chips have assumed

great importance. The corn chips and tortillas pre-

pared from alkali-treated corn dough have similar

flavors and textures. The ground, alkalized corn

dough, or masa (Table 2) is conveyed to the hopper

of the tortilla cutting head by means of a screw-type

extruder. A thick sheet of masa is extruded between

sizing rolls, and the resulting ribbon is cut into dices

of appropriate size. Tortilla blanks are baked in gas-

fired ovens at 315



C for 30–32 s. Tortillas discharged

at 79



C are cooled to 29–32



C in an atmospheric

multilayered conveyer.

0039 Corn chips are prepared from amixture of white and

yellow corn, varying in ratio depending upon the color

desired in the final product. The alkalized dough is cut

into pieces of desired length and shape, and transferred

directly into cooking oil held at about 190



C. After the

moisture content has been reduced to a few percent,

the chips are salted, cooled, and packaged.

0040 Cereal grains other than corn can also be formed

into chips and fried; the alkalizing process is omitted

in these cases. Shredded wheat, formed into multiple

layers, salted and baked, forms the basis of Triscuit.

0041 The high-fiber, high water-holding capacity (WHC)

and low calorific value of corn bran makes it suitable

for low-calorie and variety-baked snack foods, e.g.,

cookies, crackers, etc.

0042Fabricated potato snacks can be classified into

four groups: (1) dry collet processes; (2) single-screw

extrusion of dry potatoes; (3) forming and frying of

moist dough; and (4) forming of a high-solids dough

into a thin sheet which is then cut into pieces and

fried. The latter process is used in the manufacture of

simulated potato chips.

0043Simulated potato chips may be formed by methods

resembling those used in the cookie and cracker

industry. It is necessary to formulate the dough with

physical properties that make it suitable for rolling out

into a thin sheet. This is achieved by the inclusion of

substantial amounts of cereal flour. Another approach

is to use ungelatinized starch in the dough, and then

steam-treat the pieces after all the forming operations

have been completed. After sheeting, the dough is cut

into pieces of the desired shape and size, and then fried

or baked. Simulated potato chips can also be prepared

from reconstituted dehydrated potatoes.

Low-Pressure Extruded Fried Indian

Snacks

0044A lot of legumes are manufactured into flours and

are used as the basis for formulations that are ex-

truded in low-pressure systems. One prominent

market is in the Indian snack food area that produces

a large variety of snack food-type noodles (sev,

omumpodi). The number of shapes, sizes, and ingre-

dients used is diverse, but basic principles involved

in producing such products are quite similar. In

extruded gram flour-based snacks, flour is pro-

duced from chickpea, which is one of the main

legumes grown in India. The composition of gram

tbl0002 Table 2 Parameters for the major steps in the manufacture of an alkaline-processed corn snack

Operation Tortilla chip Cornchip

Lime content 1% of corn weight 1% of corn weight

Cooking 4–10 min >93



C. Moisture: 29% 14–45 min >93



C. Moisture 42–44%

Quenching Quickly, <66



C Quickly, <66



Steeping 8–24 h, 46–60



C. Moisture >45% 8–24 h, 46–60



C. Moisture 50–52%

Washing Wash temperature <27



C Wash thoroughly and drain: <27



Grinding Stone, masa at <38



C. Water added, moisture 52–54% Stone, masa at 46–54



C. Moisture 50–52%

Masa sheeting and forming Promptly, 21–27



C Masa is extruded or sheeted and cut

directly into frying oil

Baking 12–18 s, 399–454



C. Moisture 40%

Cooling and equilibrating Cool to 60



C within 15–30 s. Moisture 38% after

equilibration

Frying 2 min at 179



C 1.5 min at 210



Chip moisture 1.0–1.2% 1.0–1.5%

Oil content 25% 35%

From Gomez MH, Rooney LW and Waniska RD (1987) Dry corn masa flours for tortilla and snack food production. Cereal Foods of the World 35: 372.

SNACK FOODS/Range on the Market 5327

flour is approximately 11.2% moisture, 22.5% pro-

tein, 5.2% fat, and 58.9% carbohydrate. Other flours

that are commonly used as base ingredients for

this type of extrusion include soybean and pea flour.

0045 Gram flour is mixed with other ingredients to

obtain a dough that is suitable for extruding and

has an acceptable texture and taste. Other ingredi-

ents that are commonly used in the formulations for

Indian-style extruded products include rice flour,

urad dhal powder, ghee, sodium bicarbonate, chilli,

cumin, paprika, coriander, turmeric, asafetida, and

pepper. Gram flour is typically mixed with rice flour,

other spices, and water to obtain dough that is

extremely sticky. The moisture content of this

dough varies depending on what the manufacturer

requires but typical moisture levels vary from 40

to 60%.

0046 The type of die that is used for extruding will

determine the style of product manufactured.

Common shapes include a round product with diam-

eter varying from 1.2 to 6 mm. Other shapes include a

star or a ribbon. The diameter of the die and the

number of holes on the die plates will produce differ-

ent production volumes.

0047 The noodles are fried using a single-zone, indirectly

fired frier. The temperature used is approximately

180



C and the frying time varies from 30 s to 5 min,

depending on the moisture content of the dough,

diameter, and shape of the extruder die.

Corn Snacks

0048 Corn-based snacks fall into three categories: extruded

from corn meal, baked and fried from masa, and corn

chips or simulated potato chips.

0049 Extruded snacks are made of corn meal with, oc-

casionally, a small amount of another grain, such as

rice or wheat, added. The moistened meal is passed

through extrusion cooking equipment, giving a collet,

which is an expanded matrix of gelatinized starch.

The dimensions are determined by the kind of die

used, the cut-off knife speed, and other mechanical

factors. The collet has a moisture content of 8–10%

and is quite tough and chewy, an aspect which is

remedied by baking or deep-frying to obtain a final

moisture level of around 2%. The dried collets are

flavored with cheese (applied in a powdered form),

chilli, barbecue sauce, sour cream and onion, or a

number of other flavors. Other extruded snacks con-

sist of hollow extrudates which are modified to make

rectangles, ovals, or ornamental shapes, and filled

with all kinds of savory or sweet fillings. These snacks

are quite popular, and the most popular flavors for

extruded snacks are chocolate, butterscotch, and

peanut butter. Delicate fruit creams, such as wild

strawberry, lemon-lime, bitter orange, sour cherry,

kiwi, peach, and cola, are also being used to fill

extrudates.

0050Baked and fried snacks make up the largest share

of the corn-based snack market. They are produced

using centuries-old processes that have been modi-

fied by the adoption of modern technology. Cleaned

corn is placed in steam kettles and covered with a

dilute solution of lime (Ca(OH)

). The mass is

brought to near-boiling temperature, and held for a

period of time depending upon the nature of the

corn used. It is then cooled and allowed to steep

for 8–16 h. During steeping, water penetrates the

kernel and gives the desired degree of friability

to the endosperm. The cooling and steeping also

loosen the outer hull and germ, which are removed

from the corn by washing. The washed kernels are

ground to produce masa, a cohesive, plastic corn

meal with a moisture content of approximately

50–60%. Masa is the raw material for corn and

tortilla chips. To make corn chips, masa is extruded

through a slot to give a ribbon of dough. Cut off by

a knife, the raw chips fall into hot fat for deep-

frying. They are transported through the frying

tank by a traveling belt in 2–5 min. During this

time, the starch is gelatinized and the moisture

level is reduced to approximately 2% to give the

crisp bite of the finished chip. After the traveling

belt brings the chips out of the bath, they are given

a light dusting of salt and flavoring poser, if re-

quired, and then packed. Whole kernel corn can

be heat-expanded by selecting a corn variety,

drying, soaking, separating the corn kernels from

water, heating the soaked kernels in edible oil to

expand, and cooking the interior starch. The fried

kernels are separated from oil and seasoned.

0051Tortilla chips are produced more or less as in a

traditional process. The masa is rolled out into a

thin sheet, cut into the desired shape, and transported

into an open-flame oven. The heat sets the structure,

drives out most of the moisture, and changes the

flavor slightly by creating small amounts of Maillard

reaction products. The chips are held in a tempering

chamber to equilibrate moisture and stresses through-

out the chip. Finally, they are deep-fried to create a

crisp texture, salted or seasoned, and packaged. Use

of dry corn masa in the preparation of corn tortillas

and other corn-based snacks is advantageous as it

eliminates the capital cost of cooking, washing, and

grinding equipment, avoids the problems associated

with high solids, high biological oxygen demand

waste water; minimizes variability, and improves

consistency and quality as well as the partial size

distribution requirement of the end products. (See

Tortillas.)

5328 SNACK FOODS/Range on the Market

Legume-Based Indian Snacks

Fried Green Peas

0052 Fried peas can be eaten as a fried snack or consumed

as a part of a mix of snack food products.

0053 After the variety of pea has been chosen it is neces-

sary to soak the peas in sodium bicarbonate solu-

tion containing green food coloring (within Asia).

The purpose of adding green food colouring is to

enhance the green pigmentation of the surface of the

peas.

0054 The peas are obtained in the dehydrated form and

rehydrated in water at room temperature for approxi-

mately 8 h. If the temperature is too high, it will cause

the starch within the peas to gelatinize and the protein

to denature. The moisture content of the peas increases

to approximately 48–57%. After soaking, the peas

swell to approximately twice their original size. The

soak time is critical to minimize the level of fines pro-

duced as peas soaked for longer than 9 h tend to pro-

duce a higher level of fines as their skins get removed

more easily during the cooking process. If the peas are

soaked for excessively longer periods of time, they may

ferment and cannot be utilized by the manufacturer.

0055 The addition of sodium bicarbonate produces a

multitude of effects. Initially it will increase the pH

of the soak water and brightness will occur to a

greater extent with the presence of green food

coloring in the soak water. The increase in pH of the

soak water insures that the water absorbed into the

peas has a higher pH than the one it contained. It acts

as a form of chemical leavening. The reaction

involves the acid (contained within the pea) and

soda (sodium bicarbonate). One of the main purposes

of using this chemical is to produce carbon dioxide

when the peas are fried. This gives fried peas a lighter

texture and a better mouth feel.

0056 After soaking, the peas are fried to reduce the

moisture content below 2.5%. By having the flexibil-

ity to vary the temperature of the frying oil, the prod-

uct quality of the peas can be improved. If the frying

oil temperature is not controlled then the moisture

content in the final product may be too high or too

low, the texture may be too hard, the surface of the

peas may blister, there may be an overexpansion of

the peas giving excess fines, and product capacity may

be reduced.

Fried Chickpeas

0057 Due to their high protein and low fat content, fried

chickpeas are a healthy alternative to other snack

foods. The dried chickpea contains 7–10% water,

12–31% protein, 4–10% fat, 58–68% carbohy-

drates, 3–5% fiber, and 2–5% ash.

0058Chickpeas are soaked for approximately 10 h at

room temperature, increasing the moisture content

to approximately 53%. The chickpeas are removed

from water, rinsed, and drained to insure excess

surface moisture is removed.

0059The chickpeas have an anatomy that resembles the

green pea and therefore the problems experienced

during frying are very similar. It is necessary to insure

the frier has the flexibility to vary the initial and final

frying temperature (as was the case with green peas).

If a single zone temperature is used, either the oil has

to be set at a low temperature, or if the temperature is

too high this will cause problems with rupturing of

the skin and increase in level of fines. If the tempera-

ture is too low then the product output will be

reduced and oil absorption will increase. The slow

increase in temperature during frying will increase the

output obtained and decrease oil absorption.

Fried Lentils

0060The chemical composition of dried lentils is approxi-

mately 23% protein, 1% fat, 1% fiber, 61% carbo-

hydrates, and 14% water.

0061The lentils are soaked for 3 h in water at room

temperature to a final moisture content of 52%,

rinsed and drained to remove excess water.

0062This legume performs differently when fried, as

compared to green peas or chick peas. A single tem-

perature zone can be used because the product is not

as susceptible to thermal shock when it initially enters

the frier. A temperature of 180



C is used to obtain a

rapid decrease in moisture content of the legume. The

time required to fry this legume is very short because

of the large surface area of the product and the rapid

heat transfer into the product.

Meat-Based Snacks

0063There are a few snacks that are composed primarily

of animal-derived raw materials. Expanded pork

rinds, also called broken skins or skeen, have been

popular as a between-meal snack in the southern USA

for many years. These are pieces of hog skin which

have been processed so that they puff to many times

their original volume. The flavor is bland and reflects

the oil in which the skin has been processed. The

texture is very crisp and friable; they are not as hygro-

scopic as many other puffed snacks.

0064The raw materials are green belly skins, green fat

hog skins and green ham skins from any type of hog;

belly skins give the best finished product. The skins

are first dipped into an air-agitated brine solution

held at 100



C for 30 s. The brine may contain 12 kg

dextrose, 11 kg sucrose, and 68 kg salt in 909 l in

SNACK FOODS/Range on the Market 5329

water. After dipping, the skins are drained and cooled

at room temperature. Then the skin is diced into 127-

or 254-mm squares, ready for further processing.

0065 Chimni, a processed seafood snack popular in

Japan, is gaining popularity as a main dish rather

than a snack consumed with drinks, but it involves

high labor.

Jerky

0066 The name ‘jerky’ is derived from a dried-meat prod-

uct which is popular in the USA. Many countries have

their own form of dried-meat products. The product

name varies, as does the form in which it is eaten. The

Americans call it ‘jerky’ and eat it as a leathery whole

tissue, or comminuted into strips. The American

Indians call it ‘pemmican;’ they grind the diced meat

and mix it with fat before eating it. In South Africa it

is called ‘biltong.’ The French version is called

‘grisons;’ before being eaten, the dried meat is

smoothed with hot cheese.

0067 Meat jerky was originally prepared by the Ameri-

can Indians, who salted strips of muscle tissue from

deer, buffaloes, and other game animals and cured the

strips in sun or over smoky fires for long periods of

time. Commercially, beef jerky is made by marinating

strips of beef, drying the marinated meat, and finally

cutting the dried strips to the desired dimensions. Beef

jerky can also be prepared by subjecting a mixture of

ground and chunk beef to a saline treatment for 12 h

or more and then to freezing temperatures for 1–3

weeks. The meat preparation is then sliced into strips

and dried.

Other Snack Foods

0068 The future of traditional snack foods depends upon

the development of new forms and flavors. Pretzels

and salt sticks, crackers, and nut mixtures have been

modified, and the market of these products has been

increased.

0069 Soft pretzels available in fresh, frozen, and micro-

wavable forms have resulted in growth of the pretzel

market. In most countries, the market of pretzels and

salt sticks has increased with the introduction of

health-oriented products that are salt-free, choles-

terol-free, and possess increased fiber content. Other

new pretzels and salt stick products are produced in

various shapes and sizes. The new products are also

available in such varieties as savory-flavored, sweet-

flavored, chocolate-coated, brightly colored, and

peanut-butter-filled.

0070 Along with the salted peanuts and nut mixtures

that continue to be popular all over the world, the

current market for nut-based snacks is influenced

by: (1) an increased demand for flavored nuts; (2)

the growing popularity of high-quality exotic nut

and dried-fruit mixtures; and (3) the increasing

success of premium nuts such as cashew, pistachio,

and macadamia nuts. The development of flavored

nuts and nut mixtures has resulted in a virtually limit-

less list of new products, including products such as

hickory-smoked and honey-roasted nuts, nut mixtures

containing rice, lentils, coconut, and vegetables, and

nuts of all types flavored with garlic, soy sauce, herbs,

ham, barbecue, and many newly developed flavors.

0071Khao kriap wane (KKW) is a popular Thai glutin-

ous rice-based snack food made from pounded, gelat-

inized glutinous rice which is sun-dried and puffed by

direct flame roasting. Puffed KKW does not stay

crunchy for more than 3 h after puffing. It can be

stored for less than 2 months in low-density poly-

ethylene (LDPE) or for greater than 6 months in

aluminum/polyethylene laminate or polypropylene

and retains crunchiness.

0072Novelose, a speciality starch, consists of at least

30% dietary fiber and functions well in direct

expanded extruded products. It also has a synergistic

effect with traditional cellulosic fiber and counteracts

negative processing aspects. (See Cashew Nuts and

Cashew Apples.) Specialty and modified starches can

provide a number of functional benefits to snack

foods like replacement of fats and oils, satisfying

consumer demand for healthier snacks for tasty and

appealing reduced-fat products.

0073A fruit snack bar, prepared using apricot pulp and

soyabean slurry, contains 15.3% moisture, 7.8% pro-

tein and 16.5 mg ascorbic acid 100 g

1

, with good

flavor. A snack product comprised of dried agglomer-

ated, sugar-soaked fruit or vegetables like apples,

carrots, and beets, followed by drying, has a low

water activity, bulk density, and crisp tender eating

quality.

0074A bagged expanded cooked snack comprises a

number of individual morsels with several added vita-

mins, such as thiamin, riboflavin, niacin, ascorbic

acid, vitamin D, and at least one added mineral other

than sodium. It may be a savoury product with an oil

or fat content of 5–40% by weight.

0075Rice flour can improve the texture and handling of

multigrain products or substitute completely for

another type of grain. Blending long-grain rice flour

increases the crispiness in fried or baked snack chips

based on wheat or corn. Waxy rice flour can reduce

chip hardness and at the same time can provide a

melt-in-the-mouth texture which is usually achieved

with extra fat. Adding 5–10% waxy rice flour to a

baked or fried chip product diminishes chip breakage

during packaging.

0076Shelf-stable grain-based Indian snacks include fried

products (paras, fried products made from bengal

5330 SNACK FOODS/Range on the Market

gram meal, fried products made from rice and

legumes, fried dhals); moist fried products, popped

and puffed cereals, expanded cereals, beaten (flaked)

rice, and extruded foods (extruded pellets, ready-

to-eat expanded products, corn and tortilla chips).

Kokoro, an indigenous corn-based snack food prod-

uct prepared using deep frying of a corn, onion, and

shrimp blend, is popular in Nigeria.

Quality Control for Snack Foods

0077 The extent of quality control analysis in the snack

food industry is quite variable, ranging from

completely subjective testing procedures to series

of elaborate instrumental analyses performed on a

continuous basis. The maintenance of uniform

quality in snack foods is essential for the very exist-

ence of the business. Quality control expresses

the objectives of a group of people who do the

sampling, testing, and other activities related to the

evaluation of product conformance to predetermined

standards. It is the expended responsibility of the

group to correct problems which could result in

a defective product. (See Quality Assurance and

Quality Control.)

0078 Quality control aims at maintenance of quality at

levels and tolerances acceptable to the buyer, while

minimizing costs to the vendor. It can also be defined

as the application of sensory, physical, and chemical

tests in industrial production to prevent undue vari-

ation in quality attributes, such as color, viscosity, and

texture. In addition to satisfying the consumer, the

product must meet the requirements of government

regulatory agencies. A snack food which does not

meet the minimum acceptability requirements of

all customers may result in only a few complaints,

but a product which does not meet all of the legal

requirements may be confiscated and the manufac-

turer subjected to punitive fines and other penalties.

A product may look good, taste good, have good

texture, and perform well in its intended application,

and still be unfit for distribution. To be suitable for

sale it must also be wholesome, conform to all applic-

able labeling and packaging requirements, and be pre-

pared and stored under conditions tending to prevent

contamination by noxious or esthetically undesirable

materials.

0079 The quality of the finished product is inseparable

from the quality of the components. Seldom can

processing operations compensate for raw material

inadequacies. Unless the raw materials are of good

quality, it is very difficult to obtain a good-quality

finished product. Standards must be developed and

strictly adhered to while processing the various ingre-

dients, during the production and processing steps, as

well as during handling, packaging, and storage of the

finished snacks.

0080During pretzel production, a number of problems,

particularly in the cooking process, may arise. These

include brittleness, dark or light color, wrinkling, loss

of glaze, breakage, browned interior, and lack of

crispness.

0081In the production of corn-based, baked, and fried

products, the consistency of the masa is very import-

ant. If excess starch granules are gelatinized during

cooking and steeping, the masa is too sticky to pro-

cess smoothly. On the other hand, inadequate

cooking may give a dry, crumbly mass which does

not work in the equipment. Potato chips undergo a

visual inspection at the end of the process, and exces-

sively dark ones or those containing discolored por-

tions or possessing some other defect are manually

removed by picking. In a modern industry, this may

be performed by computerized optical scanners. The

sensitivity of the computer scanner can be adjusted to

pick up all less-than-perfect chips, or selectively to

remove only the least desirable. Blistering of chips

on frying is quite a problem. Such chips break in

conveying, filling, or handling the filled bags. An-

other factor affecting the quality of chips is the shift

to thicker chips: it results in significant reduction in

oil absorption owing to a decreased surface area rela-

tive to the volume. Ridged chips solve the blistering

problem.

0082In general, snack foods are believed to be ‘empty

calories,’ however, lately manufacturers have started

supplementation with vitamins, minerals, or proteins.

Vitamins can affect flavor and some can also cause off-

flavors. While supplementing with nutrients, it is neces-

sary to establish a quality control program to insure the

claimed amounts in the product. Most snacks are poor

sources of protein, and the protein, which is present, is

often of poor nutritional quality. Protein supplemen-

tation is possible by increasing the protein efficiency

ratio of the protein already present or increasing the

protein content through addition of casein, soya pro-

tein isolates, or egg white. Certain combinations of

cereals and legumes are very desirable from a nutri-

tional point of view. The high snackers have low energy

and low macronutrients from the meals; however,

snacks do make an important contribution to energy

and nutrients. A high snacking frequency and choosing

from a wide variety of snack foods can result in a

balanced intake of nutrients.

See also: Almonds; Biscuits, Cookies, and Crackers:

Nature of the Products; Methods of Manufacture; Wafers;

Cashew Nuts and Cashew Apples; Peanuts; Potatoes

and Related Crops: Processing Potato Tubers; Quality

Assurance and Quality Control; Tortillas

SNACK FOODS/Range on the Market 5331

Further Reading

Anonymous (1996) Healthy starch innovations for snacks

and cereals. Food Technology Europe 3: 46.

Arya SS (1991) Grain based snack and convenience foods.

Indian Miller 21: 6.

Booth RG (ed.) (1990) Snack Food. New York: Van

Nostrand Reinhold.

Burge RM and Duensing WJ (1989) Processing and dietary

fibre ingredient application of corn bran. Cereal Foods

World 34: 535.

Chauhan SK, Joshi VK and Lal BB (1993) Apricot-soy fruit

bar: a new protein enriched product. Journal of Food

Science and Technology 30: 457.

Crocombe BI (1988) The development and production

of jerky at Mirinz’s meat products line. Bulletin of

the Meat Industry Research Institute of New Zealand

855: 126.

Frame ND (ed.) The Technology of Extrusion Cooking.

New York: Blackie Academic and Professional.

Friesen SA (1995) Heat Expanded Whole Kernel Snack

Food. United States patent.

Gomez MH, Rooney LW and Waniska RD (1987) Dry corn

masa flours for tortilla and snack food production.

Cereal Foods World 35: 372.

Gould WA (1985) Changes and trends in snack food

industry. Cereal Foods World 30: 219.

Howlett RJ (1993) Bagged Snacks. UK patent application.

Huang DP (1995) New perspectives on starch and starch

derivatives for snack application. Cereal Foods World

40: 528.

Jomduang S, Mohamad S, Muhammand K and Abu-Bakar

A (1995) Extending shelf life of ‘Khao Kriap Wane’–a

traditional Thai glutinous rice-based snack. Journal of

Science and Food Agriculture 67: 29.

Kano I (1993) A growing chimni market in Japan. Infofish

International 4: 18.

Lasekan OO, Lasekan W, Idown MA and Oja OA (1996)

Effect of extrusion conditions on the nutritional

value, storage stability and sensory characteristics of

a maize-based snack food. Journal of Cereal Science

24: 79.

Madonna MD (1983) Pretzels as low calorie snacks. Cereal

Foods World 28: 297.

Matz SA (1976) Snack Food Technology. Westport, Ct: AVI

Publishing.

Midson K (1999) Indian ethnic snacks. Processed Food

Industry 3: 38.

Robert BA and Burkes AL (1989) Crisp Fruit or Vegetable

Snack Products and Process. United States patent.

Sheng DY (1995) Rice-based ingredients in cereals and

snacks. Cereal Foods of the World 40: 538.

Slige MR (1983) Fruit and nut ingredients. Cereal Foods of

the World 25: 286.

Stauffer CE (1983) Corn-based snacks. Cereal Foods World

28: 301.

Stauffer CE (1983) Corn masa. Baking and Snack. October:

35.

Tettweiler P (1991) Snack foods worldwide. Food Tech-

nology 45: 58.

Dietary Importance

A S Bawa and J S Sidhu, Guru Nanak Dev University,

Amritsar, India

Background

0001This article deals with the dietary importance of pro-

cessed snack foods with a passing reference to fruits

and fruit bars. However, these as well as fruit juices

may be included under the term ‘snack foods.’ In

general, snack foods are considered as ‘junk foods’

or ‘empty calories.’ Our diet is generally based upon

three principal meals a day, and the role of snack

foods is to offer a light, convenient, and enjoyable

food option, when, for reasons of hunger or sociabil-

ity, a food selection is required at a time between that

allotted for principal meals. Thus, snack foods are not

designed to be alternatives for three main meals a day.

They are convenient to eat, involving no preparation

time or effort by the consumer. Snacks are eaten not

only to satisfy hunger or supply the nutrients to our

body, but also for social reasons. On many occasions,

the inclusion of snack foods in our diet is not justified

in terms of nutritional demands. The nutritional

value of different snack foods, extent and frequency

of consumption by different people, and the need for

fortification have been discussed.

0002Snack items and processed foods are presumed to

have a high sodium content, and this should be

avoided. Teenage boys are most likely to have a low

intake level of calcium, iron, magnesium, and vitamin

, and teenage girls consume these nutrients at still

lower levels. The food items most frequently con-

sumed by both sexes between meals are cakes,

cookies, pies, candy, and desserts. The most popular

foods are salted snack foods, such as chips (crisps),

pretzels, and popcorn. Males incorporate more

breads, wafers, and other bread products into their

snacks than females, whereas females eat more snacks

containing condiments, fat spreads, and dips than do

males. (See Calcium: Physiology; Iron: Physiology;

Magnesium; Sodium: Physiology; Vitamin B

: Prop-

erties and Determination.)

0003The real nutritional concerns about snack foods

center on the sodium, energy, vitamin, mineral, and

dietary fiber contents.

Nutritional Value of Different Types of

Snack Food

Potato Chips (Crisps)

0004Nutritionally, 28 g (1 oz.) of potato chips provide

647 kJ (154 kcal), contributed by 2 g of protein, 14 g

5332 SNACK FOODS/Dietary Importance

of carbohydrates, and 10 g of fat. A portion of potato

chips (25 g) contains 8% of the recommended daily

allowance of vitamin C, 3% of thiamin, 11% of nico-

tinic acid, 8% of iron, 11% of vitamin B

,4%of

phosphorus and 4% of magnesium. Potatoes are also

an important source of dietary fiber. Refer to individ-

ual nutrients.

Cookies and Crackers

0005 The principal ingredient in cookies and crackers is

unbleached, soft wheat flour, and most of the nutri-

ents in these products are derived from the flour. It

can range from more than 90% for saltines and simi-

lar products to less than 25% in products such as

enrobed wafers. The soft wheat flour used in cookies

and crackers contains 8–10% protein, with the higher-

protein flours generally being used for crackers and

the lower-protein flours for more tender sweet goods.

With certain exceptions, the quality does not deterior-

ate on baking. Most cookies and crackers are made

from enriched flour. The main component present in

flour is carbohydrate, which is a good source of

energy. (See Flour: Dietary Importance.)

0006 Other ingredients added to cookies and crackers

influence the nutrient content of products either by

their own nutritional composition or by diluting the

nutrients contributed by enriched flour: for example,

sugar contributes energy and carbohydrates; shor-

tening contributes fat, essential fatty acids, and

energy; salt contributes sodium; leavening agents con-

tribute sodium, potassium, calcium, and phosphorus;

peanut contributes fat and nicotinic acid; fruits and

vegetables contribute vitamins A and C, fiber, and

minerals; chocolate contributes iron and fiber; and

other grains contribute minerals, fiber, and other nu-

trients similar to wheat flour. The potassium content

of cookies and crackers is 25–200 mg and 30–80 mg

per 28 g (1 oz.), respectively. During baking and stor-

age, the main nutrients lost are thiamin and vitamin

C. Lysine reacts with reducing sugars and becomes

unavailable, especially at a high pH. Plain and

sandwich cookies have similar nutrients. However,

nut-containing cookies provide comparatively more

protein, vitamins (such as nicotinic acid), and

minerals. (Refer to individual nutrients.)

Pretzels

0007 The average energy content of a 28-g of serving pret-

zels is 462 kJ. One pretzel rod contains 231 kJ; one

Dutch-style pretzel contains 460 kJ, and a handful of

twisted, three-ring pretzels contain approximately

419 kJ. Pretzels are low in energy and fat, and have

no sugar, but contain a large amount of sodium.

The average amount is 450–700 mg of sodium per

28-g serving of pretzels. However, low-salt pretzels,

containing 300 mg per 28-g serving, and unsalted

pretzels are also available for sodium-conscious con-

sumers.

0008The typical ingredients of pretzels are flour, water,

yeast, soda, and salt. The flour is from soft wheat

with a protein content of 8.50–9.50% and an ash

content of 0.40–0.50%. A 28-g serving of pretzels

offers approximately 3 g of protein, 23 g of carbo-

hydrates, and 1 g of fat. Pretzels also provide several

vitamins and minerals, including thiamin, riboflavin,

nicotinic acid, iron, magnesium, and copper. Al-

though the quantities of these nutrients are moderate,

the nutritional value of pretzels is significant, since

they contain no chemical additives or preservatives.

However, some pretzels also offer calcium, phos-

phorus, and other nutrients in significant amounts.

(Refer to individual nutrients.)

Corn Snacks

0009Corn snacks are accused of being junk food and

without nutrient content. Flour tortillas are low in

moisture and high in fat, protein, and carbohydrates,

compared to corn tortillas. The energy content is, on

average, 25% higher than that of corn tortillas. The

phosphorus and calcium contents in corn tortillas are

substantive. The iron content in corn tortillas is simi-

lar to that of wheat flour tortillas. Both the flour and

corn tortillas are significant sources of zinc; corn

tortillas are also a significant dietary source of copper

and magnesium. Tortillas contain modest amounts of

sodium and potassium, but because of the significant

losses during processing, they are an insignificant

source of thiamin and riboflavin. All tortilla products

are substantial sources of nicotinic acid. Tortillas do

not contain measurable quantities of vitamin C or

b-carotene. Refer to individual nutrients.

0010A fruit bar containing apricot pulp and soy slurry

in the ratio 70:30 has been found to be most accept-

able in terms of sensory properties. This bar con-

tained 15.3% moisture, 7.8% protein, and 16.5 mg

of ascorbic acid per 100 g, and had a good flavor (not

beany) and texture.

0011In one study, consumers in Newcastle perceived

cereal bars to be healthiest. However, an analysis of

seven popular cereal bars revealed that they are only

marginally healthier than traditional cereal snacks.

The varieties containing chocolate chips were pre-

ferred but were not necessarily the healthiest.

0012An assessment of the perception of fruits in

relation to manufactured snack foods has revealed

that fresh fruit and a canned snack fruit product

were both perceived as healthy and refreshing by

working women in the UK, manufactured snack

foods were considered more convenient and suitable

for comfort eating, and bananas and apples were

SNACK FOODS/Dietary Importance 5333

perceived as more convenient than orange and

kiwi fruit.

0013 The Nigerian snack foods, robo, kulikuli, and

kokoro, prepared from watermelon seeds, ground-

nut, or maize kernels, have 23.4–42.0% fat and

only 1.5–7.3% moisture, and a maximum shelf-life

of about 150 days at 30–31



0014 An extruded snack prepared from a blend of tapi-

oca, wheat flour, maize grits, spirulina, etc. is quite

nutritious and contains: energy 411 kcal, protein

8.7 g, fat 7.6 g, carbohydrates 77.2 g, Ca 68.0 mg, Fe

2.8 mg, vitamin A less than 3 IU, thaimin 0.1 mg,

riboflavin 0.2 mg and vitamin C less than 0.35 mg

per 100 g. It is low in fat and relatively high in Ca

and Fe, compared to other similar snacks.

0015 Overall, corn snacks can contribute positively to

the diet by providing certain nutrients and minerals

necessary for nutritional balance and they have a

good flavor and a pleasing texture.

0016 In potato chips and nuts, the salt is on the surface of

the foods, so the immediate taste perception is

of saltiness – much more so than if the salt were

uniformly distributed, as in most other foods. Many

snack foods contain moderate to high amounts of salt

on a percentage basis. The average serving of snack

foods is much less than 100 g, ranging up to 40 g and

averaging about 35 g; in comparison, many sodium-

containing staple foods are eaten in quantities greater

than 100 g. It is more sensible to examinethesodium

content of snack foodson aper-serving basis (Table 1)

because the sodium content of snack foods is much

lower than that of certain commonly consumed

foods, such as bread and butter, sandwiches, and

other foods at the bottom of the table. The sodium

content of a packet of chips, for example, is less than

that of a plain sandwich, and over six packets of

salted chips would have to be consumed to obtain

the same amount of sodium contained in a single

hamburger.

0017The second aspect of concern is the energy content

of snack foods. It is generally believed that snack

foods are both rich in energy and fattening, since

they are cooked in, or blended with, oil. A compari-

son of energy content of foods on a per-serving basis

(Table 2) shows that the consumption of lightly

cooked vegetables instead of snacks can reduce the

energy intake and that the energy content of snacks is

not as high as is popularly perceived, since hot dogs

and hamburgers have much higher energy contents. A

packet of chips does not contain much more energy

than a cup of milk or a plain yogurt, and somewhat

less than a bread-and-butter sandwich. It is much

more difficult to control the energy and fat content

of snack foods than it is to control sodium content.

The technology to produce fat-reduced potato chips

does not exist, but the level of fat can be controlled by

careful regulation of cooking parameters. Oil is es-

sential in cereal snacks to give an acceptable mouth-

feel, and with nuts, the oil is already present before

cooking. The only way to control the energy con-

sumption via snack foods is to reduce the size of the

serving; Table 3 shows gives the effect of serving size

on energy content.

0018The vitamin and mineral contents of snack foods

are another area of concern; Table 4 lists the vitamin

and mineral contents of some selected snack foods.

tbl0001 Table 1 Sodium content of some foods

Food Sodium content

(mgper serving)

Most fresh fruits and vegetables Negligible

Eggs (one medium) 54

Rump steak (130 g) 121

Fried chicken leg 122

Whole milk (1 cup, 237 ml) 128

Salted peanuts (25 g) 197

Toasted CCS (25-g packet) 220

Salted chips (25-g packet) 234

Flavored chip crisp sticks (25-g packet) 280

Flavored chips (25-g packet) 306

Bread-and-butter sandwich 367

Cheese Twisties (25-g packet) 440

Scrambled egg 534

Fritz or Devon (two slices) 650

Hot dog 1102

Hamburger 1591

Data from Delroy B (1985) The role of snack foods. Food Technology in

Australia 37(4): 154–158.

tbl0002Table 2 Energy content of some foods

Food Energy content (kJ) per

serving

Lettuce 17

Peas 163

Boiled egg (one medium) 301

Baked fish (one fillet) 326

Salted peanuts (25 g) 584

Whole milk (1 cup, 237 ml) 644

Plain yogurt (1 cup, 237 ml) 690

Potato chips (25-g packet) 739

Twisties (25-g packet) 810

Chip crisp sticks (25-g packet) 814

Bread-and-butter sandwich 865

Hamburger patty 932

Flavored and fruit yogurt (1 cup, 237 ml) 982

Fish, buttered and fried (one fillet) 1041

Hot dog 1342

Grilled steak (130 g) 1822

4.2 kJ is equivalent to 1 kcal. Data from Delroy B (1985) The role of snack

foods. Food Technology in Australia 37(4): 154–158.

5334 SNACK FOODS/Dietary Importance

The potassium content of chips is higher than sodium

in spite of the added salt, and this is significant in view

of the criticism that high sodium levels in processed

foods are associated with depleted potassium levels.

However, since snack foods are designed to be occa-

sional between meal snacks, their contribution to the

diet may be of little significance to the average person.

Cereal snacks can be fortified with added vitamins

and minerals to any desired level, but it is not

common practice, since snack foods are not consid-

ered to be suppliers of significant quantities of min-

erals and vitamins. (See Food Fortification.)

0019 The importance of dietary fiber in snack foods is

still not very clear, partly because of problems with

analytical methods; Table 5 compares the dietary

fiber content of snack foods with that of a bread

sandwich. The figures indicate that the four snack

foods contain more dietary fiber than a white-bread

sandwich, and chip crisp sticks more than a brown-

bread sandwich. Since bread is one of our best sources

of dietary fiber, and the cereals and root vegetables

from which snacks are developed are sources of the

highest-quality fiber, snack foods cannot be rejected

on the basis of their fiber content. Snack foods are

neither an important source of micronutrients nor

simply ‘empty calories.’ Snack foods prepared from

whole cereal grains can be a good source of dietary

fiber, and the addition of a few per cent of bran in

place of the purified cereal fractions improves the

fiber content of the finished products. Dairy and meat

products have negligible fiber contents, and potatoes

are rather low in this component. (See Dietary Fiber:

Physiological Effects; Effects of Fiber on Absorption.)

Levels of Snack Foods Eaten

0020The results of various previous studies (Table 6)

reveal that children and teenagers have at least one

snack during the day. Adults tend to snack less fre-

quently, and the percentage of adults who ‘snack’

decreases with age. Snacks provide at least 20% of

energy for those who eat at least one snack a day and

account for 12% of the average protein intake, 16%

of the fat intake, and 25% of the daily carbohydrate

intake. ‘Snackers’ obtain, on average, 14% of their

daily iron intake, 18% of their phosphorus intake,

21% of their magnesium and calcium intakes,

13–14% of their vitamin A, thiamin, preformed

nicotinic acid, vitamin B

, and vitamin B

intakes,

and 16–17% of their vitamin C and riboflavin

intakes. As the number of snacks eaten increases,

the amounts of nearly all nutrients and energy also

increase. An increased level of snacking makes a sig-

nificant contribution to children’s intake levels of

magnesium and zinc, and to adolescents’ intake of

vitamin B

, calcium, iron, magnesium, and zinc. On

days when no snacks are eaten, the intake of fat,

sugar, and sodium is decreased, and more food is

eaten during the main meals. Snacking has little

impact on the nutritional quality of the diet of elderly

individuals. Crisps are the most popular snack among

7–8-year-old children in Scotland and are eaten by

92% of the children. Snacks contribute 26% of

energy intake and a large proportion of macronutri-

ent intakes. Low and high snacking habits have no

significant effect on the anthropometry of children.

(Refer to individual nutrients.)

0021Children aged 9–13 years eat dessert items between

meals followed, in descending order of frequency, by

fruit and milk. The snacks most frequently eaten by

3–5-year-olds, in descending order of frequency, are

bakery products, milk, soft drinks, fruit, mild desserts,

candy, and bread. For 6–11-year-olds, the snacks

in order of importance are bakery products, soft

drinks, milk, milk desserts, candy, fruit, salty snacks,

tbl0003 Table 3 Effect of serving on energy content

Food Energy (kJ) per

serving

Fat (g) Sodium (mg)

Small apple 222.0 0.3 Negligible

Twisties (15-g packet) 460.0 5.9 250.0

Salted chips (20-g packet) 565.0 8.8 179.0

Milk (1 cup, 237 ml) 644.0 8.7 128.0

Bread-and-butter sandwich 865.0 8.6 267.0

Data from Delroy B (1985) The role of snack foods. Food Technology in

Australia 37(4): 154–158.

tbl0004 Table 4 Vitamins and minerals in snack foods

Snack food VitaminB

(mg) Nicotinic acid (mg) Vitamin C (mg) Calcium (mg) Iron (mg) Potassium (mg)

Potato chips (25-g packet) 37.0 (3%) 1.2 (11%) 2.4 (8%) 8.5 (1%) 0.8 (8%) 445.0

Twisties (25-g packet) 7.0 (1%) 0.2 (2%) 0.0 44.0 (6%) 0.1 (1%) 70.0

Chip crisp sticks (25-g packet) 78.0 (7%) 0.5 (4%) 0.0 46.0 (7%) 0.9 (9%) 64.0

Peanuts (25 g) 8.0 (1%) 0.3 (3%) 135.0

Figures in parentheses are the percentage of the recommended dietary allowance, as defined in the NH and MRC Food Legislation (1983). Data from

Delroy B (1985) The role of snack foods. Food Technology in Australia 37(4): 154–158.

SNACK FOODS/Dietary Importance 5335

and bread. Among teenage boys, the most popular

snacks are soft drinks, milk, bakery products, bread,

mild desserts, salty snacks, meats, and fruit, while

teenage girls prefer soft drinks, bakery products,

milk desserts, salty snacks, fruit, milk, candy, bread,

and meat. Among adolescents, the preference for

snack foods is bakery products, milk, fruit and fruit

juices, milk desserts, salty snacks, and bread. Table 6

lists the per capita consumption of nuts and nut mix-

tures. (See Adolescents; Children: Nutritional Re-

quirements.)

Nutritional Improvement of Snack Foods

0022 In order to counter the belief of consumers and

nutritionists that snack foods are ‘empty calories,’ a

number of manufacturers of snack foods have started

the development of products supplemented with vita-

mins, minerals, or proteins. Vitamin supplementation

is somewhat simpler than mineral or protein supple-

mentation. The cost is reasonable; a small fraction of

a per cent per portion of a supplement is restricted to

five vitamins, but vitamins can affect the flavor, and

some can cause off-flavors. Riboflavin is highly

colored, but its yellow hue is compatible with many

snacks. Storage deterioration of these labeled sub-

stances is compensated for by the addition of extra

amounts, so that the consumer should obtain the full

claimed quantity. When supplementing with any nu-

tritional factor, the manufacturer must establish a

quality-control program that will ensure that every

lot contains the claimed amount. Storage loss of

minerals is not generally observed, except for iodine.

0023Most snacks are poor sources of protein, and the

protein that is present is often of a poor nutritional

quality. Protein supplementation is possible by in-

creasing the protein-efficiency ratio of the protein

already present, or increasing the total amount of

protein present by adding some purified nitrogenous

material, such as casein, isolated soya protein, or egg

white. Untreated corn is a staple food in South Amer-

ica, and there is a need to develop more nutritious,

corn-based snack foods. These foods could serve as

vehicles for nutrients while at the same time being

readily accepted by the population. Certain combin-

ations of cereals and legumes are very desirable from

a nutritional point of view. Legumes are a better

source of lysine and total protein than cereals, and

the latter are a better source of sulfur amino acids.

Many attempts have been made to raise the protein

value of tortillas by combination with legumes. Snack

foods are generally preferred by children and teen-

agers; in these stages of life, the amount and nutri-

tional quality of proteins are important because of

their essential function in physical and mental devel-

opment. Baked snack foods containing high levels of

fiber and fat can be produced using specialty (100%

fat-free) starches, e.g., Novelose. Fried snack formu-

lations containing carboxymethyl cellulose absorb

less oil during frying, which is advantageous for

low-fat applications.

0024The high snackers have low energy and low macro-

nutrients from meals, so snacks make an important

contribution to energy and nutrients, even though a

high intake of snacks affects the quality of children’s

diets. A high snacking frequency and choosing from a

wider variety of snack foods results in a balanced

intake of nutrients.

0025An extruded snack food (soyabari snack sticks)

based on soybeans and maize (corn) rich in crude

fiber and protein contents can be produced by adding

different ingredients such as pepper, onion, salt, palm

oil, plantain, and banana. This product is acceptable

to Nigerians. A high-protein, shelf-stable, expanded

extruded snack food resembling bread sticks has been

prepared using mechanically recovered poultry meat

and wheat. (See Protein: Quality.)

0026Consumption of olestra, a fat replacer in savory

snack foods, has been found to be age- and gender-

dependent, with mean chronic and acute olestra

intakes for all ages and both genders of 3.1 and

10.2 g per day.

tbl0006 Table 6 Consumption of nuts and nut mixtures

Country Quantity (kg per capita)

The Netherlands 1.28

Germany 0.95

UK 0.66

France 0.65

USA 0.60

Belgium 0.56

Switzerland 0.18

Italy 0.10

Data from Tettweiler P (1990) Snacks ^ Food, Fun and Fashion. Dragocco

Report 3, pp. 79 –104. Holzminden, Germany: DRA-GOCCO.

tbl0005 Table 5 Dietary fiber in various snack foods

Snack Insoluble dietary fiber

(gramper serving)

White-bread sandwich 0.2

Brown-bread sandwich 1.4

Wholemeal-bread sandwich 3.1

Twisties (25-g packet) 0.3

Potato chips (25-g packet) 0.6

Chip crisp sticks (25-g packet) 1.5

Peanuts (25 g) 1.6

Data from Delroy B (1985) The role of snack foods. Food Technology in

Australia 37(4): 154–158.

5336 SNACK FOODS/Dietary Importance