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

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of drying require the transfer of moisture from the

center to the surface of the particle, and this is a much

slower process.

0020 Pneumatic-conveying ring driers and attrition

driers are also used for drying casein. These employ

inline milling and tend to produce finer casein

products than those dried in fluid-bed driers.

Cooling, Tempering, Milling, Sifting, Blending,

Packing

0021 Casein that is produced using fluid-bed driers is warm

and soft and unsuitable for grinding immediately in

some mills such as roller mills. Consequently, the

casein may be cooled and then transferred to

tempering bins where equilibration of moisture can

occur in and between all the particles during a period

of 8–24 h.

0022 The casein may then be ground and sieved,

using multideck, gyrating screens, into various par-

ticle sizes, usually < 600 mm. Very fine casein (e.g.

< 150 mm) is generally produced using pin mills.

0023 Following blending of the ground casein, it is

packed into multiwall paper bags equipped with

plastic liners and stored. The typical composition of

acid casein is shown in Table 1.

Rennet Casein

Action of Chymosin

0024 Casein may also be precipitated from milk by the

action of a proteolytic enzyme, such as chymosin,

which is present in calf rennet. Chymosin (and other

enzymes from animal or microbial sources that cause

milk to clot) splits off a portion of the k-casein (re-

ferred to as glycomacropeptide or GMP) from the

micelles. As a result, the micelles are no longer

stable in the presence of calcium ions and form a

three-dimensional gel. This process is essential in the

production of most types of cheese.

Clotting of Skimmed Milk

0025Pasteurized skimmed milk at a temperature of 29



(or lower) is mixed with calf rennet (or other milk-

clotting enzyme) in the approximate ratio (by

volume) of 1:7500 rennet to the milk. If a lower

setting temperature is used, renneting time must be

correspondingly increased. It is also possible to

reduce the quantity of rennet added under these con-

ditions and consequently allow a longer time for

rennet action to occur.

Cooking

0026The usual technique for cooking rennet casein in-

volves the injection of steam into a cooking line of

clotted milk pumped from a vat. However, the vat

cooking technique (similar to that used in cheese

manufacture) is also practiced in some countries.

The cooking temperature used in making rennet

casein usually varies from about 50 to 60



0027Dewheying, washing, dewatering, and drying of

the curd then proceed in a manner similar to that

used for acid casein, and the dried casein is also

treated as outlined previously.

0028Where indirect cooking of rennet casein is used, a

tubular heat exchanger may be used to cook the curds

and whey to a temperature similar to that used in the

direct cook (steam injection) process. Other process-

ing steps are similar to those described above but no

acidulation step is required after cooking of the

rennet casein.

0029The typical composition of rennet casein is shown

in Table 1.

tbl0001 Table 1 Typical composition and properties of casein products

Component Acid casein Rennet casein Sodium caseinate (spray dried)

Composition Amount per 100 g

Moisture (g) 11.5 11.5 4.5

Fat (g) 1.1 0.4 1.0

Protein (g) (nitrogen  6.38) 86.2 81.3 92.0

Ash (g) 1.8 8.2 3.6

Lactose (g) 0.1 0.1 0.1

Amount per 1 kg

Copper (mg) 2 2 2

Lead (mg) < 1 < 1 < 1

Iron (mg) 5–20 5 5–10

Physical properties

Color Creamy white Creamy white White

Flavor Bland, clean Bland, clean Bland, clean

Solubility in water Insoluble Insoluble Soluble

946 CASEIN AND CASEINATES/Methods of Manufacture

Coprecipitates

0030 Coprecipitates are combinations of casein and whey

proteins that are coprecipitated from heated (skimmed)

milk. When milk is heated to a temperature greater

than 70



C, some of the whey proteins are heat-

denatured and may interact with some of the caseins.

When a casein precipitant (such as acid or calcium

chloride) is added to the heated milk, the casein and

whey proteins coprecipitate together. Depending on the

pH of precipitation (which may vary from 6.6 to 4.5),

the coprecipitate will contain different quantities of

calcium (high-calcium at pH 6.6 to low-calcium at

pH 4.5). As whey proteins have a higher nutritional

value than casein (as measured by several different

biological and chemical techniques), coprecipitates

also have an enhanced nutritional value compared

with casein. The yield of coprecipitate from skimmed

milk is usually 5–20% greater than that of acid casein.

Caseinates

0031 Caseinates are produced by the neutralization of acid

casein with alkali. All caseinates are substantially

water-soluble and are typically prepared as a

solution of about 20% solids prior to spray drying.

Roller-dried caseinates may be prepared from more

concentrated solutions. It is also possible to prepare

granular, partly soluble, or semidispersible forms of

caseinate in which the casein and alkali have only

partly reacted. Sodium caseinate is the most common

form of this class of product and is prepared by

mixing a solution of sodium hydroxide, bicarbonate,

or carbonate with acid casein curd or dry acid casein

that has been suspended in water and then drying the

resultant solution (Figure 2). The dried powder

dissolves completely in water to produce a viscous,

sticky, straw-colored solution.

0032Calcium caseinate, on the other hand, produces

a thin, opaque, white colloidal dispersion in water,

similar in appearance to milk. Other caseinates,

such as those of potassium and ammonium, are simi-

lar in general properties to sodium caseinate. Magne-

sium caseinate has properties that are intermediate

between those of sodium and calcium caseinates.

However, relatively insignificant commercial quan-

tities of these products are manufactured at the

present time.

Casein dewatering

Casein mincer

Sodium hydroxide

Curd−alkali mixer

Colloid

mill

Water

(40 8C)

F1 F2

Jacketed vats

pH recording

and control

Heat

exchanger

Balance

tank

Viscometer and

viscosity control

Hot water

To spray drier

Sodium hydroxide solution

supply tank

fig0002 Figure 2 Suggested plant layout for dissolving casein for sodium caseinate manufacture. Dewatered casein curd is minced, mixed

with water, and finely milled in a colloid mill (C). The curd–water slurry is then mixed (D) with dilute sodium hydroxide solution and

transferred to the first of two jacketed dissolving vats (F

), each equipped with an agitator. The sodium caseinate solution is

subsequently pumped from the second dissolving vat (F

) and extra alkali is added, if necessary. The solution is heated by means

of a tubular heat exchanger (H) and then pumped via a balance tank to the spray (or roller) drier for drying. The viscosity of the solution

may be monitored and reduced, if necessary, by addition of hot water. From Southward CR (1985) Manufacture and applications of

edible casein products. I. Manufacture and properties. New Zealand Journal of Dairy Science and Technology 20: 79–101, with permission.

CASEIN AND CASEINATES/Methods of Manufacture 947

0033 The typical composition of sodium caseinate is

shown in Table 1. Acid (low-calcium) coprecipitates

can be dissolved in alkali in a similar manner to that

used for acid casein. Both rennet casein and high-

calcium coprecipitate (precipitated at a pH of 6 or

greater) are usually rendered soluble by means of com-

plex phosphates, such as sodium tripolyphosphate, to

produce translucent solutions with a viscosity some-

what higher than that of the corresponding caseinates.

0034 In the great majority of applications, in both edible

and technical (nonfood) uses, casein must first be

made soluble before it can be used in its final applica-

tion. Although some users convert the dry casein to

caseinate themselves, others tend to purchase the case-

inate directly from the producer (often as a ‘fresh-

curd’ caseinate). For applications in foods. (See Casein

and Caseinates: Uses in the Food Industry.)

See also: Casein and Caseinates: Uses in the Food

Industry; Cheeses: Starter Cultures Employed in Cheese-

making; Chemistry of Gel Formation; Drying: Fluidized-

bed Drying; Lactic Acid Bacteria; Pasteurization:

Principles; Starter Cultures; Whey and Whey Powders:

Production and Uses; Protein Concentrates and Fractions;

Fermentation of Whey

Further Reading

Australian Society of Dairy Technology (1972) Casein

Manual. Parkville, Melbourne: Australian Society of

Dairy Technology.

Farrell HM Jr (1988) Physical equilibria: proteins. In: Wong

NP, Jenness R, Keeney M and Marth EH (eds) Funda-

mentals of Dairy Chemistry, 3rd edn, pp. 461–510. New

York: Van Nostrand Reinhold.

Muller LL (1971) Manufacture and uses of casein and

coprecipitates: a review. Dairy Science Abstracts 33:

659–674.

Muller LL (1982) Manufacture of casein, caseinates and

coprecipitates. In: Fox PF (ed) Developments in Dairy

Chemistry, vol. 1. Proteins, pp. 315–337. London:

Applied Science.

Mulvihill DM (1989) Caseins and caseinates: manufacture.

In: Fox PF (ed) Developments in Dairy Chemistry, vol. 4,

Functional Milk Proteins, pp. 97–130. London: Elsevier

Applied Science.

Mulvihill DM (1992) Production, functional properties

and utilization of milk protein products. In: Fox PF

(ed) Advanced Dairy Chemistry, vol. 1, Proteins,

pp. 369–404. London: Elsevier Applied Science.

Southward CR (1985) Manufacture and applications of

edible casein products. I. Manufacture and properties.

New Zealand Journal of Dairy Science and Technology

20: 79–101.

Southward CR (1994) Utilization of milk components:

casein. In: Robinson RK (ed) Modern Dairy Technology,

2nd edn, vol. 1, Advances in Milk Processing, pp.

375–432. London: Chapman and Hall.

Southward CR and Walker NJ (1980) The manufacture and

industrial use of casein. New Zealand Journal of Dairy

Science and Technology 15: 201–217.

Spellacy JR (1953) Casein, Dried and Condensed Whey.

San Francisco, California: Lithotype Process.

Whitney RMcL (1988) Proteins of milk. In: Wong NP,

Jenness R, Keeney M and Marth EH (eds) Fundamentals

of Dairy Chemistry, 3rd edn, pp. 81–169. New York:

Van Nostrand Reinhold.

Uses in the Food Industry

C R Southward, Fonterra Research Centre,

Palmerston North, New Zealand

Introduction

0001Although casein, as it exists in milk, has been con-

sumed as ‘food’ for thousands of years, the extracted

form of casein had very little application in foods

prior to 1960. Instead, from early in the 20th century,

and in some cases before then, it was used as an

adhesive in wood glues and paper coating, and in

paints, fibers, plastics, and leather finishing. The

introduction of coffee whiteners and whipped top-

pings, in particular, by the food industry in the USA

during the 1960s played a significant part in the

establishment of casein products in foods. These

two product groups were based on vegetable fat and

contained casein in a water-soluble form (usually

sodium caseinate), together with carbohydrate, emul-

sifiers, and stabilizers. They were promoted as ‘non-

dairy’ foods. (As casein was derived from milk, it was

not considered to be a dairy product. Furthermore, it

had been classified as a chemical because of its long-

established use in nonfood technical applications in

adhesives, paints, etc., as described above.) Nondairy

coffee whiteners and whipped toppings were thus

presented as alternatives to the traditional dairy

products of milk, cream, and whipping cream. They

offered advantages of lower price (because the

(imported) raw materials from which they were

made were cheaper than the domestic milk solids

they were replacing), convenience, and shelf stability

(several of the products were sold in powder form).

Other nondairy products followed, many of them

containing casein, e.g., so-called imitation milks,

imitation cheese, and salad dressings. Food supple-

ments and dietary products were also produced and

a number of these were based on casein. This

article reviews the use and function of casein products

in food.

948 CASEIN AND CASEINATES/Uses in the Food Industry

General

0002 The main applications of casein products in foods,

together with their functions in such foods, are shown

in Table 1. As a high-quality protein, casein can pro-

vide nutrition in foods, although this is often not the

main reason for its use. It is frequently incorporated

into food products for its ability to impart so-called

‘functional’ properties of whipping, foaming, fat

emulsification, film formation, water binding, and

thickening. Consequently, casein can have a signifi-

cant effect on the texture or consistency of a food.

Animal Feeding and Pet Foods

0003 During the middle of the 20th century, many experi-

ments were undertaken in the USA and, to a lesser

extent, in Europe and elsewhere, to determine the

effect of feeding cows with iodine and iodinated

casein (sometimes referred to as ‘thyroprotein’)on

their nutrition and milk yield. A number of studies

suggested that milk yield was increased, but there was

sufficient conflicting evidence for the practice not to

be widely adopted. Extensive nutritional feeding

trials for ruminants were undertaken in the late

1960s and 1970s to determine the effect – on milk

production and wool growth, respectively – of feed-

ing ‘protected’ casein to cows and sheep. The casein

was protected by reaction with formaldehyde, which

prevented it from being broken down by the rumen

microflora. It could pass undigested to the abomasum

where the acidic conditions were able to promote the

digestion of the casein. These studies were also

extended to determine how the feeding of polyunsat-

urated oils, encapsulated in formalin-treated caseins,

to ruminants affects the quantity of polyunsaturated

fat in meat and milk. Again, however, this was not

adopted commercially.

0004Casein (generally in the form of sodium caseinate)

may be used as a nutritional supplement in pet foods

and calf milk replacers, and it has also been reported

as an ingredient in fish food. Some recent reports in

the literature indicate that casein can be used to pro-

duce novel textured pet foods, as well as the more

traditional nutritional foods.

Bakery Applications

0005The water-binding properties of casein (as well as

nutrition) are important for bakery applications in

which casein products are incorporated. Soluble

forms of casein (such as caseinates) tend to bind too

much water and may make some foods too sticky or

‘doughy.’ Accordingly, insoluble or partly soluble

casein products are often used, because these have

less water binding than the fully soluble caseinates.

Some bakery products that have been made with case-

ins include doughnuts, waffles, cake mixes, and

bread. A number of examples of the use of casein

products in bakery applications, taken from the

recent literature, are shown in Table 2. Figure 1 illus-

trates the use of casein products in biscotti.

Cheese-like Foods

0006Casein has been used as an extender and texture

modifier in processed cheese, and even to increase

the yield of cheese from cheese milk (e.g., in Europe).

However, the most significant use of casein in cheese

products has probably been in the production of

tbl0001 Table 1 Use and function of casein products in foods

Application Principal functions

Animal and pet foods Nutrition, binder for moisture and fat

Bakery products Nutrition, texture, water binding

Beverages, including soups Emulsifier, stabilizer, nutrition

Coffee whiteners and creamers Resistance to feathering, emulsifier

Confectionery Nutrition, texture

Cultured products Stabilizer, emulsifier, consistency, nutrition

Extruded snack foods Texture

High-fat powders and shortenings Emulsifier, whipping

Icecream, mousse, and desserts Whipping, foaming, emulsifier

Imitation cheese and other cheese-like foods Texture, emulsifier

Infant foods Nutrition

Instant breakfasts and dietary preparations Nutrition

Meat products Emulsifier, water binding

Pasta Nutrition, texture

Pharmaceutical products Nutrition, therapeutic, film formation

Spreads Texture, stabilizer

Whipped toppings Stabilizer, emulsifier

CASEIN AND CASEINATES/Uses in the Food Industry 949

so-called ‘imitation’ or synthetic cheese (often re-

ferred to as cheese analogs). This product, similar in

properties to processed cheese, is made from water,

casein (e.g., acid casein, rennet casein, or sodium or

calcium caseinate, singly or in mixtures), vegetable

fat, stabilizers, and emulsifiers. The food industry in

the USA was first to develop imitation cheese (at least

in name), which could be seen as a similar develop-

ment in the cheese industry to the much earlier pro-

duction of margarine as an ‘imitation’ butter. Just as

coffee whiteners and whipped toppings (and artificial

milks) were developed in the US food industry in the

1960s as cheaper and/or convenience foods to com-

pete with milk and cream (see elsewhere in this art-

icle), so imitation cheese appeared. The commercial

production of imitation cheese first occurred in the

USA in the early 1970s, and the quantity produced

grew, during a period of several years, to a maximum

of about 5% of the total cheese sales in the USA.

Imitation cheese found its application as a cheaper

alternative to natural cheese, particularly in fast-food

outlets, in frozen pizza and hamburgers, for instance.

Figure 2 illustrates the use of rennet casein in an

imitation Mozzarella cheese, used on a pizza. In con-

sideration of its nutritional properties, imitation

cheese was also approved for use in the American

school lunch program. The main function of the

casein product in this application is to provide the

required body and texture, with emulsification of fat,

as well as the melting properties of the finished cheese

in pizza. This last-named function is achieved by

careful formulation, using food acids and stabilizing

salts to achieve the correct pH and mineral balance in

the cheese that will cause it to melt during the cooking

of the pizza to provide the expected ‘stretch’ and

‘stringing’ properties required for pizza cheese. Al-

though the use of imitation cheese in the UK and

Japan has been mentioned in the literature, its main

area of commerical significance is in the USA.

0007Other applications of casein in the cheese food

industry include surface coating of whole cheese and

cheese granules, using the natural film-forming prop-

erties of casein products. Several examples of the use

of casein products in cheese-like foods, taken from

the recent literature, are shown in Table 3.

Beverages

Imitation Milks

0008In the USA, so-called ‘filled milk’, which contains

vegetable fat and skimmed milk solids, has been

tbl0002 Table 2 Use of casein products in bakery applications

Examples Casein productused % Use/functionof casein product

Bread Sodium caseinate 2–30 Emulsification

Glazing agent Casein, casein salt 5–15 Film formation

Blini (pancake) Sodium caseinate 2.9–5 Increased storage life, friability

High-protein wafer Casein 50 Texture, nutrition

fig0001 Figure 1 (see color plate 17) Biscotti, representing baked prod-

ucts that can be made using high-calcium milk protein. Courtesy

of NZMP (North America) Inc.

fig0002Figure 2 (see color plate 19) Pizza, representing the use of

imitation Mozzarella cheese that can be made using rennet

casein. Courtesy of NZMP (Wellington) Ltd.

950 CASEIN AND CASEINATES/Uses in the Food Industry

sold for many years. In the late 1960s and 1970s, a

new class of milk –‘imitation milk’–appeared on the

market. This contained vegetable fat and various

other ingredients, including protein as sodium or po-

tassium caseinate or from soy beans, and a carbohy-

drate source such as corn syrup solids. Artificial milks

were also reported in the UK and the USSR. The

lower cost of the ingredients and the absence of lac-

tose (for which some people show intolerance) were

no doubt significant factors in the establishment of

such products. However, concerns were voiced over

the generally lower nutritional quality (e.g., lack of

vitamins and minerals and, sometimes, lower protein

content) and often poorer flavor compared with

‘normal’ cows’ milk. Casein products have also been

used to fortify fresh milk, though this has occurred in

Europe rather than in North America.

0009 Several examples of the use of casein products in

beverages, taken from the recent literature, are shown

in Table 4.

Cream Liqueurs

0010 Casein, in the form of sodium caseinate, has found

application recently in cream liqueurs, especially in

the UK and the Irish Republic, where they have been,

apparently, one of the fastest-growing markets for

cream. Other ingredients include sugar, alcohol, and

trisodium citrate. In this application, the sodium

caseinate acts mainly as an emulsifier or emulsion

stabilizer.

Coffee Whiteners and Creamers

0011As shown in Table 1, the main functions of casein

(as sodium caseinate) in coffee whiteners are to

provide emulsification and to promote resistance

to ‘feathering.’ It has been claimed that sodium

caseinate (or other protein) also imparts body,

provides some whitening (though this is mainly

due to the fat) and improves flavor. Although both

liquid and dry (powdered) coffee whiteners have

been produced, the most popular by far appear to

be the latter because, as mentioned in the introduc-

tion to this article, they have the advantages of

being shelf-stable and convenient to use. In addi-

tion, the low price of the major ingredients (veget-

able fat and carbohydrate, usually as corn syrup

solids) compared with that of (US domestic)

milk solids makes coffee whitener an attractive

alternative to milk or cream. Figure 3 shows the use

of a coffee whitener that contains high-calcium milk

protein.

Soups, Gravies, etc.

0012When casein products are used in soups, their pur-

pose may be for nutrition (e.g., as calcium caseinate)

or for increasing the consistency or viscosity of the

mixture (possibly in the form of sodium caseinate), as

illustrated in Figure 4. Occasionally, hydrolysates of

casein products may be used in soups and gravies for

flavor enhancement.

tbl0003 Table 3 Use of casein products in cheese-like foods

Examples Casein productused % Use/functionof casein product

Simulated cheese Rennet casein 25 Texture, nutrition

Coating of cheese pieces Casein 2 Free-flow agent

Fat-free cheese analogs Rennet casein 15–35 Texture

Protective protein coating for Sodium caseinate/ 3–14 Film coating

cheese casein

Imitation cheese Calcium caseinate 12 Texture

tbl0004 Table 4 Use of casein products in beverages, including coffee whiteners and creamers

Examples Casein product used % Use/functionof caseinproduct

Soluble tea product Acid casein 10–40

Inhibits tea cream formation

Powder for cream liqueur Sodium caseinate 4–14

Emulsion stabilizer

0.8–2.8

Foaming coffee whitener Caseinate 1–2.5 Whiteness and foaming

Stabilizer for wine Alkali caseinate 5–60

Stabilizer against changes in color or taste

Coffee whitener Casein 0.1–10 Emulsion stabilizer

Iced chocolate Calcium caseinate 5.6–6.7 Texture/fat replacer

Dry basis.

In powder.

Expressed as a percentage of the stabilizer.

CASEIN AND CASEINATES/Uses in the Food Industry 951

Sour and Cultured Milk Products

0013 In the manufacture of yogurt, casein products have

been incorporated for protein enrichment, and im-

provement in consistency and stability; they give less

syneresis than standard yogurt products.

0014 Imitation sour cream products have been produced

from vegetable fat, sodium caseinate, and other ingre-

dients. The purposes of adding sodium caseinate to

these products are to act as a stabilizer, to increase the

consistency, and to emulsify the fat – functions that

sodium caseinate performs in mayonnaise as well.

Although some publications have claimed nutritional

fortification as a reason for incorporating casein /

caseinates in cultured milk products, this does not

seem to be as significant a reason for their use in

this context as the ‘functional’ properties mentioned

earlier. Some examples of the use of casein derivatives

in cultured and sour milk products, taken from the

recent literature, are shown in Table 5.

Desserts, Icecream, Whipped Toppings,

and Confectionery

0015Sodium caseinate functions in frozen desserts and ice-

cream as a stabilizer (Figure 5), improves the whip-

ping properties of the mix and imparts ‘body’ (also

known as consistency or thickening). Other proper-

ties of sodium caseinate that are important in these

products include emulsification, foam stability, and

film formation.

0016The incorporation of casein products in icecream

has not been commercially extensive, generally

because of various legal restrictions. Several icecream

substitutes, however, did appear in the USA in the

1960s (e.g., Mellorine) and some of these products

incorporated casein (usually as sodium caseinate) into

their formulations.

0017As described in the introduction to this article,

whipped toppings which contained vegetable fat,

water, and sodium caseinate (together with other

ingredients) appeared in the USA in the 1960s as

specific competitors for whipping cream. In this ap-

plication, sodium caseinate is used in forming a film

to trap aerating gases. It also functions in fat encapsu-

lation, as a bodying agent and as a stabilizer. Hydro-

lyzed caseinates, with enhanced whipping and

foaming properties, are also produced for food prod-

ucts like these. Such products are now manufactured

in other countries, including the UK, Italy, Israel, and

fig0003 Figure 3 Coffee whitener/creamer, representing imitation

dairy products that can be made using high-calcium milk protein.

Courtesy of NZMP (Wellington) Ltd.

fig0004Figure 4 Canned creamed soup, representing convenience

foods that can be made using sodium caseinate. Courtesy of

NZMP (North America) Inc.

952 CASEIN AND CASEINATES/Uses in the Food Industry

Japan. A number of examples of the use of casein

products in desserts and whipped toppings, taken

from the recent literature, are shown in Table 6.

0018Casein products are used much less in confection-

ery than are other milk products (e.g., nonfat dry

milk, whole milk powder, and sweetened condensed

milk). Nevertheless, their use has been described in

toffees, caramels, and fudges, where they can form a

tough, chewy body, and in marshmallow and nougat

to produce heat-stable whips and foams. Casein pro-

teins have also been used to produce high-protein

chocolate snacks and confectionery sticks or bars

(Figure 6).

Spreads and Fat Replacers

0019In the wealthier and industrialized countries, in par-

ticular, concern over health and nutrition has been

focused, at least to some extent, on maintaining a

healthy diet and weight. ‘Fat,’ both in the sense of

appearance and in food intake, has taken on a

generally undesirable image, and butterfat (with its

generally high content of saturated fats), in particular,

appears to have been a high-profile target of the

health sector of most of these countries. One of the

responses to these concerns has been the introduction

of lower-fat spreads to complement or replace the

traditional fats. In some of these products, casein

(usually in the form of sodium caseinate) has been

used to stabilize the water phase and to improve the

texture of the product. In addition, casein has been

used in some (processed) cheese spreads, presumably

for similar (functional) reasons.

tbl0005 Table 5 Use of casein products in sour and cultured milk products

Examples Caseinproduct used % Use/functionof caseinproduct

Fat-free cream cheese Caseinate 8–12 Fortification, (mouth feel)

Mayonnaise Casein 0.7 Emulsifier

Cre

me fraiche-type Casein 9.5–40

Texture, stabilizer

Mayonnaise Calcium caseinate 5–6.6 Texture, fat replacer

Salad dressing Sodium caseinate 0.9

Restricts oxidation

Dry basis.

Expressed as a percentage of the emulsion.

fig0005 Figure 5 (see color plate 20) Frozen dairy dessert, represent-

ing dairy products and analogs that can be made using milk

protein isolates. Courtesy of NZMP (North America) Inc.

tbl0006 Table 6 Use of casein products in desserts, icecream and whipped toppings

Examples Casein productused % Use/function of casein product

Jelly food base Casein solution 2–20 Water binding

Acid dessert Sodium caseinate 0.01–0.3 Stabilizer

Whipping cream Casein 5 Stabilizer

Gelling agent Casein 37.1 Water binding/replacer for gelatin

Chocolate mousse Calcium caseinate 4–5 Texture, fat replacer

CASEIN AND CASEINATES/Uses in the Food Industry 953

0020 From a different perspective, the food industry

(again starting in the USA) developed some

fat-replacer foods that exhibited the mouth feel and

other desirable properties of fat-based products,

without containing any fat. These fat replacers were

based on water-insoluble proteins or carbohydrates,

with about half the energy–weight ratio of fat. They

were very finely milled to minimize the detection of

any individual particles by the tongue but, neverthe-

less, exhibited the desirable ‘creamy’ mouth feel

found in fat-based foods, such as cream, for example.

Products such as Simplesse

were introduced to the

market, and generated considerable interest. A range

of alternative products that contained various fat

replacers came on to the market with claims for

helping weight reduction. A number of foods that

are claimed to provide fat replacement are shown in

Table 7. These examples have been extracted from

the recent literature.

Meat and Fish Products

Comminuted Meats

0021 The reason for using casein products (usually as

sodium caseinate) in comminuted meat products

such as sausages and mincemeat is to emulsify the

fat, bind water, and generally improve consistency.

Sometimes, milk protein may be added for nutritional

purposes. The use of casein in meat products is

strictly controlled by legislation in most countries

and the quantity that may be added is generally less

than 5% of the weight of the meat. One estimate

suggests that the potential world market for the use

of high-protein milk products in processed meats is

about 100 000 tonnes.

Textured Protein

0022Meat analogs (with a texture resembling the fibrous

nature of meat) have been prepared from casein,

either using a spinning technique (similar to methods

used for producing textile fibers in the 1930s, in

which a protein solution is forced through spinnerets

into a coagulating bath) or by production of chewy,

meat-like gels. The general disadvantage of using

casein in this form is that, when the fibers are heated

in a moist environment, they tend to melt together

and lose their individual fibrous structure (which is

why casein readily forms a smooth plastic or molten

mass in the production of processed cheese – or casein

plastic for buttons). However, the addition of heat-

denaturable proteins (such as egg white or whey pro-

tein) can overcome that disadvantage.

Fish Products

0023Just as casein is used for fat emulsification and water

binding in comminuted meat products, so it has

found some application in a number of fish products,

especially those formed from minced fish and in

paste-like forms. The examples in Table 8, which

have been taken from the recent literature, show

some uses of casein or caseinates in meat and fish

products that utilize a number of properties of casein

other than those commonly ascribed to casein in this

application.

Pasta, Snacks, and Fried Foods

0024When casein is used in pasta products, it is mainly to

enhance their nutritional quality because the high

fig0006 Figure 6 (see color plate 21) Candy bars, representing confec-

tionery products that can be made using modified milk proteins

and milk protein isolates. Courtesy of NZMP (North America) Inc.

tbl0007 Table 7 Use of casein products in fat replacers

Examples Casein productused % Use/functionof casein product

Fat-free cream cheese Caseinate 8–12 Fortification, (mouth feel)

Fat substitute in foods Caseinate 50–60

Structure (‘unctuous’ texture)

Coffee whitener Sodium caseinate 10–15

Fat substitute

Fat-free cheese analogs Rennet casein 15–35; 20–30

Texture

Expressed as a percentage of the total protein.

Wet basis.

Preferred range.

954 CASEIN AND CASEINATES/Uses in the Food Industry

lysine content of the casein complements the low

lysine- and high sulfur-containing amino acids of

wheat and other vegetable proteins present in such

products. In some cases, casein plays an important

part in forming a suitable texture matrix for the pasta

product. Thus, casein products have been reportedly

used in macaroni, spaghetti, rice, and noodles.

0025 Casein products are used in extruded (high-

protein) snack foods to produce the required texture

and for nutritional fortification. In fried foods, it

appears that the film-forming properties of casein

may also be used, either as coatings or to reduce oil

absorption during the cooking/frying stage in prepar-

ing the food. A number of examples of the use of

casein in pasta and fried foods, taken from the litera-

ture, are shown in Table 9.

Edible Films

0026 The film-forming properties of soluble casein prod-

ucts, such as sodium and calcium caseinates, have

been referred to earlier in Tables 1 and 3. This specific

property of casein products was recognized many

years ago, when casein was used in technical, non-

food applications such as paper coating, and in paints

and leather finishing. Commercially, the film-forming

ability of caseinates in foods is seen at the oil–water

interface in the formation of emulsions in coffee whit-

eners, desserts, and whipped toppings, and at the air–

water interface in whipping and foaming products

(such as whipped toppings). These same properties

have been used in the production of sausage skins.

More recently, caseinates have been used to coat fruit

and vegetable products as a means of maintaining

their freshness. As a hydrophilic (water-loving) sub-

stance, casein produces films that, on their own, are

not very resistant to the passage of moisture vapor.

However, they do appear to provide good mechanical

strength, and to act as an oxygen barrier. Research

has therefore included the study of combined films of

casein/caseinate and lipid material in which the lipid

repels or resists the passage of moisture vapor and

the caseinate provides the matrix and mechanical

strength, with resistance to the passage of oxygen.

Some examples from the recent literature are shown

in Table 10.

Microencapsulation

0027Encapsulation of oils was practiced in feeding trials

for animals in the early 1970s, as referred to earlier in

this article. This technique was used as a means of

conveying a nutritional supplement, in a protected

environment, through a part of the animal’s digestive

tract (where it would otherwise have been broken

down) to the area where the supplement would have

the intended benefit. Often referred to as microencap-

sulation, this principle has been used now for many

years as a means of applying drug therapy in humans

and in animals, and as a means of preventing undesir-

able odors and flavors of beneficial compounds from

being rejected as having an unacceptable smell or

producing a foul taste. Although not as widely used

for microencapsulation as gelatin, casein products do

find application in these fields, as indicated in the

examples from the recent literature that are shown

in Table 11.

Pharmaceutical and Medical Applications

0028Various casein preparations have been used in a range

of pharmaceutical applications. These include casein

tbl0008 Table 8 Use of casein products in real and imitation meat and fish products

Examples Caseinproduct used % Use/functionof casein product

Fibrous meat substitute Calcium caseinate 30

Texture

Powdered oil flavor Sodium caseinate 1–10

Emulsion stabilizer

Meat patties Sodium caseinate 2–4 Increases storage life

Minced fish Calcium caseinate 8 Cryoprotectant

w/w.

Wet basis.

tbl0009 Table 9 Use of casein products in snacks, fried foods, pasta, etc.

Examples Casein productused % Use/function of casein product

Emulsion for dough for frying Casein 1–5 Reduces oil absorption

Instant food products Caseinate 5 Water binding

Coating for potatoes Caseinate 0.05–10 Emulsifier

Powder for fried food in microwave oven Casein 10–50 Coating

Noodles Casein 20–80 Oil absorption

CASEIN AND CASEINATES/Uses in the Food Industry 955