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

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Quality Assurance

0026 During production, it is important to carry out an

ongoing routine inspection of processing conditions

and finished product. The former includes items such

as the A unit outlet temperature, which must be fre-

quently checked, adjusted, and recorded by the oper-

ator. Product evaluations are usually carried out by

the quality control inspectors and laboratory techni-

cians. (See Quality Assurance and Quality Control.)

0027 Samples from the packing lines are taken every

15–30 min and checked for weight performance

versus limits for each product type. Line samples are

then checked for package quality, including: carton or

container denting or crushing; dirt or oil spots; parch-

ment wrap defects for stick margarine, such as poor

folds of the parchment or foil; inadequate gluing of

carton inflaps; improper placement of lable.

0028 Packaging materials are then removed, and the

product’s external appearance is evaluated. Prints

are sliced in two or three places for internal examin-

ation, and a cone can be cut out of the center of the

tub products. The outer texture is checked for slack or

overfill, sloshing, product adhering to the lid or wrap,

blistered or grainy texture, discoloration, oil separ-

ation, dull sheen, etc. After cutting, the inner texture

is checked for oil or water separation and streaked,

grainy, vacillated, cheesy, or porous texture.

0029 Margarines undergo sensory evaluation to detect

any off-quality characteristics, such as lack of flavor,

or oil off-flavors such as oxidized, rancid, faulty oil

processing, sour, plastic, fruity, artificial, and aged

characteristics. If required, quality-rating systems can

be established with defect scores assigned by

the importance of the defect for the product. For

example, a 100-point scale could be used, with 10

points assigned to packaging and 30 points each for

outer texture, inner texture, and flavour. The assigned

defect points are then subtracted from 100. A grade

below an arbitrary level such as 70 would indicate that

the relatedproduct should be placed on hold for further

evaluation and disposition. (See Sensory Evaluation:

Sensory Characteristics of Human Foods.)

See also: Acids: Natural Acids and Acidulants;

Cholecalciferol: Properties and Determination; Colloids

and Emulsions; Colorants (Colourants): Properties and

Determination of Natural Pigments; Properties and

Determinants of Synthetic Pigments; Emulsifiers:

Organic Emulsifiers; Uses in Processed Foods; Fatty

Acids: Properties; Quality Assurance and Quality

Control; Retinol: Properties and Determination;

Spectroscopy: Nuclear Magnetic Resonance;

Triglycerides: Structures and Properties; Vegetable

Oils: Oil Production and Processing; Sensory

Evaluation: Sensory Characteristics of Human Foods;

Ground Nut Oil

Further Reading

Carr R (1986) Oilseeds, fat and oils. National Research

Council Training Program, Chatham, Ontario, pp.

10–14.

Dritschel M (1970) How to evaluate margarine quality.

Food Engineering, October: 90–93.

Krytz K (1989) Formulation and packaging margarines and

shortenings. Annual Meeting of the American Oil Chem-

ists’ Society, Cincinnali, Ohio, May 3–6, 1989. Journal

of the American Oil Chemists Society 66(4): 459–460.

Moore E (1974) Margarine and cooking fats. Unilever

Educational Booklet Series, No. 4, pp. 7–14.

Ward J (1988) Processing canola oil products. Journal of the

American Oil Chemists Society 65: 1731–1734.

Wiederman L (1978) Margarine and margarine oil, formu-

lation and control. Journal of the American Oil Chem-

ists Society 55(11): 823–829.

Composition and Analysis

M Vaisey-Genser, The University of Manitoba,

Winnipeg, Manitoba, Canada

Introduction

0001Margarine is the earliest of the designed food staples.

As such, it can be tailored to deliver nutritional and

functional advantages in terms of fatty acid compos-

ition, the addition of essential micronutrients, spread-

ability, and performance as a bakery fat. Accurate

methods are necessary to guide margarine design and

to monitor the legitimacy of claims on margarine

labels. This article will describe the required compos-

ition of margarine, provide examples of the fatty acid

profiles of contemporary products, and comment

on the methods for margarine analysis and quality

control.

Margarine Composition

0002The margarine of each country is subject to local

standards of identity and regulations, which normally

complement the international standard of the Joint

FAO/WHO Food Standards Programme as set by the

Codex Alimentarius Commission. The existing stand-

ard for margarine as set in 1989 (CODEX STAN

32-1981, Rev. 1-1989) is currently under review.

Ultimately, it is to be replaced by a general ‘Standard

for Fat Spreads and Blended Spreads,’ a proposal

being drafted to address reduced-fat as well as full-

fat spreads. The goal is to assure food safety concur-

rent with the globalization of food trade. As of July

1999, the draft proposal was at Step 3 of what can be

3714 MARGARINE/Composition and Analysis

an eight-step Codex approval process. In the interim,

the 1989 standard for margarine prevails. The ‘essen-

tial composition and quality factors’ of margarine

and its endorsed ‘food additives’ are set out in

Sections 3 and 4, respectively, of the 1989 Codex

Standard, as follows:

Essential Composition and Quality Factors

0003 Raw materials (1) Edible fats and/or oils, or mix-

tures of these, whether or not they have been sub-

jected to a process of modification; (2) water and/or

milk and/or milk products.

0004 Minimum fat content 80% m/m of the product.

0005 Maximum water content 16% m/m of the product.

0006 Additions The following substances may be added

to margarine: (1) vitamins – vitamin A and its esters,

vitamin D, vitamin E and its esters, other vitamins

(maximum and minimum levels for vitamins A, D,

and E and other vitamins should be laid down by

national legislation in accordance with the needs of

each individual country, including, where appropri-

ate, the prohibition of the use of particular vitamins);

(2) sodium chloride; (3) sugars; (4) suitable edible

proteins. (See Cholecalciferol: Properties and Deter-

mination; Retinol: Properties and Determination;

Tocopherols: Properties and Determination.)

Food Additives

0007 Colors (1) b-carotene, 25 mg kg

1

(2) annatto ex-

tracts, 20 mg kg

1

calculated as total bixin or

norbixin; (3) curcumin or turmeric, 5 mg kg

1

calcu-

lated as total curcumin; (4) b-apo-8

-carotenal,

25 mg kg

1

; (5) methyl and ethyl esters of b-apo-8

carotenoic acid, 25 mg kg

1

.(See Colorants (Colour-

ants): Properties and Determination of Natural Pig-

ments; Properties and Determinants of Synthetic

Pigments.)

0008 Flavors Natural flavors and their identical synthetic

equivalents, except those that are known to represent

a toxic hazard, and other synthetic flavors approved

by the Codex Alimentarius Commission are permit-

ted for the purpose of restoring natural flavors lost in

processing or for the purpose of standardizing flavor,

as long as the added flavor does not deceive or mis-

lead the consumer by concealing damage or inferior-

ity or by making the product appear to be of greater

actual value. (See Flavor (Flavour) Compounds:

Structures and Characteristics.)

0009 Emulsifiers (1) Mono- and diacylglycerols of fatty

acids (limited by good manufacturing practice

(GMP)) (2) mono- and diacylglycerols of fatty acids

esterified with the following fatty acids: acetic, acety-

ltartaric, citric, lactic, tartaric, and their sodium and

calcium salts (10 g kg

1

maximum); (3) lecithins and

components of commercial lecithin (limited by

GMP); (4) polyglycerol esters of fatty acids (5 g kg

1

maximum); (5) 1,2 propylene glycol esters of fatty

acids (20 g kg

1

maximum); (6) esters of fatty acids

with polyalcohols other than glycerol: sorbitan

monopalmitate, sorbitan monostearate, sorbitan tri-

stearate (10 g kg

1

maximum); (7) sucrose esters of

fatty acids (including sucroglycerols) (10 g kg

1

maximum). (See Emulsifiers: Organic Emulsifiers;

Uses in Processed Foods.)

0010Preservatives Sorbic acid and its sodium, potassium,

and calcium salts and benzoic acid and its sodium and

potassium salts (1000 mg kg

1

maximum individu-

ally or in combination expressed as the acids). (See

Preservation of Food.)

0011Antioxidants (1) Propyl gallate, 100 mg kg

1

;

(2) butylated hydroxytoluene (BHT), 75 mg kg

1

;

(3) butylated hydroxyanisole (BHA), 175 mg kg

1

;

(4) any combination of propyl gallate, BHA, BHT,

200 mg kg

1

, but limits in 4.5.1–4.5.3 not to be

exceeded; (5) natural and synthetic tocopherols,

500 mg kg

1

; (6) ascorbyl palmitate and (7) ascorbyl

stearate, 500 mg kg

1

individually or in combination;

(8) dilauryl thiopropionate, 200 mg kg

1

.(See Anti-

oxidants: Natural Antioxidants; Synthetic Antioxi-

dants.)

0012Antioxidant Synergists (1) Citric acid (limited by

GMP); (2) sodium citrate (limited by GMP); (3) iso-

propyl citrate mixture; (4) phosphoric acid and

(5) monoacylglycerol citrate (the maximum for 3, 4,

and 5 is 100 mg kg

1

individually or in combination).

0013Acidity Regulators (1) Citric acid and lactic acids

and their sodium or potassium salts (GMP); (2) l-

tartaric acid and its sodium and sodium/potassium

salts (GMP).

0014Antifoaming agents Dimethylpolysiloxane (di-

methyl silicone) singly or in combination with silicon

dioxide, 10 mg kg

1

Vitamin Fortification

0015As a manufactured food staple that is reasonably

homogeneous, margarine is a logical vehicle for forti-

fication with essential fat-soluble vitamins. The

addition of preformed vitamin A to margarine is

mandatory in several countries including the UK,

the USA, and Canada, where the levels specified are

MARGARINE/Composition and Analysis 3715

similar. In Canada, not less than 1000 mg of retinol

(3300 international units (IU) of vitamin A) per 100 g

of margarine are required. This recognizes the neces-

sity for the nutritional equivalence of margarine with

butter in respect of dietary vitamin A. Whether or not

the vitamin A potential of the carotenoids that may be

added to margarine as colorants may be counted as a

contribution to the mandatory level of fortification

varies among countries.

0016 Although the addition of vitamin A to milk has

been known to cause floral and hay-like off-flavors

due to photooxidation in the absence of light-proof

packaging, no such problems have been reported for

vitamin A-fortified margarines. The analytical vari-

ability in monitoring the amount of vitamin A present

is typically 10–15%. (See Food Fortification.)

0017 Vitamin D is added to margarine to prevent the

deficiency of a nutrient, which is not naturally avail-

able in food and is essential to prevent rickets, par-

ticularly in climates that limit the exposure of the skin

to sunshine. In Canada, it is mandatory to add vita-

min D to margarine at a level that will assure not less

than 13.25 mg (530 IU) per 100 g in the finished prod-

uct. Like vitamin A, vitamin D added to margarine

is relatively stable; however, the typical analytical

variability in monitoring the amount present has

been reported as in the order of 30%.

0018 Canadian legislation permits the addition of vita-

min E to margarine ‘if added in an amount that results

in not less than 0.6 mg (0.6 IU) of a-tocopherol per

gram of linoleic acid present.’ However, the permis-

sion has not been widely exercised. Tocopherol

isomers, particularly g and d, may be added as anti-

oxidants and confer some biological value, though

less than the a isomer. The tocopherols occur natur-

ally in vegetable oils but are subject to heat degrad-

ation. Table 1 illustrates the content of tocopherol

isomers in some margarines on the US market in

1985. It may be noted that the ratio of a-tocopherol

equivalents to C18:2 o-6 is lower in the tub margar-

ines than in the stick form due to the former’s higher

content of linoleic acid.

Enrichment with Plant Sterols

0019Plant sterols, and their hydrogenated counterparts,

stanols, have been shown to lower blood cholesterol,

which is an advantage in reducing the risk of cardio-

vascular disease. This prompted the introduction in

1995 of a Finnish margarine (Benecol) enriched with

a fat-soluble stanol ester (9%) followed in 1998 by a

stanol-enriched low-fat spread (*40% fat). In 1999,

the Unilever Research Centre in The Netherlands

announced its introduction of a new ‘heart-health

spread’ (Take Control/pro.activ) in both the USA

and Europe. This is a reduced-fat spread with 8%

plant sterols, so that regular consumption of 20 g

per day of the spread would contribute about 1.6 g

of plant sterols daily.

0020Lipid component The total fat in margarine is

routinely controlled through metering according to

formula specifications and may be monitored in in-

spection by standard methods. Of most interest, from

the perspectives of function and nutrition, is the

nature of the triacylglycerols (TAGs) that make up

the oils and fats of a margarine basestock. Since each

TAG molecule is made up of one molecule of glycerol

and three fatty acids, the structure of the constituent

fatty acids and their arrangement on the glycerol

stem affect its physical properties. These features are

dictated by the origin of the oils and fats used in

margarine formulation and by their processing prior

to blending. The lipid component of margarine is

most frequently characterized by its fatty acid com-

position. Local crops often are dominant constituents

such as canola and soybean oils in North American

products.

0021Individual fatty acids, which consist of a carboxyl

group and a hydrocarbon chain, are distinguished

from one another by chain length and by degree of

saturation with hydrogen. Shorter fatty acid chains

and greater unsaturation (i.e., less hydrogen, there-

fore more double bonds) within a TAG mixture favor

fluidity and vice versa. Unsaturation has the greater

softening effect provided that the double bonds are in

the natural or cis form. This geometric configuration

causes the fatty acid chain to double back on itself,

resulting in a bend that discourages the secondary

association among adjacent molecules, which leads

to hardening. Certain processing conditions, such as

hydrogenation, convert the natural cis isomer to a

straighter-chain trans isomer that favors hardening.

(See Fatty Acids: Properties.)

tbl0001 Table 1 Tocopherols and linoleic acid in some US margarines

Oil source Tocopherols

(mgper100 g)

Vitamin E

(a-tocopherol

equivalents)

C18:2 o-6

agd

Stick margarines

C/CH 15.2 49.7 0.5 20.2 33.8

SBH 5.4 29.1 8.2 8.4 7.6

SBH/SB/CSH 5.8 44.0 13.4 10.2 24.8

Tu b m a r g a r i n e s

C/CH 5.1 46.0 ND 9.7 43.6

SBH 5.2 34.1 10.0 8.6 30.4

SBH/CSH 4.8 3.1 1.8 5.1 29.7

Normalized wt%.

C, corn oil; CH, hydrogenated corn oil; SBH, hydrogenated soya bean oil;

SB, soya bean oil; CSH, hydrogenated cottonseed oil; nd, not determined.

Data adapted from Slover HT et al. (1985).

3716 MARGARINE/Composition and Analysis

0022 Table 2 summarizes the fatty acid composition of

some margarines on the Canadian and European

Markets between 1995 and 1998. There were some

distinct regional differences. Danish margarines had

higher levels of saturated fatty acids than those from

the United Kingdom and Canada reflecting differ-

ences in the sources of the fats and oils which made

up their respective basestocks. Canadian spreads

were significantly higher in trans fatty acids than

their European counterparts, likely due to differences

in the processing used for hardening.

0023 The data on Canadian spreads shown in Table 2 are

drawn from a study by Health Canada of 109 margar-

ine brands (30 print and 79 tub), selected on the basis

of their importance in the Canadian market share. The

relative amounts (grams per 100 g of total fatty acids)

of total trans fatty acids (TFA), t-18:1, trans,cis/cis,-

trans-18:2 (ct-18:2), trans,trans-18:2 (tt-18:2), trans-

18:3 (t-18:3), total saturated fatty acids (SFA), c-18:1

(all isomers), cis-18:2n-6 (linoleic acid) and cis-18:3n-

3(a-linolenic acid), were published in 1998. The trend

over time is a positive decrease in TFA from a ‘most

frequent occurrence’ of 30–35% in 1979–1983,

20–25% in 1990, to 15–20% in the 1995 margarines.

These changes reflect advances in processing technol-

ogy and increased use of liquid oil in blends with

partially hydrogenated oils in margarine basestocks.

However, Table 3 shows that Canadian margarines,

like those of Austria and the USA, have average TFA

levels substantially higher than those of several Euro-

pean countries and Australia. This is a nutritional

disadvantage, considering that dietary TFAs, like

saturated fatty acids, adversely affect blood lipid

patterns, increasing the risk of cardiovascular disease.

0025Analytical methods for the fatty acid compositions

shown in Table 2 varied among investigators. For the

Canadian spreads, a 1 g central plug was taken for

each of six samples of the same brand and homogen-

ized. Rather than extract the fat, samples of about

200 mg of the homegenate were converted directly to

methyl esters by treatment with 1.5 ml of NaOH in

methanol at 100



C for 5 min followed by mixing

with 2 ml of 14% BF

-methanol at 100



C for 30

min. The fatty acid methyl esters were recovered

with hexane and analyzed using an SP-2560 capillary

column in a Hewlett Packard 5890 Series II gas chro-

matograph (GC) equipped with a HP GC Chemsta-

tion. The column oven temperature was held at

165



C for 75 min, then programmed at 7



C min

1

to a final temperature of 210



C, which was held for

30 min. While this single-step GC analysis was suit-

able for samples with less than 5% trans 18:1, those

with more required the additional step of total trans

measurement by IR and appropriate corrections.

Fatty acids of the UK margarine were analyzed by

similar methods in the Netherlands. In the earlier

Danish study, fatty acids were extracted from the

margarine with isooctane following boiling with

methanol and boron trifluoride. The temperature

program and column for GC analyses were chosen

to provide good separation between cis and trans

C18:1. Certified reference materials were used by all

tbl0003Table 3 Tr a n s fatty acid (TFA) levels in margarines by country

Country MeanTFA level

(percentage of

total fatty acids)

Report source and date

Australia 13.1 Mansour and Sinclair, Asia-Pacific

Journal of Clinical Nutrition 3 (1993)

155

Austria 22.9 Ulberth and Henniger, Journal of the

American Oil Chemists Society 69

(1992) 829

Canada 23.6 Ratnayake et al. Journal of the

American Oil Chemists Society 75

(1998) 1587

Denmark 3.0 Oveson et al. Lipids 31 (1996) 971

France 3.8 Bayard and Wolff, Journal of the

American Oil Chemists Society 72

(1995) 1485

Greece 10.0 Kafatos et al. International Journal of

Food Science and Nutrition 45

(1994) 107

USA 22.6 Emken, American Journal of Clinical

Nutrition 62 (1995) 669S

As reported by Ratnayake WMN, Pelletier G, Hollywood R, Backer S and

Leyte D (1998) Tr a n s fatty acids in Canadian margarines: recent trends.

Journal of the American Oil Chemists Society 75: 1587–1594.

tbl0002 Table 2 Fatty acid composition of some Canadian and

European margarines (grams per 100 g of fatty acids)

Source/market

form

To t a l

saturates

To t a l

trans

Unsaturates

C18:1 C18:2

o-6

C18:3

o-3

Canadian print

16.5 35.4 35.8 9.1 1.9

Canadian tub

15.5 13.7 38.9 24.1 5.7

22.0 0.6 29.0 45.4 2.2

Denmark

Hard (frying) 35.0 4.2 39.3 14.0 4.4

Semisoft 34.6 1.2 32.4 31.5 4.1

Soft 27.4 1.3 21.1 49.2 0.8

Means of 10 products with the greatest market share in 1994. Adapted

from Ratnayake WMN, Pelletier G, Hollywood R, Backer S and Leyte D

(1998) Tr a n s fatty acids in Canadian margarines: recent trends. Journal of

the American Oil Chemists Society 75: 1587–1594.

Van den Bergh Foods. Adapted from Hendricks HFJ, Westrate JA, van

Vliet T and Meijer GW (1999) Spreads enriched with three different levels

of vegetable oil sterols and the degree of cholesterol lowering in

normocholesterolaemic and mildly hypercholesterolaemic subjects.

European Journal of Clinical Nutrition 53: 319–327.

Means of 20, 8, and 6 of hard, semisoft and soft margarines, respectively.

From Oveson L, Leth T and Hansen K (1996) Fatty acid composition of

Danish margarines and shortenings, with special emphasis on trans fatty

acids. Lipids 31: 971–975.

MARGARINE/Composition and Analysis 3717

investigators. (See Chromatography: Thin-layer

Chromatography; Fatty Acids: Analysis; Spectros-

copy: Infrared and Raman.)

Hardening

0026 The demand for table fats with the spreadable prop-

erties that characterize margarine could not be satis-

fied without the technology to convert liquid oil into

a semisolid product. The two commercial processes

used to achieve oil hardening are hydrogenation and

interesterification. While hydrogenation is the more

common process in North America, interesterifica-

tion, or transesterification as it may be referred to, is

widely used in parts of Europe. (See Vegetable Oils:

Oil Production and Processing.)

0027 The hydrogenation process adds hydrogen at the

double bonds of unsaturated fatty acids under condi-

tions of high temperature and high pressure in the

presence of a suitable catalyst, usually nickel. As

well as increasing the hydrogen content of the unsat-

urated fatty acids of TAGs, hydrogenation conditions

favor a shift in the position of the double bonds along

the fatty acid chain and/or a change in geometry to

a straighter-chain trans form. The trans isomers

of unsaturates, depending on their frequency, can

account substantially for the hardening that results

from hydrogenation. However, hydrogenation is a

flexible process that may be more or less selective in

its effects. By using higher temperatures with lower

pressure (e.g., 200



C, 6 psig) the polyunsaturates are

selectively hydrogenated before the monounsaturates

but, at the same time, isomerization is encouraged. In

contrast, more random hydrogenation occurs under

nonselective conditions, which use lower tempera-

tures and higher pressures (e.g., 135



C, 60 psig),

resulting in more saturates and fewer trans isomers.

0028 A comparison of the fatty acid profiles in Table 2

for the print and tub forms of Canadian spreads from

similar oil sources illustrates the influence of saturates

and total trans unsaturates on margarine firmness. As

the content of total saturates was similar in the two

market forms, the greater firmness of the print mar-

garines must be attributed to their higher content of

trans unsaturates. Because of their novel configur-

ation, trans unsaturates cannot be expected to have

the unique biological properties of their original cis

form. For this reason, trans fatty acid values are not

included in the values for monounsaturated and poly-

unsaturated fatty acids cited on food labels in North

America, although they are included in the total

fat values. (See Vegetable Oils: Composition and

Analysis.)

0029 Hardening by interesterification commonly in-

volves combining highly saturated fats and unsatur-

ated oils with a catalyst precursor such as sodium

methoxide, alkali metals, or alkyl metal alkylates

(about 0.1%) at temperatures ranging from 5 to

135



C. Hardening depends upon the concentration

of saturates because trans isomerization does not

occur under these relatively mild processing condi-

tions. It is likely that the low level of TFAs shown in

Table 2 for the UK spread reflects processing by

interesterification. Margarines made by this process

have the further advantage of crystal stability. Inter-

esterification conditions cause the fatty acids to trade

places within and among the TAGs. As a result of

these rearrangements, new and more random TAGs

are formed that are less inclined to undergo the degree

of TAG packing, which leads to large crystals. Ac-

cordingly, interesterification fosters the development

of the stable fine b

crystals that are desirable for

margarine smoothness.

Quality-control procedures

0030The control of quality in margarines begins with in-

gredient selection and continues with the monitoring

of microbiological and engineering processing condi-

tions, including packaging. The finished product

quality is assessed from the packing line for compli-

ance with in-house standards, regulatory require-

ments, labeling claims, and, where appropriate,

trade standards. (See Quality Assurance and Quality

Control.)

0031Margarine sheen and color are usually judged visu-

ally by comparison with a series of color standards

using either the Lovibond Tintometer or sets of plas-

tic or enamelled sticks arranged in color gradations

from light to dark. Alternatively, the three color

dimensions of hue, value, and chroma, may be de-

scribed by visual comparison with chips in the matte

or glossy edition of the ‘Munsell Book of Colors.’ In

this instance, hue is the color identity, value the light-

ness or brightness, and chroma the vividness or satur-

ation. The American Society for Testing and Materials

has published standards to guide such evaluations. It

is important that inspectors who do these assessments

be screened for normal color vision, be adapted to

daylight and examine the samples when they are

illuminated by a controlled source against a gray to

white background.

0032The physical properties of firmness and spreadabil-

ity are most commonly monitored by the solid fat

content (SFC) at temperatures of 10, 21.1, and

33.3



C, using low-resolution nuclear magnetic res-

onance under protocols defined by the International

Union of Pure and Applied Chemistry (IUPAC). The

IUPAC method for SFC provides a convenient

and more accurate alternative to the traditional

dilatometric determination of the solid fat index.

Nuclear magnetic resonance provides the advantage

3718 MARGARINE/Composition and Analysis

of accurate SFC readings on margarine ‘as processed.’

Recent studies have been aimed at relating the macro-

scopic rheological properties of fat crystal networks

to the various levels of structure within the network.

This involves not only the TAG structures and the

polymorphic and polytypic levels of structure but

also the morphology and spatial distribution of the

microstructure. For example, fractal scaling theory

appears promising to relate spatial distribution

within the fat crystal network to the mechanical prop-

erty of shear elastic modulus.

0033 Sensory properties of spreadability, graininess,

flavor release rate, and flavor blend call for analysis

by sensory panels that have been trained to recognize

typical margarine characteristics and defects as

opposed to naı

ve consumer panels. References that

could be useful in training for margarine assessment

can be adapted from some of those developed for

judging oxidized and sour flavor defects in butter,

and for rancid and fruity off-flavors in cheese. It is

critical that the preparation and presentation of mar-

garine samples be well controlled to limit changes due

to physical handling and temperature. Sampling the

spread as cubes, balls, or cylindrical cores is less

disruptive to texture than loading it into a container.

Temperature changes may be minimized by the use of

polystyrene foam blocks as sample holders. (See Sens-

ory Evaluation: Sensory Characteristics of Human

Foods.)

0034 Chemical measurements to control margarine

quality normally require monitoring of vitamin add-

itions and fatty acid analyses, depending on the

intended label claims. In Canada, ‘... no statements

or representations are permitted for any individual

fatty acid other than linoleic acid or for any group

of fatty acids other than polyunsaturates, mono-

unsaturates, or saturates. If a statement or claim for

linoleic acid is made, a declaration of total fat, the

above-mentioned group of fatty acids, and choles-

terol is required in addition . . . ’ The amounts of

these fat components present in a 10 g (two teaspoon)

serving must be cited. Currently, negotiations are

underway to harmonize North American nutrition

recommendations as well as the information that is

required and permitted on food labels.

See also: Cholecalciferol: Properties and Determination;

Emulsifiers: Organic Emulsifiers; Uses in Processed

Foods; Fats: Classification; Fatty Acids: Properties;

Analysis; Flavor (Flavour) Compounds: Structures and

Characteristics; Food Fortification; Preservation of

Food; Quality Assurance and Quality Control; Retinol:

Properties and Determination; Sensory Evaluation:

Sensory Characteristics of Human Foods; Tocopherols:

Properties and Determination; Vegetable Oils: Oil

Production and Processing; Composition and Analysis

Further Reading

Campbell I (1995) Food labeling in Canada. In: Przybylski

R and McDonald BE (eds) Development and Processing

of Vegetable Oils for Human Nutrition, pp. 114–120.

Champaign, IL: AOCS Press.

Hendricks HFJ, Westrate JA, van Vliet T and Meijer GW

(1999) Spreads enriched with three different levels of

vegetable oil sterols and the degree of cholesterol

lowering in normocholesterolaemic and mildly hyper-

cholesterolaemic subjects. European Journal of Clinical

Nutrition 53: 319–327.

Johnson B (1999) Bakery margarines. Cereal Foods World

44: SR9–SR12.

Narine SS and Marangoni AG (1999) Relating fat crystal

networks to mechanical properties: a review. Food

Research International 32: 227–248.

Ratnayake WMN, Hollywood R and O’Grady E (1991)

Fatty acids in Canadian margarines. Canadian Institute

of Food Science and Technology Journal 24(1/2): 81–86.

Ratnayake WMN, Pelletier G, Hollywood R, Backer S and

Leyte D (1998) Trans fatty acids in Canadian margar-

ines: recent trends. Journal of the American Oil

Chemists Society 75: 1587–1594.

Rousseau D and Marangoni AG (1998) The effects of inter-

esterification on physical and sensory attributes

of butterfat and butterfat–canola oil spreads. Food

Research International 31: 381–388.

Slover HT, Thompson RH, Davis CS and Merola GV

(1985) Lipids in margarines and margarine-like foods.

Journal of the American Oil Chemists Society 62:

775–786.

Vaisey-Genser M and Vane BK (1995) Sensory evaluation

of margarine. In: Warner K and Eskin NAM (eds)

Methods to Assess Quality and Stability of Oils and

Fat-containing Foods, pp. 76–106. Champaign, IL:

AOCS Press.

Yano J and Sato K (1999) FT-IR studies on polymorphism

of fats: molecular structures and interactions. Food

Research International 32: 249–259.

Dietary Importance

D H Morris, Mainstream Nutrition, Toronto, Ontario,

Canada

M Vaisey-Genser, University of Manitoba, Winnipeg,

Manitoba, Canada

Historical Background

0001Emperor Napoleon III prompted the invention of mar-

garine in 1869 by calling for a cheap alternate to butter

to feed his armies as they marched across Europe. A

French chemist, Hippolyte Me

ge Mourie

s, responded

with a formula in which an extract from beef tallow

MARGARINE/Dietary Importance 3719

replaced butterfat. Between 1871 and 1874, Me

Mourie

s sold his patent to Dutch, British, US, and

Prussian companies. Present-day companies based in

The Netherlands continue to be world leaders in mar-

garine design and production. This article considers the

importance of margarine in the diet from the perspec-

tive of its economic, sensory, and nutritional character-

istics. In recent years, margarine has emerged as an

important functional food. Although both standard

butter and margarine are 80%-fat products and hence

high in energy, margarine, being a formulated food, can

be designed to have nutritional and sensory features

that differ from its prototype.

Economic Issues

Price

0002 Margarine is now accepted as a food staple in most

countries where table-spread use is habitual. Initially

margarine’s advantage over butter was chiefly one of

price. By the beginning of the twenty-first century,

margarines had become available within a range of

prices, from lower-cost ‘regular’ brick- or stick-type

products to higher-cost soft ‘tub’ margarines that

could claim a nutritional advantage based on fatty

acid composition. This versatility is illustrated in

Table 1, which lists the prices of several margarines

available in a Canadian superstore in October 2000,

together with a summary of the nutrition information

presented on the package. The price of Becel margar-

ine, which qualified for the most detailed label claim,

was comparable to that of butter. The generic brick

margarine was the least expensive, being about a

third of the price of butter. Accordingly, consumers

may reduce food costs by purchasing their spreads

primarily on the basis of price. The irony of the

price-based choice among Canadian margarines

is that it favors the health prospects of the more

affluent. Lower-income consumers, who as a group

might have less nutrition knowledge, would be

expected to choose the cheaper product. The cost to

their families is to miss the opportunity of establish-

ing a healthier eating pattern.

0003However, economic considerations by the thrifty

may explain why a 1982 survey of over 500 western

Canadians indicated that margarine was the most

commonly used fat for home-baking products such

as cookies and cakes. Consumer interest in using

margarine as an alternate to shortening is recognized

in parts of Europe (e.g., in Switzerland) where 100%-

fat ‘margarines’ are available in grocery stores.

Patterns of Use

0004North American table-spread consumption patterns,

shown in Figure 1, indicate that margarine use in

Canada increased to match that of butter by 1975

and has exceeded it ever since. In the USA, the dom-

inance of margarine began more than a decade earlier,

following the passage of the Margarine Act enacted

by President Truman in 1950 to lift restrictive taxes

and laws on margarine production and sales. Concur-

rent with the increased dominance of margarine, the

consumption of table spreads in total has shown a

steady decline in both North American countries.

This is likely a response to promotional campaigns

of health authorities to reduce fat intake in the

interest of decreasing the risks of obesity and cardio-

vascular disease.

Sensory Characteristics

0005From the sensory perspective, the presence of fat

helps make food taste good – smoother, creamier,

richer, and more tender. This is so whether the fat is

a structural ingredient as in meat or an avocado, as an

ingredient in sauces or baked goods, or as a spread

on toast or in sandwiches. Consumers surveyed in

tbl0001 Table 1 Examples of table-spread prices (Canada, October, 2000)

Brand Market form Price of a 1-lb (0.45 kg)

container (Cdn $)

Labelclaim

Margarine

Generic Brick $1.09 % RDI for vitamins A, D

Generic Soft $1.49 % RDI for vitamins A, D; amount of calories, saturated, monounsaturated,

and polyunsaturated fatty acids in 10 g (2 tbsp)

Supermarket brand Soft $1.69 % RDI for vitamins A, D

Imperial Soft $2.29 % RDI for vitamins A, D

Becel Soft $2.89 % RDI for vitamins A, D, E; 0 trans fatty acids; amount of cholesterol,

saturated, monounsaturated and polyunsaturated fatty acids in

10 g (2 tsp); low in saturated fat, nonhydrogenated

Butter

Supermarket brand Brick $2.99

Beatrice Brick $3.99

RDI, recommended daily intake.

3720 MARGARINE/Dietary Importance

Canada between 1989 and 1997 cited taste as the

primary reason for choosing a particular food, one

which they were reluctant to forgo, even though 44%

agreed that people should be cautious when serving

food with fat. Similarly, in a survey of the dietary

practices of some 200 aboriginal adults in the north-

ern USA published in 1999, ‘taste’ was the most

frequently mentioned barrier to cutting the intake of

high-fat foods. In these cases the term ‘taste’ appar-

ently was synonymous with how much the respond-

ents liked the food; that is, it expressed their hedonic

response to the overall sensory character of the food.

0006 With respect to margarine, experienced sensory

consultants, who were enlisted by Consumer Reports

in 1982 to evaluate 17 different US margarines, de-

scribed an excellent margarine as one with ‘a pale

yellow color, a slight hint of dairy flavor and aroma,

an appropriate texture for its type, melts readily in the

mouth, and has no more than a hint of the parent oil’s

flavor or aroma.’ A later study of US consumer opin-

ion of margarine attributes judged ‘good taste’ and

‘good texture’ as the most important features. In this

instance, taste might have been more appropriately

termed flavor, which embodies both tastes and odors.

Texture

0007 Textural characteristics of margarines include firm-

ness, spreadability, smoothness, and mouthmelt. With

each of these, it is critical that the temperature of the

margarine samples be rigorously controlled before and

during testing. Of the four textural parameters cited

above, firmness is the quality that best lends itself to

measurement with standard laboratory instruments.

For example, ‘resistance to shear’ can be measured

physically with an Instron or other shearing device.

What is measured is either the force required to obtain

a given deformation or the deformation achieved under

a given force. Such instrumental readings can be related

to sensory estimates of firmness by the hand pressure

required to cut with a knife, again provided that there is

strict temperature control of the sample and related

implements.

0008Spreadability represents the ease with which a

spread can be applied in a thin, even layer to a con-

trolled surface such as a slice of bread. It is a complex

sensory characteristic reflecting the relative amount

of solid fat present together with its crystalline

structure. For a product to be spreadable, it must be

plastic or moldable at the temperature of use, which

will normally be between 4 and 22



C. Fat plasticity

depends upon the triacylglycerols involved in the

margarine formula and the fineness of the fat crystal

matrix which accounts for its structure. The advan-

tage of margarine is that it ‘worksoftens’ more easily

than butter does, even when their initial hardness

values are equal. That is why margarines can be

spreadable when taken directly from the refrigerator,

whereas butter cannot. Easy spreading has a greater

advantage than simply the work involved. The

thinner layer of spread achievable with margarine

contributes to the public health goal in developed

countries to decrease fat intake.

1955

Retail weight (kg per capita)

(a) (b)

1965 1975

Year

1985 1995 1955 1965 1975

Year

1985 1995

fig0001 Figure 1 North American patterns of table-spread consumption. (a) Canada; (b) USA. Continuous line, total butter and margarine;

dotted line, margarine; dashed line, butter. Data sources: Anonymous (1977) Margarine US per capita consumption may fall this year.

Journal of the American Oil Chemists Society 54: 840A–841A; Statistics Canada (1998) 32–230-XB; US Department of Agriculture (1966–

1998), Oil Crops Situation and Outlook, Washington, DC: USDA.

MARGARINE/Dietary Importance 3721

0009 Smoothness to the tongue is expected of a good table

spread. It reflects a structure of crystals that are small

enough to be imperceptible in the mouth, a size that has

been estimated to be in the order of 22 m through con-

trolled storage studies where crystal size was measured

under a polarized light microscope and related to sens-

ory tests of smoothness. Margarines with larger crys-

tals or clusters of smaller ones packed together will be

perceived as the defect of sandiness or graininess.

0010 Mouthmelt sensation from a table spread is im-

portant to both its texture and release of flavor. Mar-

garines will be criticized as waxy or gummy if they

fail to melt rapidly and completely in the mouth.

Prompt melting has another advantage; it generates

a pleasant cooling effect due to absorption of heat of

crystallization. Sensory testing using stopwatches has

confirmed that butter melts in the mouth faster than

the same amount of margarine does, but the degree of

temperature change realized in the mouth has not yet

been published.

Flavor

0011 Flavor is a combined sensory response by receptors in

the mouth and nose to taste and odor stimuli. It is a

sensation complicated by individual variations in

dentition, breathing rate, and salivary flow.

0012 Of the four basic tastes – sweet, salty, sour, and

bitter – saltiness is the most relevant to table spreads,

and then only where the use of salted spreads is the

norm. In the latter case, salt is added for its value as a

preservative as well as for taste, and even then at

relatively low levels, usually 1–3%. The high fat con-

tent of standard table spreads appears to mask salti-

ness perception. Sensory tests of butter prepared with

a range of salt levels showed that salt intensity in the

spread was only one-tenth the magnitude of the same

concentrations in water, although the growth of the

salty sensation over increasing concentration was

similar in both media. Apparently the oil in which

the salt/water solution is suspended limited the inten-

sity of salt perception. The eight-member trained

panel used in this experiment considered that a level

of 1% salt in butter was the most pleasant of eight

concentrations ranging from 0.5 to 4.0%.

0013 Odor perception as well as taste can be affected

by the composition of the dispersion medium. For

example, experimental margarines, containing diace-

tyl and other dairy flavors dispersed in a lipid mixture

of soybean oil melted and recrystallized with either

palm stearin or palm olein, differed in perceived

flavor intensity. Although the time for flavor intensity

to peak for both spreads was similar, total flavor was

significantly greater in the spread containing the

faster-melting palm olein. Head-space measurement

of diacetyl confirmed the results of sensory tests.

0014Gas chromatography combined with mass spectro-

photometry has been used since the 1950s to docu-

ment volatile compounds in foods using techniques of

simultaneous distillation extraction. However, identi-

fying which volatiles in margarine and other foods are

crucial to perceived flavor continues to be hampered

by several factors. These include the number of com-

pounds released at mouth temperature, the partition-

ing of flavor compounds between the oil and water

phases and between the aqueous phase in the mouth

and the gas phase in the nose, and the complexity of

their odor impact. Novel tools such as neural net-

works used with the results of increasingly sophisti-

cated methods for sample head space and oral breath

analysis appear promising.

0015Popular opinion is that butter, in comparison with

margarine, still has the better ‘buttery’ flavor

according to studies conducted during the latter part

of the 1980s and 1990s in both North America and

Europe. Where this is so, it may be a function of the

physical characteristics of the margarine emulsion. It

has been speculated that ‘if the aqueous droplets are

uniformly small and heavily stabilized with emulsi-

fiers, the flavor. . . release will be delayed.’

Nutritional Aspects

0016Margarine use increased in the 1970s and 1980s

when scientists determined that a diet high in fat,

especially saturated fat, increased blood levels of

low-density lipoprotein (LDL) cholesterol – the so-

called ‘bad’ cholesterol – and decreased blood levels

of high-density lipoprotein (HDL) cholesterol – the

‘good’ cholesterol. High blood levels of total and

LDL cholesterol are risk factors for coronary heart

disease (CHD). The margarine industry responded to

the consumers’ demand for ‘heart-healthy’ food prod-

ucts by formulating margarines that were lower in

total fat, saturated fat, and trans fatty acids. In some

countries, margarine is also a source of one or more

essential fat-soluble vitamins.

Vitamin Enrichment

0017Margarine is a convenient vehicle for the addition of

the fat-soluble vitamins A and D. The international

standard for margarine issued by the Codex Alimen-

tarius Commission of the Food and Agricultural

Organization (FAO) in Rome recommends their add-

ition. In Canada and the UK, the addition of vitamins

A and D is mandatory. In the USA, the addition of

vitamin A is mandatory, while the addition of vitamin

D is optional. Such enrichment gives margarine the

edge over butter, in which the vitamin A content

varies with the diet of the dairy cow and vitamin D

is essentially absent. Vitamin D, which assists in the

3722 MARGARINE/Dietary Importance

absorption of calcium, is naturally produced from the

sun’s activation of precursors in the skin. However, in

cold climates where skin exposure to the sun is pre-

cluded by outerwear for many months of the year,

foods fortified with vitamin D, including margarines,

are an important public health measure.

001 8 The addition of vitamin E to margarine is permit-

ted in Canada, if added in an amount that results in

not less than 0.6IU of a-tocopherol per gram of lino-

leic acid present. However, most Canadian margarine

manufacturers do not exercise this option. Fortifica-

tion of margarine with vitamin E is not permitted in

the USA, although tocopherols may be added as anti-

oxidants.

Total Fat, Saturated Fat, and Cholesterol

0019 Dietary patterns low in total fat, saturated fat, and

cholesterol are recommended to maintain a healthy

weight and reduce CHD risk. Margarine, which con-

tains no cholesterol and is low in saturated fat, is per-

ceived as a healthy alternative to butter. The

compositional differences among various margarine

products and butter are shown in Table 2.Standard

butter and standard margarine both provide the same

amount of energy (about 425kJ or 101kcal per tbsp or

15-g serving)and fat (11–12g per tbspor15-gserving);

reduced-fat margarines provide about half the energy

and fat per serving as regular margarine. Butter is a

source of dietary cholesterol, whereas margarine is not.

002 0 Diets low in saturated fat are considered desirable

because saturated fat is the main dietary determinant

of blood LDL cholesterol concentrations. Diets pro-

viding less than 10% of energy as saturated fat are

recommended for the general population; individuals

with diagnosed cardiovascular disease and elevated

blood LDL cholesterol levels are advised to consume

a diet containing less than 7% saturated fats. For an

adult consuming 8372 kJ or 2000 kcal day

1

, these

recommendations amount to a daily intake of only

16 or 22 g of saturated fat from all dietary sources.

0021One tbsp (15g) of butter provides about 7.2 g of

saturated fat, whereas 1 tbsp (15g) of hard, brick

margarine provides about 2.1g – a saving of about

5 gday

1

of the recommended saturated fat allow-

ance. Soft tub margarines, reduced-fat margarines,

and liquid margarines, which are generally recom-

mended over butter and brick margarines, all provide

less than 2g saturated fat per tbsp, allowing for an

even greater reduction in saturated fat intake. Thus,

substituting soft and liquid margarines for butter and

other saturated fats in the daily dietary pattern helps

reduce the saturated fat intake but not necessarily the

total fat intake.

Trans

Fatty Acids

0022Trans fatty acids are found naturally in butter, milk,

beef, and lamb fats and in commercially prepared,

partially hydrogenated margarines and solid cooking

fats like shortenings. Trans fatty acids are produced

in the margarine manufacturing process when liquid

vegetable oils are hydrogenated to form a semisolid or

solid fat with many of the same properties as animal

fats and, in some cases, to increase the oxidative and

thermal stability of the fat or oil. Indeed, partially

hydrogenated vegetable oils were developed in part

to take the place of highly saturated animal fats used

in spreads and for frying and baking.

0023During the hydrogenation process, some of the

naturally occurring cis double bonds in the vegetable

oil fatty acids are changed to trans double bonds, so

that the resulting trans fatty acids resemble saturated

fats more than unsaturated fats. In Canada, nearly

70% of the vegetable oils consumed by humans are

partially hydrogenated.

tbl00 02 Table 2 Fattyacidcompositionofbutterandmargarines(servingsize¼1tbsp)

ProductEnergyCholesterol

(mg)

Total

fat

Saturated

fattyacids

Monounsaturated

fattyacids

Polyunsaturated

fattyacids

Trans

fattyacids

kJkcal(g)(g)(g)(g)(g)

Butter42610231.1127.23.30.40.3

Margarine,regular,hard,cornand

soybeanoils

4231010.0112.15.23.51.9

Margarine,soft,soybean

(hydrogenatedandregular)

4231010.0111.95.13.80.8

Margarine-likespread(40%fat),

soybean(hydrogenated)

208500.060.92.42.00–2.5

Liquidmargarine4281020.0111.94.05.10

Onetablespoon¼3teaspoonsorabout15g.Valuesforsaturated,monounsaturated,andpolyunsaturatedfattyacidswereobtainedfromtheUS

DepartmentofAgriculture,AgricultureResearchService,USDANutrientDatabaseforStandardReference,Release13(1999),NutrientDataLaboratory

HomePageatwww.nal.usda.gov/fnic/foodcomp.ValuesfortransfattyacidsforallproductsexceptliquidmargarinewereobtainedfromJonnalagadda

SS,MustadVA,ChampagneCandKris-EthertonPM(1995)Margarineandplasmacholesterol–aperspectivefordietitionsontransfattyacidsinthediet.

PerspectivesinAppliedNutrition2:9–16.ThevaluefortransfattyacidsinliquidmargarinewasobtainedfromtheNationalAssociationofMargarine

Manufacturers(1999),availableatwww.margarine.org.

MARGARINE/Dietary Importance 3723