Attokaran M. Natural Food Flavors and Colorants

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Photo 9. (A) Clove on the plant. (B) Dried clove and clove oil. See color insert.

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36 Clove 147

Essential Oil

Clove bud oil has fractions which are both lighter and heavier than water. It is rich in

the phenolic constituent eugenol. Because of this, steel equipment is not suitable since

the combination of eugenol and iron gives a dark color. In England in earlier years,

glass distillation equipment was used. Today, stainless steel units are used.

Commercial steam distillation is carried out in stainless steel distillation units ﬁ tted

with a water - cooled condenser and Florentine ﬂ ask arrangement meant for heavier -

than - water oils. Generally, clove buds need no disintegration. Histochemical studies

using a microscope have clearly shown that oil cells are on the periphery of the buds,

with a slightly higher concentration at the ﬂ ower head than on the stem. Indian cloves

without disintegration yield 15 – 16% of volatile oil with a distillation time of 20 –

24 hours. Disintegration yields about 1% more. This procedure will not result in whole

deoiled buds. Whole deoiled buds are in demand and therefore steam distillation

without disintegration gives a better return. In many dishes, whole cloves have display

value, and thus deoiled whole bud has a demand. It is also possible that some deoiled

cloves are used for mixing with normal buds. Water distillation also gives slightly

higher yield but the deoiled material will be cooked and therefore will have no value.

During distillation, almost all of the oil is heavier than water and will be collected

from the bottom of the water trap. Only about 1% may be collected from the top,

which is added to the oil.

In general, when compared with a yield of 15 – 16% oil when distilled whole with

external steam for Indian cloves, Madagascar cloves will yield 14 – 15% and Sri

Lankan cloves a slightly higher yield of 15 – 17%.

Clove bud oil has a mild golden yellow color. It is a mobile liquid with warm spicy

and medicinal aroma and a ﬂ avor characteristic of the clove bud. The chief chemical

constituent is eugenol, which is present to the extent of over 70%. Other major con-

stituents are β - caryophyllene and eugenol acetate (Table 36.1 ). A large number of

other terpenes, sesquiterpenes, and oxygenative derivatives are reported in small

quantities.

In recent years, volatile oils obtained by different methods have been subjected to

analytical studies. Extraction by supercritical carbon dioxide reveals eugenol (70.91%)

as the major component, followed by β - caryophyllene (11.92%), eugenyl acetate

(10.92%), methyl pentyl ketone, methyl salicylate, humulene, and other components

(Liu et al. 2003 ). The volatile oil of clove, usually employed as a ﬂ avor for tobacco,

also shows eugenol, caryophyllene, and caryophyllene oxide (Dong et al. 2004 ). Clove

buds, after headspace hanging drop liquid phase microextraction, are examined by

Figure 36.1. Eugenol.

OCH

CH – CH = CH

148 Individual Flavors and Colorants

GC - MS. This shows eugenol, β - caryophyllene, and eugenol acetate (Jung et al. 2006 ).

Essential oils from both the fruit and bud have a high content of eugenol and

caryophyllene, but recently 2,3,4 - trimethoxy acetophenone and 2 - methoxy - 4 - (2 -

propenyl) phenol acetate have been reported in clove (Zhao et al. 2006 ). Turkish clove

shows 87.0% eugenol, 8.01% eugenyl acetate, and 3.56% β - caryophyllene (Alma

et al. 2007 ).

According to the FCC, clove oil occurs as a colorless to pale yellow liquid with a

sharp, spicy odor and taste. It darkens and thickens on aging or exposure to air.

Physical characteristics of the oil as deﬁ ned by the FCC are as follows.

Optical rotation − 1.5 to 0

Refractive index 1.527 – 1.535 at 20 ° C

Speciﬁ c gravity 1.038 – 1.060

Solubility 1 mL dissolves in 2 mL 70% alcohol

Oleoresin

Deoiled buds are dried and disintegrated by passing through a roller mill. This is

packed in a stainless steel percolation vessel and the nonvolatile portion is extracted

with a suitable solvent. A mixture of acetone and hexane will be a good solvent as it

combines polar and nonpolar properties. After removal of solvent, a yield of about

15% can be obtained. This is then blended with clove oil as per customer speciﬁ cation.

Usually, food additives such as propylene glycol and soya lecithin are added to get

proper homogeneity, clarity, and ﬂ ow characteristics.

A typical clove bud oleoresin will be a dark brown, thick, viscous liquid with warm

spicy and medicinal aroma and a ﬂ avor characteristic of clove bud. Because of the

presence of ﬁ xed oil and resinous matter of clove, oleoresin will show a more mellow,

rounded ﬂ avor. The volatile oil level is adjusted between 10% and 75% as per cus-

tomer demand.

Clove bud absolute is an alcohol extract capable of dissolving in alcoholic

fragrance preparations. It can also be made by extracting alcohol solubles from the

oleoresin.

Uses

Clove is a valuable ingredient in many sweet and savory food items. In many Asian

dishes, a clove note is important. In processed foods of this type, clove extractives

can replace a clove bud. Oleoresin has a more mellow ﬂ avor than the oil, and therefore

Table 36.1. Major components of clove bud

oil (Sri Lankan)

Component Content (%)

Eugenol 72 – 80

Eugenyl acetate 7 – 9

β - Caryophyllene 8 – 12

36 Clove 149

its use in processed food is beneﬁ cial. Clove absolute is used in expensive perfumery

preparations and in certain cigarettes.

Because of the presence of phenolic eugenol, clove bud oil is used in many dental

preparations and mouth fresheners, such as toothpaste, dentrifuge, mouthwash, and

antiseptic mouth preparations. It is also used in medicinal preparations for asthma,

arthritis, rheumatism, sprains, and toothache.

Identiﬁ cation Numbers

FEMA No. CAS US/CFR E - No.

Clove bud oil 2323

{

8000 - 34 - 8 184.1257 –

Clove bud extract 2322 84961 - 50 - 2 184.1257 –

Clove bud oleoresin 2324

{

84961 - 50 - 2 184.1257 –

Clove bud absolute – 8000 - 34 - 8 – –

References

Alma , M. Hakki ; Ertas , Murat ; Nitz , Siegfrie ; and Kollmansberger , Hubert . 2007 . Chemical composition

and content of essential oil from the bud of cultivated clove ( Syzygium aromaticum L) . Bioresources 2

( 2 ), 265 – 269 .

Dong , Li ; Zhu , Shu - kui ; Su , Xue - li ; Xing , Jun ; and Wu , Cai - ying . 2004 . Analysis of volatile compounds

of clove oil by GC - MS . Fenxi Kexue Xuebao 20 ( 4 ), 394 – 396 (Chinese) ( Chem. Abstr. 143:83160).

Jung , Mi - Jin ; Shin , Yeon - Jae ; Oh , Se - Yeon ; Kim , Nam - Sun ; Kim , Kun ; and Lee , Dong - Sun . 2006 .

Headspace hanging drop liquid phase microextraction and gas chromatography - mass spectrometry for

the analysis of ﬂ avours from clove buds . Bull. Korean Chem. Soc. 27 ( 2 ), 231 – 236 (English).

Liu , Bo ; Chen , Kaixun ; Chen , Weiping ; and Chang , Qing . 2003 . Study of extraction of clove bud by

supercritical carbon dioxide and its GC - MS analysis . Xiangliao Xiangjing Huazhuangpin (3), 3 – 4 , 26

(Chinese) ( Chem. Abstr. 141:137005).

Zhao , Chenxi ; Liang , Yizeng ; and Li , Xiaoning . 2006 . Chemical constituents and antimicrobial activity of

the essential oils from clove . Tianran Chanwu Yanjiu Yu Kaifa 18 ( 3 ), 381 – 385 (Chinese) ( Chem. Abstr.

147:230706).

Introduction

When dried, clove leaves that fall to the ground yield an essential oil with many of

the characteristics of the bud oil. This is often used as a cheaper substitute.

Plant Material

The source of the leaves is the same tree that produces the clove bud. The leaves of

clove are simple, opposite, coriaceous, exstipulate, and glabrous. It is aromatic with

a smell similar to that of the buds.

When leaves fall to the ground and dry out, they are collected for steam distillation

of the oil in the leaf. Because of the cost of collection and transportation, it is custom-

ary to water - distill the oil locally in crude stills. Oil from such sources is then mixed,

and great quantities are made. Because of iron contamination, a dark color is generally

present. But if distilled in a stainless steel or glass unit, oil has a golden yellow color

and a warm spicy and medicinal aroma and ﬂ avor characteristic of clove bud oil.

Chelation of iron by treatment with citric acid has been suggested, but, it is unknown

whether this is a practical solution.

Eugenol is the main constituent, being present at levels over 80% (for the structure,

see Chapter 36 ). β - Caryophyllene accounts for about 10%. Generally, Indonesian oil

has slightly less eugenol and more β - caryophyllene than Indian oil (Table 37.1 ). Sri

Lankan oil is closer to Indian oil.

In a recent analysis, the compounds identiﬁ ed in clove leaf oil include eugenol

(76.8%), β - caryophyllene (17.4%), α - humulene (2.1%), and eugenyl acetate (1.2%)

(Jirovetz et al. 2006 ).

Clove leaf oil, according to the FCC, is a pale yellow liquid with a sharp, spicy,

peppery odor and taste. It is soluble in propylene glycol and in most ﬁ xed oils with

slight opalescence, and it is relatively insoluble in glycerin and in mineral oil.

Physical characteristics as deﬁ ned by the FCC are as follows.

Optical rotation − 2 to 0 °

Refractive index 1.531 – 1.535 at 20 ° C

Speciﬁ c gravity 1.036 – 1.046

Solubility 1 mL dissolves in 2 mL of 70% alcohol (slight opalescence

may occur when additional solvent is added)

Clove Leaf

Syzygium aromaticum L ( Myrtaceae )

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Uses

Clove leaf oil is used as a cheaper substitute for bud oil. In some dental preparations,

leaf oil with or without admixture with bud oil is used. It is also used in such products

as massage oils, lotions, room fresheners, and aromatherapy.

Identiﬁ cation Numbers

FEMA No. CAS US/CFR E - No.

Clove leaf oil 2325 8000 - 34 - 8 184.1257 –

8015 - 97 - 2

Reference

Jirovetz , Leopold ; Buchbauer , Gerhard ; Stoilova , Ivanka ; Stoyanova , Albena ; Krastanova , Albert ; and

Schmidt , Erich . 2006 . Chemical composition and antioxidant properties of clove leaf essential oil .

J. Agric. Food Chem. 54 ( 17 ), 6303 – 6307 .

Table 37.1. GC analysis of clove leaf oil

Indonesian (%) Indian (%)

α - Pinene < 0.1 < 0.1

β - Pinene < 0.1 < 0.1

β - Caryophyllene 11 – 15 10 – 13

Eugenol 80 – 85 85 – 88

Eugenyl acetate 0.5 – 1 0.1 – 0.5

Introduction

Coca is a plant whose leaves are valued as a source of stimulant. It plays an important

role in the culture of the Andes region. In this region, the plant is considered to have

a divine inﬂ uence. Archeological evidence from South American mummies pointed

to its use even in the sixth century AD. While it is used as a masticatory, at the time

of the Inca empire, its use was restricted to nobles and the powerful of the society. As

the Inca lost control, the leaf became more widely available.

Coca leaf might be useful as a remedy for gastrointestinal diseases, for motion

sickness, and as a substitute for antidepressant medicines (Well 1978 ). It is a substitute

stimulant for coffee and adjunct in slimming and physical ﬁ tness programs. According

to Well (1978) , the effect of whole leaf is quite distinct from that of the extract, thus

the leaf can be considered safe for use in chewing gum and other products. However,

food and pharmaceutical laws of many countries do not take such a liberal view. Coca,

like cocaine, is controlled by the U.S. federal narcotics agency. The Bolivian govern-

ment argues that coca leaf should be legalized for international trade.

Plant Material

The plant is an evergreen shrub or small - sized tree. It resembles a black thorn bush

with a height of 3 – 5 m. Generally, plants grown in higher altitudes are smaller than

those grown in lower altitudes. The leaf is thin and leathery, shaped as an elongated

elliptical that tapers at both ends. It has small ﬂ owers growing as a small cluster with

a short stalk. Each ﬂ ower has ﬁ ve pale yellow petals, a heart - shaped anther, and pistil

consisting of three carpels to form a three - chambered ovary. The fruit is a red - colored

berry. Propagation is through seeds.

The leaves are the important and useful plant part. Fresh leaves, when carefully

dried, have a green color on top and are gray - green on the lower surface. When the

leaf is chewed, a pleasurable numbness is felt in the mouth with an agreeable pungent

taste.

The chief constituent is cocaine, which is an alkaloid. There are many derivatives

of cocaine and some related alkaloids in small proportion. The concentration of the

alkaloids varies with region, age of the plant, and so on. Cocaine accounts for 70 – 80%

in Bolivian leaf, while it is only 50% in Peruvian leaf (Leung and Foster 1996 ). The

leaf has carbohydrates, protein, a small amount of volatile oil, and ﬂ avones.

Coca Leaf

Erythroxylum coca Lam ( Erythroxylaceae )

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Extractives

Because of its stimulant action, coca leaf extract was used in earlier formulations of

cola - based soft drinks. Today, extracts from which cocaine has been removed are used.

Various companies have their own conﬁ dential procedures, and very little information

about the exact conditions of methods of extraction is published.

Uses

Coca leaf is a popular and invigorating masticatory used by the people of South

America. Cocaine is used as a mild local anesthetic for minor operations of the face

and its organs.

Extract freed of cocaine is heavily used in many soft drinks. It is also used in some

alcoholic beverages and confectionery items. There are many people who feel that

while extracts rich in cocaine may be injurious, the leaf itself is safe. Presently, gov-

ernments of growing regions argue that the leaf should be made legal for international

trade and should be removed from the United Nations ’ list of illegal drugs. Recently,

a liquor containing coca leaf extract was introduced in the Netherlands.

Identiﬁ cation Numbers

FEMA No. CAS US/CFR E - No.

Coca leaf extract (undecocainized) 2329 84775 - 48 - 4 182.20 –

References

Leung , Albert Y. ; and Foster , Steven . 1996 . Encyclopedia of Common Natural Ingredients , 2nd edition .

New York : John Wiley and Sons , pp. 179 – 180 .

Well , A.T. 1978 . Coca leaf as a therapeutic agent . Am. J. Drug Alcohol Abuse 5 ( 1 ), 75 – 86 .

Introduction

Cochineal insects produce a crimson - colored pigment known as carmine. The insect

is a parasite of cacti from the genus Opuntia . The insect is a member of suborder

Sternorrhyncha . There are other insects belonging to Dactylopins that are very similar

to Dactylopins coccus and produce a similar dye. Therefore, the insects are referred

to as cochineal insects. While it is probable that majority are D. coccus , other members

of the genus could be present.

The pigment was in use in early American history by the Aztecs and Mayans.

Cochineal was considered to be of high value, and various communities used it to pay

yearly tribute to the Emperor. Spaniards who traveled to America saw its potential, as

the dye was more brilliant and produced better color than those used in Europe at that

time. The dye became very popular in Europe before the present synthetic dyes came

into existence. Cochineal became a valuable item of commerce and was traded in

major commodity exchange centers such as London and Amsterdam. The newly

found, superior pigment was used by the British military for their jackets and Roman

cardinals for their robes.

In the nineteenth century, Mexico ’ s monopoly of carmine ended when the insects

were brought to the Canary Islands. In 1862, the Canary Islands sold 6 million pounds

(2.73 million kilograms) of cochineal, which represents over 400 billion insects.

While its use as a textile dye was most prominent in the presynthetic dye era,

cochineal also found use in foods and cosmetics. It made a spectacular entry in various

fruit products, beverages, confectionery, and animal products. Cosmetic rouge was a

great success; cochineal is still popular in cosmetics.

In the middle of the nineteenth century, with the appearance of alizarin - based

crimson pigment, use of cochineal fell dramatically and amounted to near nothing by

the twentieth century. However, with the present trend of using natural food additives

rather than synthetic items, it has made a comeback. However, its producers try to

hide the fact that it is of insect origin. Naturally, it is not permitted in foods for vegetar-

ians, and some religious people would not use a dye made by killing live insects. The

European Commission has recognized the color with an E - number.

Living Material

The insects that produce the carmine color are soft - bodied and ﬂ at oval in shape. The

females are important in producing the dye. Females are slightly larger than males,

Cochineal

Dactylopins coccus Costa ( Coccoidea )

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