Attokaran M. Natural Food Flavors and Colorants

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396 Individual Flavors and Colorants

Ethylene dichloride, ethyl acetate, acetone, and a mixture of hexane and acetone are

all satisfactory solvents. Generally, the yield will be about 10% with a curcumin

content of 35%. General demand is for a product with a curcumin content ranging

between 25% and 40%, which can be carried out using the right variety of raw mate-

rial. The oleoresin is a yellow to orange - red, viscous paste with the characteristic

aroma of turmeric caused by the volatile oil.

In recent years, there has been demand for crystallized curcumin of about 95%

purity. Here, there will be no aroma of turmeric because of the absence of volatile oil.

This product is made by dissolving turmeric in the solvent by warming and making

a supersaturated solution. On standing for some time, curcumin separates as crude

crystals. It is difﬁ cult to get crystals from oleoresin made through acetone extraction,

but with other solvents the crystals separate.

Crystallization can be repeated for higher strength crystals. Then crystals are ﬁ l-

tered, usually using a basket centrifuge, and washed with a small amount of solvent.

If the same solvent is used, then there is a chance for a slight loss due to solubiliza-

tion. If hexane is used, during washing there will be no dissolution. Many solvents

are used for crystallization, such as ethylene dichloride, ethyl acetate, ethyl alcohol,

and isopropyl alcohol. The choice of solvent depends on the customers ’ preference.

Minute traces of solvent can be detected by GC. There are reports of detection of

acetone residues even when it is not used. This is probably generated during the high -

temperature distillation in the procedure for estimation (Binu et al. 2007 ).

The oil part also has value as a natural color, even though the compounds are

condensed/polymerized curcuminoids, which do not crystallize, but have a similar

color, rather than curcumin.

Condensation of two molecules of vanillin with an appropriate carbonyl unit can

produce curcumin. But it has not shown biological activity attributed to natural cur-

cumin and two other allied pigments. In fact, more than a decade ago, attempts were

made to produce vanillin from curcumin derived from turmeric. This was with a hope

Table 98.2. Analysis of true turmeric oil and oil recovered from

“ oil part ”

Constituent Turmeric Oil (%) Oil from Oil Part (%)

α - Pinene < 0.3 < 0.5

Myrcene 1 – 3 0.5 – 4

Limonene < 0.5 0.2 – 4

p - Cymene 1 – 2 1 – 4

1,8 - Cineole 0.5 – 1.5 1 – 3

Geraniol < 0.3 –

Eugenol < 0.5 0.2 – 1

α - Turmerone 22 – 28 4 – 10

β - Turmerone 18 – 23 15 – 20

ar - Turmerone 12 – 18 1 – 4.0

Zingiberene 5 – 10 15 – 20

GLC column: HP Inowax; carrier: H

; detector: FID.

By area %.

98 Turmeric 397

of presenting such vanillin as semi - synthetic, and therefore much better than fully

synthetic ones.

Methods of Testing

Curcumin content is estimated by spectrophotometric ASTA method with maxima

read at 415 – 425 nm. However, this will not give the amount of crystallizable curcumin,

which will be only about two - thirds of the total curcuminoid by the ASTA method.

The oil part that separates out on crystallization gives absorption at the maxima of

curcumin. The crystallizable curcumin has to be determined by actual crystallization

and measurement of yield of the dry crystals.

Uses

Turmeric is used for ﬂ avor in a number of Indian and Asian food preparations. Mustard

paste also contains the spice. For these, oleoresin is a good replacement.

The food items in which curcumin are used include confectionery, ice cream, bever-

ages, curries, and seafood preparations.

But the greatest use of curcumin is for its nutraceutical properties. Systematic

research carried out in the National Institute of Nutrition (Polasa et al. 1991, 1992 ;

Mukundan et al. 1993 ) has shown that curcumin is an efﬁ cient antioxidant and there-

fore an effective anticancer nutraceutical. Researchers from United States have shown

that consumption of curcumin slows down cancer of the breast, prostate, lung,

and colon.

The Ayurvedic system of medicine has shown that turmeric has anti - inﬂ ammatory

and blood cleansing properties. A recent study at UCLA has indicated that consump-

tion of curcumin can help combat Alzheimer ’ s disease (Balasubramanian 2006 ).

Many cosmetic beneﬁ ts are attributed to turmeric, mainly due to curcumin.

However, turmerone produced by extraction with supercritical carbon dioxide has

effective antioxidant and antiaging properties. It is further claimed that turmerone has

high bioavailability, enabling an increase in skin tone and improved radiance. In

Ayurvedic therapy, turmeric paste is believed to make women ’ s skin smooth and free

of hair.

Many advantageous pharmacological effects of turmeric have been reviewed

(Aggarwal et al. 2003 ). It is beneﬁ cial for the treatment of prostrate cancer (Dorai

et al. 2001 ), breast cancer (Somasundaram et al. 2002 ), colon cancer (Chen et al.

2006 ), and Alzheimer ’ s disease (Balasubramanian 2006 ).

Identiﬁ cation Numbers

FEMA No. CAS US/CFR E - No.

Turmeric oil 3085 8024 - 37 - 1 182.10 –

Turmeric extract 3086 8024 - 37 - 1 182.20 –

84775 - 52 - 0 –

Turmeric oleoresin 3087 84775 - 52 - 0 182.20 –

Curcumin – 458 - 37 - 7 100

398 Individual Flavors and Colorants

References

Aggarwal , Bharat B. ; Kumar , Anushree ; and Bharti , Alok C. 2003 . Anticancer potential of curcumin.

Preclinical and clinical studies . Anticancer Res. 23 ( 1A ), 363 – 398 .

Balasubramanian , Krishnan . 2006 . Molecular orbital basis for yellow curry spice curcumin ’ s prevention of

Alzheimer ’ s disease . J. Agric. Food Chem. 54 ( 10 ), 3512 – 3520 .

Binu , Paul ; Mathulla , Thomas ; Issac , Anil ; and Mathew , A.G. 2007 . Acetone originating from curcumin

during determination of residual solvent . Indian Perfumer 51 ( 2 ), 41 – 43 .

Chen , A. ; Xu , J. ; and Johnson , A.C. 2006 . Curcumin inhibits human colon cell growth by suppressing gene

expression of epidermal growth factor receptor through reducing the activity of the transcription factor

Egr - 1 . Oncogene 25 ( 2 ), 278 – 287 .

Dorai , Thambi ; Cao , Yi - Chen ; Dorai , Bhuvaneswari ; Buttyan , Ralph ; and Katz , Aaron E. 2001 . Therapeutic

potential of curcumin in human prostate cancer III. Curcumin inhibits proliferation induces apoptosis,

and inhibits angiogenesis of LNCaP prostate cancer cells in vivo . Prostate 47 ( 4 ), 293 – 303 .

Govindarajan , V.S. 1980 . Turmeric — chemistry, technology, and quality . CRC Crit. Rev. Food Sci. Nutr. 12 ,

199 – 301 .

Krishnamurthy , N. ; Mathew , A.G. ; Nambudiri , E.S. ; Shivashankar , S. ; Lewis , Y.S. ; and Natarajan , C.P.

1976 . Oil and oleoresin of turmeric . Trop. Sci. 18 ( 1 ), 37 – 45 .

Mukundan , M.A. ; Chacko , M.C. ; Annapurna , V.V. ; and Krishnaswamy , K. 1993 . Effect of turmeric and

curcumin on BP - DNA adducts . Carcinogenesis 14 ( 3 ), 493 – 496 .

Polasa , K. ; Sasikaran , B. ; Krishna , T.P. ; and Krishnaswamy , K. 1991 . Turmeric ( Curcuma long ) induced

reduction in urinary mutagens . Food Chem. Toxicol. 29 ( 10 ), 699 – 706 .

Polasa , K. ; Raghuram , T.C. ; Krishna , Prasanna ; and Krishnaswamy , K. 1992 . Effect of turmeric on urinary

mutagens in smokers . Mutagenesis 7 ( 2 ), 107 – 109 .

Somasundaram , Sivagurunathan ; Edmund , N.A. ; Moore , D.T. ; Small , G.W. ; Shi , Yue Y. ; and Orlowski ,

R.Z. 2002 . Dietary curcumin inhibits chemotherapy - induced apoptosis in models of human breast cancer .

Cancer Res . 62 ( 13 ), 3868 – 3875 .

Introduction

Vanilla was cultivated in Mexico well before European explorers set sail for the New

World. In the ﬁ fteenth century, the Aztecs invaded and conquered central Mexico.

They developed a taste for this ﬁ ne spice and made the conquered pay them tribute

in the form of vanilla beans. The Spanish explorer Cortes introduced the spice to

Europe in 1520. Vanilla is believed to have been named after “ black ﬂ ower, ” as the

mature beans turn dark on drying.

European countries tried to grow vanilla beans in tropical countries where they had

control, but the efforts to produce beans did not succeed. After considerable investiga-

tion, it was found that pollination requires external assistance. This happened in

Mexico through a variety of bees and hummingbirds, which enjoy the nectar of vanilla

ﬂ owers. Hummingbirds ’ long beaks were able to reach inside the ﬂ ower to drink the

nectar, and in the process the anther was opened, releasing the pollen which in turn

fertilized the stigma.

Early documentation of vanilla and its uses was carried out by a Spanish missionary

in Mexico in 1560. Even though artiﬁ cial pollination was introduced in the nineteenth

century, it was a 12 - year - old French - owned slave, Edmond Albius, who developed

the more practical method of pollination, which is even now followed. This involved

use of a small stick, usually made of bamboo, which can open the anther almost like

the long beak of the hummingbird. This development enabled cultivation and produc-

tion of vanilla beans in other tropical regions.

Until the middle of the nineteenth century, vanilla beans were mainly cultivated in

Mexico. In early nineteenth century, the French took this crop to Reunion Island and

Mauritius and then to Comoros, the Seychelles, and Madagascar. Development of a

practical pollination method helped in the spread of vanilla production throughout

these African islands. Beans produced in this region are known as Bourbon vanilla.

Today, Madagascar is the most important producer of vanilla. After saffron, vanilla is

regarded as the most expensive spice.

Plant Material

Vanilla belongs to the orchid family. In fact, in that large family, vanilla is the only

variety that is commercially important as a ﬂ avoring material. The major species is

Vanilla

Vanilla planifolia Andrews, V. pompona Schiede, V.

tahitensis Moore ( Orchidaceae )

399

Natural Food Flavors and Colorants Mathew Attokaran

400 Individual Flavors and Colorants

Vanilla planifolia . Two other cultivated varieties are West Indian vanilla, Vanilla

pompona , and Tahitian vanilla, Vanilla tahitensis (Madhusoodanan et al. 2003 ).

V. planifolia is an herbaceous perennial vine, which grows as a climber on trees or

supports. It is aided by adventitious roots, which are white in color and about 2 mm

in diameter. They appear opposite to the leaves. The root proper is in the base. It has

a long, cylindrical, succulent, and branched stem. The stem is 1 – 2 cm in diameter. It

has a chlorophyll cover with stomata, so that it can engage in photosynthesis. Its leaves

are oblong - elliptic to lanceolate. They are ﬂ at, ﬂ eshy, subsessile, and alternate, with

a length of 10 – 25 cm and breadth of 3 – 10 cm. The inﬂ orescence is stout racemose,

axillary, and generally simple. The ﬂ owers are large, waxy, and pale greenish - yellow.

The lower part of the labellum develops into a central column. The tip of the column

bears a single stamen with two pollen masses covered by a cap - like hood. The slender

stalk - like portion is the ovary, which is 4 – 5 cm in length.

Photo 29. (A) Uncured vanilla beans. (B) Cured beans. See color insert.

99 Vanilla 401

The formation of the ﬂ ower is such that self - pollination is difﬁ cult because of

separation of the stamen from the stigma. In Mexico, where vanilla originated as a

commercial crop, pollination is done by a variety of stingless bees or hummingbirds.

In all other places and even in some regions of Mexico, hand pollination is the only

way to set the fruit.

Hand pollination is carried out by a pointed bamboo splinter, sharpened toothpick,

or other similar implement (Madhusoodanan et al . 2003 ). Using the implement, the

hood of the stamen is pushed back and the anther is pressed against the stigma with

the thumb, thereby spreading pollen over it. Each ﬂ ower and stigma receptivity lasts

for only a day, and therefore all pollination has to be carried on the same day. The

best time for this is in the morning.

The fruit is a capsule and takes 250 – 280 days to mature, at which point the weight

will be around 12 g. The fruits, known as beans, are narrow and cylindrical or three -

angled with a length of 10 – 25 cm and diameter of 0.5 – 1.5 cm. When plucked, the

beans are green in color and without the characteristic aroma. The aroma is developed

only after an elaborate curing process.

The beans contain numerous minute black seeds about 0.3 mm in diameter. Under

normal conditions, germination of the seeds is difﬁ cult. Multiplication is achieved

through cuttings of the vine. Today, tissue culture - developed seedlings are employed

in commercial cultivation. In most major growing areas such as Madagascar and other

African islands, as well as India and China, V. planifolia is cultivated.

V. tahitensis , as the name suggests, is of Tahitian origin and is cultivated in Indonesia,

Hawaii, and some Paciﬁ c islands. This variety fetches a lower price. Its main differ-

ence is that it has a more slender stem and narrower leaves. Its beans are reddish - brown

in color, with a size of 12 – 15 cm in length and slightly less than 1 cm in diameter. The

middle of the bean is broader, tapering toward the ends.

V. pompona resembles V. planifolia , but the leaves are longer and broader. The

ﬂ owers are greenish yellow in color and more ﬂ eshy. The beans are also ﬂ eshier but

with a roundish triangular section. The quality of this bean is regarded as inferior to

V. planifolia .

The major producers of vanilla beans are Madagascar, 6200 tonnes (about 59%);

Indonesia, 2399 tonnes (about 23%); and China, 1000 tonnes (about 10%). Others are

Mexico, Turkey, Tonga, Uganda, Comoros, French Polynesia, and Reunion, according

to an FAO report of 2006.

Harvesting and Curing

The production, curing, and utilization of vanilla is a highly developed procedure with

many variations based on region, agro - climatic conditions, variety and size of the

bean, and the local tradition. For detailed information, the reader is referred to various

books on the subject. However, the general principles of harvesting and curing are

explained in this section. Photo 29 shows harvested and cured beans.

Generally, the vine takes about 3 years to reach the fruit - bearing stage, and will

produce for about 12 years. The crop in the ﬁ rst year is likely to be smaller than in

later years. About 6 – 9 months after pollination, the bean starts to develop a yellow

color at the tip, which is an indication for harvesting.

402 Individual Flavors and Colorants

The curing processes of Mexico, the Bourbon Island, and other regions that use

V. planifolia are somewhat similar. In Mexico, vanilla beans are wrapped in blankets

and straw mats and placed in ovens for 24 – 48 hours. In other places, beans are

immersed in hot water for a short time, spread in the sun, and turned over periodically

to avoid overheating. The beans are then wrapped in blankets, placed in wooden boxes,

and allowed to sweat overnight. The spreading in the sun and wrapping are repeated

to complete the various enzymatic changes. The beans are stored on racks in holding

rooms for a few weeks to further develop the ﬂ avor. The overall curing time is 3 – 6

months. Variations in the conditions are made according to variations in the beans and

other factors. To get the best results, beans have to be picked individually making sure

that each one is at the proper level of maturity (Nielsen undated ).

In Indonesia, where V. tahitensis is cultivated, there is a tendency to pick all the

beans in a group of vines to save on labor. There can be variation in maturity, and this

is reﬂ ected in the generally lower quality obtained. The curing process involves use

of heat from oil heaters followed by other steps of curing. There have been efforts to

improve the process, allowing beans to mature longer on the vine, but, the quality

from that region is still regarded as lower than that of Bourbon beans.

In almost every region, there are recommended methods of curing to obtain the

best quality beans possible. The ﬁ nal moisture level should be 20 – 30%. At a higher

moisture level, a surface fungus may appear if beans are kept in unhygienic conditions.

Occasional opening, wiping if needed, airing, and rewrapping may be required in such

situations.

One such process has been developed by McCormicks and Co. (British Patent

1 - 205 - 829, 1970). Beans are cut into 1 - cm pieces, killed and sweated in an oven at

60 ° C for 70 – 78 hours, air oven - dried at 60 ° C to a moisture level of 35 – 40%, and then

dried in ambient temperature with fanning to obtain a moisture level of 20 – 25%.

The cured beans are processed in three forms: whole pods, powder, and extract.

Whole beans are graded according to length. A

- grade is larger than 15 cm in length.

In fact, well - formed, straight beans of 16 – 17 cm are packaged individually and attrac-

tively, to be sold in retail at premium price. A - grade is 13 – 15 cm, B - grade 10 – 13 cm,

and C - grade smaller than 10 cm. Cut pieces are also sold. The powder form is obtained

after grinding, sometimes blended with sugar, starch, or another solid diluent.

Extraction is described later.

The above grading system is not universal since pods from different regions are of

different sizes. Madagascar beans will range from 16 to 18 cm on average, with some

up to 23 cm in length. Le Reunion beans are longer, while Comoros beans are shorter.

There is also a system of grading based on appearance. Uniformity in chocolate brown

color, absence of defects such as splitting, oily appearance, and delicate ﬂ avor are all

desirable attributes. Thinness, twisted shape, reddish color, splitting, excessive drying,

and poor aroma are all defects that lower the value. Beans from plants other than V.

planifolia are also rated lower.

Chemistry

During the curing process, many enzyme - based and chemical reactions take place,

resulting in the formation of ﬂ avor - giving compounds. The most important is vanillin,

which is 4 - hydroxy, 3 - methoxy benzaldehyde (Fig. 99.1 ). A minor but important

99 Vanilla 403

component is piperonal (heliotropis), which gives aroma. Besides vanillin, cured

beans contain ethyl vanillin, vanillic p - hydroxy benzoic acid, p - coumaric acid, and

some nonvolatile components such as sugars, waxes, ﬁ xed oil, and polyphenols. The

cured beans contain 20 – 30% moisture.

Extraction

Vanilla beans have very little essential oil, though what they do produce has very

attractive volatile aroma and ﬂ avor. These are sometimes concentrated in extract or

essence form. Excessive heat harms the delicate ﬂ avor, so ethyl alcohol and supercriti-

cal carbon dioxide are the only two suitable solvents. In the case of alcohol, the last

traces of solvent are not removed and thereby too much heating is avoided. Supercritical

carbon dioxide does not require heating to remove carbon dioxide.

Of the complex ﬂ avor mixture, vanillin is the predominant and most important

constituent. In addition, there are about 200 compounds present in minute quantities

that nevertheless contribute to the aroma and ﬂ avor. As deﬁ ned by the U.S. FDA, a

onefold concentrate of vanilla ﬂ avor is 13.35 ounces of bean to 1 gallon of alcohol

(1 ounce = 28 g; 1 U.S. gallon = 3.79 L). A twofold should contain 26.7 ounces, three-

fold 40.5 ounces, and fourfold 53.4 ounces to a gallon. To be labeled as an extract, the

vanilla ﬂ avor must contain 35% of alcohol by volume. Anything less will be labeled

as “ ﬂ avor. ” Since the purpose of alcohol is to keep ﬂ avor components in dispersion,

a concentration over twofold may require more than 35% alcohol. It may be noted

that alcohol strength will be lowered by the moisture contained in the cured beans.

The vanilla sold in retail is usually single - fold. The stronger ones are used for indus-

trial purposes where large batches of food products are to be ﬂ avored (Nielsen

undated ).

In the United States, blended natural and synthetic vanillas are available as vanilla –

vanillin blends. There is also vanilla ﬂ avor with other natural ﬂ avors (WONF), but it

is not clear whether FDA clearance is available for this.

A more practical extraction method is performed on cut, cured vanilla beans. Beans

are cut into pieces of 2.5 cm and soaked in 50% aqueous ethanol for 12 days at ambient

conditions. After decanting, extraction is performed a second time. Usually, 2 kg of

solvent is poured into 1 kg of pieces each time. The combined miscella is carefully

freed of solvent by vacuum distillation, keeping the temperature well below 70 ° C.

Vanilla bean extract comes with less than 5% ethanol and 20% moisture. This nearly

80% soluble solid extract is a viscous liquid, soluble in water. It has a dark brown,

chocolate color with ﬂ avor typical of vanillin, combined with a caramelized

rummy note.

Figure 99.1. Vanillin.

OCH

404 Individual Flavors and Colorants

Similar extraction using 95% absolute alcohol gives a two - layered product with

similar organoleptic characteristics, though slightly less viscous and oil - soluble.

The quality of the vanilla bean depends on more than just vanillin content; other

constituents present in the right amounts will increase the ﬂ avor appeal of the vanillin

present. Generally, the vanillin content of a good cured bean is 1 – 2% and, in rare

cases, even up to 3%. Other chemical components present are p - hydroxy benzalde-

hyde, acetic acid, isobutyric acid, caproic acid, eugenol, furfural, p - hydroxy benzyl

methyl ether, vanillyl ethyl ether, anisyl ethyl ether, and acetaldehyde (Leung and

Foster 1996 ).

Although vanillin in the beans greatly enhances the quality, its absence does not

change the basic vanilla character or render the beans worthless (Ranadive 2006 ). A

number of major, minor, and trace constituents play signiﬁ cant roles in imparting to

vanilla its characteristic aroma and ﬂ avor. The ﬂ avor characteristics of Chinese beans

have been studied by extraction with supercritical carbon dioxide followed by analysis

using GC - MS; about 30 compounds have been identiﬁ ed (Fu et al. 2002 ).

Analytical Methods

The vanillin content is determined by the AOAC method using HPLC. However, the

most important aspect of quality evaluation requires sensory evaluation of the organo-

leptic characteristics.

Uses

Ground, cured beans are used in various preparations such as confectionery, dairy

products, baked items, and beverages. In industrial uses for these items, extracts are

generally used. Its single important use is for ﬂ avoring ice cream; the most common

ﬂ avoring for ice cream and dairy products is vanilla extract. Many other ﬂ avor prepa-

rations invariably contain vanilla, such as chocolate, custard, caramel, and even coffee.

In some of such food products, the presence of vanilla is not recognized by consumers,

although it may be playing a signiﬁ cant role in overall acceptance. An attempt to add

a vanilla ﬂ avor to cola - based soft drinks did not meet with much success.

Identiﬁ cation Numbers

FEMA No. CAS US/CFR E - No.

Vanilla beans 3104 84650 - 63 - 5 182.10 –

Vanilla extract 3105 8024 - 06 - 4 182.20 –

Vanilla oleoresin 3106 84650 - 63 - 5 182.20 –

Vanilla absolute – 8024 - 06 - 4 – –

Vanillin (natural) 3107 121 - 33 - 5 182.60 –

References

Fu , Shiliang ; Huang , Maofang ; Zhou , Jiang ; and Li , Sidoug 2002 . Determination of chemical constituents

of vanilla by supercritical CO

ﬂ uid extraction . Huaxue Yanyiu Yu Yingyoung 14 ( 2 ), 208 – 210 (Chinese)

( Chem. Abstr. 138 :136026).

99 Vanilla 405

Leung , Albert Y. ; and Foster , Steven . 1996 . Encyclopedia of Common Natural Ingredients . New York : John

Wiley and Sons , pp. 510 – 511 .

Madhusoodanan , K.J. ; Radhakrishnan , V.V. ; and Sudharshan , M.R. 2003 . Vanilla, the Prince of Spices .

Cochin, India : Spices Board India , pp. 5 – 9 .

Nielsen , Chat Jr. Undated. The Story of Vanilla . Leeuwarden, the Netherlands : Nielsen - Massey Vanillas

International .

Ranadive , Aravind . 2006 . Chemistry and biochemistry of vanilla ﬂ avour . Perfumer Flavorist 31 ( 3 ),

38 – 44 .