Attokaran M. Natural Food Flavors and Colorants

Подождите немного. Документ загружается.

196 Individual Flavors and Colorants

ground dry seeds are packed in a stainless steel distillation unit. Steam, at normal

pressure, is passed through the bed where a mixture of oil vapor and water vapor will

be formed. On cooling in a water - cooled condenser, this condenses as an immiscible

mixture of fennel oil and water. This is separated in a Florentine ﬂ ask separator for

lighter - than - water oils. The oil ﬂ oats on top. The escaping water is passed through

twice more for separation to ensure that the entire quantity of oil is recovered. The

usual distillation time is 18 hours.

The oil tends to be colorless or pale yellow. The major constituents of the oil are

anethole (Fig. 7.1 ) and fenchone. Depending on the variety of fennel, there are sweet

fennel oils (a special variety being “ dulce ” ) and bitter fennel oils. The Indian variety

is the latter and has an anethole content of 68 – 72% and fenchone content of 5 – 6%.

Sweet oils from European sources are produced in very small quantities and

are sometimes considered superior in aroma. Such oils have 85 – 90% anethole and

very little fenchone. d - Phellandrene and d - limonene are also present in smaller

amounts.

Anethole is 1 - methoxy - 4 - prop - 1 - enyl benzene. It has a double bond and, therefore,

has geometric isomers. The more commonly found and natural isomer is trans -

Photo 14. Fennel seeds. See color insert.

49 Fennel 197

anethole. It is soluble in ethyl alcohol and only slightly soluble in water. The clear

colorless trans - anethole has a boiling point of 234 ° C and a condensation point of

20 ° C. Fenchone is a 10 - carbon cyclic monoterpene with a keto group. It is a colorless

oily liquid with camphoraceous odor.

Spanish fennel seed essential oil shows methyl chavicol and fenchone. The leaves

also contain methyl chavicol, α - phellandrene, limonene, and fenchone, while the

stem has anethole, α - pinene, α - phellandrene, p - cymene, limonene, and fenchone

(Garcia - Jimenez et al. 2000 ). In a Chinese study, trans - anethole represents 65 – 78%

of the volatile oil (Wu et al. 2001 ). In an investigation in Iran, hydrodistillation

using a Clevenger trap yielded 2% oil, while open steam distillation yielded only 1.2%.

Anethole is the major component (Ashnagar et al. 2007 ). Chemical examination

of fennel cultivated in different climatic conditions in Israel by hexane extraction

and GC - MS examination reveals as many as 18 compounds, with estragole, trans -

anethole, fenchone, limonene, and α - pinene as the main constituents (Barazani et al.

1999 ).

Extraction of fennel waste shows nonvolatile compounds having antioxidant activ-

ity, one of them being rosmarinic acid. The strong radical scavenging activity of these

may explain the pharmacological effects of fennel (Perajo et al. 2004 ).

As per the FCC, fennel oil is a colorless or pale yellow liquid with the characteristic

odor and taste of fennel. If solid material separates, the sample should be carefully

warmed until it is completely liqueﬁ ed and should be mixed before using.

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

Optical rotation + 12 to + 24 °

Refractive index 1.532 – 1.543 at 20 ° C

Speciﬁ c gravity 0.953 – 0.973

Solubility in alcohol 1 vol dissolves in 1 vol 90% alcohol

Oleoresin

When coarsely ground seeds are extracted using hexane, oleoresin is obtained.

Ethylene dichloride, ethyl acetate, and a mixture of acetone and hexane can also be

used for extraction, with slightly varying quality. The main ﬂ avor characteristic will

be contributed by the essential oil. The oleoresin will have all the ﬁ xed oil and resin-

ous matter. These will act as a ﬁ xative and therefore the product will have a more

toned ﬂ avor.

Uses

Fennel extractives have a pleasant, spicy aroma and are useful in ﬂ avoring foods such

as meat, soup, sauces, and bakery products. They also have some medicinal value,

especially as a digestive. Fennel helps to increase digestive juices and has diuretic and

mild antiseptic properties. Use of fennel oil in chewing gum is recommended to take

advantage of its mouth - freshening properties.

198 Individual Flavors and Colorants

Identiﬁ cation Numbers

FEMA No. CAS US/CFR E - No.

Fennel oil 2483 8006 - 84 - 6 182.20 –

84455 - 29 - 8

Fennel extract/oleoresin – 92623 - 75 - 1 – –

Fenchone 2479 4695 - 62 - 9 172.515 –

References

Ashnagar , A. ; Naseri , N. Gharib ; and Davarian , S.K. 2007 . Isolation and identiﬁ cation of the major chemical

compounds found in fennel seeds ( Foeniculum vulgare ) grown in Mamesani (Fars Province), Iran . Int.

J. Chem. Sci. 5 ( 2 ), 537 – 541 .

Barazani , Oz ; Fait , Aaron ; Cohen , Yael ; Diminshtein , Soﬁ a ; Ravid , Uzi ; Putievsky , Eli ; Lewinsohn , Efraim ;

and Friedman , Jacob . 1999 . Chemical variation among indigenous populations of Foeniculum vulgare

in Israel . Planta Med. 65 ( 5 ), 486 – 469 .

Garcia - Jimenez , Noemi ; Perez - Alonso , Maria Jose ; and Velasco - Negueruela , Arturo . 2000 . Chemical com-

position of fennel oil, Foeniculum vulgare Miller from Spain . J. Essent. Oil Res. 12 ( 2 ), 159 – 162 .

Perajo , Irene ; Viladomat , Francesc ; Bastida , Jaume ; Schmeda - Hirschmann , Guillermo ; Burillo , Jesus ; and

Codina , Carles . 2004 . Bioguided isolation and identiﬁ cation of the nonvolatile antioxidant compounds

from fennel ( Foeniculum vulgare Mill) waste . J. Agric. Food Chem. 52 ( 7 ), 1890 – 1897 .

Wu , Meihan ; Nie , Lingyun ; Liu , Yun ; Zhang , Lei ; and Wei , Liping . 2001 . Study on chemical components

of essential oil in Foeniculum vulgare from different areas by GC - MS . Yaowu Fenxi Zazhi 21 ( 6 ),

415 – 418 (Chinese) ( Chem. Abstr. 137:145162).

Introduction

Fenugreek has been used in food and for medicinal purposes for a long time. It is

bitter, but its aroma develops on roasting.

Fenugreek, from feonum - graecum , is probably derived from the Latin word for

Greek hay. It has a long history, having been recovered from the tomb of Tutankhamen.

It was most likely used for embalming. In Iraq, charred seeds have been radiocarbon

dated back to 4000 BC. There are records of fenugreek in some ancient recipes. In

olden times, it was believed to be a hair tonic and a cure for baldness. It is believed

to give sexy bosoms for harem women.

Plant Material

The fenugreek plant grows to a height of 30 – 60 cm. It has light green leaves, which

are eaten as leafy salad greens in some regions and are cooked as a vegetable in some

parts of India.

The fenugreek seed, however, is valued as a spice. The seed is contained in slender,

beaked pods generally 10 – 15 cm long. The smooth, hard seeds, shaped like a tiny,

irregular brick, are about 3 mm in length. A pod contains, on an average, about 15

brownish - yellow seeds. On roasting, the color turns darker due to caramelization. The

interaction of proteins and carbohydrates initiates a Maillard reaction. The thermal

reaction between sugar and amino acids in many plant products produces volatile

compounds such as pyrazines and lactones. An appropriate level of roasting gives the

correct intensity of aroma and ﬂ avor.

Fenugreek seeds are rich in protein (9 – 10%), carbohydrates (40 – 45%), and ﬁ xed

oil (7 – 10%). They contain calcium, iron, phosphorus, and vitamins. The ground seed

is made into a bread in Ethiopia and other North African countries and into chappati

in India. In a recent study of Chinese fenugreek, crude protein is found in levels of

54.06% and polysaccharide of 8.72% (Yang et al. 2003 ).

Fenugreek seeds contain saponins such as diosgenin, yamogenin, and other related

compounds. Recently, two new compounds have been identiﬁ ed: methyl protodiocin

and methyl protodeltonin (Yang et al. 2005 ). It also has alkaloids such as choline and

trigonelline. Being rich in galactomannan, seeds are galactagogue and are therefore

used by lactating women to increase milk production. Extracts are also marketed as

testosterone - or muscle - boosting supplements. In the past, Eastern women have been

Fenugreek

Trigonella foenum - graecum L ( Leguminosae )

199

Natural Food Flavors and Colorants Mathew Attokaran

200 Individual Flavors and Colorants

known to use fenugreek seeds to give a boost to their busts. Efforts to debitter in order

to add to wheat ﬂ our at low levels of 1.5 – 9% shows that the protein level can be

increased only at the cost of levels of gluten and carbohydrate (Sharma and Chauhan

2000 ).

The seeds are used in the Islamic world as a cream, in tea, and in candies. It is a

Jewish custom to eat seeds just after the New Year. In the United States, fenugreek

extract is used to ﬂ avor artiﬁ cial maple syrup.

Experiments done with fenugreek seeds in both insulin - dependent and nondepen-

dent diabetic patients show their usefulness in lowering blood glucose levels. Similarly,

fenugreek seed has been known to lower serum triglyceride and low - density lipopro-

tein. However, more reliable experimental data are required.

Fenugreek seeds have a negligible amount of essential oil. The ﬂ avor develops due

to thermally affected compounds, and hence the major extractive is extract of roasted

seeds.

Oleoresin

Roasting of fenugreek seeds is carried out at different intensities. When roasted at

around 120 ° C for 10 – 20 minutes, they give an intense roasted aroma and ﬂ avor. Seeds

can then be powdered by a roller mill and extracted with methanol or ethanol. The

product may be very thick, so that it must be diluted with propylene glycol while still

warm. This aims to give sufﬁ cient ﬂ ow characteristics so that the product can be

withdrawn from the bottom opening and handled during blending with other ingredi-

ents. In Indian curry formulations, an intense ﬂ avor is desired.

A milder roasting can be done at 80 ° C for 10 – 15 minutes, and extraction can be

carried out with 80% aqueous ethanol. During desolventization, all the ethanol is

removed, which leaves small traces of moisture. This will make the product water -

dispersible even without use of propylene glycol. In Western formulations, a less

intense roasted ﬂ avor is preferred.

Although use of methanol will give a satisfactory result, use of a potable solvent

such as ethanol is needed, especially since the ﬂ avor is added at a very high level in

products such as artiﬁ cial maple syrup, which may be used in great quantities, espe-

cially by children. For the same reason, avoidance of propylene glycol and emulsiﬁ ers

is preferable.

A more satisfactory method of making extract is by performing extraction ﬁ rst and

then roasting. Fenugreek seed is ground by passing through roller mill. The seed is

then extracted using aqueous ethyl alcohol 50 – 60%. A second and, if needed, third

extraction can be carried out. The combined extract is then freed of all alcohol, leaving

a small amount of water. For this, the miscella is distilled by gentle boiling with slow

stirring so that no mechanical carryover of extract takes place. The product will be

soluble in water. The extract is then roasted at 110 – 120 ° C for 8 – 10 hours to develop

the desired roasted note. Moderate pressure of above 1 bar is needed in closed systems

to get the above temperature. Great skill and knowledge of the ﬂ avor are required to

obtain the product used as a ﬂ avor for artiﬁ cial maple syrup. Excess temperature or

roasting time will result in a burned note instead of the required roasted note. There

are minor differences in the ﬂ avor developed by different manufacturers. Generally,

50 Fenugreek 201

the roasted extract is used at a level of about 10% in corn syrup with 10 – 15% com-

mercial liquid caramel product added to adjust to the optimum shade and ﬂ avor.

Another extract that is expensive and used in very low levels is fenugreek absolute.

Originally, this was extracted with alcohol, but could also be an alcohol - soluble frac-

tion separated from a regular oleoresin. The level of roasting depends on the aroma

requirements for the speciﬁ c use. Chilling and removal of waxes is carried out to

develop a perfect absolute, almost like a ﬂ oral absolute. Different absolutes prepared

to the exact aroma characteristics required for each manufacturer are very expensive

and unique. Absolute ﬁ nds use in high - priced cigarettes, special perfumes, and rare

beverages.

Uses

The greatest use for fenugreek extract and oleoresin is for ﬂ avoring artiﬁ cial maple

syrup, which is very popular in the United States and Canada. Roasted fenugreek

extract has a strong, curry - like ﬂ avor and therefore can be used in a wide range of

savory cooked products. The extract of unroasted seeds mainly contains ﬁ xed oil with

a celery - like odor and is extremely tenacious, and therefore has attracted the attention

of fragrance experts. Fenugreek extract is also used in tobacco ﬂ avoring.

Identiﬁ cation Numbers

FEMA No. CAS US/CFR E - No.

Fenugreek extract 2485 84625 - 40 - 1 182.20 –

Fenugreek oleoresin 2486 84625 - 40 - 1 182.20 –

Fenugreek absolute 2486 84625 - 40 - 1 182.20 –

References

Sharma , H.R. ; and Chauhan , G.S. 2000 . Physico - chemical and rheological quality characteristics of fenu-

greek ( Trigonella foenum - graecum L) supplemented wheat ﬂ our . J. Food Sci. Technol. 37 ( 1 ), 87 – 94 .

Yang , Yong - Li ; Sun , Shuang - yan ; Cui , De - feng ; Zhang , Yu - Lan ; Yao , Jian ; and Zhang , Ji . 2003 . Study on

physical and chemical contents in seeds of Trigonella foenum - gracum L . Xibei Shifan Daxue Xuebao,

Ziran Kexueban 39 ( 1 ), 64 – 65 , 73 ( Chem. Abstr. 138:317522 ).

Yang , Weixing ; Huang , Hongyu ; Wang , Yongjiang ; Jia , Zhiyan ; and Li , Linlin . 2005 . Study on chemical

constituents in total saponins from Trigonella foenum - graecum . Zhongguo Zhongyao Zazhi 30 ( 18 ),

1428 – 1430 (Chinese) ( Chem. Abstr. 147:296080).

Introduction

Greater galangal (also called galanga) is native to Java and Malaysia and is therefore

referred to as “ Java galangal. ” It is also called “ blue ginger ” or Thai galangal as it is

a spice used in Indonesian and Thai cooking. There are some galangal roots belonging

to the ginger family, and collectively they are sometimes referred to as false ginger.

In early records, some references may apply equally to greater galangal and lesser

galangal. The earliest reference is by the Arabian geographer Ibn Khurdabah in the

ninth century AD. He included galangal in the list of products from a country, Sila,

believed to be China (Pruthi 1976 ). A few years later, Plutarch described galangal as

a fumigating spice used by Egyptians. It was also mentioned by Edrisi as a spice

imported from Aden, probably for use in Egypt. Marco Polo also referred to the pro-

duction of galangal in China.

Plant Material

The greater galangal plant, which grows from a rhizome, consists of stiff stalks with

a large number of long leaves. The plant grows to a height of 3 – 3.5 m. The leaves are

green in color and are lanceolate, elongated elliptically with pointed ends. The plant

bears red fruits and small, greenish - white ﬂ owers. The fruits have an aroma reminis-

cent of cardamom and are used in traditional Chinese medicines.

The rhizome has the ﬂ avor and is the source of oil. The rhizome is much harder

than normal ginger and its separation requires cutting with a heavy knife. It is easier

to slice when fresh; after drying, even greater effort is needed for slicing. The creamy

white inside has a ﬂ avor that slightly resembles pepper and pine with an underlying

camphoraceous note. It is generally deskinned by scraping. The slices are preserved

in brine or dried. Galangal is heavily used in the cooking of Thailand, Indonesia,

Malaysia, and, to a limited extent, in Caribbean culinary practices. See Photo 15 .

Early studies show that greater galangal has methyl cinnamate, cineole, camphor,

and dipentene. It has ﬂ avonoids such as quercetin and condensed products from poly-

phenols. In the rhizome from Malaysia, 40 components have been identiﬁ ed, repre-

senting 83 – 93% of the oil. These include chavicol and chavicol acetate, in addition

to eugenol, eugenol acetate, monoterpenes, alcohols, esters, and sesquiterpenes (De

Pooter et al. 1985 ). In recent years, l ′ - acetoxy chavicol acetate has been reported; this

has cosmetic qualities for use in skin care. This is also believed to be the reason for

the traditional use of greater galangal as a treatment of pityriasis versicolor and other

Galangal: Greater

Alpinia galanga (L) Willd ( Zingiberaceae )

203

Natural Food Flavors and Colorants Mathew Attokaran

204 Individual Flavors and Colorants

diseases (Nguyen and Huynh 2005 ). Greater galangal has vitamins A and C and miner-

als such as sodium and iron. The nonvolatile constituents give it anti - inﬂ ammatory

and antioxidant properties. l ′ - Acetoxy chavicol acetate has recently been studied with

reference to its clinical signiﬁ cance (Zhuo and Li 2007 ).

A recent review (Wang and Wang 2008 ) has shown that the major components of

Alpinia plants include diarylheptanoids, terpene, ﬂ avone, volatile oil, phenyl pro-

panoid, and steroids.

Essential Oil

After drying, size reduction, and steam distillation, greater galangal yields a volatile

oil. In commercial manufacture, full yield of 2.5% is obtained after steam distillation

for about 16 hours.

The oil is a light yellow mobile liquid with the mildly pungent, earthy, and cam-

phoraceous aroma typical of the rhizome. The physical characteristics obtained in the

author ’ s lab based on commercial production are as follows.

Optical rotation + 4 to − 12 ° at 25 ° C

Refractive index 1.4620 – 1.4690

Speciﬁ c gravity 0.8500 – 0.8750

Photo 15. Cut pieces of greater galanga. See color insert.

51 Galangal: Greater 205

An extensive study of the volatile oils obtained from different parts of the plant

has been carried out by Menon in 2006 . The oil from the rhizome contains carotol

(26.7%), 1,8 - cineole (30.3%), β - pinene (6.5%), camphor (5%), and fenchyl acetate

(7.2%). The root oil is shown to have fenchyl acetate (30.5%), along with 1,8 - cineole

and limonene. The major constituents of the leaf oil are fenchyl acetate (20.7%) and

β - caryophyllene (40.5%), while that of stem oil is cubenol (28.4%).

Based on commercial production, results of the analysis of the oil are presented in

Table 51.1 . Caratol is the major component followed by cineole.

The oleoresin can be obtained from dry material which has been size - reduced by

roller mill and extracted using hexane. The yield obtained is 1.8 – 2%. The oleoresin

shows a volatile oil content of around 12%.

Uses

Greater galangal rhizome is a frequently used seasoning in Southeast Asian cooking.

In processed foods, the oil and oleoresin are quite useful because of standardization

of the ﬂ avor strength. When particles of rhizome are used, they can be a source of

contamination. Such problems can be avoided if extractives are used.

The extract, which contains acetoxy chavicol acetate, can be used in medicinal and

cosmetic preparations.

Identiﬁ cation Numbers

FEMA No. CAS US/CFR E - No.

Alpinia species root oil 2500 8024 - 40 - 6 182.20 –

Alpinia species root extract 2499 8024 - 40 - 6 182.20 –

References

De Pooter , Herman L. ; Muhammad , Nor ; Omar , Coolsaet ; Brigitte , A. ; and Schamp , Niceas M. 1985 . The

essential oils of greater galangal ( Alpinia galanga ) from Malaysia . Phytochemistry 24 ( 1 ), 93 – 96 .

Menon , N.A. 2006 . Chemical composition of the volatile oils of Alpinia galanga plant parts from Kerala .

J. Essent. Oil - Bearing Plants 9 ( 3 ), 277 – 282 .

Nguyen , Dinh Nga ; and Huynh , To Quyen . 2005 . Determination of chemical structure of Pityrosporum

orbiculare antifungal agent from Alpinia galanga Swartz from Vietnam . Tap Chi Duoc Hoc 45 ( 4 ),

17 – 21 (Vietnamese) ( Chem. Abstr. 144:428869).

Pruthi , J.S. 1976 . Spices and Condiments . New Delhi : National Book Trust , pp. 123 – 125 .

Table 51.1. Analysis of java galangal oil

Constituent Content (%)

α - Pinene 1 – 2

1,8 - Cineole 22 – 28

Eugenol 2 – 3

Caratol 30 – 40