Attokaran M. Natural Food Flavors and Colorants

Подождите немного. Документ загружается.

Introduction

Nutmeg is believed to be native to the Banda Island of modern Indonesia. Ancient

Romans used it as incense for burning. In those days, nutmeg was regarded as a costly

spice. In ancient England, there was a belief that nutmeg could ward off diseases, such

as the bubonic plague.

During the Middle Ages, Arab merchants sold nutmeg to the people of Italy as an

expensive luxury item. In the sixteenth century, after their great expeditions, Portugal

took control of the Indonesian nutmeg trade. A century or two later, the Dutch and

later the British controlled the trade of nutmeg.

Nutmeg has been mentioned in Indian Vedic literature, and has importance in

Ayurvedic therapy. Large - scale commercial cultivation was introduced by the British

toward the end of the nineteenth century.

Plant Material

The fruit grows on a lush evergreen tree with a height of 10 – 15 m. The leaves grow

into a lush round mass over 2 – 3 m, making the tree an attractive one. The tree is

unisexual, with separate male and female trees. Peach - like fruits with a thick rind are

borne only on the female tree. The kernel is the nutmeg of commerce, the outside of

which is a hard, thin shell. The kernel is slightly oblong with a diameter of 2 – 4 cm.

The dried aril, a yellow to red colored, soft, broken layer that surrounds the shell, is

mace, another spice (see Chapter 73 on mace). See Photo 23 .

A major producer of nutmeg is Indonesia. In the Americas, the traditional source

of nutmeg was the island of Granada. The nutmeg from that region is known as West

Indian, while that of Indonesia is called East Indian nutmeg. Today, Sri Lanka and

India are substantial producers, but the oil resembles that of West Indian nutmeg.

Dried nutmeg is generally high priced, though a popular grade of raw material for

the manufacture of extractives is called BWP (broken, wormy, and punky), which is

cheaper.

Chemistry

Nutmeg contains about 6% protein, 35% fat, nearly 50% carbohydrates, and 4%

crude ﬁ ber. It has mineral matter and some vitamins, including a small quantity of

vitamin A.

Nutmeg

Myristica fragrans H ( Myristicaceae )

307

Natural Food Flavors and Colorants Mathew Attokaran

Photo 23. (A) Nutmeg fruit on the tree. (B) Opened fruit showing nutmeg covered

with mace. (C) Nutmeg with mace over it. See color insert.

308

78 Nutmeg 309

The main fatty acid of the fat is myristic acid, a 14 - carbon saturated fatty acid.

About 75% of the triglycerides are trimyristin. Having plenty of saturated glycerides,

the fat of nutmeg is a semisolid product, which, because of its consistency, is popularly

called nutmeg butter.

The characteristic constituent of nutmeg essential oil is myristicine, or 3 - methoxy -

4,5 - methylendioxy - allyl benzene (Fig. 78.1 ).

Essential Oil

After size reduction to a coarse powder using a roller mill, nutmeg is packed in a

stainless steel vessel and steam is passed through the bottom. The yield of oil separated

from water on cooling is 6 – 12%. The quality of oil is measured according to the

content of the oxygenated heavy dicyclic terpene myristicine. While West Indian, Sri

Lankan, and Indian nutmeg yield an oil with about 2% myristicine, good Indonesian

oil has a much higher myristicine content, sometimes as much as 9 – 10%. In identical

conditions, shelled nutmeg gives an oil yield of 9.5% for Indonesian, 8% for Sri

Lankan, and 5 – 6% for Indian nutmeg.

Analysis of Indian, Sri Lankan, and Indonesian nutmeg oil has been carried out,

and the results are presented in Table 78.1 . Sabinene and pinenes are major compo-

nents but are not very signiﬁ cant.

Nutmeg oil is an almost colorless to pale yellow liquid with the characteristic spicy

and stimulating aroma of nutmeg.

In a study that compared West Indian nutmeg oil with East Indian, it was noted

that Jamaican oil shows lower quantities of phenyl propanoids, myristicine, and

safrole. In addition, three isomers of ocimene have also been noticed in Jamaican oil

(Simpson and Jackson 2002 ). Nutmeg oil from Nigeria shows 49.09% of sabinene,

13.19% of α - pinene, 6.72% α - phellandrene, and 6.43% of terpinen - 4 - ol (Ogunwande

et al. 2003 ). Or combining silica gel column separation with analysis, isovanillin is

found in nutmeg oil along with dehydro - diisoeugenol, myristicine, elimicine , and

some nonvolatile constituents (Li et al. 2006 ). In another recent investigation of the

oil obtained by solvent - free microwave extraction followed by GC - MS analysis, 42

components representing 98.62% of the oil were revealed. The main volatiles are

sabinene (23.93%), myristicine (11.06%), α - pinene (9.52%), β - pinene (8.95%)

4 - terpineol, limonene, elimicine, p - cymene, and safrole (Zheng et al. 2007 ). In a study

of the oils from nutmeg of East Indian, West Indian, and Papua origins, there are

similarities in the composition of volatiles. The aroma - dominating compound in East

Figure 78.1. Myristicine.

310 Individual Flavors and Colorants

Indian oil is myristicine, in West Indian oil elimicine, and in Papuan oil safrole (Ehlers

et al. 1998 ).

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

the characteristic odor and taste of nutmeg. Two types of oils, East Indian and West

Indian, are commercially available. It is soluble in alcohol.

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

East Indian type West Indian type

Optical rotation + 8 to + 30 ° + 25 to + 45 °

Refractive index 1.474 – 1.488 1.469 – 1.476 at 20 ° C

Speciﬁ c gravity 0.880 – 0.910 0.854 – 0.880

Solubility 1 mL in 3 mL 90% alcohol 1 mL in 4 mL 90% alcohol

Oleoresin

The deoiled nutmeg has 15 – 24% nutmeg butter, which is mainly trimyristin. It can

be extracted with hexane. Sri Lankan and Indonesian nutmeg plants give a higher

yield than Indian. On blending with oil, the oleoresin with appropriate volatile oil

content can be made. Generally, 30 – 40% oil content is preferred but any range

between 10% and 90% can be used.

Nutmeg oleoresin has a light yellow to reddish - brown color, the lighter color being

obtained if extracted from a shell - free nutmeg.

Uses

Oil and oleoresins are used in a wide range of meat preparations. They are also used

in baked goods, liqueurs, chewing gum, confectionery, and soups. A large amount of

oil is used in cola - based soft drinks.

Table 78.1. Composition of nutmeg oil from three origins

Constituent Nutmeg Oil (Area %)

Indonesian Sri Lankan Indian

α - Thujene 4 – 6 2 – 5 2 – 4

α - Pinene 14 – 17 12 – 16 13 – 17

Camphene 0.3 – 0.8 0.2 – 0.6 0.3 – 0.8

Sabinene + β - pinene 20 – 30 35 – 45 37 – 45

δ - 3 - Carene 1.5 – 3 2 – 4 2 – 4

Limonene 2 – 5 3 – 6 3 – 5

β - Phellandrene 3 – 5 2 – 4 4 – 6

p - Cymene 1.5 – 3 0.5 – 1.5 1 – 3

α - Terpinene 8 – 11 4 – 8 6 – 9

Terpinen - 4 - ol 6 – 10 5 – 8 5 – 8

Safrole 1 – 2 0.7 – 1.5 1.0 – 1.5

Geraniol < 0.5 < 0.5 < 0.5

Methyl eugenol 1 – 2 0.3 – 0.8 0.5 – 1

Myristicine 6 – 10 2 – 3 1.5 – 2.5

Elimicine 0.2 – 0.8 1 – 2 1.5 to 2.5

78 Nutmeg 311

Myristicine is an insecticide that can be described as naturally occurring in the

plant world. It has mild neurotoxic effect and is a monoamine oxidase inhibitor. There

is scope for future researchers to take advantage of the possible use.

In Ayurvedic therapy, nutmeg is believed to be a remedy for digestive disorders,

for dehydration caused by vomiting and diarrhea, and for colds and related disorders.

The oil and oleoresin can ﬁ nd use in modern medical compositions designed for the

above disorders.

Identiﬁ cation Numbers

FEMA No. CAS US/CFR E - No.

Nutmeg oil 2793 8008 - 45 - 5 182.20 –

84082 - 68 - 8

Nutmeg oleoresin (including CO

extract) – 84082 - 68 - 8 182.20 –

References

Ehlers , Dorothea ; Kirchhoff , Jolanta ; Gerard , Dieter ; and Quirin , Karl - Werner . 1998 . High performace

liquid chromatography analysis of nutmeg and mace oils produced by supercritical CO

extraction —

comparison with steam distilled oils — comparison of East Indian, West Indian and Papuan oils . Int. J.

Food Sci. Technol. 33 ( 3 ), 215 – 223 .

Li , Xiufang ; Wu , Lijun ; Jia , Tianzhu ; Yuan , Zimin ; and Gao , Huiguan . 2006 . Chemical constituents from

Myristica fragrans Houtt . Shenyang Yaoke Daxue Xuebao 23 ( 11 ), 698 – 701 , 734 (Chinese) ( Chem. Abstr.

147 :308487).

Ogunwande , I.A. ; Olawore , N.O. ; Adeleke , K.A. ; and Ekundayo , O. 2003 . Chemical composition of essen-

tial oil of Myristica fragrans Houtt (nutmeg) from Nigeria . J. Essent. Oil - Bearing Plants 6 ( 1 ),

21 – 26 .

Simpson , Gregory I.C. ; and Jackson , Yvette A. 2002 . Comparison of the chemical composition of East

Indian, Jamaican and other West Indian essential oils of Myristica fragrans Houtt . J. Essent. Oil Res.

14 ( 1 ), 6 – 9 .

Zheng , Fuping ; Sun , Baoguo ; Xie , Jianchun ; Liu , Yuping ; Du , Dandan . 2007 . Analysis of nutmeg oil by

GC - MS coupled with solvent - free focused microwave extraction . Shipin Kexue 28 ( 9 ), 484 – 487

(Chinese) ( Chem. Abstr. 150 :442068).

Introduction

Onions have a long history, as traces have been detected in settlements dating back

to 5000 BC. It is believed that the onion originated in West Asia. It is one of the oldest

cultivated crops. Cultivation may have taken place around 3000 BC, as evidence sug-

gests that in Egypt, workers who built the pyramids were fed with onions. Egyptians

worshipped it as a symbol of eternal life. In Greece, athletes consumed it to purify

the blood, and Roman gladiators rubbed it on their muscles to ﬁ rm them up. Doctors

were believed to have prescribed onions for a wide range of purposes such as to regu-

late bowel movement and male sexual performance as well as to relieve headaches,

coughs, snakebites, and even hair loss.

A wide range of foods use onion, which is both a spice and vegetable. Onion is

also noted for its ability to cause eye irritation. This drawback encourages develop-

ment of processed onion products, including extractives, for use as a ﬂ avor and for

seasoning. In fact, “ onion without tears ” was the marketing slogan of one of the

manufacturers of extractives.

Plant Material

Onion is a bulb (shown in Photo 24 ) of a biennial plant. Though it grows underground,

it is a shoot portion developed for storing food for the plant, and is not a root tuber.

Being widely used, there are several cultivars in different parts of the world suiting

the climatic conditions. Agricultural research has enabled the development of onions

of different sizes, with colors varying from white to red, and with different total solids.

Because of its widespread use as a vegetable and large - scale processing into dehy-

drated products, only countries that have a great surplus can afford to process it into

extractives. Because of the importance of texture quality, especially when onion is

used as a vegetable, extractives have a demand only for use as a pure ﬂ avor.

According to the Food and Agriculture Organization of the United Nations, China

produces nearly 10,000 tonnes and India 5500 tonnes of a total world annual produc-

tion of 64,101 tonnes. This is followed by the United States, Turkey, Pakistan, Russia,

South Korea, Japan, Egypt, and Spain.

Onion

Allium cepa L ( Alliaceae )

313

Natural Food Flavors and Colorants Mathew Attokaran

314 Individual Flavors and Colorants

Chemistry

Onion on dry basis has 70 – 75% carbohydrates and about 10% protein, minerals, and

some water - soluble vitamins, though these nutritional properties will not be relevant

when extractives are used.

The ﬂ avor of the onion has been studied in detail. The ﬂ avor precursors isolated

include methyl - propyl and propenyl derivatives of l - cysteine sulfoxide. From these,

thiosulfonates and thiosulﬁ nates are formed, which cause the odor when fresh onions

are cut or crushed. When onions are boiled, further decomposition results in the for-

mation of di - and trisulﬁ des. Dimethyl thiophenes are formed when the onion is fried.

The tear - producing constituent is believed to develop due to splitting of the precursor

S - propenyl sulfoxide; the unstable propenyl sulfenic acid may be the tear - producing

agent. This decomposes in 90 – 100 seconds to thiopropanal S - oxide and, subsequently,

into propanal.

The reactions leading to ﬂ avor and tear - producing agents have been studied by a

number of researchers. There are some useful reviews on the subject by Abraham et al.

(1976) and Arnault and Aunger ( 2006 ).

Essential Oil

The volatile oil content depends on the variety of onion used. Generally, the Indian

variety has a negligible oil content. In some varieties, oil forms on water distillation

Photo 24. Onion; cut pieces show structure. See color insert.

79 Onion 315

as a dark brown oil, which has a tendency to crystallize on standing. The yield is

0.01 – 0.02%. It is reported that oil is produced from some Chinese varieties. The main

constituents are n - propyl and methyl - n - propyl disulﬁ des. Because of the very low

yield and high cost, it may be more practical to use oleoresin.

According to the FCC, onion oil occurs as a clear, amber - yellow to amber - orange

liquid with a strong, pungent odor and a taste characteristic of onion. It is soluble in

most ﬁ xed oils, in mineral oil, and in alcohol. It is insoluble in glycerin and in pro-

pylene glycol.

Physical characteristics suggested by the FCC are as follows.

Refractive index 1.549 – 1.570 at 20 ° C

Speciﬁ c gravity 1.050 – 1.135

Oleoresin

The extract can concentrate to two items: the water - soluble constituents and fat -

soluble, nonpolar constituents. The former can be obtained by crushing the material,

mixing well with water, and decanting the water phase. This step can be repeated, but

to keep a strong ﬂ avor, it is better to keep to a maximum yield of 15%. The spent

residue can be extracted with a nonpolar solvent such as n - hexane. It may be necessary

to pump solvent from the bottom and take the miscella from the top for greater efﬁ -

ciency. The combined miscella is freed of solvent and this can be added to the water -

soluble part to yield a “ green ” or fresh onion oleoresin, which is water - soluble.

Alternatively, hexane extraction can be carried out as the initial step, followed by

water extraction. If oil - soluble oleoresin is required, the hexane extractable can be

diluted with ﬁ xed oil or mono - and diglyceride along with diluents such as propylene

glycol to reduce the strength and unit cost. It may be noted that on boiling, the ﬂ avor

may lose its freshness and hence boiling with water is not desirable.

On roasting, onion gives a very appealing ﬂ avor. The above process can be carried

our after roasting cut onion pieces at 100 – 120 ° C for up to 15 minutes. Here, also,

water - soluble and oil - soluble oleoresins can be made as in the case of “ green ” oleo-

resin. The strength depends on the dilution. The ﬂ avor is contributed by the breakdown

of sulfur - containing compounds of onion ﬂ avor and volatile oil including simple

organic sulﬁ des.

In recent years, some interesting research has been carried out on onion volatile

components. Thiopropanal S - oxide, the lachrymatory (tear - producing) factor, has been

analyzed in fresh onion juice, and thiosulﬁ nates and zwiebelanes have been quantiﬁ ed.

Frozen and freeze - dried onions, on the other hand, lose the lachrymatory factor but,

on analysis, are similar in other components (Mondy et al. 2002 ). From freeze - dried

onion, volatiles obtained by steam distillation extraction followed by extraction with

dichloromethane yield 24 sulfur - containing compounds representing 36.87% of total

volatile chemical (Takahashi and Shibamoto 2008 ). These volatiles, as well as the

aqueous fractions in the distillate, show anti - inﬂ ammatory activity. Quercetin and its

glycosides represent the ﬂ avonols in onion (Lombard et al. 2002 ; Zielinska et al.

2008 ).