There are many plant products that are used as natural fl avors especially in cookery. Some of them make excellent savory fl avors in soups, snacks, dressings, and in ready - made seasonings, provided they are made into usable extractives .

Allied Spices

Some of the major spices have close cousins that have special fl avors. Thus, ginger has related products such as the different types of galangals (Chapters 51 – 53 ), and black pepper has long pepper (Chapter 71 ).

Allium species have many members that are utilized in culinary practices. Two well - exploited Allium products are garlic and onion, presented in Chapters 55 and 79 , respectively. A recent study on the effect of different heat treatments generally used in cooking treatments on various Allium products showed interesting changes to their volatile and nonvolatile constituents (Kramer et al. 2006 ).

Shallot , Allium oschaninii , originated in Asia and through India it spread to the Mediterranean region. Many people believe that it originated in an ancient city of Ashkelon, in the geographical territory of the present Israel. In taste, it resembles onion but with slightly more sweetness and a milder fl avor. It has the some tear - producing quality when cut. Shallots are much smaller than onions (see Photo 30 ).

Shallots are widely used in the cooking of Southeast Asian countries and in South Asia. Two popular dishes of South India where shallot plays a prime role are sambar and rasam. It is also used in pickles. However, because of poor marketing, shallots are relatively expensive in Europe and in the United States.

Research studies on the shallot are very few. Its tear - producing property is generally assumed to be similar to that of the onion, but there could be subtle differences. It is reported to contain polyphenols of the fl avonoid type.

Unlike the onion, shallot does not contribute to the texture of food and its fl avor is more delicate. Many people prefer shallot to onion in omelettes mainly because they can enjoy the special fl avor without biting into thick pieces. All of these facts point to the possible success of an extract suitably made, which can serve as a unique and welcome fl avor in many foods.

Scallion , Allium wakegi , is known by many names such as spring onion, salad onion, and green onion. Scallion is similar to shallot in fl avor but with subtle changes. It does not have a fully developed bulb like other Allium products, but has a white,

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Natural Food Flavors and Colorants Mathew Attokaran

© 2011 Blackwell Publishing Ltd. and Institute of Food Technologists. ISBN: 978-0-813-82110-8

410 Future Needs

tender, swollen lower end with a green, hollow, upper portion. They have a pungent taste but are milder than onions. They are used either cooked or eaten raw, and used in soups, noodles, and seafood preparations.

Chives , Allium schoenoprasum , are perhaps the smallest member of the Allium species. They are grown in North America, Europe, and Asia. Chives are unique in that they are a plant that has thrived in both the New and Old Worlds. It is an herba-ceous perennial plant with a well - formed but small bulb, 2 – 3 cm long and about 1 cm wide.

Chives are available fresh throughout the year and hence are popular in European cuisines. They can also be dry frozen without much effect on the taste. Like garlic, chive has many sulfur - containing fl avoring compounds and is believed to have some medicinal properties. It is rich in vitamins A and C and contains minerals such as iron and calcium. Although chives have been cultivated in Europe from ancient times, chemical studies on the plant are rather limited. There is reason to take up scientifi c studies so that a well - standardized extractive is available for use in processed foods.

Garlic chives , Allium tuberosum , are also known as Chinese chives or Chinese leeks. The wild ones are classifi ed as Allium ramosum . They have become acceptable

Photo 30. Shallot. See color insert.

100 Opportunities in Natural Flavors 411

in the English - speaking world, but have been popular in China and other Asian coun-tries for quite some time. The plant has strap - like leaves, straight, thin, tall fl ower stalks, and attractive white fl owers. Both stalks and leaves are used in stir - fried foods in China, Japan, and Korea. It is a popular spice for dumplings with eggs, meat, or seafood. Garlic chives are commonly used to make a type of pancake. The fl avor has a typical chive taste but with a distinct garlic note. Like other Allium cooking ingre-dients, garlic chives may also play an important role if extractives are made available for processed food industry.

Leek , Allium ampeloprasum , also referred to as Allium porrum , is another member of the onion family. The edible part is the white onion - like bulb and the light green stalk, which is primarily the lower portion of the leaf sheaths. The dark green upper portion is not used.

The leek is known to have been in ancient Egypt and was a favorite food of the Roman Emperor Nero. The leek is the national emblem of Wales and Shakespeare refers to the custom of wearing a leek as an ancient tradition in Henry V.

Leeks can be boiled or fried and gives excellent taste to soups. It is also used raw in salads. While its texture is important, development of a leek extract for use as a natural fl avor is worth a try, especially using parts of the plant that are not used in cookery.

The bell pepper is the same genus and species, namely, Capsicum annuum , as hot chili or paprika. It is valued as a vegetable but has a unique and attractive fl avor. In fact, production of synthetic bell pepper fl avor has been attempted, though the natural fl avor is well worth the trouble. Efforts should be made to use wastage and unused parts of the plant product. It produces very low amounts of capsaicin.

The bell pepper is native to Mexico, Central America, and northern parts of South America. The seeds are believed to have been carried to Europe in 1493, and later spread to Asia and Africa as a very tasty vegetable with mild hotness. Because of its bell shape, it was called bell pepper, though it is sometimes referred to as sweet pepper. In India, it is very common to call the bell pepper “ capsicum, ” while in Indonesia it is referred to as “ paprika. ” It is generally used in culinary practices as a green mature fruit before ripening. On ripening, bell pepper may assume a yellow to red color.

On a wet basis, the fruit has 4.64% carbohydrate, 2.40% sugars, 1.7% dietary fi ber, 0.17% fat, and 0.86% protein. It has a wide range of vitamins belonging to the B group, ascorbic acid, and a number of minerals. On ripening, it is a rich source of carotenes and lycopenes, all valued as nutraceuticals.

Turmeric also has closely related spices whose fl avor is enjoyed regionally (Govindarajan 1980 ). Some of them are as follows.

Curcuma aromatica grows in most parts of India. Generally, it is cultivated where its more valuable cousin turmeric proper ( Curcuma longa ) (see Chapter 98 ) is grown. More than just a spice, it has value in cosmetics. A small but steady production of the essential oil is made in South India.

C. aromatica is a perennial tuberous herb with an aromatic yellow rhizome. The rhizome looks like that of turmeric but is darker with an olive - green tint. The fi ngers are longer and thinner. The oil has a pale yellow color with an odor that is quite dif-ferent from that of turmeric. The yellow shade is due to curcumin, which turns into a volatile fraction during steam distillation.

412 Future Needs

Temoe lawak , Curcuma xanthorrhiza R, is similar to turmeric and is popular in Indonesia. The rhizome is mostly valued for its medicinal properties. The rhizome has a very high content of 7 – 11% v/w of essential oil. It is closely related to Curcuma domestica oil. The oil has camphor, p - tolyl methyl carbinol, and a large percentage of myrcene.

Zedoary , Curcuma zedoaria R, is cultivated for its starch and its typical aroma. Rhizome and oil are highly aromatic with a gingery, camphory, bitter note. However, its use is restricted to only a few regions.

Mango ginger , Curcuma amada R, is a root crop that is more commonly utilized than the others described above. It has a distinct mango fl avor and is therefore used in pickling. It also has limited medicinal use.

Analysis shows the presence of hydrocarbons, α - pinene, ocimene, and curcumins. Linalool, camphor, cuminyl alcohol, turmarone, and some ketoalcohol have also been reported.

The extractive of mango ginger has an appealing fl avor. It has a sweet, bitter, and cooling note with an aroma combining green mango, turmeric, and ginger. The essen-tial oil and oleoresin need more detailed analysis, as they have the potential to be utilized as a natural fl avor .

Masticatory Products

There are some plant products that have become quite popular as a masticatory in different parts of the world. These materials have been able to earn sustained interest mainly because of something special in their fl avor. Two such products patronized by local people in South America and Africa are coca leaves (see Chapter 38 ) and kola nuts (see Chapter 65 ). How these became wildly popular through a world - renowned soft drink is one of food technology ’ s major success stories of modern times.

Arecanut , Areca catechu , is the kernel of a palm tree. Also called betel nut, are-canut is an extremely popular masticatory in India and other Asian countries. The fact that a vast industry has developed around this crop speaks volumes on its popularity. The kernel, often referred to as a nut, is surrounded by a husk and therefore externally resembles a miniature coconut. The size of the nut with husk is 5 – 8 cm in length and 3 – 6 cm in diameter.

The chemistry of the arecanut has been well studied. When ripe, it has 7 – 35% polyphenols on dry basis, which give the nut its welcome astringent taste. At an immature stage, the polyphenol level is much higher, going up to 50%. Both ( + )cat-echin and ( − )epicatechin have been identifi ed, but the main polyphenol is leucocyani-din, much of which is present as condensed polymeric tannin. Traces of leucopelargonidin also have been reported (Mathew et al. 1969 ).

The nut also contains an alkaloid, arecolin, present to an extent of 0.1 – 0.9%. There are also some allied alkaloids at much smaller levels. Research on the chemistry of the arecanut has been limited, although, Wang et al. (1999) published a paper on its catechin content.

There have been reports that chewing the arecanut brings about oral cancer. However, many consumers chew arecanut along with unrefi ned tobacco. Usually, the chew mix also contains a bit of slaked lime. The carcinogenic property is more likely

100 Opportunities in Natural Flavors 413

due to the presence of tobacco and slaked lime. It is believed that an extract of are-canut, mostly made of leucocyanidin derivatives, is as harmless as tea extract.

The catechins of tea, which are fl avan - 3 - ols, are now considered to be an excellent antioxidant. It is quite possible that the fl avan - 3,4 - diols of arecanut are an equally effective antioxidant. The low level of arecoline makes it unlikely to be a harmful chemical. Like most other alkaloids present in foods used as stimulants, it acts on the nervous system, but consumers (especially of earlier generations) love the fi ne astrin-gent fl avor.

In recent years, the popularity of chewing arecanut has decreased, as the younger generation considers the habit to be unfashionable. Despite this trend, processors produce more sophisticated products by blending dry spices and pieces of dessert nuts, and the interest in India is being sustained to some extent.

Katha , Acacia catechu , is used in India as a masticatory, generally with the chewing mix containing arecanut and betel leaf. Acacia catechu is a moderate - sized deciduous tree, 9 – 12 m in height. Gummy exudate from the wood is brown in color with a brittle, crystal - like structure.

The extract has polyphenols and a good astringent taste. One of the main properties of a polyphenol - rich masticatory is its ability to counter a feeling of nausea; this property is also valuable in a fl avor mix.

Betel leaf , Piper betle , is a climber like black pepper. The fresh leaf is highly valued for its fi ne herbal aroma, contributed by the essential oil it contains. It is rich in phenol - based terpenes, which give the oil a medicinal note. It contains chavibetol, chavicol, estragole, eugenol, and hydroxy catechol. The volatile oil content of a fresh leaf is 0.12 – 0.14% (Sharma et al. 1987 ).

One of the main effects of chewing arecanut and betel leaf is that secretion of saliva is activated. This is a point to be noted for fl avor formulation, especially those repre-senting savory fl avor.

Others

Sarsaparilla , Smilax offi cinalis , is the root of a plant grown in different parts of the world, especially in the Americas. The name probably comes from the Spanish word zarga for “ shrub ” and parilla for “ little grape wine. ” The dried root is used in soft drinks as a fl avor, of which root beer and Sioux City sarsaparilla are two examples. It is also made into sweetened drinks in Taiwan, India, and other countries.

There are related plants such as Aralia nudicaulis and Aralia racemosa that are used as substitutes. The European medical world considers sarsaparilla to be a tonic, diuretic, sweating agent, and blood purifi er. However, although it has so much poten-tial, sarsaparilla has not emerged as a fl avor usable in different kinds of food, espe-cially as a standardized extract.

Many fl avor notes are produced by steps that commonly occur in everyday life. Malting brings about the subtle fl avor caused by the biochemical changes that occur during germination of grains. On roasting, fl avor improves in the case of dessert nuts and spices. Poppy seed and roasted sesame seed, for example, can yield a good fl avor extract. Dried green mango, known as Amchoor , is used in northern parts of India as a popular souring agent. If the product is well standardized or, even better, if a

414 Future Needs

concentrate of water or aqueous alcoholic extract is made, it has the potential to be promoted as a natural fl avor. Another example is horseradish, a popular condiment in Japan and other parts of the world. It has a pungent, sulfur - containing fl avor. It would be worthwhile to produce standardized extractives so that they can be enjoyed in other parts of the world. If one looks around, there are many fl avor - contributing plant materials, which are, at present, restricted to only certain regions. Simple operations like ripening, germination, crushing, and thermal treatment may even add other desir-able fl avor notes to these plants. These are opportunities for the development of novel fl avors.

References

Govindarajan , V.S. 1980 . Turmeric — chemistry, technology and quality . CRC Crit. Rev. Food Sci. Nutr. 12 , 199 – 301 .

Kramer , Gerhard ; Sabater , Christopher ; Brennecke , Stefan ; Liebig , Margit ; Freiherr , Kathrin ; Ott , Frank ; Ley , Jacob P. ; Webber , Berthold ; Stoeckigt , Detlef ; Roloff , Michael ; Schmidt , Claus Oliver ; Gatfi eld , Ian ; and Bertram , Heinz - Juergen . 2006 . The fl avor chemistry of culinary Allium preparations . Dev. Food Sci. 43 , 169 – 172 .

Mathew , A.G. ; Parpia , H.A.B. ; and Govindarajan , V.S. 1969 . The nature of complex proanthocyanidins . Phytochemistry 8 , 1543 – 1549 .

Sharma , M.L. ; Rawat , A.K.S. ; and Balasubrahmanyam , V.R. 1987 . Studies on essential oil of betel leaf . Indian Perfumer 31 ( 4 ), 319 – 324 .

Wang , Gangli ; Yu , Jiandong ; Tian , Jingai ; and Zhang , Ji . 1999 . Analysis of chemical composition of catechin and epi catechin by RP - HPLC . Yaowu Fenxi Zazhi 19 ( 2 ), 88 – 90 ( Chem. Abstr. 130 :301773).