Ginger - Production, Main uses in food processing

Ginger

1 Introduction

The spice ginger is obtained from the underground stems or rhizomes of Zingiber officinale

(Rosc.), a herbaceous tropical perennial belonging to the family Zingiberaceae. In cultivation, it is usually grown as an annual. The whole plant is refreshingly aromatic, but it is the underground rhizome, raw or processed, that is valued as spice. Its medical value is increasingly being recognized. Ginger originated in South-East Asia, probably in India

(Burkill, 1966; Purseglove et al., 1981). The name itself supports this view. The Sanskrit name Singabera gave rise to Greek Zingiberi and later the generic name Zingiber.

Ginger (Zingiber officinale Rosc.) is a monocotyledon belonging to the family Zingiberaceae and to the order Zingiberales. In the Zingiberaceae, it belongs to the subfamily Zingiberoideae, which are aromatic with unbranched aerial stems, distichous leaves, open sheaths and hypogeal germination, mainly confined to the old world tropics with the centre of distribution in Indo-Malaysia (Purseglove et al., 1981). Among them, ginger is a slender perennial herb, 30100 cm tall with palmately branched rhizome- bearing leafy shoots. The leafy shoot is the pseudostem formed by leaf sheath and bears

812 distichous leaves. The inflorescence is a spike which generally springs directly from the rhizome.

The subfamily Zingiberoideae is also noted for two important spice crops, turmeric

(Curcuma longa L.) and cardamom (Elettaria cardamomum Maton). It also includes a number of subsidiary spice plants belonging to the genera Aframomum, Amomum, Kaempferia, Languos (Alpinia) and Phaeomena (Nicolaia). The genus Zingiber Boehm has about 8090 species of perennial rhizomatous herbs distributed throughout South- East Asia and extending to Queensland and Japan (Purseglove et al., 1981).

2 Chemical structure

The ginger rhizome contains steam volatile oil, fixed fatty oil, pungent compounds, resins, proteins, cellulase, pentosans, starch and mineral elements. The composition of

these components varies with type of cultivar, region, agroclimatic conditions, maturity and nature of rhizome, i.e. fresh or processed (Purseglove et al., 1981). The dry ginger on average contains moisture (10.85%), volatile oil (1.8%), oleoresin (acetone extract)

(6.5%), water extract (19.6%), cold alcohol extract (6.0%), starch (53%), crude fibre

(7.17%), crude protein (12.4%), total ash (6.64%), water soluble ash (5.48%) and acid insoluble ash (0.14%) (Peter and Kandiannan, 1999).

The characteristic organoleptic properties of ginger are due to steam volatile oil and non-volatile solvent extractable pungent components. The pleasant aroma of ginger is caused by more than 70 constituents present in steam volatile oil. Among them the sesquiterpene hydrocarbon (-)- -zingiberene predominates and accounts for 2030% of the oil obtained from dry ginger (Purseglove et al., 1981). The warm pungent taste is caused by a number of components predominated by gingerols followed by shogaols and zingerone (Kulka, 1967). The aroma and flavour of fresh ginger will be different from dry ginger as some of the volatile oils will be lost by evaporation during drying (Purseglove et al., 1981).

3 Production Ginger is cultivated in several parts of the world, the most important producing regions being India, China, Nigeria, Sierra Leone, Indonesia, Bangladesh, Australia, Fiji, Jamaica and Nepal. Among them India and China are the dominant suppliers to the world market

(Table 1).

In terms of quality, Jamaican and Indian ginger are considered superior followed by West African. Jamaican ginger possesses delicate aroma and flavour and is sometimes considered as first grade. Indian ginger, entering the world market as Cochin and

Calicut ginger, has a lemon-like byenote for which some have a preference over Jamaican ginger. Chinese ginger is low in pungency and mainly exported as preserves in sugar syrup or as sugar candy. Nigerian and Sierra Leone dried ginger possess somewhat camphoraceous and coarser odour and is rich in aroma and pungency factors. There is demand for them for oil distillation and oleoresin extraction.

Primary products of ginger rhizomes for flavouring purposes are fresh ginger, preserved ginger in syrup or brine and the dried ginger. Secondary products are ginger powder, oils and oleoresins from dry ginger.

Table 1 Area and production of ginger in the important ginger producing countries (1990,

1995, 1999)

Country 1990 1995 1999

Area (ha) Production Area (ha) Production Area (ha) Production

(tonnes) (tonnes) (tonnes)

India 54,000 154,000 90,100 170,800 70,000 235,000

China 5,333 54,284 12,502 130,698 13,450 157,018

Nigeria 84,000 42,000 140,000 79,000 145,000 80,000

Bangladesh 6,967 42,830 6,900 39,000 7,700 39,000

Jamaica 274 865 161 452 180 620

Nepal 1,250 3,500 1,000 3,000 1,200 3,200

Indonesia 9,612 79,891 10,000 82,631 9,900 80,351

Source: FAO Statistical Database lllp;//www-fao.org

3.1 Fresh ginger

Fresh ginger is outstanding for flavouring as it contains the full note of the spice compared to other products from it. Fresh rhizomes with low fibre content but rich in aroma, pungency, fat and protein are preferred for green ginger purposes. The crop for this purpose can be harvested from 180 to 195 days after planting. Further maturity causes a progressive increase in crude fibre and decrease in protein and fat content.

3.2 Preserved ginger

Immature green ginger is preserved in brine or sugar syrup. Crystallized ginger is also made from the ginger in sugar syrup by further processing. Crystallized ginger is the peeled ginger impregnated with sugar syrup, dried and coated with crystalline sugar. Succulent ginger rhizomes with very little fibre and less pungency are preferred for preserved ginger. The raw material has to be harvested within 195 days of planting. The processing technology of preserved ginger varies with country. (A basic idea will be obtained from Chinese technology.)

3.3 Dry ginger

Dry ginger obtained by drying of fresh ginger comes in the spice trade for the preparation of ground ginger and extraction of oleoresin and oil. It is available in a number of physical forms. It can be peeled (scraped or uncoated) or non-scraped (coated or non- peeled) and sometimes partially peeled or rough scraped. In the scraped grade, the cork skin has been removed clearly without damaging the underlying tissue. Grades designated as bleached or limed are also available. They are prepared from clean peeled or partially peeled whole rhizomes by treating with lime or sulphurous acid to achieve white colour. Physical grades like black ginger, splits and slices are also available.

Dried ginger is prepared from mature rhizomes which have developed full aroma, flavour and pungency, and harvesting is usually carried out at between eight to nine months after planting. For dry ginger making, cultivars with medium-sized rhizomes with high curing percentage are preferred. The processing of dry ginger involves the following steps:

1. Removal of roots and thorough washing of rhizomes.

2. Preparation of rhizome for drying, which involves either peeling, splitting or slicing. When whole-coated rhizomes are to be dried, preparation is by immersing in boiling water for about 10 minutes. Black ginger is prepared like this.

3. Sun drying: during drying, rhizomes lose moisture, about 6070% of their weight, and achieves a final moisture of 712%.

Jamaican ginger is clean peeled using a special knife and, after thorough washing, sun dried. Indian ginger is rough scraped, non-bleached or bleached (limed). In this, the skin is partially scraped off with a sharpened piece of bamboo. Steel knives are not used as they stain the produce. Mechanization is possible in dry ginger processing, in grading, peeling and drying. But mechanical grading and peeling produce an inferior quality produce. Most of the producing countries resort to traditional methods which employ manual labour mainly.

The appearance, the content of volatile oil and fibre, the pungency level and a subjective assessment of aroma and flavour are important in the quality evaluation of

dried ginger. Cleanly peeled dried ginger in the whole form possessing the best appearance generally find a place in the grocery trade. Lower grades of clean peeled, coated whole, split and sliced types are used for blending in the preparation of powdered mixed spices. All types may be used for oil distillation and oleoresin extraction, but the coated types are the most extensively used for these purposes.

3.4 Ginger powder

Ginger powder is made by pulverizing dry ginger to a mesh size of 50 to 60. Ginger is ground to release the flavour, the finer the powder, the more readily available the flavour and readily dispensable in the matrix. Some flavour may be lost by heat development during grinding. This can be minimized by adopting cryomilling and freeze grinding.

3.5 Ginger oil

Ginger oil is produced commercially by steam distillation of freshly ground dry ginger. The yield of oil varies from 1.5 to 3.0% with an average of 2.0%. The oil obtained is a green or yellow mobile liquid which becomes viscous on ageing (Purseglove et al.,

1981). The most suitable material for oil distillation is coated African ginger, followed by Nigerian splits and Cochin ginger. Ginger oil can also be recovered by steam distilling fresh ginger peelings and the yield is 1.5 to 2.8%.

3.6 Ginger oleoresin

Ginger oleoresin is obtained by extraction of powdered dry ginger with suitable organic solvents like alcohol, acetone and ethylene dichloride, etc. Concentration of solvent extract under vacuum and complete removal of traces of solvent yields oleoresin of ginger. The yield, flavour and pungency of extracted oleoresin vary with cultivars, maturity of rhizome, choice of solvent and the method of extraction employed. Generally a yield of 3.99.3% with an average of 6.5% on dry weight of ginger is obtained. Commercial ginger oleoresin usually has a volatile oil content of 2530% and a replacement strength of 1 kg oleoresin for 28 kg good quality ground spice. They are offered to the consumer in liquid form or dispensed on sugar or salt.

4 Main uses in food processing

The refreshing pleasant aroma, biting taste and carminative property of ginger make it an indispensable ingredient of food processing throughout the world. Fresh ginger, ginger powder from dry ginger, oleoresin and oil are all used for this purpose. Fresh ginger is unique for its flowery flavour and spicy taste. Hygienic oleoresin and oil in convenient consumer friendly packing and dispenser system find a place in the culinary art of developed countries and upper society strata of developing countries.

Ginger preserve and candy are also in great demand for use in confectionery. Chocolate manufacturers utilize the preserve for enrobing. It is also used in jams and marmalades. The syrup in which ginger is preserved is valued for pickle and sauce making. It is also used in the production of ginger bread (Pruthi, 1993).

In western countries ginger is used widely for culinary purposes in gingerbread, biscuits, cakes, puddings, soups and pickles. It is also used in the production of alcoholic

beverages like ginger beer, ginger ale, and ginger wine. Earlier it was much favoured for spicing wines and possets (Purseglove et al., 1981). In the East, fresh ginger chopped into small bits and in the ground form are very much used in vegetarian and non-vegetarian food preparations. It is also used in pickling, soft drink making, confectionery and curry powder preparations. The unique speciality of Chinese cookery owes very much to the use of fresh ginger as ground paste. In India, in meat and fish dishes it is indispensable to make it palatable and digestible. Buttermilk containing crushed fresh ginger, green chillies, salt and curry leaf is a delicious drink and appetizer of South India. Puliyingi a curry prepared from finely chopped fresh ginger and ripe tamarind fruit extract as main ingredients is unique in taste and is indispensable in social and festival feasts of the Malabar coast. Certain Indian recipes for ginger wine, fish, meat and tomato curry preparations are given below:

Ginger wine

Ingredients

Fresh ginger cut into pieces 1 kg

Yeast small pinch

Sugar 1 kg

Water 1.5 litre

Method

1. Cook the ginger pieces in a pressure cooker for 10 min.

2. When cold, keep for fermentation along with ³

₄ kg sugar and yeast for 21 days.

3. Every other day the contents are turned.

4. On completion of fermentation, wine is squeezed out from the fermented ginger.

5. To improve the appearance, the remaining ¹

₄ kg sugar is burned to brown colour and mixed with the wine.

Consuming one teaspoon of ginger wine daily is good for digestion and health.

Spicy Lamb Fry Masala

Ingredients

Lamb 750 g

Onions 2 medium size

Ginger 20 g

Garlic 4 cloves Green chillies 1 teaspoon Garam masala powder 1 teaspoon Curry leaves 10 g Coriander powder 1 tablespoon Red chilli powder 4 teaspoon Turmeric powder teaspoon Capsicum teaspoon Fresh tomatoes 2

Ground black pepper 2 teaspoons Coriander leaves to garnish Lemon juice to taste

Salt to taste

Oil 20 g

Fresh lemon 1

Method

1. Cut the meat into half-inch cubes and wash them.

2. Cook meat with salt along with sliced onions, ginger, garlic, red chilli powder, turmeric powder, garam masala powder and coriander powder on a slow fire until meat is tender and all water has evaporated.

3. Slice some onions and saute them in a little oil.

4. Add cooked meat and saute it until well fried.

5. Add sliced tomatoes, capsicum, green chillies and fry them.

6. Add ground black pepper, chopped coriander leaves and lemon juice.

7. Serve with a garnish of onion rings, curry leaves and sliced fresh lemon.

Garcinia fish curry

Ingredients

Fish kg

Chilli powder 4 tablespoons Turmeric powder 1 teaspoon Garlic flakes 10

Ginger julienne 1 inch piece Garcinia 4 pods Coconut oil 2 tablespoons Mustard 1 tablespoon Fenugreek 4 seeds

Curry leaves 1 spring Salt to taste Water 2 glasses

Method

1. Cut the fish into dices and wash under running water.

2. Heat up an earthenware pot, pour the coconut oil, crackle mustard, fenugreek.

3. Saute garlic, ginger and curry leaves and add chilli powder and turmeric powder.

4. Stir till it gets cooked and add water to it.

5. Add cleaned garcinia pods and the diced fish into it.

6. Cover the pot and boil it until fish gets cooked.

7. Check for the seasoning and finish it off with a dash of coconut oil.

Tomato curry

Ingredients

Onions 2 medium Tomatoes 4 medium Cumin powder 1 teaspoon Ginger 10 g Coriander powder 1 teaspoon Turmeric powder 1 teaspoon Dry red chillies 4

Mustard 1 teaspoon Oil 2 tablespoons Cashew nut 10 g Chilli powder 1 tablespoon Yoghurt 2 tablespoons

Method

1. Fry sliced onions until brown.

2. Grind coriander powder, chilli powder and turmeric powder with sliced ginger into a smooth paste along with yoghurt.

3. Add ground condiments to browned onions.

4. Cut tomatoes into quarters and add to brown mixture.

5. Fry for 2 minutes.

6. Add 2 cups of water and boil for 5 minutes.

7. Add salt.

8. Give a tempering of mustard, red chillies and cashew nuts.

5 Functional properties

The nutritive value of ginger is given in Table 2. Ginger is much used in traditional Indian (Ayurveda) and Chinese medicine (Sivarajan

and Balachandran, 1994). Recent research has supported its functional value in the following areas:

 Ginger has excellent antioxidant properties. Antioxidants are increasingly linked to the prevention of certain cancers (Kikuzaki et al., 1994) and coronary heart disease, as well as their more established role in preserving lipid-based foods. Studies include the role of components such as gingerol in inhibiting linoleic acid autoxidation (Kikuzaki and Nakatani, 1993), extending the shelf-life of meat (Ziauddin et al., 1995), dehydrated pork

(Fuijo et al., 1969) and fermented meat sausage (Al-Jalay et al., 1987).

Table 2 Nutritional composition of dry ginger (per 100 g)

Composition Quantity

Water (g) 7.0

Food energy (k cal) 380

Protein (g) 8.5

Fat (g) 6.4

Carbohydrates (g) 72.4

Ash (g) 5.7

Calcium (g) 0.1

Phosphorus (mg) 150

Sodium (mg) 30

Potassium (mg) 1400

Iron (mg) 11.3

Thiamine (mg) 0.05

Riboflavin (mg) 0.13

Niacin (mg) 1.90

Vitamin activity (RE) 1.5

 There are a number of studies of the antimicrobial activity of gingerols, for example in relation to Bacillus subtillis and E. coli (Yamada et al., 1992) and Mycobacterium

(Galal, 1996; Hiserodt et al., 1998)

 Ginger has a known influence on the eicosanoid cascade which influences such functions as wound healing, inflammation and platelet aggregation, and is involved in conditions such as arteriosclerosis (Srivasta, 1986; Sankawa, 1987; Kiuchi et al.,

1992; Kawakishi et al., 1994).

 Ginger has beneficial effects on the digestive system, enhancing gastrointestinal motility, and is used traditionally for the treatment of stomach ache, vomiting and indigestion (Yamahara et al., 1990). It has also been investigated for its gastroprotectant and anti-ulcer activity (Yamahara et al., 1988; Yamahara et al.,

1992; Yoshikawa et al., 1994).

 A recent study has investigated antitumour properties in gingerol, notably in inhibiting skin cancer (Park et al., 1998).

 Ginger checks cholesterol biosynthesis and thereby inhibits hypercholesterolema

(Tanabe et al., 1993). Its role in Chinese herbal medicine in controlling obesity has also been investigated (Wijaya and Wu, 1995).

The various functional properties of ginger are discussed in detail in Kikukazi (2000).

6 Quality specifications India and China are the worlds largest producers and exporters of ginger. Other important producers are Jamaica, Nigeria, Sierra Leone, Thailand and Australia. USA, United Kingdom, Germany, Japan, Saudi Arabia, Singapore, Hong Kong and Canada are the major importers of ginger. The importing countries give top priority to the health of their citizens and it is important that the ginger imported conforms to the quality standards prescribed by the particular country. Exporting countries also fix standards to supply required quality products to the consumers.

6.1 Indian standards In India, the world leader in ginger export, the Bureau of Indian Standards (BIS) has AGMARK grading system for dry ginger and ginger powder. It categorizes Calicut ginger and Cochin ginger to different grades as given in Table 3 based on the size of rhizome, extraneous matter, lime content as calcium oxide and very light pieces present. Among them only garbled non-bleached Cochin and Calicut meet the United Kingdom Standards.

6.2 United States standards The United States Government Standard defines ginger as the washed and dried or decorticated and dried rhizome of Zingiber officinale Rosc. The standards stipulated for ginger are given in Table 4.

The ginger imported to the United States should also conform to the cleanliness specifications stipulated by the American Spice Trade Association (ASTA) (Table 5) and also the regulations enforced by the Food and Drug Administration (FDA). The FDA has fixed defect action levels for whole ginger as shown in Table 6.

Table 3 Grades of whole dry ginger with specifications as per the ISI specification No. IS:1908-1961

Grade Special characteristics Size of Extraneous Light Lime as CaO

rhizome matter in pieces by by weight in

percentage count in percentage

(max.) percentage (max.)

(max.)

1. NGK/NGC Pieces irregular in Not less 2 Not Nil

Garbled, non- shape and size. Pale than 20 allowed

bleached brown, fibrous with mm in

Calicut/Cochin peel not entirely length

removed. Light pieces removed by garbling

2. BGK/BGC Pieces irregular in Not less 2 Not 2.5

Garbled shape and size. Pale than 20 allowed

bleached brown, fibrous with mm in

Calicut/Cochin peel not entirely length

removed. Lime bleached. Light pieces removed by garbling

3. NUGK/K Pieces irregular in Not less

Ungarbled non- shape and size. Pale than 20

bleached brown, fibrous with mm in

Calicut/Cochin peel not entirely length

a) Special removed. 3 5

b) Good 4 10

c) Non- Not

specified specified

4. BUGK/C Pieces irregular in Not less

Ungarbled shape and size. Pale than 20

Bleached brown, fibrous with mm in

Calicut/Cochin peel not entirely length

a) Special removed. Lime 3 5 4

b) Good bleached. 4 10 6

c) Non- Not

specified specified

Table 4 US government specifications for dry ginger and powder

Total ash per cent not > 7.0

Acid insoluble ash per cent > 1.0

Crude fibre per cent not > 8.0

Volatile oil expressed as ml per 100 g not < 1.5

Moisture per cent not > 12.0

Starch per cent not < 42.0

Sieve test (for powdered ginger only)

US standard sieve size 110.30

Percentage required to pass through not < 95.0

From US Federal Specifications: Spices ground and whole and spice blends. No.EE-S-531 H, June 5, 1975

(Purseglove et al., 1981).