Tamarind Production and Sources

Tamarind

1 Introduction

Tamarindus indica L., commonly known as tamarind tree is one of the most important multipurpose tree species in the Indian sub-continent. It is a large evergreen tree with an exceptionally beautiful spreading crown, and is cultivated throughout almost the whole country, except in the Himalayas and western dry regions (ICFRE, 1993, Rao et al., 1999). The tamarind fruit pulp has been an important culinary ingredient in India for a very long time. Almost all parts of the tree find some use or other in food, chemical, pharmaceutical and textile industries, and as fodder, timber and fuel (Dagar et al., 1995;

George and Rao, 1997).

Tamarind is thought to have originated in Madagascar (Von Maydell, 1986; Hocking,

1993). It is now cultivated throughout semi-arid Africa and South Asia, where it has become naturalized in several regions. It has been planted extensively in Bangladesh, India, Myanmar, Malaysia, Sri Lanka, Thailand and several African, Australian, Central American and South American countries. The fruit became known in Europe during the Middle Ages. Tamarind fruit was at first thought to be produced by an Indian palm, as the name tamarind comes from a Persian word Tamar-I-hind, meaning date of India. Its name amlika in Sanskrit indicates its ancient presence in the country (Mishra, 1997). In Myanmar it is reported as one of the commonest village trees in the dry zone (Troup,

1921). Commercial plantations are reported in Belize, Central American countries and in north Brazil (Sharma and Bhardwaj, 1997).

In India, tamarind is known by a wide variety of vernacular names: Assamese Tetuli; Bengali amli, nuli, textili tentul; Gujrati amali, ambali; Hindi ambli, amli, imli, tamarulhindi; Kannada hunase, hunase-mara, hunse; Malayalam puli; Marathi amli, chinch, chitz; Oriya koya, tentuli; Punjabi imli; Parsian Tamarhindi; Tamil Puli, pulia-maram; Telugu Chinta; Urdu imli. In Arabic it is Tamre-Lindi, in French tamarind, in Spanish and Portuguese tamarindo and English-speaking people call it tamarind (Mishra, 1997).

The genus Tamarindus is a monotypic genus and belongs to the sub-family

Caesalpinioideae of the family Leguminosae (Fabaceae). Tamarind is a moderate-sized

to large, evergreen tree, up to 24 m in height and 7 m in girth. The morphology of the tree in detail has been described by several authors (Singh, 1982; Parkash and Drake, 1985; George and Radhakrishna, 1993; ICFRE, 1993; Dubey et al., 1997). The most useful part is the pod. Pods are 7.520 cm. long, 2.5 cm broad and 1 cm thick, more or less constricted between the seeds, slightly curved, brownish-ash coloured, scurfy. There are

312 seeds in each pod contained in loculi, enveloped by a tough, leathery membrane, the so-called endocarp. Outside the endocarp is the light-brownish, red, sweetish acidic, edible pulp, traversed by a number of branched, ligneous strands. The outermost covering of the pod is fragile and easily separable. The pods begin to ripen from February to April

(Cowen, 1970; Duke, 1981; 1CFRE, 1993; Dubey et al., 1997; Choudhary and

Choudhary, 1997; Rao et al., 1999).

2 Production

Rough estimates are available on production of tamarind in India. One estimate has production at over 3 lakh tonnes in 199495. Tamarind cultivation is concentrated in the states of Tamil Nadu, Andhra Pradesh, Karnataka, Orissa and Kerala (Jambulingam and Fernandes, 1986; Anon., 1997; George and Rao, 1997; Rao, 1997; Vennila and Kingsley,

2000).

2.1 Sources

Among 52 spices under the purview of the Spices Board (Govt. of India), tamarind occupies sixth position in terms of export earnings (George and Rao, 1997). It is exported as fresh, dry and paste. Export of tamarind seed also takes place both in unground and ground forms. Export of tamarind and seed in different forms for five years from 199293 is provided by Anon. (1996a, 1996b). Tamarind products are exported to around 60 countries.

Tamarind fruits begin to ripen during the months of FebruaryMarch. The pods are allowed to ripen on the tree until the outer shell is dry and thereafter harvested and the shells are removed manually. The pulp is separated from the seeds and fibres and dried in the sun to reduce its moisture level. Then it is packed in palm leaf mats, gunny bags or polythene bags and stored in a dry place. The average composition of the pod is accounted as 55% pulp, 34% seeds and 11% shell and fibres (Ishola et al., 1990; Shankaracharya, 1997, 1998). All these operations are manual and therefore very labour- intensive. Mechanical methods for extracting pulp (Benero et al., 1972), chemical composition of juice concentrates (Nagaraja et al., 1975), preservation of sweet tamarind in Thailand (Chumsai-Silavanich et al., 1991) and physico-chemical composition of commercial tamarind powder (Manjunath et al., 1991) have been reported.

A tamarind dehuller was designed and developed at the Post Harvest Technology

Scheme (ICAR), UAS, Bangalore with a hulling capacity of 500 kg/h (Ramkumar et al.,

1997). The hulling efficiency of the machine developed was reported to be 80% for the large size curved fruits, while for the small fruits, the efficiency was only 58%.

Pulp loss during storage was very low in black polyethylene (0.18%) and plastic

(0.17%) compared to phoenix mat (1.35%) and metal (1.53%) (Ramakumar et al., 1997). Feungchan et al. (1996) conducted studies on factors related to colour change of tamarind pulp from brown to black to yellow in storage and recommended mixing of 10% powdered salt and cold storage to prevent this. Based on observations on post-harvest

physiological and chemical changes in tamarind fruit, Lakshminarayana and Hernandez- Urzon (1983) had suggested that tamarind may be processed within one week after harvest in order to get maximum yield.

Tamarind pulp/concentrate is one of the essential components in Indian culinary habits. It is a common article of trade and is preserved and stored for marketing in a number of ways (Lewis et al., 1957; Lewis and Neelakantan, 1959, 1964; Benero et al.,

1972; Patil and Nadagouder, 1997). Patil and Nadagouder (1997) reported that commonly, the pulp freed from fibre and seed is mixed with 10% salt and beaten down with mallets so as to exclude air and packed in gunny bags, lined with palm leaf- matting. In another process, the salted pulp is trodden into a mass and made into balls, which are exposed to the sun and dew for about a week. Concentrates of the pulp, more or less jelly-like in consistency, are also marketed.

3 Main uses

3.1 Pulp

The fruit-pulp is the chief agent for souring curries, sauces, chutneys and certain beverages throughout the greater part of India. Tamarind fruit is also reported to be used as a raw material for the preparation of wine-like beverages (Giridharlal et al., 1958; Sanche, 1985; Latino and Vega, 1986; Benk, 1987). According to the research findings of CFTRI (Central Food Technological Research Institute), Mysore, India, the pulp could be preserved well for 68 months, without any treatment, if it is packed in airtight containers and stored in a cool dry place (Shankaracharya, 1997). The edible portion of the ripe pod reportedly contains moisture 63.368.6%; protein 1.63.1%; fat 0.270.69%; total sugars

22.030.4%; sucrose 0.10.8%; cellulose 2.03.4% and ash 1.21.6%. The dried pulp contains moisture 20.921.3%; protein 3.15.0%; fat 0.10.6%; total carbohydrates 67.4

70.7%; fibre 5.618.3%; tartaric acid 818%; invert sugars 3040%; ash 2.42.9% and

270 calories. Lewis et al. (1957b), Shankaracharya (1997, 1998), remarked that the sweetness of the so-called red-variety of tamarind might be due to the presence of lesser amounts of free-acids in the pulp. According to these investigators the colour of the red- tamarind pulp is due to an anthocyanin pigment called chrysanthemin. The common variety contains a leucocyanidin pigment. Nearly 60 volatile compounds have been detected in tamarind pulp (Zhang and Ho, 1990; Shankaracharya, 1998).

3.2 Concentrate

Juice concentrate of tamarind is produced and marketed in India and abroad (Raghuveer,

1997). The product is promoted as being very convenient for culinary purposes and the food industry. The CFTRI, Mysore, has developed processes for the manufacture of juice concentrate and powder of the pulp (Sankaracharya, 1998). Formulae for preparing spiced sauces and beverages from the pulp have also been reported (Patil and Nadagouder, 1997). The approximate composition of the concentrate according to CFTRI report is as follows: total tartaric acid 13%; invert sugars 50%; pectin 2%; protein 3%; cellulosic material 2%; and moisture 30%. Tamarind juice concentrate was found to be more viscous than sucrose solutions (Manohar et al., 1991).

3.3 Seeds

Following the estimation of the composition of seeds and evaluation of its properties, Marangoni et al. (1988) opined that tamarind seeds are potential sources of food or food ingredients. They recorded that seeds formed about 35% of the whole fruit with 30% testa and 70% endosperm (kernel). When analysed seeds were found to contain 17.120.1% protein; 6.08.5% fat; 65.172.2% carbohydrates; 0.74.3% crude fibre and 2.33.2% ash. The chemical composition and nutritive value of tamarind seeds and kernels was determined by several workers (Bose et al., 1954; York et al., 1993; Siddhuraju et al.,

1995; Patil and Nadagouder, 1997). Bhattacharya et al. (1993, 1994a) reported that the kernel protein is rich in lysine, glutamic acid, aspartic acid, glycine, leucine and potassium, but deficient in sulphur-containing amino acids. Dehusked tamarind seeds have been found to be a rich source of pectin, the jelly-forming constituent of many fruits, vegetables, seeds, etc. (Kumar, 1997). According to him proper utilization, can give an impetus to the jam and jelly industry which until now was dependent upon the imported jelly powder, and can also lead to the development of various other industries which use pectin as one of its raw materials. Methods of isolation and purification of the pectin have been described and its possible commercial uses indicated (Kumar, 1997).

3.4 Kernel powder

The powder, commercially known as tamarind kernel powder (TKP), is found to be extensively used as a sizing material in the textile industry as well as in the food industry

(Rao and Subramanian, 1984; Bal and Mukherjee, 1994; Patil and Nadagouder, 1997). These analysts attribute the sizing properties of TKP to the presence of a polysaccharide

(called jellose) to the extent of 6%. Other reported constituents are proteins, fibre, fat and inorganic salts and some free sugars and tannins. The jellose is also much used in confectionery, especially in the United States, and some European countries. Its use has been recommended in preparing jujubes, as a stabilizer in ice creams and mayonnaise

(Patil and Nadagouder, 1997). Use of white TKP in three food products, jelly, fortified bread and biscuit was also detailed by Bhattacharya (1997), Bhattacharya et al. (1991,

1994b). It can be used in cosmetics, and in pharmaceutical and insecticidal preparation. It can also be used as an adhesive in bookbinding, cardboard manufacture and plywood industry, and in sizing and weighing compositions in the leather industry (Daw et al.,

1994; Patil and Nadagouder, 1997; Prabhanzan and Ali, 1995). The fatty oil from the kernels resembles peanut oil and is reported to be useful in the preparation of paints and varnishes and for burning lamps which can be extracted by solvent extraction (Pitka et al., 1977; Reddy et al., 1979; Patil and Nadagouder, 1997).

3.5 Seed testa

The testa is reported to contain 40% water solubles, 80% of which is a mixture of tannin and colouring matter (FRI, 1955). In the production of TKP or the jellose, large quantities of testa are left as a residual by-product. The use of testa in dyeing and tanning has been suggested. Several authors (Rao and Srivastava, 1974; Glicksman, 1986; Tsuda et al.,

1994, 1995; Sankaracharya, 1998) have suggested that seed coat, a by-product of tamarind gum industries can be used as a safe and low-cost antioxidant for increasing the shelf-life of foods by preventing lipid peroxidation. Studies have been carried out on the utilization of spent (detanned) tamarind seed testa as a substrate to grow Pleurotus florida, in order to convert organic wastes into biofertilizer and also to assess the

suitability of this testa as a substrate along with spent wattle. The yield of mushroom was

17% when wattle-tamarind seed testa was used. The spent material after harvesting the mushroom degraded easily in the soil indicating its suitability as organic manure

(Madhulatha and Pitchai, 1997).

3.6 Minor uses

The tender leaves, flowers and the young seedlings are eaten as a vegetable. The analysis of tender leaves gave: moisture 70.5%; protein 5.8%; fat 2.1%; fibre 1.9%; other carbohydrates 18.2% and minerals 1.5%. The mineral and vitamin constituents (in mg/

100 g) were as follows: calcium, 101; magnesium, 71; phosphorus, 140; iron, 5.2; copper,

2.09; chlorine, 94; and sulphur, 63; thiamine, 0.24; riboflavia, 0.17; niacin, 4.1; and vitamin C (Anon., 1976; Karuppaiah et al., 1997). Young leaves of T. indica yielded 1.16 lipids (dry wt.) with chloroform-methanol and differentiated the neutral lipids, glycolipids and phospholipids (Sridhar and Lakshminarayana, 1993).

The leaves are eaten by goats and cattle. The flowers are considered to be a good source of honey (Ramanujam and Kalpana, 1992) which is rich golden in colour, but has slight acidity peculiar to its flowers. The tree also yields a valuable timber and the wood is used mostly for agricultural implements, tool-handles, wheels, mallets, rice pounders, and oil-mills and for turnery.

4 Functional properties

Medicinal values have been claimed for various preparations from the fruit, leaves, flowers, bark such as the antiscorbutic properties of the pulp, laxative action of the fruit juice and diuretic properties of leaf sap (Ghosh, 1987; Lakshmanan and Narayanan, 1990; Lewis et al., 1970; Mustapha et al., 1996; Rajan et al., 1989; Rao, 1995; Sano et al.,

1996). An infusion of the leaves is said to be cooling and useful in bilious fever. A poultice of the fresh leaves is applied to swellings and boils, and for relieving pain, and that of the flowers in inflammatory infections of the conjunctiva. The bark is astringent and is given in diarrhoea; in lotions and poultices, it is also applied to sores and boils. In some countries, the bark is reported to be prescribed in asthma, amenorrhoea, and as a tonic and febrifuge (Anon., 1976).

The treatment of salted dried fish by TKP was found to be the best in preserving the quality of salted fish (Shetty et al., 1996). While investigating the nutritive value of kernel proteins Sano et al. (1996) and Patil and Nadagouder (1997) remarked that it is comparable to that of cereal proteins based on their observations that replacement of 25% or less of rice by this kernel powder produced a significant improvement in the overall nutritive value of rice diet.

5 Quality issues

Tamarind has many problems associated with quality parameters due to high moisture level and seed, fibre and rind contents. Tamarind is reported to be adulterated with foreign matter which are both organic and inorganic in nature. They are considered to be due to poor post-harvest management practices including processing (Rao and George,

1996; George and Rao, 1997). Directorate of Marketing and Inspection and Bureau of

Table 1 Agmark specifications (%/wt max) tamarind seedless Character/grade Special A B C Moisture 15 17 20 20

Seed content 5 10 15 20

Foreign matter (organic) 4 6 8 10

Foreign matter (inorganic) 1 1.5 2 2

Table 2 Agmark specifications (%/wt max) tamarind dry Character/grade Special A B Seed content 35 40 45

Fibres 6 8 10

Rind 3 4 6

Insect damage 2 3 5

Moisture 15 20 25

Table 3 Agmark specifications (%/wt max.) tamarind seed Character/grade Special A Extraneous matter 1 2

Damaged and discoloured 2 5

Wt/lit 900 800

Moisture 9 10

Indian Standards have prescribed quality specifications for seedless tamarind (Table

1), dry tamarind (Table 2) and tamarind seed (Table 3) (Anon, 1996c). The

Indian Standard specifications are available for tamarind juice concentrate (IS:5955,

1993), pulp (IS:6364, 1993), for kernel oil (IS:189, 1977), IS: 511, 1962 for kernel powder and IS 9004, 1978 for seed testa.

6 References

ANON. (1976), Tamarind. In The Wealth of India (Publications and Informations

Directorate, CSIR Vol X, 11422. ANON. (1996a), Spices Export Revie w, 199596. Spices Board, Cochin, India. ANON. (1996b), Spices Statistics. Spices Board, Cochin, India. ANON.. (1996c), Agmark Grade Specifications for Spices. Spices Board, Cochin, India. ANON. (1997), Area and Production of Spices in India and the World. Spices Board,

Cochin, India.

BAL S and MUKHERJEE R K (1994), Functional and nutritional properties of Tamarind kernel protein, Food Chem, 49(1), 19.

BENERO J R, RODRIGUEZ A J and COLLAZO-DE-RIVERA A (1972), Tamarind, Jour. Agri. of the Univ. of Puerto-Ric o, 56(2), 1856.

BENK E (1987), Tropical and subtropical wine-like beverages, Alcohol Industrie 100, 87,

129.

BHATTACHARYA S (1997), Utilisation of Tamarind Seed Kernel in Food Industry, Proc. Nat. Sym. on Tamarindus indica L, Tirupathi (A.P.), organized by Forest Dept. of A.P. India, 2728 June, 1997, pp. 1628.

BHATTACHARYA S, BAL S., MUKHERJEE R K and BHATTACHARYA, S (1991), Rheological behaviour of tamarind (Tamarindus indica) kernel powder suspension, J. Food Engineering, 13, 1518.

BHATTACHARYA S, BAL S, MUKHERJEE R K and BHATTACHARYA S (1993), Some physical and engineering properties of tamarind (Tamarindus indica) seed, J. Food Engineering, 18, 7789.

BHATTACHARYA S, BAL S, MUKHERJEE R K and BHATTACHARYA S (1994a), Studies on the characteristics of some products from tamarind (Tamarindus indica) kernel, J. Food Science and Technology, 31(5), 3726.

BHATTACHARYA S, BAL S, MUKHERJEE R K and BHATTACHARYA S (1994b), Functional and nutritional properties of tamarind (Tamarindus indica) kernel protein, Food Chemistry, 49, 19.

BOSE S M, SWAMINATHAN M and SUBRAMANYAM V (1954), Nutritive value of Tamarind seed, Bull. Cent. Fd. Technol. Res. Inst., 3, 678.

CHOUDHARY P and CHOUDHARY S S (1997), Chemocytomorphological studies in Tamarindus indica. Proc. Nat. Sym. on Tamarindus indica L, Tirupathi (A.P.), organized by Forest Dept. of A.P., India, 2728 June, 1997, pp. 2314.

CHUMSAI-SILAVANICH, CHAKAMAS-WONGHALAUNG and SOMCHIT-NIYOMTHAI (1991),

Tamarind, Food, 21(1), 94112.

COWAN D Y (1970) Tamarind. In Flowering Trees and Shrubs in India. Thacker & Co. Ltd, Rampart Row Fort, Bombay, 512.

DAGAR J C, SINGH G and SINGH N T (1995), Evolution of crops in agroforestry with teak

(Tectoma grandis), maharukh (Ailanthus excelsa) and tamarind (Tamarindus indica) on reclaimed salt-affected soils, Journal of Tropical Forest Science, 7(4), 62334. DAW Z Y, EL GIZAWY S A and SAID A M B (1994), Microbiological evaluation of some local juices and drinks, Chemic Mikrobiologic Technologic der Lebensmittel, 16(12), 815. DUBEY P, MISRA C M, SINGH S L and BURFAL B S (1997), Relative Performance of Tamarindus Indica Linn. on Usar Soils, Proc. Nat. Sym. on Tamarindus indica L., Tirupathi (A.P.), organized by Forest Dept. of A.P., India, 2728 June, 1997, pp.

2625.

DUKE J A (1981) Handbook of Legumes of World Economic Importance, Plenum Press, New York, 26871.

FEUNGCHAN S, YIMSAWAT T, CHINDAPRASERT S and KITPOWSONG P (1996) Effects of

Plant Regulators on Fruit Setting, Thai J. Agric. Science, Special Issue 1, 4851.

FRI (1955). Tamarind seed has many uses, Indian Farming, (8), 212, 24.

GEORGE C K and RADHAKRISHNAN V V (1993), Tree Spices Trees and Tree Farming, P. K. Thampan, Peckay Tree Crops Development Foundation, Cochin.

GEORGE C K and RAO Y S (1997), Export of Tamarind from India, Proc. Nat. Sym. on

Tamarindus indica L., Tirupathi (A.P.), organized by Forest Dept. of A.P., India, 27

28 June, 1997, pp. 15661.

GHOSH B (1987), Some unreported medicinal uses of plants used by the tribals of district

Begusarai, Bihar, India, Jour. Econ. Taxon Bot., 10(1), 18790.

GIRIDHARLAL, DAS D P and JAIN N L (1958), Tamarind beverage and sauce. Ind. Fd. Packer, 12, 1316.

GLICKSMAN M (1986), Tamarind seed gum. In Food Hydrocolloids. Ed M. Glicksman, Vol III, CRC Press, Boca Raton.