Tamarind monograph.pdf - Crops for the Future
Tamarind monograph.pdf - Crops for the Future
Tamarind monograph.pdf - Crops for the Future
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should have <strong>the</strong> characteristic flavouring when dissolved in water and be<br />
free of any burnt or o<strong>the</strong>r undesirable flavours; it should have good keeping<br />
quality and be free from any insect pests, fungal growth or extraneous<br />
materials.<br />
The TKP, when boiled in water containing boric acid and phenol as<br />
preservatives, gives a very good paper adhesive (Anon, 1976). In India, TKP<br />
is used as a source of carbohydrate <strong>for</strong> <strong>the</strong> adhesive or binding agent in paper<br />
and textile sizing, and weaving and jute products (Anon, 1976;<br />
Shankaracharya, 1998) as well as textile printing (Khoja and Halbe (2001).<br />
The sizing property of TKP is due to <strong>the</strong> presence of up to 60% of <strong>the</strong><br />
polysaccharide. A high grade adhesive from tamarind seed kernels could be<br />
prepared by roasting <strong>the</strong> seeds at 110� C <strong>for</strong> 15 minutes, de-hulling to<br />
remove <strong>the</strong> testa, powdering and passing through a 180 mesh sieve and<br />
making a porridge by boiling with water. Then it is mixed with 200% hot<br />
water, 5% glucose and 12% sodium bicarbonate and is ready <strong>for</strong> use<br />
(Devadas and Gothandapani, 1993).<br />
TKP can be mixed with o<strong>the</strong>r concentrates to make ca. 25% manufactured<br />
cattle feed. Ano<strong>the</strong>r commercial application can be in production of varnish<br />
(Kumar and Sethuraman, 2000), and TKP can be used as a vegetable<br />
clarifier (Mungare et al., 2001).<br />
3.6.2 Pectins<br />
Polysaccharides obtained from tamarind seed kernels <strong>for</strong>m mucilaginous<br />
dispersions with water and possess <strong>the</strong> characteristic property of <strong>for</strong>ming<br />
gels with sugar concentrates, like fruit pectins. However, unlike fruit pectin,<br />
tamarind polysaccharide can <strong>for</strong>m gels over a wide pH range, including<br />
neutral and basic conditions. <strong>Tamarind</strong> polysaccharides are also not affected<br />
by boiling in neutral aqueous solutions, even if boiled <strong>for</strong> long periods. Fruit<br />
pectins undergo degradation on boiling and fall to one-third of <strong>the</strong>ir original<br />
value after one hour of boiling. There<strong>for</strong>e tamarind polysaccharide can be<br />
useful as a gel <strong>for</strong>mation agent, and may be substituted <strong>for</strong> fruit pectins.<br />
<strong>Tamarind</strong> polysaccharide does not contain galacturonic acid and<br />
methyluronate and is <strong>the</strong>re<strong>for</strong>e not regarded as a true pectin; it is termed<br />
‘jellose’ (Rao, 1948).<br />
Mara<strong>the</strong> et al. (2002) compare <strong>the</strong> gelling behaviour of ‘jellose’ or polyose<br />
which was isolated from tamarind kernel powder (TKP) in 50% yield by<br />
alcohol extraction of an acidified boiled aqueous extract subsequently dried<br />
and pulverised. The gelling behaviour of polyose vis-à-vis pectin, and its<br />
blends with pectin was studied in a 65° Brix sucrose solute as a function of<br />
pH and concentration. One per cent pectin gave a good firm gel, while<br />
80:20 and 60:40 blends of pectin/polyose gave a firm gel at 1.5 and 2.0%<br />
respectively. A 40:60, 20:80 and 0:100 blend of pectin polyose gave a good<br />
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