Tamarind monograph.pdf - Crops for the Future
Tamarind monograph.pdf - Crops for the Future
Tamarind monograph.pdf - Crops for the Future
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
set at 2.0% beyond which <strong>the</strong> jellies were hard and difficult to chew. Two<br />
per cent polyose from TKP adequately substitutes 1% pectin in ready-to-eat<br />
jelly.<br />
Jellose is prepared on a large scale by adding TKP to 30-40 times its weight<br />
of boiling water, containing citric or tartaric acid at a concentration of 0.2%.<br />
It is <strong>the</strong>n stirred vigorously and boiled <strong>for</strong> a fur<strong>the</strong>r 30-40 minutes. The<br />
solution is kept overnight <strong>for</strong> setting and <strong>the</strong> supernatant liquid is siphoned<br />
off and concentrated under vacuum, passed through a filter press and <strong>the</strong>n<br />
dried in a drum drier. The resultant product is pulverised in a ball mill. A<br />
good sample of jellose should have a relative viscosity of 5.0% at 35º C in<br />
0.5% solution, which is somewhat higher than corn starch. Jellose is much<br />
cheaper than corn starch and is required in smaller quantities.<br />
An invention <strong>for</strong> <strong>the</strong> extraction of polysaccharides from seed kernels has<br />
been developed and patented by Gordon (1968). As <strong>the</strong> pulp also contains<br />
pectin, an integrated process has been developed <strong>for</strong> <strong>the</strong> production of<br />
pectin, tartarates and ethanol. In this process, <strong>the</strong> pulp is repeatedly extracted<br />
with boiling water and <strong>the</strong> filtered extract is cooled to separate potassium<br />
bitartarate. The supplement is concentrated under vacuum and <strong>the</strong> pectin is<br />
separated by <strong>the</strong> addition of alcohol. The filtrate, after recovering <strong>the</strong><br />
alcohol, is treated with lime to precipitate calcium tartarate. The remaining<br />
sugars are fermented with yeast and alcohol is recovered. The recovery is<br />
about 2.5% pectin, in addition to 12% tartaric acid and 12% alcohol, which<br />
makes <strong>the</strong> process economic and attractive. Krishna (1955) reported a<br />
process <strong>for</strong> <strong>the</strong> extraction of tartarates with acidified ethanol and subsequent<br />
extraction of pectin. After removing <strong>the</strong> alcohol, <strong>the</strong> residual syrup could be<br />
used <strong>for</strong> edible purposes. This process has been patented under <strong>the</strong> Indian<br />
Bureau of Standards, Indian Patent No: 52, 1955. <strong>Tamarind</strong> pectin resembles<br />
apple pectin and has <strong>the</strong> following composition (Table 3.1).<br />
Table 3.1 Average chemical composition of tamarind pectin<br />
Constituent Per cent<br />
Moisture 7.7-8.9<br />
Ash 2.3-3.0<br />
Calcium pectate 70.0-80.4<br />
Methoxyl 7.9-9.9<br />
Uronic acid 43.0-56.4<br />
3.6.3 <strong>Tamarind</strong> juice concentrate<br />
<strong>Tamarind</strong> juice concentrate (TJC) is a convenient product, as it is easy to<br />
dissolve and reconstitute in hot water (Anon, 1982 b). It can also be stored<br />
<strong>for</strong> long periods. <strong>Tamarind</strong> juice concentrate is prepared by extracting<br />
cleaned pulp with boiling water using <strong>the</strong> counter current principle, where<br />
37