Minerals and phytic acid content in different varieties of rice and their changes due to traditional cooking methods
Keywords:
Hssenlial Minerals. Phytic Acid. Decantation . Percent Retention.Abstract
I'wcIn'c dil’lercni varieties o f partioiled and raw milled rice have been analyzed for their
conlenl ol essential minerals (i .e. l-'e. Zn. C'u. C'a, Mg. P. Na and K) and phylie acid. Rice was
cixiked according to two different traditional cooking methods (with or without decantati(m of
cooking water) and changes in minerals and phytic acid content have been determined. Iron,
zinc and copper conlenl in dil'fereni varieties o f rice were found in the range o f (1.4 1 -1 .0.'^mg.
0..S 1 -1 .04mg and (l.()7-().24mg/l(IOg edible portion, respectively. Iron and zinc content were
R)und relativeh high in HR-10 variety. High amount of zinc was also found in BR-22 variety
while raw. milled paijam variety contained highest amount o f copper. Decrease in these micro
minerals content was observed in cooked rice and iron content was se v e r eh’ affected when
cooking water was decanted. On average only 44.0^"^ o f iron remained in parboiled milled
rice. Raw. milled paijam variety lost most o f its iron conlenl when cooked by decanlation i)f
cooking water and retained only 4.0%. Zinc content was found to increase in rice cooked
without decantation o f cooking water (ll.^.O'^^ retenlion). due to addition o f zinc from
domestic tap water used for cooking. Copper content was found to decrease in both cooking
metht)ds. Macro minerals like C'a. Mg and Na present in low' amount in rice and ranges
between 0 .4 3m g - 1.90mg. 17 .37mg-26.4mg and 2.fimg-l.'i.78mg/IOOg I'.P. respectively.
Increase in C'a and Na content was found in cooked rice in both cooking methods due to
addition o f these minerals from domestic tap water. Decrease in Mg content was observed in
rice by both cooking methods. The phosphcirus and potassium content in uncooked rice were
in the range o f 1 1 7 .8 3m g - I 7 l . l5m g and I ( )2 .4 6mg - I8 0 .2 lmg / I0 0 g K.P. respectively. In both
cooking methods, considerable loss o f these minerals was found. A good amount of phytic
acid was present in rice (9 1 .9 7 -1 7 6 .0 2m g / l0 0 g dry wt. basis). Considerable amount o f this
phytic acid was destroyed due to cooking.