| dc.description.abstract | The main objective of this study was to determine the bioavailability of essential trace
elements in some at; the traditional foodstuffs commonly consumed by the Kamba
community in Kenya. Raw food samples were collected from Machakos, Makueni, Kitui
and Mwingi districts of Eastern province of Kenya while cooked food samples were
prepared in the laboratory as is traditionally practiced by the Kamba community. The
EDXRF analytical technique was used to determine the total and bioavailable trace
element content in the raw and cooked forms of the foodstuffs.
Total iron content in raw decorticated maize ranged from 67 to 1140 ug/g while the
content in raw beans ranged from 227 to 647 ug/g for samples analysed from the four
districts. In the Wimbi flour, the content ranged from 64 to 569 ug/g. On average, beans
recorded the highest iron content, which was significantly higher compared to the other
two foodstuffs. Zinc content in the three foodstuffs did not vary widely and ranged
between 11 and 71 ug/g except for Wimbi flour samples from Mwingi district, which had
an average content 'of 278 ug/g.
Half of the raw decorticated maize samples had total manganese content < 20 ug/g (DL) with the other half having an average content of 53.8 ulg/g. Thirty percent of the raw
beans samples analysed had total manganese content of < 20 ug/g (DL) while the other
70% recorded an average content of 54.3 ug/g ..!Manganese content in raw Wimbi flour
had a significant difference (p :s 0.05) in comparison to the other two foodstuffs and had
an average content of 235 ug/g. Copper content in the three foodstuffs was established to
be the lowest of the four essential trace nutrients. Seventy five percent of the samples of
these foodstuffs had copper content < 10 ug/g (DL) while the other 25% had an average
content of 15.8 ug/g.
In cooked Muthokoi diet which is prepared by mixing maize and beans in the ratio 2: 1,
total iron content ranged from 42 to 1597 ug/g in the four districts. Total zinc content did
110tvary widely and ranged from 20 to 40 ug/g, Manganese content in Muthokoi ranged
from values <20 to 219 ug/g while copper ranged from values <10 to 30 lug/g. The use of
clay pots for cooking Muthokoi was found to increase trace element levels than when
either aluminium or stainless steel pots were used. Also the practise of discarding soup
(Kithoi) from the food led to 33% loss of the essential trace element iron.
Iron bioavailability in Muthokoi ranged from 0.1 to 26.3% giving an average value of
6.3%. A correlation analysis between total calcium and bioavailable iron contents
revealed that the two were negatively correlated giving the indication that calcium may
have inhibited iron absorption. Zinc bioavailability in Muthokoi ranged from 0.3 to
34.4% and had an average of 8.9%. Manganese bioavailability ranged from 0.1 to 13.9%
while copper bioavailability ranged from 1.7 to 19.2%.
In the Wimbi porridge, iron bioavailability ranged from 0.7 to 7.5% having an average
content of 2.9%, which was lower than 7.5% obtained in Muthokoi. Zinc bioavailability
in the porridge was on average 8.3%, which was slightly higher than the value obtained
in Muthokoi of 7.5%. Manganese bioavailability in the porridge was on average 3.7%,
being slightly lower than 5.1% obtained in Muthokoi. Copper bioavailability in the
porridge was on average about 8.7%, which was lower than the 18.7% obtained in
Muthokoi. Fermentation of the Wimbi flour used for porridge preparation for weaning
children was found to increase bioavailability of Mn, Fe, Cu &. Zn from 1.5%, ..0.9%,
5.7% and 1.1% at 0 hours to 67.5%,3.45%,29.1 %;nd 11.5% respectively after 72 hours. | en |
