EVALUATION OF SOME HEAVY METALS CONCENTRATIONS IN CHOCOLATE, CANDIES AND TOMATO PUREE IMPORTED FROM CHINA
EVALUATION OF SOME HEAVY METALS CONCENTRATIONS IN CHOCOLATE, CANDIES AND TOMATO PUREE IMPORTED FROM CHINA
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Date
2014-12
Authors
ONYEBUCHI, OCHU,
JOY
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Abstract
This study was initiated as a follow-up information on some impounded products
tomato puree (Samples A and B) chocolates and candies (Samples C, D, E and F) imported
from China, and sold in Nigerian markets. This result as their failure to meet National
Agency for food drug administration and control (NAFDAC) regulatory standard. Samples
A, B, C, D, E and F were collected in five markets from each six states of the six
geographical zones: North-West (Kano), North-East (Bauchi), North-Central (Kogi),
South-West (Lagos), South-East (Abia), and South-South (Rivers) of the country. In order
to evaluate the quality of the products, the levels of some heavy metals (Cu, Mn, Fe, Ni,
Zn, Ti and Cr) were evaluated in the samples using X-ray fluorescence (XRF).
Concentrations of metals in both tomato puree ranged 4.0 – 4.5 mg/g for Cu, 18.0 –
42.5mg/g for Mn, 26.0 – 62.5mg/g for Fe, 4.0 – 56.0mg/g for Ni, 27.0 – 35.2mg/g for Zn,
ND – 25.0mg/g for Ti, and ND – 20.0mg/g for Cr while concentrations of metals in both
chocolates and candies ranged 3.0 – 4.2 mg/g for Cu, 40.0 – 55.7mg/g for Mn, ND –
102.5mg/g for Fe, ND – 305.0mg/g for Ni, ND – 42.5mg/g for Zn, ND – 23.8mg/g for Ti,
and ND – 10.8mg/g for Cr. The concentrations of all the metals studied were generally
higher in samples A and B compared to recommended levels of these metals in vegetable
crops. Also, the data showed that these metals are at higher levels in samples C, D, E and F
compared to other studies in candies and chocolates in Nigeria. Correlation analysis among
metals revealed positive correlations, which indicates similar sources of these metals. Also,
evaluation of dietary intake of these products daily revealed that sample A (except for Cu
and Fe), B, C (except for Cu), D and E are above the daily dietary recommended limit for
all the metals studied in food. Thus, frequent intake of these contaminated products is likely
to induce health effects arising largely from Cu, Mn, Fe, Ni and Zn.
Description
A THESIS SUBMITTED TO THE
SCHOOL OF POST GRADUATE STUDIES,
AHMADU BELLO UNIVERSITY, ZARIA
IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR
THE AWARD OF MASTER OF SCIENCE IN
ANALYTICAL CHEMISTRY
Keywords
EVALUATION OF SOME HEAVY METALS,, CONCENTRATIONS IN CHOCOLATE,, CANDIES,, TOMATO PUREE,, IMPORTED,, FROM CHINA.