Comparative Study of the Nutritional, Anti-Nutritional and Heavy Metal Compositions of Some Indigenous and Newly Imported Rice Varieties in Nigeria

Abstract

A comparative study of the nutritional, anti- nutritional and heavy metal compositions of one indigenous (local rice) and two selected of the newly Long grain rice (Basmati and imported rice) varieties got from different markets in Awka Anambra State were carried out. This was performed using compositional analyses of Association of Official Analytical Chemists (AOAC, 1984) and Atomic Absorption Spectrophotometer (AAS) for heavy metal evaluation. The proximate analysis showed that the rice varieties had high percentage Carbohydrate contents with 75.75% least for imported rice and 84.45% highest for Basmati rice and relatively low moisture content of 2-4.2%. All of the rice varieties studied showed low fat content of 0.4-1.0%. The ash content was very high in Basmati rice at 8.5% and lowest in imported rice at 1.0%. Local and imported rice varieties had high contents of crude fibre of 6.5% and 5.0% respectively but low in Basmati rice at 1.5%. Imported rice had an appreciable high protein content of 15.05% followed by local rice of value 8.75% whereas the protein content is very low in Basmati at 3.15%. High fibre and protein contents added more advantage to local and imported varieties. The anti-nutrients in the samples studied were very low compared to its normal intake; and so are safe for consumption. The heavy metal content of the samples studied were higher than the provisional tolerance intake regulations by WHO/FAO except for zinc content, which was within the standard. Thus from the obtained results, it was observed that the results for local rice was the best when compared with other rice varieties studied in terms of higher nutrients, less heavy metals and low anti-nutrients.